Fabri, Honoré Dialogi physici in quibus de motu terrae disputatur 1665 Lyon la fabri_dialo_025_la_1665.xml 025.xml

DIALOGI PHYSICI, IN QVIBVS De Motu Terræ Di&longs;putatur, MARINI ÆSTVS NOVA cau&longs;a proponitur,

Nec non aquarum & Mercurij &longs;upra. libellam elevatio examinatur.

AD EMINENTISSIMVM CARDINALEM FACCHINETTVM.

Auctore R. P. HONORATO FABRI. Societatis IESU.

LVGDVNI,Sumptibus CHRISTOPHORI FOVRMY, in vico Mercatorio, &longs;ub &longs;igno Occa&longs;ionis.

M. DC. LXV. CVM PERMISSV SVPERIORVM.

IRREGULAR PAGINATION

LECTORI.

REM i&longs;tam, provt ge&longs;ta e&longs;t fideli narratione tibi expono, Candidi&longs;&longs;ime Lector, elap&longs;o proxime Iunio ab Eminenti&longs;&longs;ime CARDINALI FACCHI­NETTO, &longs;ub cujus au&longs;piciis, hoc ip&longs;um, quod in manibus habes, opu&longs;culum in lucem prodire volui, pro &longs;umma illa, qua pollet humanitate, ad prandium invitatus &longs;um, vt deinde pomeridianis horis, cum eruditi&longs;&longs;imis homini­bus, de nonnullis experimentis Phy&longs;icis di&longs;&longs;ertationem in&longs;ti­tuerem, cui Eminenti&longs;&longs;imus pro eo, quo e&longs;t in rem literariam affectu, intere&longs;&longs;et. Aliquid fortè de me inaudierat, & vt amici nunquam ferè de amico ni&longs;i hyperbolicè, illud, quod in me &longs;entio, vel nullum, vel admodum tenue ingenium, plus æquo efferre dignati &longs;uerant: parvi tamen, & hora condicta adfui, quamvis alioquin tenuitatis meæ con&longs;cius, vt morem Eminenti&longs;&longs;imo gererem; præ&longs;ertim; cùm opera pre­tium foret, Eminenti&longs;&longs;imum ab ea, quam per amicorum hy­perbolem, de me conceperat, opinione dimovere; quod mihi &longs;anè pro votis &longs;ucce&longs;&longs;i&longs;&longs;e facilè crediderim, vbi me Emi­nenti&longs;&longs;imus vix balbutientem audivit. Vt vt &longs;it, de va­riis à nobis actum e&longs;t; &longs;ed præ&longs;ertim de motu Terræ, Maris æ&longs;tu Aquarum & Mercurij in tubis erectis elevatione, alii&longs;­que huc pertinentibus. Cum autem is, quem &longs;ub Augu&longs;tini no­mine in &longs;cenam induxi, à me po&longs;t aliquot men&longs;es, efflagita&longs;&longs;et,vt ea, qu nuda voce prolata à me acceperat, &longs;cripto tradi­ta ip&longs;i con&longs;ignarem, &longs;atius fore putavi, &longs;i publicam in lucem Typis mandata prodirent; cùm &longs;æpè accidat, vt ex amanuen­&longs;ium incuria, multi næ vi ac fœdi errores in ex&longs;cripta irre­pant. Cæterùm more Platonico & Tulliano Dialogi formam adhibui, tum quia magis expedita e&longs;t, tum quia hoc ferè mo­do res ip&longs;aperact fuit illam autem &longs;ententiam meam e&longs;&longs;e facile intelliges, quam &longs;ub nomine Antimi vel doceo, vel approb. Sihæc pauca tibi arri&longs;erint, dulci&longs;&longs;ime Lector, dabo operam, vt alia quàm plurima iis &longs;uccedant; admi&longs;cui pau­ca Geometrica, non data opera &longs;ed ferè coastus, vt &longs;altem inde videas, quantum Geometria, non modò vtilis, verùm etiam nece&longs;&longs;aria &longs;it, ad res Phy&longs;icas pro dignitate pertractan­das. Vale.

DIALOGVS PRIMVS.

In quo argumenta pro ad&longs;truenda Copernici hypothe&longs;i adducta, reijciuntur.

ILLA dies aibo &longs;ignata lapillo, qua me immerentem &longs;anè, lauto &longs;imul & literatio convivio excepi&longs;ti, CARDINALIS EMINENTISSIME, Nunquam mihi venit in mentem, ni&longs;i & &longs;ingularis humanitatis tuæ, qua tibi omnium animos arcti&longs;&longs;imè devinxi&longs;ti, & docti&longs;&longs;imo­rum illorum hominum, qui congre&longs;&longs;ui no&longs;tro interfue­runt, jucundi&longs;&longs;ima recordatio &longs;uavi&longs;&longs;imo voluptatis &longs;en­&longs;u animum meum perfundat : ita enim confabulando amœnus, promptus arguendo, &longs;olvendo &longs;ubtilis, explicando elegans & limpidus omnibus no­bis vi&longs;us es, vt conjuncta eloquentiæ &longs;apientia, ad fundenda oracula, tua voce, tuis verbis vti videretur. Vt autem perpetuum docti&longs;&longs;imi congre&longs;&longs;us monumentum extet, cuius ego aliqua pars, licet exigua fui, literis illum & typis con&longs;ignatum ad po&longs;teritatem tran&longs;mittere con&longs;titui; vt &longs;altem in­telligant homines, Eminenti&longs;&longs;imum Principem non politicis modò & gra­vioribus &longs;tudiis, verùm etiam amœnioribus literis plurimùm delectatum fui&longs;&longs;e. Sed in &longs;cenam per&longs;onatos Actores induco, quos in arena literaria di&longs;ceptantes audire priùs volui&longs;ti: &longs;ingulos facilè agno&longs;ces, quamvis enim, vt fieri &longs;olet, nomina tantulùm mutata fuerint, eos tamen, in quos &longs;ingula optimè quadrant, nullo negotio per&longs;picies Sed ad rem venio.

Antimus. E&longs;t, quod mihi &longs;ummoperè gratuler, docti&longs;&longs;ime Augu&longs;tine, quod jamdudum à me de&longs;ideratam, hodierna die, abundè, vt &longs;pero, tui copiam mihi facturus &longs;is; mirum enim, quanto eruditæ con&longs;uetudinis &longs;tudio tenerime &longs;entiam, quæ grati&longs;&longs;imos, di&longs;cendi nova, & a&longs;&longs;equendi hactenus incomperta, igniculos in me accendit, & quadam, vt &longs;ic loquar, vellicatione. Ingenium &longs;timulat, ad ea nonnunquam expromenda, quæ lon­ga meditatione, & repetita cogitationum huc illuc ver&longs;atione, vix vnquam elici potui&longs;&longs;ent. A te igitur illa audire percupio, quæ & &longs;itim meam ex­tinguant, & opinionem de te meam, quamvis alioquin maximam longè &longs;uperent & po&longs;t &longs;e relinquant.

Augu&longs;tinus. Hoc ip&longs;um tibi à me dictum e&longs;&longs;e puta; huc venis, Antimo, vt doceas, non verò vt di&longs;cas; & &longs;i fortè identidem à me aliquid oppo-nendum &longs;it, eo dumtaxat fine hoc à me fiet, ad vberiorem explicationis lucem extorquendam. Eminenti&longs;&longs;imus Princeps, eo animo te invitavit, vt cùm de te multa à nobis inaudii&longs;&longs;et, de rebus Philo&longs;ophicis di&longs;&longs;erentem audiret; & non modico huiu&longs;ce rei de&longs;iderio teneri &longs;e, nobis &longs;emel atque iterum &longs;ignificavit.

Antim. Quid tandem à me expromi queat, quod Eminenti&longs;&longs;imi auri­bus dignum &longs;it, profectò non liquet; quicquid enim, etiam cum aliquo mentis ni&longs;u excogito, nugas inter & qui&longs;quilias mihi &longs;emper huc v&longs;que reponendum e&longs;&longs;e vi&longs;um e&longs;t, qua&longs;i verò mea pluris faciam, quàm me?

Augu&longs;tin. Dic, vt voles, illud &longs;altem con&longs;tat, quidquid vel ex tuis lu­cubrationibus, vel ex tuo di&longs;&longs;erentis ore accepi, mihi &longs;ummoperè pla­cui&longs;&longs;e: vnum tamen e&longs;t, ne quid di&longs;&longs;imulem, quod in te aliqui de&longs;ide­ra&longs;&longs;ent, ne &longs;cilicet tanto adversùs Copernicanam hypothe&longs;im odio flagra­res, in quo nonnullis paululùm excedere mihi vi&longs;us es; poteras haud du­biè oppo&longs;itam &longs;equi, quam & ego demi&longs;&longs;a fronte o&longs;culor, cum iis præ&longs;er­tim, qui Eccle&longs;ia&longs;ticam vitam amplexi, Pontificiis &longs;tare debent decretis, quibus in Galileum eiu&longs;dem &longs;ententiæ egregium & nunquam &longs;atis lauda­tum propugnatorem animadver&longs;um e&longs;t; &longs;ed non erat, quod tam alienum animum o&longs;tentares.

Antim. Vix me teneo, Augu&longs;tine, dum hæc à te audio, præter omnem expectationem meam: odium vocas contrarium &longs;en&longs;um, ab&longs;que vllo im­moderato affectu, in iis præ&longs;ertim, in quibus opinari, cuique liberum e&longs;t. Nullo, crede mihi, odio, nullo contentionis &longs;tudio ducor; &longs;ed cùm quædam in hypothe&longs;i Copernicana di&longs;pliceant, quæ in oppo&longs;ita nullum mihi negotium face&longs;&longs;unt, facere non potui, quia hanc illi anteponerem; nunquam tamen inficias iturus, præclarum inventum e&longs;&longs;e; Copernicum A&longs;tronomorum &longs;ui temporis principem jure cen&longs;eri, eumque Galileum fui&longs;&longs;e, qui nulli, quod &longs;ciam, impar ingenio æ&longs;timandus &longs;it, quique eo no­mine vel maximam gloriam &longs;ibi comparavit, quod argumenta, quibus præfata hypothe&longs;is impugnabatur, ita diluerit, vt maximo inde plau&longs;u re­lato, ii&longs;dem illam potiùs confirma&longs;&longs;e videatur, cùm vero certum &longs;it, nec ip&longs;e Galileus hoc inficietur, nullam demon&longs;trationem hucu&longs;que excogi­tatam fui&longs;&longs;e, qua hypothe&longs;is Copernicana probetur, ab antiqua illa, quæ terram in mundi centro immobilem ad&longs;truit, di&longs;cedendum e&longs;&longs;e non puta­vi; præ&longs;ertim cùm hæc novis argumentis, &longs;i non demon&longs;trari, plurimùm &longs;altem confirmari po&longs;&longs;it, quibus, vt liberè dicam, quod &longs;entio, mihi valdè per&longs;ua&longs;um e&longs;t, hanc multis nominibus alteri e&longs;&longs;e anteponendam.

Augu&longs;tin. Docti&longs;&longs;imis illis, tui certè amantibus, & quos &longs;ingulari etiam cultu per&longs;equeris, haud modicum ri&longs;um moveres, i hæc fortè à te audi­rent, nec vllum mihi dubium e&longs;t, quin per jocum, vel ironiam hæc à te dici putarent, vtpote qui apprimè &longs;cias, Copernicanam hypothe&longs;im iis rationum momentis in&longs;tructam e&longs;&longs;e, quæ vt demon&longs;trationem Geometri­cam minimè adæquant, quod certè vltrò damus, ita proximè ad eam acce­dunt, atque adeò communi Doctorum omnium con&longs;en&longs;u longè aliâ pro­babiliorem jure cen&longs;eri.

Antim. Hebetiori, quæ&longs;o, ingenio igno&longs;ce, optime Augu&longs;tine, quod energiam illam rationum, quæ pro Copernico militant, nondum a&longs;&longs;equi potuit; nec mirum profectò, lippos enim oculos &longs;ubtilia fallunt, ac &longs;e&longs;e iis &longs;ubducunt; quate vt &longs;um inprimis veritatis amans, me tibi plurimùm ob&longs;trinxeiis, &longs;i præfatas rationes ea mihi claritudine exponas, quâ, vt mi­rificè vales, ita & mihi opus e&longs;&longs;e fateor, ad debiliores mentis oculos re­creandos.

Augu&longs;tin. Non legi&longs;ti apud Galileum, ita limpidè ac per&longs;picuè explica­tas, vt nihil meo judicio, clarius aut liquidius legi po&longs;&longs;it?

Antim. Legi haud dubiè; Vt enim Authorem illum maximi facio, ita nihil ab eo in publicam lucem editum fuit, quod &longs;tatim avidè &longs;æpè ac &longs;æ­piùs non legerim; hoc tamen tibi per&longs;uadeas, velim, prædictas rationes, quamvis alioquin eleganti&longs;&longs;imè ab eo explicatas, illa vi & nervo, vt dicis, pollere mihi non videri, &longs;ingulas accuratè perpendi & ponderavi, nec op­po&longs;itæ &longs;ententiæ &longs;tudium obfuit; nam crede mihi; vnius dumtaxat veri­tatis amore ducor, quam &longs;ive Copernicus porrigat, &longs;ive Ptolemæus, &longs;ive Ari&longs;toteles, &longs;ive Democritus; illa æquè grata & chara mihi &longs;emper accidit. Sed quæ&longs;o te, periculum faciamus, vt &longs;altem dum no&longs;tri venerint, hoc mo­dicum tempus cum æ&longs;tu fallamus.

Augu&longs;tin. Per me licert &longs;ed cur&longs;im, iis tamen prætermi&longs;&longs;is, quæ inter Academicos quidem, non tamen inter Philo&longs;ophos locum obtinent, quas potiùs rationum vmbras, quàm veras rationes appellare &longs;oleo.

Antim. Optimè judicas, quid enim juvat, tantirem momenti levi&longs;&longs;imis fulcire adminiculis: Nonnulla obiter indico. Sol, inquiunt, tes inter cor­poreas nobili&longs;&longs;imus, in nobili&longs;&longs;imo loco, &longs;cilicet in mundi centro, collo­cari debuit; qua&longs;i verò infimus locus &longs;upremo nobilior reputandus &longs;it, & tenebro&longs;us orcus radianti præferendus Empyreo: &longs;ed pergunt, qui&longs;quis alterius operâ indiget, ad illum accedere debet, neque hunc, &longs;ed illum moveri par e&longs;t; cùm igitur reliqua corpora benigno Solis influxu indi­geant, hunc certè immotum con&longs;i&longs;tere, illa verò circa perennem illum beneficæ naturæ fontem ite oportuit. Bellè profectò; Solem rerum crea­tarum Principem faciunt, qui tamen omnibus &longs;ervit, & non modò ani­mantibus, verùm etiam plantis dignitate cedit; Æquum igitur e&longs;t, vt circa terram eat, cuius gratia conditus e&longs;t, non verò vt tellus eiu&longs;que incolæ circa Solem ite cogantur. Denique ex culina ip&longs;a nova depromunt argu­menta; Videmus, inquiunt, verum ad immotum ignem in gyros verti, quod certè rationi con&longs;entaneum e&longs;&longs;e videtur; quidni ergo pariter terre&longs;tris globus, qui calore Solis foveri & recreari debet, circa Solem, non Sol cir­ca terram volvatur? Hoc argumentum culinam olet, vnde profectum e&longs;t.

Augu&longs;tin. Sed hæc omittamus, quæ no&longs;tri per jocum potiùs, quàm &longs;eriò dixerunt; ad &longs;eria igitur & gravia, quæ nobis non de&longs;unt, veniendum e&longs;t: illud inprimis maximi ponderis e&longs;&longs;e videtur, quod in hypothe&longs;i no&longs;tra (&longs;ic eam di&longs;putan di gratia deinceps appellabo) per &longs;implici&longs;&longs;imum eum­que proprium motum omnia explicemus, ablegatis alienis motibus, illoque præ&longs;ertim, quem raptus vocant, primi &longs;cilicet mobilis, quo ab Ortu ad Occa&longs;um inferiores &longs;phæræ tanta velocitate ferri dicuntur, vt &longs;tella fixa &longs;ub Æquatore, vnico temporis minuto leucarum miriadas conficiat, quod certè non fidem modo, verùm etiam cogitationem ip&longs;am &longs;uperat. Hunc porrò motum ablegamus, & &longs;implici ac diurna telluris globi circa &longs;uum centrum turbinatione, &longs;eu revolutione præfatum motum &longs;up­plemus.

Antim. Ab hoc vltimo incipio; quia nonnulli multam vim in eo fa­ciunt; cum tamen me parum, aut nihil pro&longs;us afficiat; nempe diver&longs;as motuum velocitates per comparationem quamdam optimè intelligimus; Sit enim quodlibet terræ punctum in æquatore, &longs;uppo&longs;ita ve&longs;tra hypo­the&longs;i, illud, vt probè no&longs;ti, in turbinatione præfati globi, præ&longs;cindendo a motu centri, ita movetur, a&longs;&longs;umpto &longs;cilicet, quodam medio motu, vt vo­cant, vt &longs;ingulis horis 900. circiter miliaria Italica conficiat, 15.verò &longs;in­gulis minutis primis, vno denique &longs;ecundo minuto, 250. pa&longs;&longs;us geome­tricos, hoc e&longs;t 1250. pedes; vt autem comparationem in&longs;tituam, con&longs;ide­ro motum glandis plumbeæ ex maiore catapulta explo&longs;æ, quæ vno &longs;ecun­do minuto 1000. pedes circiter conficit; vnde vides punctum illud paulò dumtaxat velociùs moveri.

Augu&longs;tin. Su&longs;tine tanti&longs;per; ne&longs;cio quid intelligas per illum medium motum.

Antim. Intelligo motum æquabilem, ita vt &longs;ingulis horis punctum illud æquale &longs;patium decurrere cen&longs;eatur, cùm tamen &longs;ecus ac­cidat.

Augu&longs;tin. Non capio, exi&longs;timo enim rem ita e&longs;&longs;è, & æqualibus tempo­ribus, æqualia &longs;patia decurri.

Antim. Ita &longs;anè nobis apparet, id tamen haud dubiè per errorem; nempe punctum illud motu quodam mixto movetur, ex motibus orbis & centri, &longs;ic enim vocare &longs;oles; Vnde fit, vt pro diver&longs;o ad &longs;olem a&longs;pectu, modò tardiùs, modò velociùs moveatur; quia motus orbis ab hora &longs;exta ve&longs;pertina ad &longs;extam oppo&longs;itam matutinam additur motui centri, ab hac verò ad illam detrahitur; ac proinde punctum illud in meridie collocatum tardi&longs;&longs;imè in a&longs;pectu oppo&longs;ito, &longs;cilicet, mediænoctis, veloci&longs;&longs;imè movetur quod vt ad rudiores calculos reducam, &longs;uppono, exempligratia, diametrum magni orbis, quem Sol&longs;ecundùm meam, & terra &longs;ecundùm ve&longs;tram hypo­the&longs;im decurrit, continere diametros terræ 2000. hoc po&longs;ito, motu centri, vno &longs;ecundo minuto, decurruntur pedes circiter 6942. & motu orbis pe­des 1250. adde vnum alteri, venient pedes 8192.hoc e&longs;t &longs;patium, quod di­ctum punctum decurritin media nocte, tempore vnius &longs;ecundi minuti detrahe verò, erunt pedes 5692. hoc e&longs;t, &longs;patium, quod eodem tempore, decurrit in meridie; Vides inæqualitatem. Semoto igitur illo inæquali motu, ex motibus orbis & centri re&longs;ultante, æqualem tantummodò con&longs;i­dero motum orbis, quo punctum terre&longs;tris globi in Æquatore, &longs;ingulis mi­nutis &longs;ecundis, pedes circiter 1250.decurrit.

Augu&longs;tin. Quid tum? Non video, quid tibi velis, ad infirmandum illud argumentum, quod ab incredibili velocitate motus raptus, &longs;eu primi mobilis contra ve&longs;tram hypothe&longs;im ducitur.

Antim. Jam iam videbis. Suppone terre&longs;tem globum in mundi centro, eo motu orbis torqueri, de quo &longs;upra; &longs;uppone radium à centro terræ in Æquatoris plano ductum indefinitè, vt aiunt, id e&longs;t, ad quamcumque longitudinem productum, eatque per centra Lunæ, Solis, lovis, Satur­ni, & cuiu&longs;piam &longs;tellæ fixæ, ac &longs;imul totus radius, eo, quo dixi orbis mo­tu, moveatur circa immobile centrum; certè po&longs;ito quod Luna di&longs;tet a terra 50. &longs;emidiametris terre&longs;tris globi, velocitas motus Lunæ ad veloci­tatem puncti Æquatoris in quo dictus radius terræ &longs;uperficiem &longs;ecat e&longs;t in ratione & ad velocitatem motus Solis, po&longs;ito quod Sol di&longs;tet à centro terræ 2000. &longs;emidiametris e&longs;t in ratione Solis verò motus ad Iovis motum, erit in rationne & ad motum Saturni in ratione de­nique ad &longs;tellæ fixæ motum in ratione, &longs;tatue, vt voles, an fortè ita vt fixarum di&longs;tantia à mundi centro &longs;it dupla di&longs;tantia Saturnij, tibi non &longs;ufficit? Ponamus ita vt &longs;it quintupla, aut majorem adhuc, &longs;i voles; an verò cogitationem omnem &longs;uperat, vnum motum e&longs;&longs;e ad alium in ra­tione quater decupla, immò centupla & millecupla? Crede mihi, hi &longs;unt effectus imaginationis in fraudem inductæ; Vbi enim &longs;emel &longs;tatuitur vnus motus, & huius cum aliis comparatio, huiu&longs;modi terricula illicò eva­ne&longs;cunt.

Augu&longs;tin. Rem probè intelligo; & &longs;anè miror, nonnullos in hoc argu­mento tantam vim & energiam agnovi&longs;&longs;e, vt præ cæteris ad illam hypo­the&longs;im confirmandam adhibendum e&longs;&longs;e putarint: non erat etiam quod aliqui antiqui &longs;y&longs;tematis a&longs;&longs;ertores, & acerrimini propugnato­res ad divinam potentiam confugerent, licèt illa in tanta motuum velocitate mirificè &longs;plende&longs;cere nec non &longs;uas partes agere vi­deatur.

Antim. Rectè mones, Augu&longs;tine, huc divina potentia accer&longs;enda non e&longs;t, cùm ex mera motus naturalis acceleratione, hæc eadem pe&longs;picua e&longs;&longs;e con&longs;tet; &longs;ic enim v. g. motus glandis ex catapulta explo&longs;æ, vt dictum e&longs;t &longs;upra, quo &longs;cilicet vno &longs;ecundo minuto, glans pedes circiter 1000. decurrit, æquabilis e&longs;&longs;e &longs;upponitur; iam verò &longs;i eadem catapulta &longs;ursùm rectà explodatur, de 500.dumtaxat pedes motu retardato glans perveniet, & in de&longs;cen&longs;u eundem velocitatis gradum motu accelerato acquiret; cùm igitur quælibet altitudo a&longs;&longs;umi queat ad libitum, ex qua corpus grave de&longs;cendat motu accelerato, quilibet etiam velocitatis gradus ob­tineri pote&longs;t; quo dato tempore, datum quodlibet &longs;patium, motu æqua­bili decurratur, igitur prædicta motuum velocitas inter præcipua divi­næ potentiæ miracula minimè reponenda e&longs;&longs;e videtur; quamquam, ne­que hîc dee&longs;t, vnde divinam potentiam homines laudent, cùm id in &longs;a­cris literis nobis innuatur, laudet que P&longs;almi&longs;ta Dominum, ex pernici&longs;&longs;i­mo Solis motu, nec e&longs;t, quod Heterodoxi, qui &longs;acræ Scripturæ ita &longs;e ad­hærere patant, a literali eiu&longs;dem &longs;en&longs;u, vnius Copernici gratia di&longs;cedant, ea&longs;que laudes ex eo capite &longs;upremo cœlorum Conditori atque motori Deo, gratis, vt aiunt, recu&longs;ent.

Augu&longs;tin. Benè e&longs;t, in hoc vterque convenimus, &longs;ecùs fortè in alio puncto, à me propo&longs;ito, quod à facilitate & &longs;implicitate &longs;y&longs;thematis peti­tur; vno enim, vel altero terre&longs;tis globi motu no&longs;tra hypothe&longs;is con&longs;tat, cùm tamen ve&longs;tra motus ita multiplicet, etiam &longs;ibi invicem contrarios, vt res illa, vel omnino impo&longs;&longs;ibilis, vel &longs;altem maximè difficilis e&longs;&longs;e videa­tur.

Antim. Primo &longs;anè a&longs;pectu, rem i&longs;tam minùs &longs;edulò con&longs;ideranti, ita e&longs;&longs;e videtur; &longs;i tamen penitiùs illam in&longs;piciamus; primum errorem faci­lè ca&longs;tigabimus: & verò vt in vno Solis &longs;y&longs;temate periculum facia­mus, quotuplice motus opus e&longs;&longs;e putas ad &longs;alvanda omnia phæno­mena?

Augu&longs;lin. Duo motus, ni fallor, omnia &longs;alvant, orbis &longs;cilicet & centri, terre&longs;tris globi, quie&longs;cente Sole in mundi centro.

Antim. Tibi omnino impo&longs;itum fuit, vel vt verius puto, tibi excidit, Primò enim, motu centri opus e&longs;t; annuo, &longs;cilicet in Ecliptica, iuxta &longs;eriem &longs;ignorum, nec qui&longs;quam hoc negat: Secundò, motu orbis diurno, quo terra ita rotatur, vt pars &longs;uperior globi tendat in ortum; hîc autem mo­tus fit circa axem mundi, vel plani Æquatoris. Terrius motus nece&longs;&longs;a­rius e&longs;t, annuus &longs;cilicet, quo terra ita &longs;emel voluitur circa Axem Eclipticæ, vt pars inferior, quæ Solem &longs;pectat, tendát in ortum; hoc enim motu obti­netur, vt Axis Æquatoris &longs;ibi ip&longs;i &longs;emper maneat parallelus; aliquis fortè per incogitantiam quartum motum etiam adhiberet, quo &longs;cilicet Axis Æquatoris vtrimque de&longs;cribit circulos polares, circa polos Eclipticæ, &longs;ed hic motus à tertio diver&longs;us non e&longs;t, vt con&longs;ideranti patebit, & licèt aliqui etiam ex iis, qui terram mobilem ad&longs;truunt, hunc diver&longs;um motum &longs;ta­tuant, ego tamen, vt &longs;incerè tecum ago, diver&longs;um à motu orbis annuo mi­nimè &longs;tatuo. Addo denique quartum motum Solis, circa proprium cen­trum, axemque immobilem, & inclinatum ad planum Eclipticæ, &longs;ine quo macularum motus 27. circiter dierum explicari nequit: hunc etiam ne­mo ve&longs;trum inficiatur.

Augu&longs;tin. Cuncta hæc et&longs;i vltro damus, nihil tamen ob&longs;tat, quin adhuc &longs;y&longs;tema no&longs;trum &longs;implicius e&longs;&longs;e dicamus, & ex paucioribus motibus, quàm ve&longs;trum componi. Ve&longs;trum enim, &longs;i rectè memini, in vno Solo 7. vel 8. motus po&longs;tulat. Primus e&longs;t motus raptus, &longs;eu primi Mobilis ab or­tu ad occa&longs;um, &longs;cilicet diurnus: &longs;ecundus, motus in Ecliptica annuus; tertius, motus Solis circa proprium axem inclinatum, ferè men&longs;truus: quartus motus eju&longs;dem circa axem erectum ad planum Eclipticæ, an­nuus: quintus motus prioris axis inclinati, de&longs;cribentis vtrinque circellos circa Solarem axem erectum ad planum Eclipticæ, item annuus: &longs;extus, motus Apogæi Solis iuxta &longs;eriem &longs;ignorum: &longs;eptimus motus præce&longs;&longs;io­nis Æquinoctiorum; octavus motus obliquitatis Zodiaci, vt vocant: et&longs;i fortè mutetur excentricitas, de quo nonnulli dubitarunt: nonus motus adjiciendus e&longs;&longs;et; vides, quantam motuum farraginem &longs;y&longs;tema ve&longs;trum po&longs;tulet: quorum aliqui, cùm &longs;int oppo&longs;iti, vt annuus & men&longs;truus &longs;olaris globi, quantumvis circa diver&longs;os axes, nec aliunde in &longs;olarem &longs;phæram traducantur, &longs;ed vterque per &longs;e, vt aiunt, Soli competat, inde &longs;ortè ture cuipiam impo&longs;&longs;ibiles videbuntur.

Antimus, Ita luditis &longs;impliciorum animos maioris &longs;implicitatis obtentu; & dubito, an &longs;eriò, an verò per iocum hæc dicas; tu quoque imponere mihi cogitabas; Apage igitur prefatam motuum farraginem; ego enim vnum dumtaxat, cumque &longs;implici&longs;&longs;imum motum admitto in &longs;olari &longs;y&longs;te­mate, quod ne&longs;cio, an mirum tibi accidat.

Augu&longs;lin. Mirum pror&longs;us, immò fal&longs;um, neque id, opinor mihi vn­quam per&longs;uadebis; cum per&longs;picuum &longs;it (neque ve&longs;tri hoc negant) ad Sal­vanda cuncta phænomena, prædictos omnes motus, &longs;i fortè vltimum ex­cipias, quem non ita omnes a&longs;&longs;everanter ad&longs;truunt, nece&longs;&longs;arios e&longs;&longs;e.

Antim. Ne quæ&longs;o dubites, vbi rem a me intellexetis, tibi fortè per­&longs;uaderi &longs;ines; ea quippe dicam quæ, ni fallor, luce meridiana clariora &longs;int. Sol vno Eodemque motu &longs;implici&longs;&longs;imo movetur ab ortu ad occa&longs;um, &longs;ub Ecliptica semper mobili, circa axem mundi cum duplici inclinatione, &longs;ursum, deor&longs;um, &longs;ini&longs;tro&longs;um; & rotatione, &longs;eu turbinatione, circa axem æquè in­clinatum ad planum Eclipticæ, ac &longs;ibi &longs;emper parallelum. En tibi mo­tum &longs;implicidimum, quo &longs;uppo&longs;ito, cuncta facile ac planè explicantur.

Augu&longs;tin. Non intelligo; immò hæc mihi ab&longs;urda & repugnantia e&longs;&longs;e videntur; nec capere po&longs;&longs;um, quî fiat vt omnia facile & plané hoc modò explice utur.

Antim. Cuncta &longs;eor&longs;im explico, Cogita, &longs;i vis, Solem à puncto Æqui­noctij verni ab ortu ad occa&longs;um ita ferri, vt po&longs;t 24. horarum motum, orbem &longs;uum nondum ab&longs;olverit, &longs;uper&longs;itque vnus ferè gradus, paulò minùs; fing tantula &longs;imul Solem inclinatione ire versùs Boream, & &longs;igna vtriu&longs;que loci in cœlo ve&longs;tigia, atque ita deinceps moveri Solem puta, &longs;ignatis &longs;ingulorum locorum ve&longs;tigiis; vbi verò Sol ad Tropicum Cancri pervenerit, &longs;uppone qua&longs;i repercu&longs;&longs;um versùs Au&longs;trum eodem modo deflectere, multiplicatis revolutionibus, donec ad Tropicum Ca­pricorni perveniat, a quo eodem modo versùs Boream deflectat donec tandem ad Æquatorem denuò redeat; per &longs;ignata ve&longs;tigia &longs;i ducas circu­lum,, erit Ecliptica, quam circa mundi Axem finges moveri, & ab eius polis circulos polares de&longs;cribi; ita autem &longs;ol attemperat reciprocam il­lam inclinationem, &longs;eu declinationem versùs Au&longs;trum & Boream, vt nunquam à prædicto Eclipticæ circulo di&longs;cedat, quod quomodò obtineat, paulò po&longs;t dicam.

Augu&longs;tin. Sed i&longs;ti &longs;unt duo motus, alter cuiu&longs;dam qua&longs;i librationis, al­ter circularis.

Antim. Vnicus e&longs;t motus, augu&longs;tine, &longs;ed per modum &longs;piræ; quis enim negat turbinem proiectum &longs;implici motu moveri, id e&longs;t, eodem impetu ad talem lineam determinato; nempe hoc &longs;uppono cerrum, ex alibi firma­ta motuum doctrina, eundem impetum ad diver&longs;as lineas determinati po&longs;­&longs;e, &longs;ic pila repercu&longs;&longs;a &longs;implici motu movetur, licet linea motus per quam feretur, duplicem determinationem &longs;upponat &longs;cilicet à linea motus directi, & à plano reflectente; Non e&longs;t igitur dubium, quin prædictus Solis motus &longs;implici&longs;&longs;imus &longs;it. Pati modo cogita Solem &longs;imul inclinari ab Apogeo ad Perigeum, & vici&longs;&longs;im, hæc &longs;ecunda determinatio, vel in­clinatio &longs;implici motui non obe&longs;t, vt patet: In hoc porrò motu, Ecliptica etiam mori fingitur circa Axem mundi, ac proinde Eclipticæ &longs;ectio in Solari globo eadem &longs;emper e&longs;t; denique, finge, Solem circa &longs;uum cen­trum ita revolvi 27. circiter dierum &longs;patio, ab ortu in occa&longs;um, ratione il­lius hemi&longs;phærij, quod ad terram &longs;pectat, vt axis, circa quem voluitur, in­clinatus &longs;it ad Eclipticæ planum, & &longs;ibi &longs;emper parallelus; quod &longs;anè &longs;im­plicitatem motus non de&longs;truit; &longs;ic enim &longs;æpè ac &longs;æpiùs globos projicimus; imò hic naturalis e&longs;t globorum motus.

Augu&longs;tinus. Duo &longs;unt motus, ni fallor, orbis, &longs;cilicet, & centri &longs;implex igitur motus non e&longs;t.

Antimus. Igitur motus naturalis, quo corpus grave, v.g. globus fertur deor&longs;um non e&longs;t motus &longs;implex, &longs;ed mixtus, quod nemo dixerit, cum &longs;im­plici&longs;&longs;imus &longs;it, vtpote ab eodem principio, &longs;cilicet à gravitate: &longs;i enim de­mittas globum, primò quidem per planum inclinatum, ex quo inde per li­berum aëra perpendiculariter de&longs;cendat, videbis illicò duos illos motus quos dicis, centri & orbis; qui tamen reverà duo motus non &longs;unt, &longs;ed vnus ab vna eademque gravitate profectus.

Augu&longs;tinus. Nonnulli ex ve&longs;tris, vt &longs;alvent paralleli&longs;mum illius axis, cir­ca quem Sol revolvitur, adhibent alium motum revolutionis annuum cir­ca Solis axem, axi Eclipticæ parallelum.

Antimus. Ita pror&longs;us. Sed e&longs;t motus fictus, eo fine, vt meliùs res illa in­telligatur: vt enim terra circa axem axi Elipticæ parallelum revolui dici­tur annuo motu, in ve&longs;tra hypothe&longs;i ab occa&longs;u ad ortum, ratione hemi­&longs;phærij ad Solem ver&longs;i, vt axem, circa quem fit motus diurnus, &longs;emper pa­rallelum &longs;ervet, ita pror&longs;us &longs;olaris globus revolui dicendus e&longs;t annuo mo­tu, ad prædictum phœnomenum Axis paralleli &longs;alvandum; &longs;ed vtrimque hic motus fictitius e&longs;t, cùm &longs;implex turbinationis motus &longs;ufficiat, circa Axem inclinatum ad planum Eclipticæ, &longs;emper &longs;ibi ip&longs;i parallelum. Ana­logiam habes in acu magnetica, quæ cum pixide &longs;ua ita movetur, vt &longs;ine novo motu, &longs;ibi parallela &longs;emper maneat.

Augu&longs;tin. Igitur non tres, aut quatuor motus in no&longs;tra hypothe&longs;i &longs;ta­tuendi &longs;unt, vt &longs;upra dicebas; cum vnus duntaxat, eo quo explicas modo &longs;ufficiat: cur ergo quatuor nece&longs;&longs;arios e&longs;&longs;e fingis?

Antim. Iuxta morem ve&longs;trorum, & aliorum locutus &longs;um, qui prædictos motus di&longs;tingunt; fateor tamen, in ve&longs;tra hypothe&longs;i, duos motus &longs;uffice­re, alterum turbinationis in terre&longs;tri globo, &longs;ervato, vt dixi, paralleli&longs;mo Axis; alterum &longs;implicis revolutionis in Sole, circa Axem pariter inclina­tum, vt dixi, ad planum Eclipticæ. In no&longs;tra verò vnus duntaxat motus &longs;ufficit turbinationis, circa axem pariter inclinatum ad planum Eclipticæ, & &longs;ibi &longs;emper parallelum, cum gemina illa inclination ereciproca, in Bo­ream, & Au&longs;trum, & &longs;ur&longs;um atque deor&longs;um; &longs;ic turbo actus, orbes &longs;uos ita de&longs;cribit, vt aliquando majores, aliquando minores &longs;int; quod certè, vt dixi, &longs;implicitati motus turbinationis non ob&longs;tat: Ex his autem, vt per&longs;picuè vides, no&longs;tra hypothe&longs;is &longs;implicior cen&longs;enda e&longs;t, ac proinde ex hoc &longs;altem primo capite, ve&longs;træ anteponenda.

Augu&longs;tin. Omittis duos alios motus, quos adhibent, &longs;cilicet obli­quitatis Zodiaci, præce&longs;&longs;ionis Æquinoctiorum, & fortè mutationem excentricitatis.

Antim. Vobis æquè atque nobis prædicti motus explicandi e&longs;&longs;ent; &longs;ed negotium neutri parti face&longs;&longs;unt, cùm &longs;emper eadem maneat Zodiaci obliquitas, &longs;emper eadem excentricitas; quod verò &longs;pectat ad Æquino­ctorium præce&longs;&longs;ionem, tu illam explicare potes, adhibito tardi&longs;&longs;imo &longs;tel­larum motu, ortum versùs, ego verò, &longs;i dicam, paulò tardiùs &longs;tellas move­ri ab Ortu ad Occa&longs;um, quàm primum Mobile, ac proinde videri &longs;emper or­tum versùs recedere à punctis Æquinoctiorum, id e&longs;t à &longs;ectionibus Æqua­toris & Æclipticæ; neque in hoc alia re&longs;tat difficultas, atque adeò, tuum illud primum argumentum &longs;olutum manet; iam propone alia, &longs;i quæ habes.

Augu&longs;tinus. Vt vt &longs;it, Negari non pote&longs;t, quin no&longs;tra hypothe&longs;is ad calculos A&longs;tronomicos magis accommodata &longs;it.

Antimu. E&longs;to, demus hoc, quod tamen facilè à me negari po&longs;&longs;et; cum vtrinque &longs;imiles ferè calculi adhibendi &longs;int, ad quem finem, non realibus & veris, &longs;ed fictitiis orbibus vtimur; omi&longs;&longs;o diurno Solis motu, fingimus Solem moveri in Ecliptica motu annuo, item Apogæi motum, cum fictitio circulo, &longs;eu circello ad calculos reducimus; &longs;ic calculis vtimur ad rationes dati & accepti firmandas; cuncta igitur hæc ad calculationem adhiben­tur, cùm res perinde &longs;e habeat. atque &longs;i ita e&longs;&longs;et. In quo, vt vides, nulla e&longs;t difficultas. Sed de hoc argumento plura infra, &longs;i hoc tibi gratum accidat: iam verò reliqua exprome, &longs;i quæ habes adversùm nos.

Augi&longs;tinus. Crede mihi, Antime, abundè &longs;uppetunt, illudque in primis, quod in hac mea hypothe&longs;i planetarum pa&longs;&longs;iones ea facilitate ex­plicantur. quá ne&longs;cio an major ex cogitari po&longs;&longs;it; puta &longs;tationes, retrogre&longs;­fiones, accelerationes &c.

Antim. Hic profectò Achilles ve&longs;ter e&longs;t; &longs;ed non invictus, meo iudi­cio; faveor explicari po&longs;&longs;e alicuius planetæ, puta Saturni, retrogre&longs;&longs;ionem v.g. (figuram tecum non adhibeo, qui res i&longs;tas facilè intelligis) &longs;i enim ter­ram colloces in eo Eclipticæ gradu, qui ab alio di&longs;tet, in quo e&longs;t Saturnus vno quadrante integro circuli, Saturnus in eo loco, in quo e&longs;t, non videbi­tur &longs;ed in alio remotiore.

Augu&longs;tinus Adhibe quæ&longs;o aliquid &longs;chematis, vt res i&longs;ta clariùs à me intelligatur.

Antim. Schemate opus e&longs;&longs;e non putarem, quia tamen ita iubes, tibi morem geram. Sit A. centrum vniver&longs;i, &longs;itque BCDE magnus Orbis, vt vocant, in quo, primo loco, iuxta tuam hypothe&longs;im, terre&longs;trem globum moveri &longs;uppono; &longs;it orbita Martis FRPS. Terra moveatur ex C. per B. in con&longs;equentia, vt vocant, id e&longs;t, iuxta&longs;eriem Signorum; Item Mars ex F per R. &longs;upponatur Mars in F, & terra in B; Supponamus lineam AF pro­ductam ad &longs;tellas, terminari ad principium Cancri, ac proinde AB. pro­ductam ad initium Libræ; ex puncto B, Mars videbitur per lineam BFL. Igitur in eo Zodiaci puncto, quod, a principio Cancri versùs Occa&longs;um di­&longs;tat, toto angulo BFA, vel quod idem e&longs;t, FAM. Item &longs;i &longs;tatuamus initio Terram in D, Martem in S. erit Mars in Perigæo, & in oppo&longs;itione; &longs;patio vorò &longs;ex men&longs;ium, circiter, Mars ab S. pervenit ad F, & Terra à D.ad IB; tunc autem Mars e&longs;t in mediocri di&longs;tantia, & videtur retrogredi à puncto in, quo non videtur ex B, &longs;ed in quo e&longs;t, ad punctum L, vel K, in quo non e&longs;t, &longs;ed in quo videtur ex B.

In no&longs;tra comnunique hypothe&longs;i, hæc æquè facilè explicantur, &longs;it enim Terra in Centro A &longs;it BCDE orbita Solis, &longs;it FRPS, deferens centrum Epicych Marris; &longs;it demum ONCM, Epicyclus Martis, cuius motus, cir-ca proptium centrum, &longs;it ab Oin N, id e&longs;t, in con&longs;equentia, &longs;ecundùm partem &longs;uperiorem, nec non eodem cum centro motu; Sit igitur centrum Epicycli in S. planeta in D, id e&longs;t in Perigæo ; centrum S feratur in P, erit Plane­ta in M ; igitur ex A videtur in K ; ergo videtur retrogredi: &longs;upponamus au­tem motum Martis e&longs;&longs;e duorum annorum; in ve&longs;tra hypothe&longs;i ; Terra ex D prefecta, redit in idem punctum D. decur&longs;o orbe, eo tempore, quo Mars ex S. profectus pervenit in R ; in S autem erat in Perigæo ; in R verò e&longs;t in Apogæo ; videtur denique Mars retrogradus, quando e&longs;t in S. & acceleratus quando e&longs;t in R. Pari modo in no&longs;tra hypothe&longs;i, eodem tem­pore, centrum Epicycli ex S pervenit in R, & planeta pervenit in I, & vt in D e&longs;t Perigæus, ita in T e&longs;t Apogæus, di&longs;tantiis verinque ferè æquali­bus. Mars item in D. e&longs;t retrogradus, in I verò acceleratus. Vtrùm verò hæc ob&longs;ervationibus con&longs;entiant, hoc loco minimè di&longs;puto; hoc tantùm demon&longs;tra&longs;&longs;e contentus, vtrimque fore &longs;imilia pa&longs;&longs;ionum phænomena, accelerationum; &longs;cilicet, &longs;tationum, repre&longs;&longs;ionum &c. Vter verò explican­di modus magis aptus &longs;it, magi&longs;que naturæ ip&longs;i congruat, demon&longs;trandum re&longs;tat.

Augu&longs;tin. Nemini profectò dubium &longs;it, quin res tota planior in no­&longs;tra hypothe&longs;i cen&longs;eatur, in qua &longs;implex & vnica Martis orbita &longs;tatui­tur, cùm tamen in tua, duos circulos ponas, deferentem &longs;cilicet, & Epicyclum; ac proinde duos etiam motus; in mea vnicum dumtaxat agno&longs;cis.

Antim. Haec quæ dicis, ad &longs;peciem vera & per&longs;picua e&longs;&longs;e videntur; cùm tamen &longs;ecus &longs;it; nam in tua quoque hypothe&longs;i, gemin orbes, & totidem motus ponendi &longs;unt; ni&longs;i enim terræ motum &longs;imul cum Martis motu ad calculos reducas, nunquam prædicta phænomena invenies; vn­de motum pro motu, circulum pro circulo reddimus; Orbitam Martis eandem vterque ponimus, &longs;cilicet FRPS, diver&longs;imode tamen illa vti­mur; tu enim vis ab ea deferri planetam, ego verò centrum Epicycli. Tu magnum orbem accer&longs;is, in quo terram moveri decernis, ego Epicyclum Martis, eiu&longs;dem omnino &longs;emidiametri in quo planeta movetur; vterque igitur geminos orbes & circulos ponimus.

Augu&longs;tin. Magnus orbis etiam a te ponendus e&longs;t, in quo Sol ip&longs;e mo­veatur; orbes igitur multiplicas.

Antim. Magnus orbis ad prædictarum pa&longs;&longs;ionum phænomena, mihi nece&longs;&longs;arius non e&longs;t; &longs;tatuta terra immobili in centro A, cum orbita Mar­i, & Epicyclo, eo modo, quo dixi; nam etiam &longs;emoto magno illo orbe, prædicta phænomena, regre&longs;&longs;ionum, accelerationum, &longs;tationum &c. nece&longs;­&longs;ariò con&longs;equentur.

Augu&longs;tin. Pace tua dixerim, Antime; ni&longs;i enim magnum orbem &longs;ta­tuas, & in eo Solem moveri, &longs;upponas, nunquam obtinebis, vt Mars Perigæus, &longs;it &longs;emper oppo&longs;itus; Apogæus verò, Soli &longs;emper coniun­ctus &longs;it.

Antim. Equidem nunquam habemus Martem Soli coniunctum, vel oppo&longs;itum, ni&longs;i Solem e&longs;&longs;e &longs;upponamus; nec etiam e&longs;&longs;e pote&longs;t, ni&longs;i alicu-bi &longs;it; &longs;it in B etiam immobilis, & Mars in D. hic erit Perigæus & oppo­&longs;itus: moveatur autem tum centrum Epicicli S, tum ip&longs;e Epicyclus, eo modo, quo diximus, quando centrum Epicycli erit in R, planeta erit in T; igitur Apogæus & coniunctus; atque ita deinceps emen&longs;is revolutioni­bus iuxta præ&longs;criptum motum, Mars &longs;emper erit Perigæus in oppo&longs;itio­ne, Apogæus in coniunctiono; Iam &longs;umus ergo pares, & vtrinque par numerus e&longs;t circulorum & motuum: vter verò modus rationi & naturæ magis con&longs;entaneus &longs;it, videndum re&longs;tat.

Augu&longs;tin. Vtrique parti, &longs;uus videbitur in rem i&longs;tam magis quadrare; quid enim pro tua cau&longs;a dici po&longs;&longs;it, non video, quod pro mea æquè non militet.

Antimus. Secus e&longs;&longs;e crediderim; nempe ille modus veritati, rationi, & naturæ magis con&longs;entaneus e&longs;t, qui nec &longs;en&longs;um, nec intellectum in erro­rem inducit, &longs;ed exhibet planetam in eo loco, in quo revera e&longs;t; is enim poti&longs;&longs;imùm oculorum finis, vt objectum, & tale quale e&longs;t, & in loco in quo e&longs;t, exhibeant. Atqui iuxta no&longs;trum modum, video ex A Martem in M, per lineam rectam productam ad verum locum Eclipticæ, in quo e&longs;t, cùm tamen iuxta tuum, ex B, videam Martem in eodem loco Eclipticæ, in quo tamen non e&longs;t, &longs;ed in alio, ad quem terminatur recta AF. Igitur in mea hypothe&longs;i, nec &longs;en&longs;us fallitur, nec intellectus; & provt terum natura po&longs;tulat, videtur Planeta in eo loco, in quo e&longs;t; in tua verò, & &longs;en&longs;us fal­litur, & per &longs;en&longs;um intellectus; Licit hic deinde ex aliis notionibus &longs;en­&longs;um corrigat; & contra rerum naturam & rectæ rationis ordinem, plane­ta &longs;emper in eo loco videtur, in quo non e&longs;t, & nunquam in eo, in quo e&longs;t, citra puncta oppo&longs;itionum & conjunctionum. Fateor vltrò, &longs;en&longs;us ali­quando falli, & multis &longs;ubjici fallaciis; &longs;ed profectò id accidit, vt aiunt, per accidens; nam per &longs;e &longs;en&longs;us non fallit, nec fallitur; &longs;ed meo iudicio, ab­&longs;urdum dictu e&longs;t, naturam oculis &longs;emper illudere volui&longs;&longs;e, quod tamen ex tua hypothe&longs;i nece&longs;&longs;ariò &longs;equitur; Video Solem moveri, ac Terram &longs;ta­re, turpiter erro, Sol enim quie&longs;cit, Terra movetur; terre&longs;trem globum in centro Vniver&longs;i e&longs;&longs;e video, & Solem in ætherea regione extra medium; &longs;ed oculi hallucinantur; nam Sol in centro e&longs;t, atque inter Sydera Tellus: Video Martem in 20. gradu Geminorum, oculo minimè impedito, etiam ex centro ter; fallor, erroque toto cœlo; cùm Mars reverâ &longs;it in principio Cancri; &longs;ic nobis Natura gratis impo&longs;uit, & in perpetuo errore ver&longs;ari voluit, quis hoc credat? Quis homini cordato per&longs;uadeat? præ&longs;ertim vbi nulla nece&longs;&longs;itas vrget, nulla ratio po&longs;tulat, nulla cogunt phænomena.

Augu&longs;tin. Illa facilitas Apogæi ac Perigæi, quæ in no&longs;tra hypothe&longs;i mirabilis e&longs;t, negari profectò nequit.

Antim. Quæ major facilitas excogitari pote&longs;t, quàm illa, qua res Apo­gæi ac Perigæi per Epicyclum explicatur? Quis &longs;tatim non capiat, Mar­tem in O e&longs;&longs;e Apogæum, in C verò Perigæum ? Quis non videt, eodem modo terram ab E, per EBC, accedere ad Martem F, quo Mars ab O per ONC, accedit ad terram A, &longs;cilicet ab O in N, & ab E in B, iuxta rationem &longs;inuum ver&longs;orum, ab N verò in C, & à B in C, iuxta rationem &longs;i-nuum rectorum arcuum decur&longs;orum: In his, crede mihi, nulla e&longs;t diffi­cultas, &longs;ed par vtrinque facilitas; no&longs;ter tamen modus naturæ, veritati, & rationi congruit, ve&longs;ter errori & fallaciis patrocinatur. Hic autem ac­curatas revolutionum men&longs;uras non definio, &longs;ed illud duntaxat intendo æquè facilè in no&longs;tra hypothe&longs;i, atque in tua, explicari illa omnia, quæ ad Planetarum pa&longs;&longs;iones &longs;pectant, licet no&longs;tra hypothe&longs;is naturæ ac rationi magis congruat. Sed ne in hoc quidem pares e&longs;&longs;e videamur, per te mihi liceat, quæro, rem i&longs;tam paulò minutiùs enucleare. Suppone, Martem, cum eo velocitatis gradu, quo velociùs Sole movetur, moveri ab ortu in occa&longs;um, haud dubiè Solem po&longs;t &longs;e relinquit, & po&longs;t aliquot revolutio­nes, modò e&longs;t in Quadraturis, modò in oppo&longs;itione, modò in Coniunctio­ne; &longs;it enim v.g. Sol in C, Mars in F, & vterque versùs occa&longs;um eat, &longs;ci­licet Sol à C, versùs D, Mars ab F, versùs S ; haud dubiè Mars Solem à tergo relinquit versùs ortum, atque adeò po&longs;t aliquot revolutiones Mars erit in F ; & Solem a&longs;piciet in B, tum in F ; po&longs;tea in D, ac demum eum a&longs;&longs;equetur in C, redibitque Conjunctio; Vides, vtrumque moveri &longs;implici&longs;&longs;imo motu; Cogita duos equos in duobus circulis currentes, quorum alter velociùs &longs;uum orbem ab&longs;oluit; Hinc Mars &longs;emper a&longs;&longs;equi­tur partem ortivam di&longs;ci Solaris; hinc &longs;emper ve&longs;pertinus occidit He­liacè, id e&longs;t, immergitur in radios Solis, ac proinde de&longs;init videri; Matuti­nus verò Heliacè oritur; id e&longs;t, emergit ex radiis &longs;olaribus, Sole po&longs;t &longs;e relicto versùs ortum; ac proinde incipit videri.

Augu&longs;tin. Optimè &longs;anè intelligo, quomodò ex diver&longs;o velocitatis gra­du, &longs;uppo&longs;ito etiam motu &longs;implici&longs;&longs;imo, vtriu&longs;que Planetæ diver&longs;i a&longs;pe­ctus &longs;equantur, & &longs;uppleatur vtriu&longs;que motus ortum versùs, motu illo diurno; &longs;ed quæ&longs;o te, quomodò Apogæum & Perigæum explicabis?

Antim. Per&longs;picuè omninò; &longs;uppo&longs;ito enim illo velocitatis gradu, quem Mars motu recto acqui&longs;ivit, eo temporis momento, quo cœpit agi in orbem, &longs;imul vna cum Sole, retinuit tantulam inclinationem primus ille impetus deor&longs;um, ab Apogæo, &longs;cilicet, in quo tune erat, cum volui cœpit, eamque ad in&longs;tar motus accelerati, v&longs;que ad mediocrem di&longs;tan­tiam, & ab hac v&longs;que ad Perigæum ad in&longs;tar motus retardati; atque ita deinceps: Ita porrò hæc inclinatio, qua Planeta deor&longs;um &longs;ur&longs;umque vi­bratur, eo modo, quo dixi, attemperata e&longs;t, vt men&longs;ura illius periodi, qua &longs;cilicet Planeta ab Apogæo ad Apagæum redit, &longs;it ferè æqualis, priori pe­riodo, quæ &longs;cilicet intercedit, ab vna Conjunctione ad aliam Conjunctio­nem, ac proinde, po&longs;ito quod, Mars initio, cum primùm cœpit moveri mo­tu circulari, e&longs;&longs;et in Apogæo & in conjunctione, nece&longs;&longs;atiò &longs;equitur oppo­&longs;itionem fieri, cùm e&longs;t in Perigæo, ac &longs;imul deinde ad Coniunctionem & Apogæum redire. Cur autem prædictæ inclinationis &longs;it talis men&longs;ura, vel periodus, facilè dictu e&longs;t; po&longs;ito &longs;cilicet, quod Naturæ Auctor ita di&longs;po­nere voluerit; nempe negari non pote&longs;t, quin res &longs;ecus e&longs;&longs;e potuerit, ac diver&longs;us motuum & revolutionum modus; &longs;ed &longs;tatuto &longs;emel hoc ordi­ne, finis Planetæ fuit, ita volvi, & ad Solem componere &longs;e&longs;e; proportio­nata igitur fuit ad hunc finem prædicta inclinatio, imò & talis medio-cris di&longs;tantia, &longs;uppo&longs;ito tali velocitatis gradu acqui&longs;ito, &longs;ive à Motore extrin&longs;eco, &longs;ive per motum acceleratum prævium.

Augu&longs;tin. Hæc &longs;anè in rem i&longs;tam optimè quadrarent, &longs;i Mars Perigæus &longs;emper e&longs;&longs;et oppo&longs;itus, & Apogæus &longs;emper coniunctus, quod tamen cum veritate non con&longs;entit; Nam &longs;æpè extra oppo&longs;itionem e&longs;t Perigæus & Apo­gæus extra coniunctionem; quod certè in hac tua hypothe&longs;i ab&longs;urdi&longs;&longs;imum e&longs;&longs;et; &longs;upponamus enim Martis Apogæum in O, Perigæum in E, & con­iunctionem citiùs fieri, quàm Mars perveniat ad Apogæum ; haud dubiè coniunctio non fiet in O, &longs;ed versùs ortum, id e&longs;t, versùs R. Igitur po&longs;t alteram revolutionem punctum coniunctionis promovebitur vltra, versùs ortum, atque ita deinceps; igitur po&longs;t multas revolutiones, eveniet tan­dem, vt coniunctio fiat in Perigæo, & Mars in Solem fortè impingat.

Antim. Nodus i&longs;te nullo negotio &longs;olvitur; &longs;i enim Sol &longs;emper e&longs;&longs;et in mediocri di&longs;tantia, haud dubiè coniunctio &longs;emper fieret in Apogæo, & oppo&longs;itio in Perigæo ; &longs;i autem Sol &longs;emper e&longs;&longs;et in Perigæo, oppo&longs;itio fie­ret vltra Perigæum, citrà verò &longs;i Sol &longs;emper e&longs;&longs;et in Apogæo ; nempe Sol circa &longs;uum Apogæum ver&longs;ans, maiores orbes decurrit, igitur tardiùs ab&longs;olvit; Quid mirum igitur, &longs;i Mars citiùs illum a&longs;&longs;equatur? cùm ta­men Sol Perigæus paulò minores circulos de&longs;cribat, citiùs igitur illos ab­&longs;oluit, Mais igitur tardiùs illum a&longs;&longs;equitur: At cùm Sol &longs;emper recurrat ab Apogæo ad Perigæum per mediocrem di&longs;tantiam, & vici&longs;&longs;im, iu&longs;ta fit compen&longs;atio breviorum & maiorum orbium, & pro diver&longs;a coniuga­tione vtriu&longs;que Apogæi & Perigæi, e&longs;t enim diver&longs;a vtrinque revolutio­num periodus modò præit Coniunctio Apogæum, modò &longs;ub&longs;equitur, v. g. &longs;i Sol circa Apogæum ver&longs;etur cum tardiùs orbes &longs;uos, vtpote ma­iores decurrat, citiùs illum Mars a&longs;&longs;equitur; ac proinde coniunctio præit Apogæum ; &longs;i verò circa Perigæum, citiùs &longs;uos orbes conficit, ac pro­inde tardiùs illum Mars a&longs;&longs;equitur, ac proinde &longs;equitur po&longs;t Apogæum coniunctio. Hæc ni&longs;i facilia &longs;int & ex &longs;implici&longs;&longs;imis principiis deducta, quid &longs;implex &longs;it & facile, nequit intelligi. Suppono hoc loco Solem in Apogæo po&longs;itum, maiorem orbem de&longs;cribere, &longs;cilicet diurnum, mi­nimum verò in Perigæo, licèt &longs;ecus aliquando accidat, de quo infra; Sed ad rem hanc &longs;ufficit, Solem aliquando maiores, aliquando mino­res, aliàs mediocres orbes per annum decurrere; exempli autem gra­tia, &longs;uppono, maiores e&longs;&longs;e in Apogæo, minores in Perigæo, medio­cres in mediocri di&longs;tantia.

Augu&longs;tin. Negari non pote&longs;t, quin hæc &longs;int facillima; at vnum &longs;cire averem, cur Mars aliquando matutinus bis emergat, & &longs;emel occul­tetur.

Antim. Vnus Keplerus, &longs;altem quod &longs;ciam, hoc a&longs;&longs;erit, cui tamen parum fidei habendum e&longs;&longs;e puto; Vt vt &longs;it, hoc etiam facilè explicari pote&longs;t; nam &longs;i Coniunctio præcedat Apogæum, cùm Mars &longs;uos orbes citiùs ab&longs;oluat, quàm Sol &longs;uos, Solem po&longs;t &longs;erelinquit versùs ortum, at­que adeò emergit; quia verò paulò po&longs;t proximè accedit ad Apogæum, & Sol ad Perigæum, Mars tardiùs, Sol citiùs &longs;uum orbem decurrit, hinc Sol Martem a&longs;&longs;equitur; hinc Martem occultari nece&longs;&longs;e e&longs;t; quia verò po&longs;t aliquod tempus, Sol à Perigæo, & Mars ab Apogæo recedunt, Mars citiùs &longs;uos orbes decurrit; hinc Solem po&longs;t &longs;e relinquit; hinc demum emergit. Si hoc phænomenum verum e&longs;t, vix puto aliam illius cau&longs;am a&longs;&longs;ignari po&longs;&longs;e; &longs;ed vt iam indicavi, Kepleri dictis parum fidei haben­dum e&longs;&longs;e putarem; præterquàm quòd fieri potuit, vt cra&longs;&longs;iores vapores Martem circa horizontem ortivum oculis &longs;ubduxerint per aliquot dies, quibus deinde di&longs;cu&longs;&longs;is, &longs;e&longs;e iterum Planeta videndum præbuerit, ac proinde non fuerit vera immer&longs;io, vel emer&longs;io; Vt vt &longs;it, nec enim de hoc laboramus, &longs;i phænomenum verum e&longs;t, in no&longs;tra etiam hypothe&longs;i &longs;ua cau&longs;a & ratione non caret, & vix &longs;cio, quonam pacto in ve&longs;tra ex­plicari po&longs;&longs;it.

Augu&longs;tin. Rectè omnia explicas, Antime, nec etiam dubito, quin ablegato etiam ve&longs;tro Epicyclo, retardationem, accelerationem, retro gradationem, &longs;tationem Martis explices; &longs;upponamus enim, Martei motu &longs;emper æquabili &longs;uos agere orbes, cum maiorem circulum de&longs;cribat in Apogæo, & minorem in Perigæo, hunc citiùs, tardiùs illum perficit; Supponamus autem, versùs Apogæum &longs;uum orbem decurrere tar­diùs, quàm &longs;tellas, citiùs verò ver&longs;us Perigæum; haud dubiè versùs Apo­gæum, longè retro à &longs;tellis relinquitur versùs ortum, vnde progredi videtur in con&longs;equentia &longs;ignorum, idque maiore intervallo, quò propiùs ad Apogæum accedit; minore verò, quo longiùs ab eo recedit; at verò versùs Perigæum &longs;tellas ver&longs;us ortum po&longs;t &longs;e relinquit; igitur versùs oc­ca&longs;um progredi videtur, id e&longs;t, à &longs;tella recedere, quod retrogredi vocant; vbi demum &longs;uum orbem æquè citò conficit atque &longs;tella, &longs;tare dicitur: Hæc &longs;atis bene intelligo, etiam, ex principiis Phy&longs;icis, quæ per optica tan­tùm in no&longs;tra hypothe&longs;i, explicantur; nonnulla tamen à te &longs;cire de&longs;ide­ro, v. g. vtrùm Mars in mediocri di&longs;tantia citiùs &longs;uum orbem decurrat, quàm &longs;tellæ, an verò tardiùs; deinde, cur Mars &longs;it retrogradus breuiori tempore, & longiore directus; cur ab Apogæo ad Quadraturam plus temporis ponat, quàm ab i&longs;ta ad Perigæum.

Antim. Mars haud dubiè in mediocri di&longs;tantia tardiùs &longs;uum orbem quàm &longs;tellæ, & non procul à Perigæo æquè citò illum decurrit; vnde non mirum e&longs;t, &longs;i cum ab vna coniunctione ad aliam dies circiter 780. &longs;eu revolutiones &longs;pirales intercurrant, &longs;it directus in 705. retrogradus in 73. in 2. demum &longs;tationarius. Si autem in mediocri di&longs;tantia &longs;uum orbem æquè citò ac &longs;tella conficeret, æque diu e&longs;&longs;et retrogradus, ac directus; ac proinde nunquam ad oppo&longs;itionem pervenire po&longs;&longs;et, & in Perigæo e&longs;&longs;et etiam Soli coniunctus, vt Venus; vnde parum omnino regreditur, &longs;i ob&longs;ervationes con&longs;ulamus, quibus haud dubiè &longs;tandum e&longs;t, non verò fictitio Sy&longs;temati.

Augu&longs;tin. Sy&longs;tema ex ob&longs;eruationibus &longs;tatuitur, ac proinde his &longs;tan­tibus, &longs;y&longs;tema etiam &longs;tare nece&longs;&longs;e e&longs;t.

Antim. Vis liberè dicam, quod &longs;entio; cum ex multis ob&longs;ervationi­bu: &longs;y&longs;tema &longs;tatuatur, eo &longs;emel &longs;tatuto, reliquas ad illud vt plurimùm accommodant v.g. ad explicandas huiumodi pa&longs;&longs;iones planetarum, puta Martis, nonnulli cum Ptolemæo Epicyclum po&longs;uerunt, alij cum Tycone circulum cuius centrum in Sole &longs;emper fixum e&longs;&longs;et; alij cum Copernico orbem excentricum circa Solem immobilem in centro mundi; his autem &longs;tatutis, ac definitis circulorum diametris; periodis, &longs;itu, &c. omnes ob­&longs;ervationes ad prædicta &longs;y&longs;temata, vt dixi, accommodant, licèt vt pluri­mum, aliquæ parum congruant. Hinc non mirum, &longs;i fortè &longs;upponant, Mar­tem pluribus gradibus retrogredi, quam re ip&longs;a retrogrediatur. Sed iam ad alia tua po&longs;tulata gradum fac

Augu&longs;tin. Su&longs;tine parumper, vnum exciderat, quod jam in mentem venit; dixi&longs;ti enim paulò ante, ni fallor, Solem in Perigæo &longs;uum orbem citiùs, in Apogæo tardiùs conficere; dies igitur no&longs;tri &longs;unt inæquales.

Antim. Novum profectò dictu non e&longs;t; nempe in antiqua etiam hypo­the&longs;i Ptolemaica, ex duplici capite illa dierum inæqualitas petitur; primò ex eo quod Sol in Apogæo excentrici in con&longs;equentia versùs ortum videa­tur tardiùs promoveri, contra verò velociùs in Perigæo ; igitur in Apogæo citiùs orbem &longs;uum ab&longs;olvit, diurnum &longs;cilicet, ab ortu ad occa&longs;um, tardiùs verò in Perigæo: Igitur circa Sol&longs;titium æ&longs;tivum, ex hoc capite &longs;unt bre­viores, & circa brumale, longiores. Secundò ex a&longs;cen&longs;ione recta & obli­qua Eclipticæ, nempe æquali tempore major arcus a&longs;cendit obliquæ, quàm rectæ; Igitur Sol in Sol&longs;titiis in quibus e&longs;t a&longs;cen&longs;io recta, tardiùs, in Æqui­noctiis, in quibus e&longs;t obliqua velociùs orbem diurnum ab&longs;olvit. Sed his rejectis, ex alio capite, prædictam inæqualitatem etiam duci po&longs;&longs;e dicimus; &longs;cilicet ex inæqualibus circulis, &longs;eu &longs;piris à Sole decur&longs;is, cum eodem &longs;ci­licet velocitatis gradu; vnde reverà fit, vt Apogæus majorem, & tardiùs, Perigæus verò breviorem & citiùs orbem decurrat; Vellem, vt fideli fune­pendulo inæqualitatem illam probares, numerato &longs;cilicet vibrationum nu­mero, idque &longs;ub initium Iulij & Ianuarij: Tunc enim e&longs;t aliqua, etiam for­tè &longs;en&longs;ibilis circulorum in æqualitas, igitur & dierum; & plures vibratio­nes numerantur intra &longs;patium &longs;emihoræ &longs;ub initium Iulij, Sole in Apogæo exi&longs;tente, quàm &longs;ub initium Ianuarij, quo tempore Sol in Perigæo ver­&longs;atur; & his vibrationibus, crede mihi, aliquam differentiam invenires, minimam certè, at, ni&longs;i &longs;allor, &longs;en&longs;ibilem.

Augu&longs;tin. Si hæc cum veritate con&longs;entiant, nullus dubitat, quin A&longs;tro­nomos plurimùm tibi ob&longs;trinxeris, &longs;ed antequam meis po&longs;tulatis facias &longs;atis, &longs;i tibi grave non e&longs;&longs;et, vellem, vt rude &longs;altem tui &longs;y&longs;tematis Solaris &longs;chema mihi exhiberes.

Antim. Prolixior reverà e&longs;&longs;em, &longs;i rem hanc, vt par e&longs;t, explicandam &longs;u&longs;ciperem; &longs;ed quandoquidem rudiorem dumtaxat delineationem fla­gitas, eò libentiùs tibi morem geram.

Sit igitur centrum mundi A, Axis mundi BC, diameter Æquatoris KF, diameter Tropici Cancri ID, Capri­corni LH, Apogæum D, Perigæum L, mediocris di&longs;tantia AQ, quæ di&longs;po­&longs;itio fortè fuit anno mundi 5400. Sit angulus obliquitatis Zodiaci DAF, item HAF, &longs;upponamus Solem in Apogæo cum tali velocitatis gradu, quo circa Axem mundi æquabili mo­tu &longs;uum orbem diurnum decurrit ab Ortu ad Occa&longs;um, cum duplici in­clinatione, altera &longs;cilicet versùs centrum A, ad in&longs;tar motus accelerati, v&longs;que ad mediocrem di&longs;tantiam, & retardati ab hac ad Perigæum, atque ita deinceps; altera verò versùs E, ad in&longs;tar pariter motus accelerati v&longs;que ad Æquatorem, & retardati ab Æqua­tore ad Tropicum, atque ita deinceps; cùm autem circuli &longs;int, vt diametri, vel &longs;emidiametri, erunt orbes decur­&longs;i, &longs;i tamen decurruntur orbes, vt B D, AQ, CH; & cùm AQ, &longs;it haud dubiè major, quàm BD, maximus circulus decurritur circa Æquatorem quod certè in hac hypothe&longs;i &longs;ingulare non e&longs;t, cùm etiam in Ptolemaica, & Tyconica locum habeat Dixi, cautè, &longs;i tamen decurrantur orbes, quia orbes non decurruntur, &longs;ed &longs;piræ, quæ ita componuntur, per majorem aut minorem di&longs;tractionem, vt &longs;ingulæ æquales ferè &longs;ingulis evadant, dico ferè, quia non nego, aliquam ine&longs;&longs;e inæqualitatem, vt &longs;upra dictum e&longs;t. Finge igitur, &longs;epo&longs;ito motu circulari, Solem duplici inclinatione, eo modo, quo &longs;uprà dictum e&longs;t, in&longs;tructum, ite, ac redire, tum versùs centrum mun­di A, tum à D ad E per arcum DE, & vtraque &longs;uo gaudeat acce&longs;&longs;u & rece&longs;&longs;u; hoc quidem motum retardatum, illo verò acceleratum imitante, &longs;itque men&longs;ura acce&longs;&longs;us primæ inclinationis FQ, vel EV, & rece&longs;&longs;us VH; Secundæ verò, acce&longs;&longs;us DF, & rece&longs;&longs;us FE, atque ita vici&longs;&longs;im; finge igi­tur, inquam, Solem ita moveri, &longs;epo&longs;ito motu circulari diurno; ibit haud dubiè per lineam curvam DQH.

Augu&longs;tin. Quis amabo &longs;ciat, lineam illam curvam e&longs;&longs;e? quid &longs;i dixe­rim e&longs;&longs;e rectam in latere cylindri, vel coni? Deinde &longs;i curva e&longs;t, quis de­finiat, quæ & qualis &longs;it? vide, quàm ab&longs;tru&longs;a & ob&longs;cura nobis obtru­das.

Antim. Recta e&longs;&longs;e non pote&longs;t in latere cylindri: &longs;it enim DE recta, &longs;i fieri pote&longs;t; erit AE æqualis, AD; igitur Perigæum æquè di&longs;tabit a Apògæum, quod repugnat; nec etiam in latere coni. Sit enim DH re­cta; &longs;itque exempli gratia HE ferè totius AE; haud dubiè AX e&longs;t brevior AH vt con&longs;tat ex Trigonometria; accedit enim propiùs ad per­pendicularem; omitto calculos, quia res e&longs;t per&longs;picua, etiam tyronibus Geometris; dixi exempli gratia, cùm re ip&longs;a minor &longs;it.

Augu&longs;tin. Quæ&longs;o te, Antime, tibi per&longs;picuum e&longs;t, aliis fortè non item, memini aliquando à magno Geometra, tibi haud ignoto, audii&longs;&longs;e, cum de te, tua que hypothe&longs;i &longs;ermo incidi&longs;&longs;et, DH, e&longs;&longs;e latus coni.

Antim. Scio, quem intelligas, hoc etiam mihi primùm, ne quid tibi di&longs;­&longs;imulem in mentem venerat, & maximè in votis hoc erat; &longs;i enim DH &longs;it latus coni, volvaturque BDEC, circa Axem BC, genitum erit fru&longs;tum ma­jus coni, quod &longs;i &longs;ecetur per Axem DL, erit &longs;ectio elliptica &longs;imul, & ecliptica, vnde Kepleri & aliorum ellip&longs;is ex Phy&longs;icis principiis demon­&longs;trata maneret; &longs;ed, vt iam dixi, DH non e&longs;t linea recta; &longs;i enim, &longs;i fieri pote&longs;t, ducatur recta DGE; igitur AX e&longs;t minor AH, quod re­pugnat, vt dixi; cùm enim angulus DAF &longs;it gradus 23.30. min. erit. DG illius &longs;inus rectus; igitur AG &longs;inus complementi; iam verò in hoc libel­lo tabularum &longs;inuum, invenio, vt vides, GA e&longs;&longs;e æqualem &longs;inui recto anguli grad 66.30 minut. qui e&longs;t ad &longs;inum totum, vt 91706.ad 100000.Igi­tur GF erit vt 8794.Igitur fere totius AD. Sed HE &longs;upponitur Igi­tur AH e&longs;t maior AG, & potiori iure maior AX, quæ minor e&longs;t AG: quanquam, vt dixi, fortè E e&longs;t minor AE.

Angu&longs;tinus. Satis e&longs;t; igno&longs;ce, hæc Geometrica pene mihi exciderunt; &longs;ed &longs;i linea DQH curva e&longs;t, vix &longs;ciri pote&longs;t, quænam & qualis &longs;it.

Antimus. Hoc etiam &longs;ciri pote&longs;t; e&longs;t enim linea quædam motus mix­ti, à magno Archimede iam olim inuenta; fac enim radium DA volui in hoc plano circa A, motu quidem accelerato, donec perveniat ad AF, retardato verò donec veniat ad AE, & &longs;imul vna punctum D ire versùs A in radio AD mobili, motu quidem accelerato, donec decurrerit &longs;egmen­tum radij æquale VE, retardato verò, tantundem; dictum punctum D ibit per curvam DQH modò acce&longs;&longs;us & rece&longs;&longs;us vtriu&longs;que motus &longs;int æquè diuturni; vnde vides curvam DQH e&longs;&longs;e veram &longs;piralem Archi­medis; ac proinde Sectio per axem DL, in &longs;olido genito à plano BDQ HC circa axem BC revoluto, quæ munere Eclipticæ defungitur, non e&longs;t vera ellip&longs;is, cuius tractatio ad præ&longs;entem quæ&longs;tionem non pertinet.

Augu&longs;tin. Iam vtcumque tuam Solarem hypothe&longs;im concipio, vis enim Solem &longs;implici motu æquabili diurno ferri ab Ortu ad Occa&longs;um, cum gemina inclinatione, eo modo, quo dixi&longs;ti; & cum vno ferè gradu &longs;in­gulis diebus à &longs;tellis retroagatur, videtur &longs;emper inhærere prædictæ el­lipticæ mobili circa eundem Mundi Axem; ita tamen vt &longs;patio 24. hora­rum quodlibet illius punctum &longs;uum integrum orbem decurrat, itemque in ea moveri ab Occa&longs;u ad Ortum, ita vt &longs;patio vnius anni totam decur­rat; &longs;ed hic motus non e&longs;t realis, vt vocant, &longs;ed tantùm apparens, ita­que hæc &longs;atis bene intelligo; &longs;ed non levis difficultas mihi e&longs;&longs;e videtur, tum in explicando Apogæi motu, tum in excogitanda aliqua ratione Ano­maliæ Solis; Sol enim, vt nemo ne&longs;cit, &longs;tatuto Apogæo in D, plures dies ponit à Tropico Cancri ad Æquatorem, quàm ab Æquatore ad Tropicum Capricorni.

Antim. Rectè omninò: Hinc vides, ni fallor, duo triangula ABD, ACH e&longs;&longs;e proportionalia, quia æquiangula; ac proinde, vt AD ad AH, ita BA ad AC; igitur AC e&longs;t minor AB; igitur breviore tempore de­curritur: &longs;epo&longs;ito enim motu circulari, cum prima inclinatione, &longs;it mo­tus acceleratus à B ad A, & retardatus ab A versùs C, &longs;i &longs;patia &longs;int, vt lineæ BA, AC, &longs;itque inter BA, AC media proportionalis BY, erunt tempora vt YB, AB; &longs;unt enim &longs;patia in duplicata ratione tempo­rum. Hoc autem ex duplici analogia facilè intelligitur; Prima e&longs;t;

Sit corda ten&longs;a BC, tendatur vltrà in BAC, affixo gemino clavo in FG, redit in BC motu accelerato; hic e&longs;t acce&longs;&longs;us; per rece&longs;&longs;um verò pervenit in FEG; ita vt DE &longs;it ad DA, vt DF ad DB; tempus autem acce&longs;&longs;us e&longs;t ad tempus rece&longs;&longs;us, vt AD ad DE. Alia verò &longs;it hæc; &longs;it BI funependulum in perpendiculo, pendens ex B, &longs;itque affixus clavus in F, ita prima &longs;emivibratio fiat per arcum AI, altera verò per IE, &longs;it inter AD, DE, media proportionalis AO, tempus vibrationis AI erit ad tem­pus vibrationis IE, vt AD ad AO; &longs;unt enim tempora in &longs;ubduplicata ratione &longs;patiorum, vt con&longs;tat ex doctrina motuum. Vtraque analogia facilè applicatur. Quod verò &longs;pe­ctat ad rationem motus accelerati, vt ad calculos reduca­tur, fortè po&longs;&longs;et accipi quadrans circuli BZ, qui repræ&longs;en­tet tempus acce&longs;&longs;us divi&longs;um in quotcunque partes æqua­les. v. g. accipiatur (in Figura priore) BN, arcus 30. graduum demittatur NM perpendicularis, acce&longs;&longs;us pro­motus e&longs;t illo tempore &longs;egmento BM, vel vt ad Phy&longs;icas cau&longs;as propiùs accedatur, acciperet aliquis &longs;emiparabo­lam ABZ, cuius Axis &longs;it BA, applicata quælibet, &longs;eu &longs;emiba&longs;is AZ, hæc &longs;i dividatur in quotcumque partes æquales, puta in 90. repræ&longs;entat tempus acce&longs;&longs;us, v.g. ab initio acce&longs;&longs;us &longs;it tempus AO 45.graduum; ducatur ON parallela Axi AB, tum appli­cata NM, applicatæ AZ parallela, BM erit men&longs;ura &longs;patij decur&longs;i in acce&longs;&longs;u, nec fortè vna progre&longs;&longs;io multùm differt ab alia, vt patet ex calculatione; vix enim a&longs;&longs;umptis quotcunque partibus temporis, diffe­rentia &longs;patiorum acce&longs;&longs;us vnum gradum integrum adæquat; &longs;ed profectò, vt A&longs;tronomicè vtramque probo, ita neutram phy&longs;ice admitto; germa­nam dabimus &longs;uo loco & Phy&longs;icam. Hæc enim obiter quatenus ad rem no&longs;tram facit, hîc tantùm indico; &longs;ed alibi ju&longs;tum cúmque integrum tra­ctatum edemus

Augu&longs;tinus. Acce&longs;&longs;us ab Apogæo ad Perigæum, & vici&longs;&longs;im, eodem modo ad calculos reducitur, a&longs;lumpta &longs;emiparabola &longs;ub Axe EV; item-que rece&longs;&longs;us &longs;ub Axe HV, applicata qualibet ba&longs;i, quæ in partes qua&longs;­cunque divi&longs;a repræ&longs;entat tempus, tum acce&longs;&longs;us, tum rece&longs;&longs;us.

Antim. Optimè; vnum tamen ob&longs;erva, in acce&longs;&longs;u ita dividi tempus, quod repræ&longs;entatur per lineam AZ, vt incipiat ab A & terminetur in Z; in rece&longs;&longs;u verò incipiat à Z, & de&longs;inat in A: idem dico de acce&longs;&longs;u & re­ce&longs;&longs;u Apogæi. Iam verò ad id, quod de motu Apogæi quæ&longs;iveras re&longs;pon­deo, periodum inclinationis, &longs;eu motus Apogæi, æqualem non e&longs;&longs;e perio­do alterius inclinationis; ita vt, Sol citiùs redeat ad Tropicum Cancri, vnde di&longs;ce&longs;&longs;erat, ab&longs;oluto totius Eclipticæ motu, quàm ad Apogæum, quod tantùm attingit paulo pò&longs;t: igitur interea Sol tantulùm promove­tur in Ecliptica, hinc Apogæum videtur moveri &longs;ecundùm &longs;eriem Signo­rum, &longs;ed adeò lentè, vt vix &longs;ingulis annis 1. minutum conficiat; & hic motus e&longs;t tantùm apparens. Hæc dixi ad reducendum ad calculos Ano­maliæ motum; nam re ip&longs;a AD habet minorem proportionem ad AH. &longs;eu BD ad CH, quàm tempus, quo Sol Apogæus in Cancro decurrit arcum Eclipticæ æ&longs;tivum, à principio &longs;cilicet Cancri ad Libram, ad tem­pus quo arcum autumnalem de&longs;cribit, &longs;unt enim &longs;piræ paulò laxiores in hoc arcu; ac proinde pauciores; igitur pauciores dies; quod ideò fit, vt vna &longs;pira diurna Solis &longs;it ferè æqualis alteri diurnæ; &longs;ic enim &longs;upplet natu­ra æqualitatem motuum; quod &longs;anè multis aliis exemplis comprobare po&longs;&longs;em, &longs;i fortè ita iuberes. Ex his reliqua, ni fallor, quæ ad Solare no&longs;trum &longs;y&longs;tema pertinent, facilè intelliges.

Augu&longs;tin. Ita e&longs;t: quare ad prima illa po&longs;tulata de Marte redeo; vnum, ni fallor, &longs;upererat, cur &longs;cilicet Mars à coniunctione, vel Apogæo ad Quadraturam, plus temporis ponat, quàm à Quadratura, &longs;cilicet re&longs;­pectu Solis, ad Oppo&longs;itionem, vel Perigæum.

Antimus. Miror à te, qui adeò per&longs;picax es, non videri; cùm enim Mars ab Apogæo & Coniunctione ad mediocrem di&longs;tantiam orbes &longs;uos tardiùs conficiat; haud dubiè minoribus intervallis Solem po&longs;t &longs;e relin­quit, quàm dum à mediocri di&longs;tantia tendit ad Perigæum; quia orbes &longs;uos citiùs decurrit; igitur maioribus intervallis Solem po&longs;t &longs;e relinquit; igitur cum æqualibus temporibus, ab Apogæo ad mediocrem di&longs;tantiam, & ab hac ad Perigæum perveniat, & cum eo tempore, quo ab Apogæo pervenit ad mediocrem di&longs;tantiam, minore arcu Solem po&longs;t &longs;e relinquat, maiore verò æquali tempore, quo à mediocri di&longs;tantia pervenit ad Pe­rigæum; inde &longs;equitur, vt arcus hinc inde &longs;int æquales, provt reverà æquales apparent, à Coniunctione ad Quadraturam, & ab hac ad Oppo&longs;i­tionem, a&longs;&longs;umenda e&longs;&longs;e inæqualia temporum intervalla, maius &longs;cilicet ab Apogæo ad Quadraturam, minus verò ab hac ad Perigæum.

Augu&longs;tin. Hæc adeò facilia Sunt, vt nimia facilitas non nihil de pre­tio detrahere videatur; iam verò mihi facilè per&longs;uadeo, reliqua omnia, quæ ad alias pa&longs;&longs;iones &longs;uperiorum Planetarum pertinent, pari facilitate ex iactis à te principiis explicari po&longs;&longs;e.

Antimus. Ita e&longs;t pror&longs;us; nam res eodem modo explicatur in Iove & Saturno; ni&longs;i quod cùm Iupiter maioribus intervallis Solem po&longs;t &longs;e relin-quat, quàm Mars, illum citiùs à tergo a&longs;&longs;equatur; ac proinde à Coniun­ctione ad Oppo&longs;itionem minus temporis excurrat; atque adeò, cùm il­lud temporis intervallum, æquè dividatur à mediocris di&longs;tantiæ momen­to, ad eundem finem obtinendum, Iovis &longs;cilicet Apogæi, in Coniunctio­ne, & Perigæi in Oppo&longs;i; brevior e&longs;t acce&longs;&longs;uum & rece&longs;&longs;uum periodus in Iove quàm in Marte; vnde frequentiùs recurrunt Coniunctiones in Iove, quam in Marte; cur verò Iupiter matutinus emergat, ve&longs;pertinus verò immer­gatur, cur plus temporis ponat à Coniunctione ad Quadraturam, quàm ab hac ad Perigæum; cur aliquando retrogredi, & &longs;tare aliquando vi­deatur, eodem modo in Iove explicamus, quo iam in Marte explicuimus; item cur Iupiter citiùs in con&longs;equentia moveri videatur circa Apogæum ; hic porro Planeta dies ponit in &longs;ua revolutione integra, nimirum à Con­iunctione ad Coniunctionem 399. ita vt diebus 283. directo motu feratur, &longs;cilicet apparenter; diebus 118. retrogrado; 4. verò &longs;it &longs;tationarius. In Saturno cuncta hæc locum habent; ni&longs;i quod maioribus adhuc intervallis Solem po&longs;t &longs;e relinquit versus Ortum; ac proinde pariodus revolutionis à Coniunctione ad Coniunctionem brevior e&longs;t, illa autem e&longs;t dierum 378. ita vt &longs;it directus diebus 244. retrogradus 136. &longs;tationarius fere 8. Hæc omnia ex ii&longs;dem no&longs;tris principiis nece&longs;&longs;ariò con&longs;equuntur.

Augu&longs;tin. Inaudij non nihil de motu Apogæi; trium &longs;uperiorum Plane­tarum; ne&longs;cio, vtrùm in tua hypothe&longs;i rectè illud explicare po&longs;&longs;is.

Antimus. Recti&longs;&longs;ime Nam &longs;upponamus, Apogæum Marris coniuncti e&longs;&longs;e in primo Arietis gradu; cùm illius revolutio ab Apogæo ad Apogæum, duret diebus 780. Sol bis redit ad idem punctum diebus fere 731. quibus detractis ex 780. re&longs;tant adhuc 49. ac proinde po&longs;t 49. ferè dies, Mars tan­tùm a&longs;&longs;equitur Solem, quibus per totidem ferè gradus Eclipticæ Sol pro­gredi videtur; Igitur Apogæum Martis tunc erit circa gradus 19. Tauri. Igitur &longs;ingulis annis & diebus 25. Apogæum Martis 25. circiter gradi­bus in con&longs;equentia moveri videtur. In Iove autem, cum illius revolutio fiat diebus 399. detractis 365. &longs;uper&longs;unt adhuc 34. quibus Sol totidem decurrere videtur; Igitur Apogæum Iovis po&longs;ito quod prior Coniunctio fuerit in primo gradu Arietis, erit in 4. gradu Tauri. Igitur &longs;ingulis annis & diebus 34. Apogæum Iovis moveri videtur in con&longs;equentia 34. grad. In Saturno denique, cùm eius revolutio fiat diebus 378. ex his &longs;i detrahas 365. &longs;uper&longs;unt 13. Igitur, ne idem repetam, &longs;ingulis annis, diebus 13. Apogæum Saturni moveri videtur in con&longs;equentia gradibus 13. circiter Sunt autem huiu&longs;modi motus apparentes tantùm, in mea hypothe&longs;i, vt tute&longs;cis, qui ramen ex illo reali &longs;implici&longs;&longs;imo nece&longs;&longs;ariò con&longs;equuntur, nec alio Apogæo excentrici opus e&longs;&longs;e crediderim.

Augu&longs;tin. Dubito, an po&longs;&longs;is alia explicare in tua hypothe&longs;i, quæ no­&longs;træ tantum hominum plau&longs;um conciliarunt, v. g. quod Saturnus directus Iovi & Marti conjungi non po&longs;&longs;it, ni&longs;i hi &longs;int directi; nec Marti retrogrado, alij duo, ni&longs;i &longs;int retrogradi, licèt Saturno retrogrado alij duo conjungi po&longs;&longs;int, licèt directi &longs;int, & Iovi retrogrado Mars dire­ctus.

Antim. Hæc &longs;unt ve&longs;træ hypothe&longs;eos miracula; &longs;ed hæc in no&longs;tra hy­pothe&longs;i facilè explicantur.

Sit enim Saturnus in I, Mars in M, Sol in C, cùm &longs;ingulis diebus, &longs;eu dìur­nis revolutionibus Mars relinquatur à Stellis Ortum versùs 3 ò. circiter, dum &longs;cilicet directus e&longs;t, & Saturnus. 2. Sit arcus FM, grad. 22. 15. minutis circiter; po&longs;t 45. dies Mars erit in F, Saturnus verò di&longs;tabit à puncto I, Ortum versùs grad. 3. igitur &longs;eptimo po&longs;t die, Mars Saturno conjungetur, directus directo; item Iupiter Marti; crat autem Saturnus in Apogæo, vt con&longs;tat, conjunctus &longs;cilicet Soli. Supponamus autem Martem oppo­&longs;itum in R, Solem in D, Saturnum in I, cùm Saturnus à &longs;tatione haud pro­cul ab&longs;it, e&longs;t enim juxta Quadraturam, tanto intervallo Mars regredi ne­quit versùs F, vt Saturno directo jungatur; quia &longs;tatim Saturnus &longs;tatio­nem attingit, & paucis po&longs;t diebus, fit retrogradus: eadem ratio facit pro Iove, vt &longs;cilicet nunquam Saturno directo, retrogradus jungatur. Sed vt hæc paulò accuratiùs di&longs;cutiamus; cùm Saturni & Solis conjun-ctiones &longs;æpiùs recurant, quia &longs;cilicet &longs;ingulis annis, Saturnus minoris arcus intervallo, à Stellis versùs Ortum relinquitur, ac proinde revolu­tionis Conjunctionum periodus brevior e&longs;t; igitur citiùs ab Apogæo ad Perigæum de&longs;cendit, imo inter di&longs;tantias Saturni Apogæi & Perigæi à centro mundi, longè minor e&longs;t proportio inæqualitatis, quàm inter di­&longs;tantias Martis Apogæi & Perigæi, ab eodem mundi centro; etiam a&longs;&longs;um­ptis Axibus acce&longs;&longs;uum & rece&longs;&longs;uum æqualibus, v. g. &longs;it di&longs;tantia Saturni Apogæi 100. Perigæi 90. Martis vero Apogæi 50. Perigæi 40. vtrinque a&longs;&longs;umitur idem Axis, id e&longs;t, eadem differentia di&longs;tantiarum, &longs;cilicet 10. e&longs;t autem major ratio 50. ad 40. &longs;cilicet 1/4 quam ad 90. &longs;cilicet &longs;ed ita &longs;e habent motus, vt di&longs;tantiæ; igitur vt Saturnus in Apogæo tantulùm versùs Ortum excurrit, ita & in Perigæo versùs Occa&longs;um; Hîc enim Stel­lam po&longs;t &longs;e relinquit; illic verò à Stella retro relinquitur; igitur modicum arcum in &longs;ingulis revolutionibus, tum directo, tum retrogrado motu decurrit: Mars verò longè majorem. Sit ergo Mars directus in M, Sa­turnus in I, cùm Mars longè majorem arcum directus decurrat, quàm Saturnus, conjungitur tandem Saturno versùs Ortum, ita vt primùm pars ortiva Martis cum occidua Saturni coëant: Sit verò Saturnus retrogra­dus in I, &longs;itque Mars in N etiam retrogradus, cùm hic etiam longè ma­jorem arcum decurrat retrogrado motu, jungetur Saturno versùs Occa­&longs;um, pars &longs;cilicet Occidua Martis, cum Ortiva Saturni: Si vero Mars &longs;it directus in M, exi&longs;tente Sole inter CB, alter versùs alterum fertur, jungentúrque inter FM, quo loco Mars directus e&longs;&longs;e pote&longs;t, & Saturnus retrogradus, nempe Martis &longs;tatio e&longs;t infrà trigonum a&longs;pectum, Saturni verò paulò infrà quadratum; hinc motus Saturni retrogradus diuturnio&longs; e&longs;t, licèt in minore arcu fiat; quid mirum igitur, &longs;i in eodem loco con­juncti e&longs;&longs;e po&longs;&longs;int Mars & Saturnus; licèt hic &longs;it retrogradus, ille directus; eadem ratio probat Saturno retrogrado etiam Iovem directum jungi po&longs;&longs;e; & Iovi retrogrado Martem directum.

Augu&longs;tin. Nunquam profectò mihi per&longs;ua&longs;i&longs;&longs;em ex principiis Phy&longs;icis, hæc tam facilè demon&longs;trari potui&longs;&longs;e; tota res eò reducitur, Saturnum eo velocitatis gradu moveri, vt paulò infrà mediocrem di&longs;tantiam, æquè citò &longs;uum circulum diurnum decurrat, ac Stellæ &longs;uum. Iupiter verò adhuc infrà, qua&longs;i in trigono; Mars demùm infrà trigonum; idem autem futuris &longs;æculis futurum e&longs;t; cùm eundem velocitatis gradum hi Planetæ &longs;ervaturi &longs;int, cum gemina illa inclinatione, de qua &longs;uprà; ex hoc enim illa, de quibus huiu&longs;que di&longs;&longs;eruimus, nece&longs;&longs;ariò con&longs;equuntur; nam Saturnus altior motum retrogradum diuturniorem habet; licèt in mino­re arcu, quàm Iupiter & Mars, directus verò breviorem, Idem dicitur de Iove re&longs;pectu Martis; hinc revolutio &longs;eu temporis periodus Saturni, illa &longs;cilicet, quæ inter duas Conjunctiones intercipitur, brevior e&longs;t, quàm Iovis, & huius etiam, quàm Martis brevior; hinc frequentiores recurrunt &longs;tationes in Saturno, quàm in Iove, & in hoc, quà in in Mar­te; hinc Saturnus minorem arcum Eclypticæ decurrit, tum directo, tum retrogrado motu; quia &longs;cilicet parum differt illius circulus diurnus confe-ctus in Perigæo, à circulo decur&longs;o in Apogæo ; E&longs;t enim minor propor­tio vnius ad alium; hinc per plures dies &longs;tare videtur; quia licèt reip&longs;a non &longs;tet, tam parum tamen promovetur & recedit à Stella, seu versùs Ortum, &longs;eu versùs Occa&longs;um, vt eandem à Stella di&longs;tantiam &longs;ervare vi­deatur; Cuncta hæc ita per&longs;picua &longs;unt, vt negari profectò non po&longs;&longs;int, quale do vltrò in hac tua hypothe&longs;i, huiu&longs;modi pa&longs;&longs;iones Planetarum æquè facilè explicari atque in mea.

Antim. Imò longè faciliùs & cum multiplici prærogativa: Nam pri­mò &longs;implici&longs;&longs;imum motum adhibeo; realem &longs;cilicet & æquabilem, circa mundi Centrum; tu verò duos, & fortè plures, eó&longs;que minimè æquabi­les; vtrumque in Excentrico circa centra ad libitum excogitata & ficta. Secundo, nunquam vides Planetam extrà Perigæum & Apogæum, in eo vero loco in quo e&longs;t, ac proinde perpetuæ fallaciæ &longs;ubjaces; ego in eo loco, in quo reverà e&longs;t, Planetam video. Tertiò, tu &longs;en&longs;um decipi a&longs;&longs;eris, quamvis rectè applicatum; ego vt & in aliis minimè falli repo­no, nec qui&longs;quam hoc jure ad&longs;truat, ni&longs;i aliqua ratione fretus. Quartò; denique habeo in mea cau&longs;as Phy&longs;icas, eá&longs;que tritas & vulgares in doctri­na motuum, i&longs;torum omnium effectuum, Apogæi &longs;cilicet, Perigæi, accelera­tionis, retardationis, &c. Tu verò meras fallacias, & oculorum illu&longs;iones e&longs;&longs;e contendis. Igitur non æquè facilè in tua hypothe&longs;i, ac in mea, res i&longs;ta ex­plicatur, &longs;ed in mea longè faciliùs, planiùs, &, vt &longs;ic loquar, connaturaliùs.

Augu&longs;tin. Vt vt &longs;it, quoad hæc, antequam ad alia, quæ fortè magis vrgent, accedam, ex te &longs;cire vellem, quonam modo latitudinem Planetarum in tua hypothe&longs;i explices; quod eò libentiùs audiam, quò mirabilior mihi videtur ille modus, quo in hypothe&longs;i no&longs;tra explicatur; in qua &longs;uppo&longs;ita orbitæ ex­centricæ Planetæ inclinatione ad planum Eclypticæ, latitudinis variatio per diver&longs;um terræ mobilis &longs;itum optimè explicatur; nempè arcus, qui maximam latitudinem metitur, in limitibus &longs;ub majore vel minore angulo apparet, quo remotior, vel propior oculus &longs;tatuetur; quod vt in &longs;chemate explicem,

Sit centrum mundi A, planum ecli­pticæ EGKH, excentricus FGI H, cuius centrum e&longs;t in D ; nodi G H, arcus inclinationis excentrici F E, IK, Tellnris orbita BLCM. Sit Terra in B, Planeta in limite Bo­reali F ; apparebit prædictus arcus &longs;ub angulo FBE, po&longs;ita verò Terra in C, apparebit &longs;ub angulo FCE, qui priore minor e&longs;t; Si verò &longs;tatua­tur in limite Au&longs;trali, I & Terra &longs;it in C, videbitur arcus IK &longs;ub an­gulo ICK, & ex B &longs;ub angulo IBK, &longs;ed ex Optica, per&longs;pi­cuum e&longs;t, angulum ICK majorem e&longs;&longs;e angulo FBE, quia CI minor e&longs;t BF; hinc phænomena illa, &longs;en potiùs generalia pronuntiata clari&longs;&longs;imè explicantur, &longs;cilicet Planetæ oppo&longs;iti in eodem limite majorem e&longs;&longs;e Lati­tudinem, quàm conjuncti; item Planetæ oppo&longs;iti in limite Au&longs;trino, La­titudinem majorem e&longs;&longs;e quàm in Boreali; vides, quàm clarè & per&longs;picuè in mea hypothe&longs;i hæc explicentur.

Antim. Fateor, hæc non &longs;ine plau&longs;u ab hominibus excepta fui&longs;&longs;e; &longs;ed re penitiùs con&longs;iderata, &longs;ummæ difficultates etiamnum re&longs;tant, quibus &longs;uperandis tuæ hypothe&longs;eos a&longs;&longs;ertores fru&longs;trà omninò de&longs;udârunt, immò nequidem inter &longs;e conveniunt, &longs;i rectè memini, in definienda huiu&longs;mo­di Planetarum latitudine, excentricorum inclinatione, Nodorum, & Apogæi motu, limitum libratione; atque adeò vltro fatentur, adhuc opus e&longs;&longs;e novis Ob&longs;ervationibus, ad rem hanc meliùs &longs;tatuendam. In mea hypothe&longs;i res &longs;atis expeditè explicatur, per &longs;ecundam illam inclinationem à Tropicis ad Æquatorem, & vici&longs;&longs;im, juxtà rationem motus accelerati & retardati; cùm autem Mars modò citiùs, modò tardiùs orbem &longs;uum decurrat, quàm Stellæ &longs;uum, &longs;emper verò citiùs quàm Sol, ni&longs;i fortè Mars &longs;it in Apogæo, & Sol in Perigæo, & cùm motus &longs;ecundæ inclina­tionis tardiùs fiat in Marte quàm in Sole; cùm demùm Mars ab Æqua­tore declinare po&longs;&longs;it versùs Boream & Au&longs;trum, gradib. circiter 25. ex his &longs;equitur, latitudo Martis, eaque varia, cùm aliquando relinquat Eclipticam versùs Boream, vbi di&longs;cedit à Nodo, in Signis de&longs;cendenti­bus, in a&longs;cendentibus verò, versùs Au&longs;trum; variatur etiam Latitudo ex varia di&longs;tantia Martis. Cæterùm vnum ob&longs;erves velim, optime Augu­&longs;tine, nullum mortalium hactenùs ad iu&longs;tos calculos minorum Planeta­rum, immò nec fortè Lunæ latitudinem reduxi&longs;&longs;e; præ&longs;ertim Martis, vt vel ip&longs;e Keplerus vltrò fatetur, qui vult, hæc latere in pandectis æternitatis; hinc tot excentrici, epicycli, circelli, deviationes, incli­nationes, reflexiones, librationes, centra diver&longs;a, excentricitates; ne­que adhuc Martem A&longs;tronomi tot tamque variis & multiplicatis retibus comprehendere potuerunt; vtor igitur, ad calculos, qualibet hypothe&longs;i, vt A&longs;trologus; vt Philo&longs;ophus eam dumtaxat admitto, quæ cum princi­piis Phy&longs;icis con&longs;entit; calculi verò difficultas ex eo provenit, quod &longs;int ferè innumeræ combinationes Apogæorum Solis & Martis; Nodorum item, qui versùs Ortum in con&longs;equentia promoveri videntur; nempè ex diver­&longs;o Nodorum & Apogæorum loco ac &longs;itu, diver&longs;a Latitudinis mutatio ne­ce&longs;&longs;ariò &longs;equitur. Hæc in Saturno & Iove etiam locum habent; atque adeò, ni fallor, ex dictis habes, in mea hypothe&longs;i, trium &longs;uperiorum Planetarum pa&longs;&longs;iones haud difficulter explicari, idque per principia Phy­&longs;ica, quæ ex doctrina moruum &longs;upponimus: quare &longs;i me audis, ac tibi putas à me factum e&longs;&longs;e &longs;atis, exprome alia argumenta, &longs;i quæ &longs;uppetunt pro tua hypothe&longs;i.

Augu&longs;tin. Veneris & Mercurij Conjunctiones in Copernicana hypo­the&longs;i, ea claritudine explicantur, qua ne&longs;cio, an major excogitari po&longs;&longs;it, itémque Apogæa & Perigæa, tum etiam aliorum Planetarum &longs;uperiorum, &longs;ed jam prævideo, quid pro tua hypothe&longs;i de hoc argumento dicturus &longs;is.

Antim. Apogæa & Perigæa facillimè in mea hypothe&longs;i explicantur per &longs;implicem motum æquabilem realiter, vt aiunt, inæqualem verò appa­renter, prima illa inclinatione, de qua &longs;uprà, in&longs;tructum; Apogæum au­tem e&longs;t &longs;emper circa Conjunctionem, & Perigæum circa Oppo&longs;itionem; quia ii di&longs;tantiæ fines &longs;upponuntur, i&longs;que velocitatis gradus impre&longs;&longs;us vel acqui&longs;itus, quibus &longs;uppo&longs;itis, æqualia &longs;int tempora acce&longs;&longs;us atque re­ce&longs;&longs;us, & &longs;emirevolutionis Conjunctionum & Oppo&longs;itionum; Sed hæc abundè &longs;uprà explicata &longs;unt; quare ad Venerem & Mercurium iam venio; quorum motus in mea hypothe&longs;i æquè facilè explicantur.

Sit enim centrum mundi B, orbita Solis ADCE, Apo­gæum Veneris S, Perigæum I, mediocris di&longs;tantia D: &longs;uppo­namus Venerem eo gradu ve­locitatis moveri, qui minor &longs;it illo, quo Sol movetur, ita vt inter di&longs;tantias BS, BN, tardiùs quàm Sol &longs;uum orbem decurrat, citiùs verò inter di&longs;tantias BN, BI. Itaque &longs;it Venus in Apogæo S, mo­vetur Occa&longs;um versùs &longs;impli­ci&longs;&longs;imo motu, &longs;imúlque ac­cedit ad mediocrem di&longs;tantiam BD, relinquitur autem à Sole versùs Ortum, a&longs;&longs;umptòque &longs;egmento acce&longs;&longs;us SO, Ve­nus erit in P, digre&longs;&longs;a &longs;cilicet à Sole angulo DBP; addito verò &longs;egmento acce&longs;&longs;us OD, erit Venus in mediocri di&longs;tantia, digre&longs;&longs;a à Sole arcu DL; a&longs;&longs;umpto porrò &longs;egmento rece&longs;&longs;us DN, erit in M ter­mino maximæ digre&longs;&longs;ionis, quam metitur angulus DBM grad. circiter 47. in M erit &longs;tationaria re&longs;pectu Solis, cùm nec ab eo vltrà digredi, nec ad illum accedere videatur; Dum verò ab&longs;olvit aliud &longs;egmentum rece&longs;&longs;us NI, redire ad Solem videtur, quia &longs;uos orbes citiùs decurrit vtpote mi­nores, donec tandem ad Perigæum I perveniat; MI accedit proximè ad lineam rectam; idem &longs;tatuatur pro acce&longs;&longs;u ab I, ad D, & rece&longs;&longs;u à D ad S, eritque figura integra cuius &longs;emifiguram tantùm hîc habes.

Augu&longs;tin. Cur amabo cum Tyconicis Epicyclum FHKG non a&longs;&longs;umis, in quo eadem &longs;alvabis phænomena, non verò figuram irregularem & in­cognitam?

Augu&longs;tin. Multa ob&longs;tant, quo minùs Epicyclum adhibeam. Primò, Licet Venus plus temporis ponat ab Apogæo ad maximam digre&longs;&longs;ionem, quàm ab hac ad Perigæum, non tamen iuxtà proportionem acceptam in Epicyclo: Sit enim arcus DV 45. grad. ducatur BV, tum perpendicularis DR, hæc erit &longs;emidiameter Epicycli, quanquam a&longs;&longs;umpto angulo maxi­mæ digre&longs;&longs;ionis grad. 47. &longs;emidiameter Epicycli erit paulo maior quàm DR; &longs;ed &longs;it vt DR; haud dubiè arcus FHR e&longs;t triplus arcus RK. Igitur tempus po&longs;itum ab Apogæo ad maximam digre&longs;&longs;ionem triplum e&longs;t illius, quod ponitur à maxima digre&longs;&longs;ione ad Perigæum, &longs;ed reverà triplum non e&longs;t, &longs;ed in minore proportione. Secundò BF e&longs;t ad BK ferè vt 12. ad 2. Igitur cùm circuli &longs;int vt diametri, circulus quem Venus decurtit in Apo­gæo F, e&longs;&longs;et dodecuplus illius, quem conficit in Perigæo K ; immo & in maiore proportione, cum angulus maximæ digre&longs;&longs;ionis &longs;it maior angulo grad.45. nempe ad gradus 48. immò & 49. nonnunquam accedit.

Augu&longs;tin. Hæc eadem ratio contra te militat, na &longs;uppo&longs;ita tua hy­pothe&longs;i, BS erit &longs;altem dupla BI, igitur circulus, quem Venus decurrit &longs;ub radio BS, e&longs;t duplus illius, quem decurrit &longs;ub radio BI, hunc igitur &longs;uppo&longs;ito motu &longs;emper æquabili, vt dicis, &longs;ub duplo etiam tempore Ve­nus decurrit, quod tamen Phænomenis non con&longs;entit.

Antim. Mentem meam omnino a&longs;&longs;ecutus es, & rectè contra me con­cluderes, &longs;i radium BS duplum radij BI ponere cogerer; &longs;ed vt tute &longs;cis, in exemplis non requiritur veritas; re igitur ip&longs;a provt diver&longs;a ratio motus po&longs;tularit, Apogæum & Perigæum ad D propiùs &longs;tatuam: ex his autem vides, quàm facilè omnia explicentur, primò po&longs;t Conjunctionem Apo­gæam, Venus versùs ortum à Sole digreditur, quia tardiùs Sole movetur versùs occa&longs;um. Secundò Venus vbi ad mediocrem di&longs;tantiam pervenit, puta in L, adhuc vltra digreditur, quia tardiùs Sole movetur. Tertiò nun­quam opponitur Soli; quia antequam perveniat ad Quadraturam cum Sole, citiùs quàm Sol orbem &longs;uum decurrit; igitur à Sole vltra non digreditur. Quartò plus temporis ponit ab Apogæo S, ad maximam digre&longs;&longs;ionem M, quàm ab hac ad Perigæum; quia tempus acce&longs;&longs;us SL, æquale e&longs;t tempori rece&longs;&longs;us LMI, &longs;ed MI citiùs decurritur quàm LMI; e&longs;t enim pars mi­nor toto. Secundò versùs Apogæum promoveri videtur in con&longs;equentia; versùs Perigæum in ancedentia; quia versùs Apogæum tardiùs, versùs Perigæum citiùs orbem &longs;uum ab&longs;olvit, ab ortu &longs;cilicet ad occa&longs;um. Sextò Emer&longs;io Veneris po&longs;t Conjunctionem Apogæam, e&longs;t ve&longs;pertina; quia Ve­nus à Sole versùs ortum digreditur, po&longs;t Conjunctionem Perigæam, e&longs;t matutina; quia Venus Solem po&longs;t &longs;e relinquit ver&longs;us ortum: ergo in illa apparet ve&longs;pere, in hac verò mane; &longs;ed paulò ante Apogæum fit immer&longs;io matutina; quia cum Venus tunc &longs;pectet Solem versùs ortum, mane appa­ret, & cùm Sol eam a&longs;&longs;equatur, mane immergitur; at paulo po&longs;t ante Pe­rigæum, fit immer&longs;io ve&longs;pertina; quia cùm Venus tunc Solem &longs;pectet ver&longs;us occa&longs;um, ve&longs;pere apparet, & cùm Solem a&longs;&longs;equatur, ve&longs;pere im­mergitur.

Augu&longs;tin. Sed quid de hac linea SPL, aliquis &longs;ortè putaret e&longs;&longs;e para­bolam; hoc enim aliquando &longs;altem amicis innuere vi&longs;us es.

Antim. Multa haud dubiè con&longs;ideranda &longs;unt, vt ritè definiatur, quæ & qualis &longs;it hæc linea: in modico arcu orbis va&longs;ti&longs;&longs;imi, qui ad in&longs;tar lineæ rectæ a&longs;&longs;umi pote&longs;t, pro parabola, phy&longs;icè loquendo, accipi pote&longs;t, & hoc ip&longs;um e&longs;t, quod iam aliàs innui cùm de Saturno confabularer; nem­pe ex duplici motu recto, altero &longs;cilicet naturaliter accelerato, altero æquabïli, hæc linea parabolica na&longs;citur, vt multi demon&longs;trarunt. Dixi phy&longs;icè loquendo, quia neque arcus circuli e&longs;t linea recta, neque lineæ ductæ ad idem centrum &longs;unt parallelæ, neque fortè motus apparens in illo arcu e&longs;t æquabilis. At verò in Venere, in qua longè maior arcus a&longs;&longs;u­mitur, vt DL, cùm hic a&longs;&longs;umi non po&longs;&longs;it, vt linea recta, quæ &longs;it ba&longs;is &longs;emi­parabolæ, linea SPL non e&longs;t, etiam phy&longs;icè loquendo, parabolica. Vt autem nonnihil, obiter &longs;altem, indicem, &longs;it BN radius illius circuli, quem Venus æquali tempore cum Sole decurrit, &longs;it vt BS ad SN, ita circulus &longs;ub radio BC ad arcum SX; &longs;it SO &longs;egmentum acce&longs;&longs;us ducto ex B arcu OP, ducetur linea per punctum P: pari modo alia puncta habebun­tur; cogita punctum S moveri per SD motu accelerato, & &longs;imul cum axe BS versùs X, circa centrum B, initio, velociùs: &longs;ub finem, tardiùs; de&longs;cri­bet curvam SPL, quæ e&longs;t &longs;pecies quædam &longs;piralis, &longs;eu fortè nova quæ­dam &longs;pecies parabolæ, in qua, arcus paralleli in locum applicatarum &longs;ub&longs;tituuntur; ita vt v.g. quadratum OP ad quadratum DL, &longs;it vt SO, ad SD, & vt tantulum Geometrizemus, cùm hæc figura &longs;it homogenea &longs;emiparabolæ, &longs;unt enim arcus vt applicatæ, &longs;i ducatur arcus LD in SD, habebitur area dictæ figuræ: &longs;i autem idem arcus DL ducatur in DB, habebitur &longs;ector BLD. Igitur figura SLD e&longs;t ad dictum &longs;ectorem, vt SD ad DB. Sit etiam vt BD ad BS, ita BS ad tertiam BF, erit &longs;ector BLD ad &longs;ectorem BHS, vt BD ad BF; &longs;unt enim &longs;ectores &longs;imiles in duplicata; igitur &longs;ector BLD ad reliquum trapezium LHSD vt BD ad DF, vel vt BD ad DF. Igitur LSD ad dictum trapezium vt SD ad FD; igitur LSD ad reliquum triangulum SHL vt DS ad DF minùs SD.

Augu&longs;tin. Hæc mihi non parum arrident; &longs;ed omitte quæ&longs;o hæc Geo­metrica, alioquin vix ab iis te ab&longs;trahere potero; probè igitur intelligo, quomodo in hac tua hypothe&longs;i, omnia quorum huc v&longs;que memini&longs;ti Ve­neris Phænomena explicentur; nonnulla tamen &longs;uper&longs;unt, quæ fortè plus negotij face&longs;&longs;unt v.g. cur maxima Veneris declinatio modò maior &longs;it, modò minor, cur Venus aliquando matutina, &longs;imul & ve&longs;pertina eodem die videatur; cur eiu&longs;dem latitudo Borealis &longs;it maior quàm Au&longs;tralis, alia­que huju&longs;modi.

Antim. Parum negotij cuncta hæc mihi face&longs;&longs;unt, &longs;ecus fortè vobis ac proinde tot epicyclos, excentricos, circellos, librationes arcus, Ellip&longs;&longs;es, Epicyclorum Epicyclos multiplicatis; quibus etiam admi&longs;&longs;is, vix fi­nem vobis propo&longs;itum obtinetis; itaque illa omnia cum meo &longs;implici&longs;&longs;imo motu facillimè explico: vbi enim Venus pervenit ad M, id e&longs;t, ad illum circulum ineundum quem æquali cum Sole tempore decurrit, dum hic e&longs;t in mediocri di&longs;tantia D ; &longs;i Sol &longs;it in Apogæo, cum in con&longs;equentia, id e&longs;t versùs Ortum Sol plus promoveri videatur, quia maiorem circu­lum de&longs;cribit, igitur tardiùs, haud dubiè Venus à Sole minùs digredi videtur ad quàm Sol propiùs accedit, igitur in hoc ca&longs;u, maxima digre&longs;-&longs;io Veneris minor erit; &longs;ecus accidet, &longs;i tunc Sol degat in Perigæo, quia &longs;cilicet breviorem circulum, ac proinde citiùs decurrit. Igitur versùs Oc­ca&longs;um longiùs à Venere amovetur, hinc maior huius digre&longs;&longs;io, quæ dein­de pro diver&longs;o loco Solis diver&longs;a erit. Minima igitur inter maximas fiet Sole exi&longs;tente in Apogæo ; exempli gratia; maxima verò Sole exi&longs;tente in Perigæo, media denique, Sole mediocrem di&longs;tantiam tenente, variæ deinde pro variis locis, in quibus Sol ab Apogæo vel Perigæo plùs, vel minùs di&longs;tat. Quod verò &longs;pectat ad alterum po&longs;tulatum, æquè facile ex­plico; cùm enim latitudo Borealis veneris maior &longs;it quàm au&longs;tralis, &longs;up­ponamus Venerem non procul à Perigæo cum latitudine Boreali 9. grad. Sole v. g. exi&longs;tente iuxta Tropicum Capricorni, arcus diurnus Veneris, longè maior e&longs;t, arcu diurno Solis, vt patet ex vulgaribus tabulis; quid mirum; igitur, &longs;i & ante Solem oriatur, & po&longs;t illum occidat; ac pro­inde mane & &longs;ero &longs;e&longs;e videndam præbeat? neque hic re&longs;tat vlla difficultas, ni&longs;i fortè cur latitudo Borealis Veneris &longs;it maior au&longs;trali, cum tamen Mer­curij latitudo Au&longs;tralis Boreali maior &longs;it; partim à Sole ratio petenda e&longs;t, cuius &longs;cilicet Apogæum modò e&longs;t in &longs;ignis Borealibus, modo in Au&longs;tra­libus, partim à diver&longs;is Coniunctionum & maximarum digre&longs;&longs;ionum lo­cis, ex quibus diver&longs;æ latitudinis ratio &longs;equitur; v. g. &longs;upponamus ma­ximam digre&longs;&longs;ionem ve&longs;pertinam in. 1. gradu Acietis ab&longs;que vlla latitu­dine, erit Sol v.g. in grad. 15. Pi&longs;cium, cùm autem hinc Venus cendat versùs Perigæum, & &longs;uos orbes citiùs Sole perficiat, haud dubiè &longs;tatim relinquit Eclipticam ver&longs;us Ortum & Au&longs;trum; vnde &longs;equitur latitudo Borealis & tardi&longs;&longs;imus motus in con&longs;equentia, donec tandem fiat re­trograda, & paulò po&longs;t Coniungatur Soli Perigæa, nec non tamdiu du­ret retrogradatio po&longs;t Coniunctionem, quamdiu duravit ante Coniun­ctionem, cre&longs;cente &longs;emper latitudine Boreali; donec ad maximam di­gre&longs;&longs;ionem matutinam perveniat, modò &longs;it in &longs;ignis a&longs;cedentibus, id e&longs;t à principio Capricorni ad principium Cancri. Si autem &longs;upponamus ibi­dem Planetam, &longs;cilicet in 1. grad. Arietis ab&longs;que latitudine, in digre&longs;­&longs;ione maxima matutina, Sol erit v. g. in gr. 15. Geminorum, vt patet, & cùm Venus hinc tendat ver&longs;us Apogæum, Orbes &longs;uos tardiùs Sole decurrere incipit; Igitur relinquit Eclipticam versùs Occa&longs;um & Bo­ream vnde &longs;equitur latitudo Au&longs;tralis, quæ continuo cre&longs;cit versùs Can­crum: hæc forte regula generalis &longs;tatui po&longs;&longs;et, Venetis latitudo Borea­lis, quamdiu movetur tardiùs Sole, id e&longs;t à maxima digre&longs;&longs;ione matutina v&longs;que ad maximam ve&longs;pertinam, in Signis a&longs;cendentibus, decre&longs;cit, in de&longs;­cendentibus cre&longs;cit; contra verò Au&longs;tralis in a&longs;cendentibus cre&longs;cit, & decre&longs;cit in de&longs;centibus; quamdiu verò movetur citiùs Sole, latitudo bo­realis in a&longs;cendentibus cre&longs;cit, in de&longs;cendentibus decre&longs;cit, in his demum Au&longs;tralis cre&longs;cit & decre&longs;cit in illis; cùm autem &longs;int ferè innumeræ con­iugationes, Signorum a&longs;cendentium & de&longs;cendentium, coniunctionum, digre&longs;&longs;ionum, itemque Apogæi & Perigæi; Veneris & Solis; quid mi­rum, &longs;i tanta varietas in Phænomenis deprehen&longs;a A&longs;tronomos eò adegerit, vt fateantur vltro, certum Sy&longs;tema Veneris, in quo omnia Phænomena explicentur nondum &longs;tatui po&longs;&longs;e, ri&longs;i plures & magis accuratæ Ob&longs;erva­tiones fiant. Porrò cum Venus proximè ad terram accedat, & circa hori-zontem vt plurimum Ob&longs;ervetur, non e&longs;t dubium, quin refractio eius La­titudinem non parum mutet, ac proinde valde difficile &longs;it, certam regu­lam ex Ob&longs;ervationibus, quæ tot fallaciis oculorum &longs;ubjiciuntur &longs;tatuere; &longs;ed ne &longs;im prolixior, & &longs;altem extra chorum, hæc omitto, cùm manife&longs;tè con&longs;tet, in qualibet hypothe&longs;i ; hæc valde difficilè explicari; in ea tamen, quam indicavi longè faciliùs. De Mercurio nihil dico, quia eadem pro illo faciunt, quæ de Venere diximus, ni&longs;i quòd &longs;uas revolutiones citiùs ab&longs;olvit, minu&longs;que digreditur à Sole, quàm Venus; ac proinde illius Ob­&longs;ervationes longè difficiliores. De diver&longs;is pha&longs;ibus horum Planetarum nihil etiam dico; quia non dubitas; opinor, quin facillimè citra ve&longs;tram hypothe&longs;im explicentur: quare his peractis, vide quæ&longs;o, vtrùm alia pro tua hypothe&longs;i &longs;uppetant argumenta.

Augu&longs;tin. Omi&longs;&longs;is A&longs;tronomis, quæ haud dubiè &longs;atis feliciter &longs;olvi&longs;ti, alia duo &longs;unt, quæ magnum no&longs;træ hypothe&longs;i plau&longs;um pepererunt, pri­mùm petitur à maris æ&longs;tu, alterum à Magnete: quod ad primum &longs;pectat, &longs;upponimus, Terram moveri motu quodam mixto ex motu orbis & cen­tri, qua&longs;i ad in&longs;tar rotæ in plano, vt iam &longs;upra in&longs;inua&longs;ti, ac proinde par­tes illius inæquali motu ferri, alias tardiùs, alias velociùs. Suppono præ­tereà aquam in va&longs;e, &longs;eu cymba vectam, vbi cymba motum remittit, ex­currere versùs illam partem, in quam cymba tendit; in oppo&longs;itam verò, vbi cymba motum accelerat, cogita quæ&longs;o aquam Occani, qua&longs;i in va&longs;ti&longs;­&longs;ima concha, à Globo Terræ delatam & circumactam, &longs;ed dicto motu inæquali, haud dubiè vbi motus acceleratur, aqua versù; Occa&longs;um ex­currit, vbi remittitur, versùs Ortum: En tibi germanam cau&longs;am æ&longs;tus marini, quæ certè, vt cum no&longs;tra hypothe&longs;i optimè con&longs;entit, ita in aliis explicari non pote&longs;t.

Antim. Negare non po&longs;&longs;um, quin hoc fuerit ingenio&longs;um inventum, fictum tamen & commentitium. Primo enim ita æ&longs;tus diurnus &longs;uas pe­riodos metitur, vt ad motum Lunæ dumtaxat, diurnum &longs;cilicet, non Solis aut Terræ &longs;e&longs;e componat; nam &longs;ummi æ&longs;tus, vel &longs;ummæ aquarum elevationis terminus e&longs;t Luna meridiana, tum in hoc, tum in oppo&longs;ito hemi&longs;phærio; principium verò e&longs;t eadem Luna, Quadrante circuli di­&longs;tans à Meridiano: Igitur Luna exi&longs;tente in Meridiano, æ&longs;tus cre&longs;cere de&longs;init, decre&longs;cere incipit, remota vero Quadrante circuli à Meridiano, hinc inde æ&longs;tus decre&longs;cere de&longs;init, & cre&longs;cere incipit: rem ita fieri per &longs;e con&longs;tanti&longs;&longs;imum e&longs;t, habeturque ex indubitatis Ob&longs;ervationibus; licèt autem per accidens fieri po&longs;&longs;it, vt crementum decremento inæquale &longs;it; hoc tamen non ob&longs;tat, quin po&longs;tero die dementum incipiat eadem hora Lunari, ac proinde 48. minutis tardiùs, quàm pridie. Quid autem ad hæc, Augu&longs;tine mi, Terræ motus conferat, nemo capiat; cùm enim ea­dem motus inæqualitas, eadem &longs;emper hora, eidem Æquatoris terre&longs;tris globi puncto in&longs;it, idem &longs;emper effectus ex eadem inæqualitate, ca­dem hora &longs;equi deberet: igitur eadem hora &longs;emper e&longs;&longs;et &longs;ummum cre-mentum æ&longs;tus, eadem, &longs;ummum decrementum; quod tamen omnibus Ob&longs;ervationibus repugnat: &longs;i enim hac ip&longs;a die, Luna in Meridie &longs;ci­licet exi&longs;tente, &longs;it &longs;ummum crementum æ&longs;tus hora meridiana, vt &longs;it in no­vilunio, cra&longs;tina die, idem &longs;ummum crementum erit minutis 48. circiter po&longs;t Meridiem; & tertio po&longs;t die hora, 1. 36. minutis po&longs;t Meridiem, at­que ita deinceps; idem de Plenilunio dicendum e&longs;t.

Augu&longs;tin. Ita fortè di&longs;poni po&longs;&longs;unt prædicti duo motus, orbis &longs;cilicet & centri, vt motus mixtus inde re&longs;ultans tales in æ&longs;tu mutationes pro­ducat.

Antim. Nullo &longs;ané modo id fieri po&longs;&longs;e, omni a&longs;&longs;everatione affirmo; quod vt clariùs exponam.

Sit A Centrum mundi, DBLC orbita terræ, vel magnus orbis, D cen­trum terræ, quam paulò majorem de&longs;cribo, ne parvitas orbis confu&longs;io­nem patiat; dum centrum D movetur versùs B, ita volvitur circulus cir­ca D, vt Eversùs I, & F, versùs H tendat. Vnde re&longs;ultat ex vtroque mo­tu æquabili motus mixtus omnino inæqualis; nempe ab H in I, per E; additur motus orbis, motui centri; id e&longs;t &longs;patio decur&longs;o &longs;olo motu cen­tri, &longs;patium æquale diametro IH ; ab I verò in H per F, idem &longs;patium detrahitur &longs;patio decur&longs;o mot centri, hinc ab H in E, acelerationis cre­menta, &longs;uprà motum centri, &longs;unt in ratione &longs;inuum ver&longs;orum arcuum decur&longs;orum; ab E in I, in ratione &longs;inuum rectorum; decrementa pariter ab I in F, &longs;unt in ratione &longs;inuum ver&longs;orum; ab F verò in H, in ratione &longs;inuum rectorum: Vnde in E e&longs;t maxima acceleratio; in F maxima retar­datio, in I & H merus motus centri con&longs;ideratur: itaque ab H in I per E, aqua Oceani juxta ea, quæ dicis, versùs Occa&longs;um excurrere deberer; ab I verò in H per F, versùs Ortum; Igitur in E &longs;emper e&longs;&longs;et maximus excur­&longs;ionis motus versùs Occa&longs;um; in F versùs Ortum; in I & H quies; quan­tum hæc Ob&longs;ervationibus repugnent, omnibus rerum i&longs;tarum peritis cogi­tandum relinquo.

Augu&longs;tin. Quid &longs;i aliquis diceret, Nautis in hoc fidem habendam non e&longs;&longs;e, qui forte ad libitum prædictas ad Lunam habitudines marino æ&longs;tui affinxerunt?

Antim. Cuique &longs;uæ artis perito credendum e&longs;&longs;e, optima ratio po&longs;tu­lat, præ&longs;ertim &longs;i periti omnes illius artis aliquid a&longs;&longs;erant, quod alioquin nihil illorum intere&longs;t. Cùm igitur Naucleri omnes periti, & principes illi autores, qui de hoc argumento &longs;crip&longs;erunt, omni a&longs;&longs;everatione affirment, rem ita e&longs;&longs;e, nemo prudens fidem iis detrectet; accedit, quod illi om­nes, qui in litore Oceani Gallici, Britannici, Anglici, Belgici habitant (neque te ad Antipodas vel Garamantas amando) omnimodam huiu&longs;ce rei te&longs;tificationem facere po&longs;&longs;unt, cùm illam præ oculis habeant; omitto alia innumera argumenta, quibus hoc ve&longs;trum commentum refutatur; quia &longs;upervacaneum puto, actum iam agere, illud tamen non omitto, quod præ cæteris vrgere videtur; &longs;uppono enim cum iis omnibus, qui vel delibârunt hanc materiam, maximam e&longs;&longs;e vim æ&longs;tus in Plenilunio, magnam etiam in Novilunio, in Quadraturis perexiguam; Quid porro ad hæc terræ motus? Nihil pror&longs;us.

Augu&longs;tin. In Novilunio Luna propios ad Solem accedit, & minores arcus decurrit, contraverò in Plenilunio.

Antim. Quid in de? An fortè Luna &longs;uos motus in Terram derivat? Mi­nimè verò, alioquin maior æ&longs;tus e&longs;&longs;etin Quadraturis, quàm in Novilunio, quod certè cum veritate minimè con&longs;entit: deinde Terra ip&longs;a in Novilu­nio tardiùs moveretur, quod nemo vnquam &longs;omniavit.

Augu&longs;tin. Saltem negari non pote&longs;t, quin terræ aut Solis motus ali­quid conferat ad mutationem illam æ&longs;tuum, quam omnes huiu&longs;que cir­ca Æquinoctia Ob&longs;ervarunt; nihil enim ad hæc Luna.

Antim. Sed quid quæ&longs;o ad hæc terræ motus? equidem in diurno ter­ræ motu, illa revolutio annua Globi, ad retinendum Axis Paralleli&longs;mum, aliquid facit, quod tamen &longs;ub &longs;en&longs;um non cadit: nempe motui orbis opponi videtur: &longs;ed reverà hoc nihil e&longs;t, nec quidquam ad hanc rem fa­cit, vt con&longs;ideranti patebit.

Augu&longs;tin. Quid autem ad hæc Luna, quis hominum aliquando dicat?

Antim. Ego fortè minimus hominum; illam enim æ&longs;tus marini cau­&longs;am affero, quæ & communibus principiis nittitur, & ad quam cuncta phænomena, quæ per &longs;e ex marino æ&longs;tu &longs;equuntur, facilè reduci po&longs;&longs;unt: &longs;ed cùm altioris indaginis res &longs;it, in alium congre&longs;&longs;um remittendam illam e&longs;&longs;e putarem, ne cœpta di&longs;ceptatio intermittatur: itaque omi&longs;&longs;o maris æ&longs;tu, quid tandem de Magnete dicis?

Augu&longs;tin. Facilè opinor conjicies; terram enim maiorem Magnetem e&longs;&longs;e dicimus cum Gilberto; vnde manife&longs;tam cau&longs;am ducimus perpetui Axis paralleli&longs;mi; &longs;ic enim polorum Magneticorum axis, Axi mundi &longs;emper e&longs;t parallelus, id e&longs;t, ad eandem &longs;emper fixam vniver&longs;i plagam conver&longs;i &longs;unt, immo nullum alium ab i&longs;to Axem mundi agno&longs;cimus.

Antim. Terram Magnetem e&longs;&longs;e non pauci communiter negant; neque rationes efficaces de&longs;unt; &longs;ed demus hoc in tui gratiam, & terra, vt vis, &longs;it va&longs;tus Magnes: igitur illius poli ad fixa cœli puncta &longs;emper &longs;pectant; rectè, quis hoc negat? Vnde &longs;i fortè vi ab extrin&longs;eco impre&longs;&longs;a, ab hoc a&longs;pectu & &longs;itu amoveretur, illico &longs;e&longs;e re&longs;titueret; optimè; quid inde? Ergo, inquies, terra movetur in orbe magno, quia illius Axis, circa quem diurnos agit orbes, &longs;ibi ip&longs;i Parallelus &longs;emper e&longs;t; nego con&longs;e­quentiam; &longs;ive enim terra moveatur, &longs;ive quie&longs;cat, ille Axis ad fixa &longs;em­per cœli puncta &longs;pectat: ergo ex hoc neutra hypothe&longs;is probari pote&longs;t; immò potiori iure mea, quàm tua inde probatur.

Augu&longs;tin. Fortè illam &longs;ubaudis demon&longs;trationem, qua ex tuis aliquis no&longs;tram hypothe&longs;im labefactare molitus e&longs;t. Fru&longs;trà licet: cùm illam Ga&longs;&longs;endus vir toto orbe literario notus illam in Docti&longs;&longs;imorum homi­num congre&longs;&longs;u, cui &longs;ummus quidam Princeps præerat, egregiè refutavit.

Antim. Certè illam demon&longs;trationis loco non habeo; nam nec terram magnum Magnetem e&longs;&longs;e, puto, nec etiam &longs;i magnes e&longs;&longs;et, ad alia quæ­dam cœli puncta, exceptis polis, re&longs;pectum haberet, volebat enim vir ille de re Magnetica optimè meritus, Magnetem in &longs;phæram tornatum, in eo &longs;emper &longs;itu manere, vt omnia illius puncta ad eadem &longs;emper vni­ver&longs;i puncta &longs;pectare debeant; quod certè variis experimentis, ii&longs;que &longs;electi&longs;&longs;imis probare conatur; non tamen meo iudicio convincit, hoc enim provenit à communi partium Magneticarum ni&longs;u, quæ Magneti ita in&longs;unt, vt &longs;ingulæ &longs;phæræ Magneticæ portiones æquali vi non pol­leant, &longs;ed aliæ plus, aliæ minùs; vnde fit vt ex communi omnium ni&longs;u. vnde tantùm &longs;itus haberi po&longs;&longs;it; vnde &longs;i &longs;phæra illa Magnetica æquales vires in omnibus &longs;uis partibus haberet, æquè ille communis ni&longs;us &longs;uum effectum &longs;ortiretur, &longs;ive hoc punctum versùs Ortum, &longs;ive Occa&longs;um ver­sùs collocetur: &longs;ed, vt verum fatear, licèt ex Magnete neutra hypothe&longs;is demon&longs;tretur, no&longs;træ tamen potiùs, quàm tuæ Magnes favet; primò enim licèt non demus terram Magnetem e&longs;&longs;e, hoc tamen tecum &longs;uppo­nere po&longs;&longs;umus, aut &longs;altem cum aliis, multas illi particulas Magneticas ine&longs;&longs;e, quod certè ex multis experimentis probatur: præ&longs;ertim ex de­clinatione acus Magneticæ; &longs;ufficienti igitur virtute in&longs;tructa e&longs;t, vt ta­lem a&longs;pectum &longs;emper retineat; virtute inquam particularum Magneti­carum, quæ in&longs;unt, quarum etiam communi ni&longs;u, cùm inæqualiter ac difformiter terre&longs;tri globo admixtæ &longs;int, obtinebitur, vt non modò duo terræ poli ad polos Mundi, &longs;ed etiam idem punctum &longs;emper ad Or­tum, idem ad Occa&longs;um &longs;emper conver&longs;um &longs;it.

Augu&longs;tin. Hanc igitur Grandamici demon&longs;trationem tuo calculo do­nas, quam tamen viri Docti&longs;&longs;imi & Sapienti&longs;&longs;imi rejecerunt.

Antim. Non habeo, vt iam dixi, pro demon&longs;tratione; quia nemo huiu&longs;que probavit, terram Magnetem e&longs;&longs;e; aut &longs;altem tot particulis Magneticis in&longs;tructam, quæ &longs;ufficiant, ad tantam molem volvendam; hoc tamen &longs;uppo&longs;ito, cum iam ex aliis corporibus Magneticis con&longs;ter, virtutem illam Magneticam per totam &longs;phæram vniformiter di&longs;tributam non e&longs;&longs;e, ex hoc nece&longs;&longs;ariò &longs;equeretur, terram ab Occa&longs;u ad Ortum, mi­nimè moveri: vnde non crat, quòd vir ille docti&longs;&longs;imus non modo de re Magnetica, verùm etiam de Chronologica optimè meritus, à nonnul­lis adeò exploderetur; hoc enim argumentum ab illo excogitatum, ad hominem, vt vocant, contra Gilbertum & alios, qui terram magnum Magnetem e&longs;&longs;e dixerunt, rem i&longs;tam omnino evincit; &longs;ecus tamen contra illos, qui terram Magnetem e&longs;&longs;e negant, aut &longs;ufficienti virtute magnetica in&longs;tructam, qua tanta moles agi queat.

Augu&longs;tin. Ne&longs;cio quid aliud indicâras; hoc enim tantum primum caput e&longs;t, ex quo Magnetem tuæ potiùs, quàm meæ hypothe&longs;i favere di­cebas, &longs;i primum e&longs;t, cur ad &longs;ecundum non venis?

Antim. Res ferè e&longs;t nullius momenti, dicam tamen, illam hypothe&longs;im ad rem magneticam potiùs facere, in qua terræ Axis fixa &longs;emper eadem­que vniver&longs;i puncta re&longs;picit, quàm illam, in qua terræ Axis per tot mil­liarium myriades in magno orbe circumfertur; Licèt enim &longs;ibi ip&longs;i &longs;em­per parallelus &longs;it, de&longs;cribit tamen vtroque termino, circulum æqualem magno orbi; in no&longs;tra fixus e&longs;t Axis, fixa cœli puncta, neutrum in tua habetur, quare vt fateor vltero, neutram ex Magnete demon&longs;trari, ita &longs;anè nemo retum i&longs;tarum rectus æ&longs;timator inficias eat, quin no&longs;tra regulis magneticis magis con&longs;entiat; &longs;ed de hoc &longs;atis, quare vide vtrùm pro tua hypothe&longs;i aliquid aliud &longs;uppetat.

Augu&longs;tin. Suppetunt quidem multa, &longs;ed ex iis, quæ à te adducta &longs;unt, &longs;at video, quàm facilè illa &longs;olvere po&longs;&longs;is; quare de hoc argumento &longs;atis &longs;uperque dictum e&longs;&longs;e puto.

Antim. Egregiè &longs;anè; &longs;ic æquis armis pugnamus. Huiu&longs;que meam hypothe&longs;im tuis argumentis impugna&longs;ti, nec dixi vnquam &longs;atis; iam verò ex arena pedem efferre velles, ne mihi copia detur tuam impugnandi.

Augu&longs;tin. Æquum e&longs;t, per me licet; &longs;ed obiter quæ&longs;o, ne iu&longs;to lo­quaciores e&longs;&longs;e videamur.

Antim. Obiter, inquis, non pauciora certè, immo longè plura argu­menta contra tuam hypothe&longs;im habeo, quàm tu contra meam igitur, &longs;i non plus, tantumdem &longs;altem temporis, ad hanc provinciam exequen­dam, iure meo po&longs;tulo.

Augu&longs;t. Crede mihi, Antime, certamen non detrecto, nec vinci metuo, timeo tamen ne prolixior di&longs;ceptatio nonnihil tædij circun&longs;tantibus afferat

Antim. Rectè mones remittamus in proximum congre&longs;&longs;um, per me licet.

Augu&longs;tin. Ne tamen aliquid fortè quod &longs;upere&longs;t huic congre&longs;&longs;ui detra­hatur; tuam illam de marino æ&longs;tu &longs;ententiam exponere poteris, vt amœ­niùs hæc di&longs;ceptatio terminetur; tenes enim, ni &longs;allor, ex lis aliquam, quæ iam ab aliis excogitatæ fuerunt.

Antim. Minimè verò; Nova e&longs;t omnino mea &longs;ententia, & à me pri­mùm excogitata, & i&longs;tarum temporis angu&longs;tiarum impatiens; quare, vt iam indicavi &longs;upra, integrum congre&longs;&longs;um implebit.

Augu&longs;tin. Illa opinion Carte&longs;ij mihi &longs;tatim venerat in mentem, qui vult à circumfluente Luna comprimi aëra, & Oceani &longs;uperficiem, ex qua pre&longs;&longs;ione, aquarum motus &longs;equatur, quem vocat æ&longs;tum; te fortè huic ad­hærere putabam; quando quidem Lunæ mentionem feci&longs;ti.

Antim. Toto cœlo erras; illam &longs;ententiam minimè approbo, quæ & phænomenis & veritati non con&longs;entit; ex illa enim &longs;equitur. Primò à Luna meridiana illum maximè comprimi maris tractum, qui tali meri­diano &longs;ubjacet, aqua verò compre&longs;&longs;a &longs;ub&longs;idit, & quoquo ver&longs;um fluit; igitur non &longs;ummum aquæ tumorem, &longs;ed maximam depre&longs;&longs;ionem meri­diana Luna conciliaret; quod repugnat ob&longs;ervationibus. Secundò Præ­dictam aëris pre&longs;&longs;ionem omnino &longs;entiremus. Tertiò In Plenilunio non e&longs;&longs;et maior pre&longs;&longs;io, tunc enim Luna vicinior non e&longs;t, quàm in Novilu­nio & Quadraturis, igitur in Plenilunio maior æ&longs;tus non e&longs;&longs;et. Quartò nullus æ&longs;tus e&longs;&longs;et in oppo&longs;ita parte terre&longs;tris Globi; quia nulla ibi pre&longs;­&longs;io; omitto reliqua cum hæc ad refutandum illud commentum, &longs;int &longs;atis.

Augu&longs;tin. Hæc etiam, vt vis, in alium congre&longs;&longs;um remittamus; avidè tamen ex te audire cupio, quid tamen novi de hoc argumento dicturus &longs;is. Interea antequam hunc congre&longs;&longs;um terminemus nonnulla ex te per­cunctabor, quæ licèt à te dicta &longs;int circa tuam hypothe&longs;im, vereor tamen, vt ea rectè, vt par e&longs;t, à me fuerint intellecta. Dixi&longs;ti Solem inclinati &longs;ur&longs;um ac deor&longs;um motu accelerato, ac retardato in reciproco acce&longs;&longs;u & rece&longs;&longs;u; quæro ex te, vtrùm Sol novum producat impetum.

Antim. Nullo modo; alioquin &longs;i per tres continuos men&longs;es (tandum­dem enim acce&longs;&longs;us ab Apogæo ad mediocrem di&longs;tantiam) motu accele­rato moveretur, immen&longs;um penè &longs;patium percurreret; igitur non pro­ducit novum impetum, &longs;ed impetus, quem habet, vel à &longs;e acqui&longs;itum vel aliunde impre&longs;&longs;um, huic inclinationi &longs;ervit &longs;imul & alteri; idque, vt dixi, ad in&longs;tar motûs accelerati & retardati; &longs;ed valdè lentè, quia maior & poti&longs;&longs;ima inclinatio, &longs;eu determinatio illius impetûs motui circulari &longs;ervit; quòd autem idem impetus duas aut plures determinationes ha­beat, res nova non e&longs;t, &longs;ed trita; cùm hoc cuilibet motui mixto & re­flexo competat.

Augu&longs;tin. E&longs;tne tibi quodpiam aliud exemplum, in quo &longs;imilem in­clinationum ad rectum acceleratum, & ad circularem æquabilem com­po&longs;itionem habeamus.

Antim. Non de&longs;unt, eáque plurima, duo in mentem veniunt, omnino &longs;imilia; primum tale e&longs;t. Sit longior tubus vitreus altera dumtaxat ex­tremitate peruius, infundatur aqua, donec &longs;emipalmus dumtaxat circiter vacuus re&longs;tet, & &longs;uppo&longs;ito ad extremum apertum arctè digito, tubus invertatur, tunc cylindrus aëris lentè ac &longs;en&longs;im a&longs;&longs;urgit, à graviore aquâ &longs;ur&longs;um extru&longs;us, dum hæc per tubilatera, id e&longs;t per cavam tubi &longs;uper­ficiem, &longs;piratim ita de&longs;cendit, quod ip&longs;is oculis per&longs;picuum e&longs;t, vt hic motus ex recto accelerato & circulari compo&longs;itus e&longs;&longs;e videatur; hinc initio &longs;pi&longs;&longs;iores & pre&longs;&longs;iores &longs;piræ, deinde verò di&longs;tractiores fiunt; e&longs;t tamen tantùm vnus impetus ad motum deor&longs;um rectum per &longs;e determi­natus, qui cùm in linea recta finem &longs;uum obtinere non po&longs;&longs;it compen&longs;at in circulari, retenta &longs;emper prima illa inclinatione ad rectum, cui quan­tum pote&longs;t, &longs;atisfacit, cùm autem etiam &longs;ecundùm id acceleratus &longs;it, in­de &longs;piras di&longs;trahi nece&longs;&longs;e e&longs;t.

Augu&longs;tin. Iam capio, quod ante dixeras, naturam &longs;upplere æquali­tatem motuum: nempe aqua, &longs;eu corpus grave toto illo tempore, quo præfatus cylindrus aëris &longs;en&longs;im a&longs;&longs;urgit, motu accelerato deor&longs;um, re­moto impedimento, longum &longs;patium in perpendiculari decurreret; &longs;ed ob&longs;tante impedimento, cùm eadem vis impetus ad&longs;it, motum rectum &longs;pirali compen&longs;at; atque adeò &longs;i tota illa &longs;pirarum congeries in lineam rectam explicaretur, æqualis e&longs;&longs;et lineæ rectæ in perpendiculo eodem tempore motu accelerato confectæ, &longs;ed applica quæ&longs;o ad &longs;piras Solares.

Antim. Repete igitur figuram 2. & con&longs;idera primo loco primam in­clinationem &longs;eor&longs;im, quâ Sol ab Apogæo ad Perigæum, & vici&longs;&longs;im, per mediocrem di&longs;tantiam, reciprocis acce&longs;&longs;ibus & rece&longs;&longs;ibus, ad imitatio­nem motus accelerati & retardati tendit reditque.

Et cogita radium AE moveri cir­ca AC, dum punctum E motu ac­celerato tendit ad V, & retardato, ab V ad H, radius AE de&longs;cribet &longs;uo motu &longs;uperficiem coni, cuius ba&longs;is diameter, erit EL, punctum verò E de&longs;cribet tot &longs;piras in dicta &longs;uperficie coni, quot revolutiones ab&longs;olventur, toto illo tempore, quo ab E, pervenit in H ; hæc au­tem &longs;pira erit conica, cuius Helices di&longs;tractiores erunt circa V, pre&longs;­&longs;iores circa E & H. Pari modo, co­gita triangulum ADE in orbem agi, circa Axem BC dum D, motu accelerato, tendit ad F, & retar­dato ab F, ad E; arcus DFE de­&longs;cribet partem &longs;uperficiei &longs;phæricæ, punctum verò &longs;piram &longs;phæricam, cuius Helices pre&longs;&longs;iores erunt cir­ca DE, di&longs;tractiores verò circa F. Si verò D iret per lineam rectam DGE, de&longs;cribet DGE &longs;uperfi­ciem cylindricam, & D &longs;piram cylin­dricam. Iam verò componatur vtraque inclinatio, ita vt D partim versùs F, partim versùs A tendat, &longs;emoto motu circulari, ibit, vt dixi, per lineam &longs;pi­ralem DQH; volvatur ADQH circa Axem BC de&longs;cribet curva DQH &longs;uperficiem &longs;olidi cuiu&longs;dam &longs;piralis; & &longs;i interea dum punctum de&longs;cribit eo duplici motu curua DQH moveatur circa eundem Axem BC, de&longs;cribet in dicta &longs;uperficie &longs;piram compo&longs;itam ex totidem Helicibus; vt autem Helices omnes &longs;int ferè inter &longs;e æquales, ob&longs;ervabis præclarum Naturæ in&longs;titutum; &longs;upponamus Apogæum Solis in D, initio Cancri cùm DI plus di&longs;tet ab FK quàm hæc ab HL, haud dubiè plus temporis ponit à Cancro ad Libram, quàm à Libra ad Capricornum; en tibi ratio­nem Anomaliæ Solis; quod verò &longs;pectat ad circulos diurnos, quos &longs;in­gulæ Helices, &longs;eu &longs;pæ repræ&longs;entant; à D ad Q tantulùm cre&longs;cunt, &longs;cili­cet vt &longs;emidiametri paralleli BD, Aque à Q verò, v&longs;que ad illud pun­ctum, in quo recta DGE &longs;ecat curvam DQH ita decre&longs;cunt, vt de&longs;cri­ptus ab illo puncto &longs;it æqualis primo; ab eo verò puncto versùs H, fiunt minores & minores circuli, ita vt vltimus, cuius radius e&longs;t CH, &longs;it ad primum, cuius radius e&longs;t BD, vt AC ad AB, vel CH ad BD; e&longs;t autem HE iuxta communem Anomaliæ men&longs;uram ferè AE, ac proin­de circulus ille vltimus e&longs;&longs;et minor primo igitur cum Sol &longs;upponatur æquali &longs;emper motu agi, longè citiès perficiet &longs;uum orbem in H quàm in D, &longs;i movetur in circulo, nempè illo iam ab&longs;oluto, &longs;uper&longs;unt huius 12. grad. igitur tempus, quo circulus diurnus decurritur in H, e&longs;t brevius tempore, quo decurritur in D 48. minutis horæ. Sed hoc e&longs;t ab&longs;urdum, imò ab&longs;urdi&longs;&longs;imum; & vt natura huic incommodo occurreret, licet &longs;pa­tium CA &longs;it minus &longs;patio AB, &longs;egmentum tamen curvæ QH vix minus e&longs;t &longs;egmento DQ igitur tantùm temporis à Q ad H, quantum à D ad Q ponere deberet; quia tamen ex hoc &longs;equeretur ab&longs;urda circulorum diur­norum inæqualitas, contra finem à Natura intentum, hæc enim &longs;pirarum diurnarum æqualitatem intendit, cùm cir culi diurni omnium reliquorum men&longs;ura &longs;int, ita di&longs;trahuntur &longs;piræ in &longs;egmento QH, vt pauciores &longs;int, quàm in &longs;egmento DQ ita tamen vt &longs;ingulæ ferè æquales &longs;int &longs;ingulis; Cogita explicatam vtramque &longs;pirarum congeriem in duas lineas rectas, maior erit ad minorem ferè vt 92. ad 89., &longs;eu vt 1103. ad 1077. So­lers igitur Natura ita attemperavit vtramque inclinationem, vt &longs;ingulæ &longs;ingulis æquales &longs;int in quantitate, & in tempore; atque ita motum vnum alio motu compen&longs;at, adhibita maiore, aut minore &longs;pirarum di&longs;tra­ctione.

Augu&longs;tin. Fru&longs;trà laboras, Antime, vt dierum æqualitatem retineas.

Antim. Hæc paulò fu&longs;iùs edi&longs;&longs;erere volui, vt intelligatur quonam mo­do naturaliter vnus motus alio compen&longs;etur, quando &longs;cilicet impeditur fi­nis Naturæ. Finis autem Naturæ e&longs;t primò, vt in connaturali di&longs;tantia Sol circa Terram eat; data enim mole vtriu&longs;que globi, dubium non e&longs;t, quin prædicta di&longs;tantia po&longs;&longs;it e&longs;&longs;e major, aut minor, connaturali; &longs;i major, cuncta rigerent; &longs;i minor, conflagrarent omnia; igitur majorem inter & minorem connaturalis, &longs;eu mediocris, aut media definienda e&longs;t; hinc manife&longs;ta ratio primæ inclinationis, per quam Sol ab Apogæo ad mediam di&longs;tantiam tendit motu recto, qui e&longs;t ad in&longs;tar accelerati; non &longs;i&longs;tit autem in dicta di&longs;tantia, vbi obtinet illam; &longs;ed propter determinationem ac­qui&longs;itam, licèt obluctetur eadem inclinatio, pervenit v&longs;que ad Peri­gæum, &longs;imili motu recto, &longs;ed propter reluctantiam, ad in&longs;tar retarda­ti. Secundò, finis Naturæ e&longs;t, vt Sol lumen &longs;uum æqualiter, quantum fieri pote&longs;t, di&longs;tribuat; vnde petitur ratio &longs;ecundæ inclinationis, quâ Sol à Tropico ad Æquatorem tendit, eo modo, quo dixi; nempe definito &longs;emel Axe mundi, circa quem &longs;phærarum cœle&longs;tium revolutiones fiant, cuius extremitates &longs;unt Poli, vi huius inclinationis Sol à D, v.g. tendit versùs F per arcum DF, qui cadit perpendiculariter in AD; cùm enim à D duci po&longs;&longs;int infinitæ lineæ, versùs Æquatorem, & vna tantùm per­pendicularis, quæ e&longs;t tangens, vel arcus, cùm radius AD continuò ten­dat versùs F ; &longs;i vna e&longs;t, determinata e&longs;t; Nec dicas, rectam DG cade­re perpendiculariter in planum Æquatoris; nam non cadit perpendicula­riter in AD; cùm tamen arcus DF vtrumque præ&longs;tet; cadit enim perpen­diculariter in vtramque, &longs;cilicet in AD, AF. Accedit, quòd Sol, quan­tum e&longs;t ex &longs;e, &longs;uppo&longs;ita di&longs;tantia connaturali à centro mundi, ad eam re­tinendam inclinat; &longs;ed &longs;i in arcu DF feratur, eadem &longs;emper manebit di­&longs;tantiæ ab A. Tertiò, finis Naturæ e&longs;t, vt omnes revolutiones diurnæ So­lis &longs;int æquales, & con&longs;equenter æquè diuturnæ, cùm hæ &longs;int commu­nis men&longs;ura omnium motuum, & temporis externi munere defungantur. Porrè vt dictos fines Sol obtineat, gemina illa inclinatio ita &longs;e&longs;e attempe­rat, vt & ab Apogæo ad Perigæum Sol eat, & diurnæ revolutiones æqua­les ferè &longs;int, &longs;i tantùm habeatur ratio primæ inclinationis, &longs;piræ fient in eodem plano, & omnes inæquales erunt, &longs;iverò &longs;ecundæ tantùm, &longs;piræ fient in &longs;uperficie &longs;phærica, eruntque omnes inæquales, vt patet ad ocu­lum, cui figura &longs;ubjacet. Itaque &longs;ecunda inclinatio ca&longs;tigat inæqualita­tem à prima inductam, deflexo Sole versùs Æquatorem; & prima par pari referens, corrigit inæqualitatem, quam alioqui prima induceret depre&longs;&longs;o Sole versùs centrum A; & cùm tantùm ferè temporis à Q ad H, ponendum e&longs;&longs;et, quantum à D ad Q &longs;unt enim &longs;egmenta DQ, QH, fere æqualia; haud dubiè tot &longs;piræ &longs;egmento QH, ine&longs;&longs;e deberent, quot &longs;egmento DQ in&longs;unt, vt æquè di&longs;tractæ vtrimque e&longs;&longs;ent; quia tamen tunc &longs;piræ &longs;egmenti QH minores e&longs;&longs;ent, ac proinde inæquales &longs;piris alterius &longs;egmenti, haud dubiè tota &longs;pirarum QH congeries brevioritempore decurreretur, quàm teta &longs;pi­rarum DQ, eodem &longs;cilicet & æquabili motu; &longs;ed &longs;upponuntur totidem vtrimque dies; igitur dies intra &longs;egmentum QH, breviores e&longs;&longs;ent; igitur to­tum tempus, quod complectitur dies intra &longs;egmentum QH, decur&longs;os, bre­vius e&longs;&longs;et tempore, quod complectitur dies decur&longs;os intra &longs;egmentum DQ Sed æqualia tempora &longs;upponuntur: itaque vt huic incommodo occurra­tur, di&longs;trahuntur &longs;piræ &longs;egmenti QH, ita vt pauciores re&longs;tent, &longs;ed ferè æqua­les, atque ita in motu per QH Compen&longs;atur ille motus, qui alioqui per &longs;pi­ras obtineri non pote&longs;t, cùm breviores &longs;int, quàm par &longs;it.

Augu&longs;tin. An fortè Sol &longs;entit, ut cogno&longs;cit, &longs;piras à &longs;e decur&longs;as e&longs;&longs;e majores aut minores? Minimè verò; Quomodo igitur tam &longs;ollicitè & accuratè inæqualitatis periculum avertit?

Antim. Quæro à te, Augu&longs;tine, An fortè aqua illa tubi vitrei &longs;entit progre&longs;&longs;um in motu deor&longs;um &longs;ibi præcludi, & impediri, vt motum re­ctum in &longs;pirabilem convertat? Minimè verò; &longs;ed cùm habeat vim atque impetum, eo &longs;anè motu movetur, quo & faciliùs moveri pote&longs;t, & in quo dictus impetus totam &longs;uam vim exerit; modò vel minima determi­natio intercedat ad talem lineam motus; &longs;ic aqua in dicto tubo ad li­neam &longs;piralem determinatur à minima inæqualitate, vel inclinatione tubi, & corpus grave, quod non pote&longs;t moveri in perpendiculari deor­&longs;um, movetur per Planum inclinatum, aut per arcum in funependulo, aut per parabolam, vel aliam lineam in projectione; item corpus refle­xum, quod per eandem lineam motum pro&longs;equi non pote&longs;t, movetur per aliam, ad quam determinatur partim à corpore reflectente, partim à primo motu; &longs;ic etiam, vt alterum exemplum tibi ante à me promi&longs;­&longs;um adducam: Calamus volatilis, quem vos Italicè vocatis Grillo, im­pre&longs;&longs;o &longs;ibi per rectam impetu, cùm motum rectum, obluctantibus pen­nis, quæ aeri facilè cedunt, totum habere non po&longs;&longs;it, qui &longs;cilicet im­pre&longs;&longs;o impetui alioquin competeret, accito &longs;pirali motu, iacturam motus recti compen&longs;at; cur verò in hanc potiùs, quàm in illam partem eant &longs;piræ, à pennis in eam ab aëre deflexis, &longs;eu detortis omni­no procedit; quòd autem maior impetus dicto calamo in&longs;it, quàm qui in eo motu recto, qui re&longs;tat, impenditur, vel ex eo liquidò con&longs;tat, quod avul&longs;is ex theca, ca&longs;u aliquo, pennis, dum in medio aëre &longs;pira­tim movetur, theca ip&longs;a, præ&longs;ertim &longs;i o&longs;&longs;ea e&longs;t, longiùs aucto motu recto, projici videatur; igitur ille impetus inerat. Sed vt ad rem no­&longs;tram redeam, cùm Sol à Q ad H totum &longs;uum motum, in &longs;piris ha­bere non po&longs;&longs;it &longs;uppo&longs;itis temporibus æqualibus di&longs;trahit &longs;piras, com­pen&longs;ans &longs;pirarum motum, motu per &longs;egmentum QH, quod breviore tempore decurrit, quam DQ, non tamen proptereà &longs;piratim motus re­mittitur &longs;ed æqualis &longs;emper remanet; nempe cum Sol in Q non tendat ad Tropicum, per curuam QH, &longs;ed per arcum interceptum inter AF, AE, minorem arcu FE, atque adeo per arcus &longs;emper minores, donec tandem perveniat in H, & cùm arcus minores citiùs perficiar, eadem vi motus; quid mirum &longs;i citiùs perveniat à Q ad H, quàm à D ad Q, ac proinde &longs;i &longs;piræ di&longs;trahantur in &longs;egmento QH, atque adeò pauciores maneant licèt enim QH. Æqualis &longs;it DQ, non tamen per QH &longs;ecunda inclinatio &longs;uam vim exerit, &longs;ed per arcus concentricos minores, quos citiùs decurrit, licèt à prima inclinatione ad curvam QH detorqueatur. Hinc &longs;emoto motu circulari, & relicta gemina illa inclinatione, adhuc &longs;ecunda inclinatio decurreret citiùs QH, qàm DQ Ex his ni fallor &longs;equi vides, tum di&longs;tractionem maiorem &longs;pirarum, tum imminutum &longs;pi­rarum numerum, tum compen&longs;ationem talem motuum, ex qua perfecta ferè &longs;pirarum diurnarum æqualitas nece&longs;&longs;ariò con&longs;equitur.

Augu&longs;tin. Si Apogæum &longs;it in Æquatore, quid tandem fieret?

Antim. Planum Troprci DI tantulùm accederet ad Æquatorem FK, à quo planum Tropici HL tantulùm æquè recederet, vt æqualis vtrinque effet di&longs;tantia, &longs;ub æqualibus tamen &longs;emper angulis DAF, EAF. Tunc autem po&longs;ito quod Apogæum &longs;it in principio Artis, plus temporis po­netur ab Ariete ad Cancrum, quàm à Cancro ad Libram; & minus à Li­bra ad Capricornum, quàm ab hoc ad Arietem; tempora tamen erunt æqualia à Cancro ad Libram, à Libra ad Capricornum, &longs;cilicet à me­diocri di&longs;tantia ad Perigæum: & ab hoc ad mediam di&longs;tantiam; erunt item æqualia inter &longs;e tempora à Capricorno ad Arietem, & ab hoc ad Cancrum.

Angu&longs;tin. Ille tuus calamus volatilis, vt vocas, mihi &longs;ummopere ar­ridet, itemque de&longs;cen&longs;i ille aquæ in tubo; aliquid &longs;imile in mentem venit, cùm &longs;cilicet aqua, &longs;eu vinum per infundibulum in dolium mitti­tur; nam circa os infundibuli vinum in &longs;piras agitur, propter illam ra­tionem, quam attuli&longs;ti. Idem accidit in quibu&longs;dam fluminibus, &longs;eu la­cubus, ex quibus aqua in profundum hiatum &longs;eu voraginem &longs;piratim de&longs;­cendit, &longs;imulque à vortice naves ab&longs;orbentur, &longs;i quæ mala &longs;ua &longs;orte eò appellantur.

Antim. Aliud omittis longè iucundius, vidi&longs;ti enim aliquando venti turbinem, qui fe&longs;tucas, folia, pulverem in orbem agit ac vorticem; immo & naves in medio mari &longs;ic à Typhone mi&longs;erum in modum abri­piuntur; vnde putas hunc venti vorticem &longs;eu turbinem ortum ducere?

Augu&longs;tin. Certè no&longs;tri Philo&longs;ophi communiter docent, hunc effe­ctum à varia reflexione procedere, quæ in circuma&longs;&longs;urgentibus monti­bus fiat.

Antim. Sat &longs;cio. Sed quænam reflexio in va&longs;ta terrarum & Oceani planitie fieri pote&longs;t? in qua nulli montes a&longs;&longs;urguat. Alia profectò ratio e&longs;t, ex eodem no&longs;tro principio petita; nempe vbi aliqua portio aëris &longs;u­perioris tractus den&longs;atur (den&longs;ari autem pote&longs;t multiplici ca&longs;u) gravior redditur inferiore; cùm autem deor&longs;um cadere non po&longs;&longs;it, ni&longs;i inferio­rem exten&longs;ione æqualem &longs;ur&longs;um extrudat, nec tam citò extrudere po&longs;­&longs;it, &longs;piratim per illius latera de&longs;cendit; Hinc turbo & vortex, cujus rei analogiam habes in adductis &longs;upra exemplis, ad hunc porrò effectum perinde e&longs;t, &longs;ive aër Superioris tractus conden&longs;etur, &longs;ive inferioris rare&longs;­cat: Hinc cum igne Typhon, aliàs cum aqua conjunctus e&longs;t; igne qui­dem quo inferioris aëris tractus &longs;tatim rare&longs;cat, ac proinde maximo im­petu aër Superioris tractus &longs;piratim ruat; aqua verò &longs;i magna Vaporum vis expre&longs;&longs;a cum igne, caloris vi, in &longs;uperiori aëris tractu &longs;tatim conden­&longs;etur, ac proinde aqua &longs;piratim etiam & præceps deor&longs;um ruat.

Augu&longs;tin. Inde fortè imber guttatim de&longs;cendit, cùm enim &longs;ur&longs;um ex­trudendus &longs;it aër, humor in de&longs;cen&longs;u in guttas dividitur ad faciliorem de&longs;cen&longs;um.

Antim. A vero aberras, Augu&longs;tine, nec i&longs;ta, quam dicis, vera ratio e&longs;t, nam & gutta maior ex &longs;ublimiore tractu de&longs;cendit, vt non rarò æ&longs;tate accidit; quia forvente æ&longs;tu, altiùs vapores a&longs;&longs;urgunt, & perexiguæ guttæ lenti&longs;&longs;imè de&longs;cendent, vt &longs;æpè vidi&longs;ti in nebula, dum re&longs;olvitur: tantulum porrò vaporis in guttulam re&longs;olvitur, hæc initio lento de&longs;cen­dit gradu, intereà multæ aliæ guttulæ minores occurrunt in de&longs;cen&longs;u, quas ip&longs;a colligit, vnde major evadit, & motus cre&longs;cit, donec tandem in Terram labatur: hinc cæteris paribus, illæ gurtæ maiores &longs;unt, quæ ex &longs;ublimiore tractu de&longs;cendunt; plures enim colligunt in de&longs;cen&longs;u mi­nores guttas, nempe ex mutuo contactu duarum guttarum &longs;equitur, vt ex duabus vnica fiat; trita res e&longs;t, &longs;ed ratio &longs;atis ab&longs;tru&longs;a: hinc æ&longs;tate, vt plurimum, guttæ imbris maiores &longs;unt, quàm hieme, hinc demum ali­quando accidit, vt iuxta verticem montis &longs;it nebula, imber verò in infe­riore tractu; &longs;ed quæ&longs;o ad rem no&longs;tram redeamus longiùs enim excur­rimus.

Augu&longs;tin. Circa tuam hypothe&longs;im multa e&longs;&longs;ent in accuratius examen vocanda, &longs;ed per tempus non licet, aliqua tamen obiter percunctabor, ac primum quidem illud, quid tibi velles, cùm &longs;upra diceres, gradum il­lum velocitatis acqui&longs;itum à Marte & à Sole, produci vel à Motore extrin­&longs;eco, vel ab ip&longs;i &longs;in et Planetis per motum acceleratum prævium.

Antim. Magnum certè hîc my&longs;terium non latet; cùm enim velim, pri­mum illum impetum Soli modò ine&longs;&longs;e, qui eidem initio inerat, eumque motui æquabili, quo huiu&longs;que Sol movetur, movebiturque impo&longs;terum, æqualem &longs;emper & eundem velocitatis gradum conciliare, cur enim & à quo dictus impetus de&longs;trueretur, cùm nunquam fru&longs;tra &longs;it? perinde &longs;anè mihi fuit, &longs;ive ab ip&longs;o Sole per motum acceleratum prævium acqui&longs;itus fuerit, &longs;ive à Deo, vel Angelo eidem impre&longs;&longs;us; Dic, vt voles, vtrum­que enim fieri potuit; nec qui&longs;quam, opinor, hoc negaverit, nec dif­ficile e&longs;&longs;et, definite altitudinem illam, ex qua Sol ad hunc velocitatis gradum acquirendum de&longs;cenderit, cognita &longs;cilicet Solis Apogæi vel Perigæi di&longs;tantia; immo & tempus in tali de&longs;cen&longs;u po&longs;itum; cum emin ve­locitate vt tempora, & &longs;patia decur&longs;a in duplicata rat. temporum, &longs;cio, v.g. vno &longs;ecundo minuto corpus grave decurrere in perpendiculo 12. pedes, & velocitatem eodem &longs;ecundo minuto acqui&longs;itam &longs;ufficere, vt motu æquabili 24. pedes decurrantur; &longs;cio quoque punctum Æqua­toris terre&longs;tris globi &longs;i hic motu orbis agatur, vno &longs;ecundo minuto con­ficere circiter 1250. pedes. Sit verò di&longs;tantia Solis à centro terræ 2000. circiter &longs;emidiametrorum, &longs;i hic numerus ducatur in illum, productus veniet hic tertius 2500000; Sol igitur vno &longs;ecundo minuto conficit to­tidem pedes: ducatur hic numerus in 60. productus erit, 150000000. tot pedes conficit vno primo minuto: ducatur etiam hic in 60. produ­ctus erit 9000000000. tot pedes conficiet vna hora; hic demum duca­tur in 24. productus erit 216000000000. tot pedes conficiet vno die; accipiatur &longs;ubduplus &longs;cilicet 108000000000. tot pedes decurri; vno die corpus grave motu naturaliter accelerato in perpendiculo deor&longs;um; Iam duco 24. in 60. & productum in 60. hic productus erit 864000. tot &longs;ci­licet minuta &longs;ecunda, quot in 24. horas, ducatur hic in &longs;e ip&longs;um, pro­ductus erit 7464960000. per quem &longs;i dividas 108000000000. quotiens erit 14 1/2 circiter, tot pedes conficit corpus grave motu deor&longs;um, vno minuto &longs;ecundo, vnde corriges Mer&longs;ennum, qui tantùm pedes 12. a&longs;&longs;i­gnat, itemque alium, qui vult corpus grave decurrere vno &longs;ecundo mi­nuto 15. pedes; quanquam hic ad verum proximè acce&longs;&longs;it, quod certè in tanto numero 12. cifrarum, qui &longs;cilicet 200. & 16. millia milliorum complectitur, parum e&longs;t. Hæc porrò eo animo dico, vt quorumdam hallucinatio ca&longs;tigetur, qui cùm hoc, eo, quo par e&longs;t, modo non di&longs;­cu&longs;&longs;erint, multa ab&longs;urda &longs;uper hac re pronunciant. Immo, vt iam fortè mecum ob&longs;ervas, &longs;i præcisè habeamus, quot pedes corpus grave in de&longs;­cen&longs;u decurrat vno &longs;ecundo minuto, habebimus haud dubiè quantum decurrere debeat vno die integro, in linea recta deor&longs;um; quæ &longs;i du­plicetur, & inflectatur in circulum, hæc for&longs;itan erit, &longs;altem proximè, magni orbis men&longs;ura; ita vt Sol motu recto prævio 24. horis decur­rerit &longs;patium æquale &longs;emicirculo magni orbis; &longs;ed quidquid &longs;it, &longs;ive hic impetus accedat ab extrin&longs;eco, &longs;ive ab ip&longs;o Sole in &longs;e producatur, perinde e&longs;t ad rem no&longs;tram; cùm Soli maximè connaturalis &longs;it, quate­nus &longs;cilicet Solaris globus ad talem finem à natura ip&longs;a, & naturæ ip&longs;ius Autore ordinatus e&longs;t; quem vt obtineret tali tantoque impetu illi opus erat; tantum igitur & talem vel ab extrin&longs;eco accepit, vel in &longs;e pro­duxit.

Augu&longs;tin. Sed quis Solern docuit in Occa&longs;um ferri, non verò in Or­tum; ire versùs di&longs;tantiam mediam, ad Æquatoris planum accedere, & turbinis in&longs;tar circa &longs;uum axem inclinatum moveri, idque in hanc partem, potiùs quàm illam?

Antim. Hæc aperire nolebam, &longs;ed profectò me cogis: &longs;i Sol ab Au­tore movetur extrin&longs;eco, nimirum à Deo, Angelorum mini&longs;terio, vt no&longs;tri Schola&longs;tici communiter docent, nec ego inficias eo, ab eodem motore cuncta hæc recipit; at ex hypothe&longs;i, quod à &longs;e ip&longs;o moveatur, quod certè tanti non e&longs;&longs;et, cùm id cuipiam corpori gravi competat; di­cerem, Solem conditum à Deo fui&longs;&longs;e &longs;upra di&longs;tantiam mediam, multis terræ &longs;emidiametris, vt dixi, ex quo loco de&longs;cendit versus mundi cen­trum, obtenta verò media & connaturali di&longs;tantia, motu circulari mo­veri cœpit, versùs Occa&longs;um: cur, inquis, potiùs quàm versùs Ortum? Quia cum creatus fuerit in Tropico Cancri circa 180. grad. longitudinis eo poti&longs;&longs;imum fine, vt in terræ &longs;uperficiem ageret, à maiori dictæ &longs;uper­ficiei tractu versùs Occa&longs;um inde excurrente ad hanc lineam determina­rus fuit, ex qua profectò prima determinatione, &longs;equuntur aliæ, &longs;cilicet, Axis mundi, polorum, Æquatoris &c. & cùm tantulum primæ determi­nationis deor&longs;um retinuerit, debilis tamen, tota enim ferè in circularem motum ivit, quid mirum, &longs;i ad Perigæum tendat? à quo rur&longs;um eodem modo versùs Apogæum regreditur; adde &longs;ecundam inclinationem, de qua iam &longs;upra, & quia globorum more, deor&longs;um in morem turbinis de&longs;cendit, retinuit illum motum orbis circa eundem Axem &longs;ibi ip&longs;i &longs;emper parallelum, vbi motu circulari agi cœpit, cui prædicta turbinatio non ob&longs;tat, Vides, cuncta hæc ex communibus illis principiis deduci, per quæ aliorum corporum motus explicantur.

Augu&longs;tin. Rectè, illud &longs;altem commodi ex hac tua hypothe&longs;i acci­dit, quod primi orbis incolæ diem primum integrum habuerunt, Sol nempe in ortiuo horizontis illorum limbo conditus fuit; id e&longs;t, in &longs;emi­circulo ortiuo magni Meridiani; & verò æquum fuit, vt Sol, qui pro­pter hominem creatus e&longs;t, no&longs;tro huic primum hemi&longs;phærio, in quo & primus homo conditus, præfulgeret: &longs;ed fortè nobilem coronam diutius quam par e&longs;&longs;et detinemus; tuam illam, quam contra no&longs;tram hypothe­&longs;im adorna&longs;ti, di&longs;putationem, in proximum congre&longs;&longs;um remittimus.

Antim. Sit, vt voles, adero cra&longs;tina die, ni&longs;i tibi fortè grave &longs;it; multi etiam ex nobili&longs;&longs;imis auditoribus futurum congre&longs;&longs;um &longs;ua præ&longs;entia ho­ne&longs;tabunt.

DIALOGVS SECVNDVS.

In quo valida contra Copernici hypothe&longs;im argumenta proponuntur.

DVBIVM mihi non e&longs;t, hanc di&longs;putationem ineunti, quin pleri&longs;que fortè iam actum agere videar, CARDINALIS EMINENTISSIMS, quotus enim qui&longs;que invenitur, vel Philo­&longs;ophorum in tractatione de Corpore Cœle&longs;ti; vel Theologo­rum in Opere &longs;ex dierum enucleando;; vel &longs;acri Textus Interpretum, in eorum locorum expo&longs;itione, in quibus Terra &longs;tare, Sol & A&longs;tra pa&longs;&longs;im moveri dicuntur; vel denique A&longs;tronomorum, in mundi &longs;y&longs;tema­te definiendo, qui hanc partam non adornet, &longs;uam falcem in hanc me&longs;­&longs;em non mittat, ac de mi&longs;ero Copernico novos triumphos agere nolit. Scribimus indocti, doctique poëmata: quanquam, vt ingenuè dicam, maxima illorum argumentorum pars, quibus nonnulli præfatam Coper­nici opinionem petierunt, non parum laudis & plau&longs;us eidem concilia­vit; ita enim ab illius defen&longs;oribus rejecta fuere, vt &longs;olutionis, &longs;eu re­&longs;pon&longs;ionis facilitas qua&longs;i ad in&longs;tar novæ demon&longs;trationis novum &longs;plendo­re in eidem &longs;ententia conciliârit, illud &longs;anè commune e&longs;t præliis etiam li­terariis, vt qui&longs;quis ho&longs;tem malè aggre&longs;&longs;us e&longs;t, & in ca&longs;&longs;um adortus, pro &longs;emivicto habentur; ne igitur eundem errorem admittam, illa dum­taxat adducam, quæ &longs;i non fortè ho&longs;tem omninò conficere, plurimùm tamen labefactare videntur; tuum erit, Eminenti&longs;&longs;ime, qui per&longs;pica­ci&longs;&longs;ima ingenij acie vales, quam nihil quantumvis arduum, vel ab&longs;tru­&longs;um effugiat, &longs;i non de integra victoria, de potioribus &longs;altem partibus à nobis in hac cau&longs;a, vt benè &longs;pero, referendis, judicare, necnon æqui&longs;&longs;i­mam ferre &longs;ententiam. Sed initium di&longs;&longs;ertationi demus.

Antimus. Omittam, vt prudenter feci&longs;ti, argumentorum qui&longs;quilias, quæ nonnulli, præ&longs;ertim ex antiquioribus rerum Mathematicarum & Phy&longs;icarum minùs peritis contra tuam hypothe&longs;im adduxerunt, quæ pe­tita &longs;cilicet petunt à ventis, & nubibus, motu projectorum, de&longs;cen&longs;u gravium, domorum ruina & lap&longs;u; quanquam nonnihil ad hominem ex his eliciam; vt enim vis, ex motu orbis retardato, in Ortum &longs;equi aqua­rum excur&longs;ionem, per quam marinum æ&longs;tum ve&longs;tri explicant, quia &longs;cili­cet obimpre&longs;&longs;um ante impetum, quem facilè aqua retinet, nec enim ni&longs;i à contrario impediri pote&longs;t, eundem pro&longs;equitur motum versùs Ortum; cuius rei præclaram certè analogiam habetis in aqua, quæ cymba vehi­tur; cymba enim motum valdè retardante, aqua versùs portum excurrit; hoc vnum e&longs;t ex præcipuis &longs;ententiæ ve&longs;træ argumentis.

Augu&longs;tinus. Ita e&longs;t, & licèt ad ea, quæ repo&longs;ui&longs;ti, obmutire & ma­nus dare vi&longs;us &longs;im, quia illa omnia, quæ ad tabulas æ&longs;tus marini eiú&longs;que phænomena pertinent, minùs calleo, vereor tamen, vt rerum i&longs;tarum peri­ris per&longs;uadere valeas; illud autem &longs;ilentium mihi poti&longs;&longs;imum impo&longs;uit, quòd &longs;anctè jura&longs;ti, in adluctis à te phænomenis, omnes ad vnum æ&longs;tus marini peritos, &longs;ive Naucleri &longs;int, &longs;ive alij, imò & ip&longs;os litorum Oceani vel idiotas incolas &longs;umma tor&longs;en&longs;ione convenire; itaque licèt ex &longs;ola ter­re&longs;tris globi circuitione æ&longs;tus marini adæquata cau&longs;a petenda non &longs;it, &longs;ed ex alia quapiam, negari tamen non pote&longs;t, quin prædictus motus aliquid conferat.

Antim: A&longs;&longs;igna priùs aliam cau&longs;am, vt videamus, an &longs;ufficiat ad hunc mirabilem effectum; &longs;i enim &longs;ufficit, nihil &longs;anè e&longs;t, quod ille Terræ motus conferat; &longs;i verò non &longs;ufficit, o&longs;tende id, ad quod non &longs;ufficit, & illius motus opem po&longs;tulat; &longs;emper enim recurret propo&longs;itum argumentum; totum illud, quidquid tandem &longs;it, quod à præfato motu efficitur, circa maximæ inæqualitatis cardines; id e&longs;t, circa Meridiem & mediam noctem, vi&longs;um &longs;emper iri; quod tamen Ob&longs;ervationibus repugnat: itaque certum e&longs;t, & per&longs;picuum ex Maris æ&longs;tu Terræ motum minimè probari; certum tamen e&longs;&longs;e dicitis, ex illo inæquali motu, varium &longs;equi aquarum motum; quod certè ad hominem &longs;ic vrgeo; &longs;i reverà e&longs;&longs;et hic motus, ex illius inæ­qualitate, varius aquarum motus &longs;equeretur, &longs;cilicet ex retardatione aqua­rum excur&longs;io versùs Ortum, ex acceleratione, excur&longs;io versùs Occa&longs;um; hoc non negatis, &longs;ed conceditis vltrò; idque in cardinibus maximæ in­æqualitatis, aut &longs;altem &longs;emper in ii&longs;dem, cùm eadem cau&longs;a idem &longs;em­per præ&longs;tet; &longs;ed in nullo certo ac fixo temporis puncte huiu&longs;modi aqua­rum excur&longs;iones fiunt, quod nemo neger, &longs;i cæcus & &longs;urdus; nullus e&longs;t igitur Terræ motus, ex quo alioqui prædicti effectus nece&longs;&longs;ariò &longs;eque­rentur.

Augu&longs;tin. Facilis re&longs;pon&longs;io nobis &longs;uppetit, qualem etiam ve&longs;tri adhi­bent, &longs;cilicet illam inæqualitatem motus, e&longs;&longs;e tantùm apparentem, iis &longs;cilicet, qui ex Solari &longs;phæra oculos in Terram conjicerent; &longs;icut Cœle­&longs;tium &longs;phærarum motus nobis è Terra ob&longs;ervantibus inæquales apparent; cùm tamen re ip&longs;a æquabiles &longs;int, igitur po&longs;ita reali motus æqualitate, vt no&longs;træ hypothe&longs;i hoc argumentum à marino æ&longs;tu petitum non prode&longs;t, ita nec obe&longs;t: iam &longs;umus ergo pares.

Antim. Merum effugium e&longs;t; cùm &longs;it vera & realis, vt aiunt, motus inæqualitas; & vt ad tuam figuram veniam.

Punctum E longè velociùs movetur, quàm F ; nam E in Ortum fertur, vtroque motu, centri &longs;cilicet atque orbis, cùm tamen F toto quidem motu centri feratur in Ortum, &longs;ed cum toto motu orbis feratur in Occa&longs;um, ex vtriu&longs;que motus maxima oppo&longs;itione, motus ex vtroque mixtus maximè retardatur, vt ex certi&longs;&longs;imis doctrinæ motuum principiis liquidò con&longs;tat. Prætereà non tantùm aquarum excur&longs;io ex dicta motus inæqualitate &longs;eque­retur, verùm etiam alia, quæ facilè cadere po&longs;&longs;ent, reverà caderent, &longs;ive in Ortum in maxima retardatione, &longs;ive in maxima acceleratione versùs Occa­&longs;um; & ad hoc eadem facit analogia tranantis cymbæ; vbi enim hæc ad li­tus appellitur, homines parum cauti, qui in illa &longs;unt, non versùs puppim re­pelluntur à littore, &longs;ed versùs proram proni ruunt; cymba enim retinet fixa ve&longs;tigia, dum interim impetus ante impre&longs;&longs;us reliquum corpus an­tror&longs;um agit; in quo etiam aliquam rationem vectis ob&longs;ervo, hinc quo altiores &longs;unt homines, in dicto ca&longs;u, faciliùs ruunt; quia vectis longior e&longs;t; &longs;ed Augu&longs;tine, hoc minimè fieri videmus.

Chry&longs;ocomus. Hoc tuum argumentum, Antime, equidem ad homi­nem, vt aiunt, maximi momenti e&longs;t; nec video quonam pacto illi, qui ex dicta inæqualitate motus, eiu&longs;modi aquarum excur&longs;iones &longs;e qui volunt, ab eo &longs;e&longs;e expediant; No&longs;tri tamen eo non vtuntur, vtpote qui &longs;ciant, ex dicta inæqualitate, etiam &longs;uppo&longs;ita, minimè &longs;equi aquarum excur­&longs;iones, nempè eo motu &longs;ingulæ partes illius globi moventur, &longs;eu tardiùs, &longs;eu velociùs, quo totius motus ratio illas moveri po&longs;tulàt; ac proinde il­lud globi punctum, quod ad Solem directè &longs;pectat de Meridie, tardè movetur in Ortum, celeriter verò, vbi e&longs;t oppo&longs;itum in ip&longs;a media no­cte; quia totus globus ita moveri po&longs;tulat &longs;ingulas &longs;ui partes, imò etiam in iis, quæ va&longs;e vehuntur, & ab extrin&longs;eco motum & impetum recipiunt, inæqualitas motus non ex abrupto, at &longs;en&longs;im &longs;ine &longs;en&longs;u inducta nullum alium effectum præter eandem rationem motus inducit; &longs;ic cymba qua vehitur aqua celeri motu, &longs;i &longs;en&longs;im remittit, ac retardat motum, aut certè tardiorem primum paulatim deinde accelerat, neque huc, neque illuc aqua excurrit, nec &longs;tantes in navi huc aut illuc inclinari &longs;e &longs;entiunt.

Antim. Ita e&longs;t; vt dicis; hoc argumentum contra illos ad hominem, vt aiunt, à me adductum e&longs;t, qui præfatos effectus ex illa motuum inæ­qualitate &longs;equi a&longs;&longs;erunt; at per te, mihi quæ&longs;o, liceat, idem argumen­tum etiam contra illos pro&longs;equi & vrgere, vt aiunt, qui negant dictos effectus ex dicta inæqualitate &longs;equi, quorum ego; vt vereor &longs;en&longs;a, ita illis, opinor, ingratum non accidet, quod rem hanc paulò accura­tiùs di&longs;cutiam, & ad certi&longs;&longs;ima doctrinæ motuum principia reducam; Primò ergo quidem &longs;uppono ex dicta doctrina, impetum &longs;emel impre&longs;­&longs;um non de&longs;trui, quamdiu fru&longs;trà non e&longs;t, & con&longs;equi pote&longs;t &longs;uum ef­fectum, &longs;cilicet motum, qui & finis illius e&longs;t, &longs;eu per eandem lineam, &longs;eu per aliam, ad quam e&longs;t nova determinatio; nulla enim e&longs;t alia ratio, propter quam impetus de&longs;truatur; &longs;ic turbo v.g. di&longs;cus æneus, Axe vtrim­que extante, in levigato plano diuti&longs;&longs;imè &longs;uos orbes agit, & &longs;i nullus e&longs;&longs;et attritus partium, & Axis ad perfectam libellam, per di&longs;ci centrum iret, nunquam hic motus ce&longs;&longs;aret. Prætereà, &longs;i globus tornatus de&longs;cen­dat per planum declive probè lævigatum, quod po&longs;t tantulam incurvatio­nem &longs;ur&longs;um ex adver&longs;o, &longs;ub eodem inclinationis angulo deflectatur; haud dubiè ad imum primi plani declivis globus non &longs;i&longs;tet, &longs;ed per aliud ad æqualem ferè altitudinem a&longs;cendet, virtute impetus, in primo de&longs;cen&longs;u acqui&longs;iti, ad hanc portò lineam ab eodem plano determinatur; analo­giam perfectam in vibrato funependulo etiam habes, & in ip&longs;a corporum repercu&longs;&longs;ione; de&longs;truitur tamen aliquid impetus in illo a&longs;cen&longs;u, &longs;cilicet à quodam impetu innato, non acqui&longs;ito, qui gravibus ine&longs;t, &, vt fa­cilè vobis per&longs;uaderem, ab ip&longs;a gravitate non di&longs;tinguitur; &longs;ic etiam ab alio impetu ob&longs;tante, vel ad aliam lineam trahente, vnde &longs;equitur de­terminatio quædam mixta, &longs;en&longs;im de&longs;truitur; &longs;ed ne longiùs excurram, illa omnia doctrinæ motuum principia hoc loco dumtaxat &longs;upponam, quæ huius doctrinæ petiti facilè concedunt, & fusè alibi pertractata nec non firmata fuêre. Primo igitur loco &longs;uppono, impetum nunquam de&longs;trui, ni&longs;i quando e&longs;t fru&longs;trà, id e&longs;t, quando motus omnis impeditur, à quo­cunque tandem &longs;it ille impetus, &longs;ive impre&longs;&longs;us ab extrin&longs;eco, &longs;ive ab ip&longs;o corpore in &longs;e productus, &longs;ive à toto, parti, &longs;ive toti à parte, &longs;ive parti ab alia parte, nam perinde e&longs;t, quoad hoc principium.

Augu&longs;tin. Hoc facilè damus, imò hoc pro generali axiomate libenter admitto, nihil vnquam de&longs;trui, ni&longs;i quando e&longs;&longs;e non pote&longs;t, ni&longs;i fru&longs;trà &longs;it. Sic anima, quæ defectu corrupti organi non pote&longs;t ampliùs operari in corpore, de&longs;init e&longs;&longs;e, omninò quidem, &longs;i extrà organum operari non pote&longs;t, vt de animabus brutarum animantium Philo&longs;ophi docent, non tamen omninò & ab&longs;olutè, &longs;ed in corpore tantùm, &longs;i extrà organum opera­ri pote&longs;t, vt anima rationalis.

Chry&longs;ec. Hoc idem principium ad alias qualitates etiam extendi pote&longs;t; caloris v.g. frigoris, &c. quæ quamdiu &longs;uum finem con&longs;equi, & præ&longs;ta­re effectum po&longs;&longs;unt, in &longs;ubjecto, cui inhærent, tamdiu in eo permanent intactæ; vt &longs;i per actionem qualitatis contrariæ novus effectus inducitur, ac proinde, vel totus prior, vel pars illius de&longs;init, tunc prima illa qualitas in &longs;ubjecto illo fru&longs;tra e&longs;&longs;e dicitur, ac proinde vel &longs;ecundùm &longs;e totam, &longs;i totus effectus abactus e&longs;t, vel &longs;ecundùm &longs;ui partem, pro rata effectus de&longs;tructi, e&longs;&longs;e de&longs;init.

Antim. Ad &longs;peciem hæc fortè cuipiam vera e&longs;&longs;e videntur; at profectò res &longs;ecus &longs;e habet in præfatis qualitatibus, de quibus modò di&longs;putatio in&longs;tituta non e&longs;t, &longs;atis mihi e&longs;t, &longs;i in no&longs;tro impetu res ita &longs;e habeat; ad­mitto etiam ea, quæ dixi&longs;ti, Augu&longs;tine, de anima rationali; de brutorum animabus aliqua fortè difficultas e&longs;&longs;et, &longs;ed huius loci non e&longs;t. Sit igitur &longs;ecundum principium ex eadem doctrina motuum huc derivatum, cor­pus eo motu movetur, quo faciliùs moveri pote&longs;t, minore &longs;cilicet &longs;um­ptu, & cum minore difficultate, compen&longs;atque vt plurimum in vno, quod in alio difficiliùs tantùm obtinere po&longs;&longs;et; hæc iam &longs;upra indicavi in primo congre&longs;&longs;u; &longs;ic cylindrus, vel in plano lævigato iacens, vel humido innatans ab altera extremitate pul&longs;us, vel tractus etiam per lineam per­pendiculariter incidentem, motu recto non movetur. &longs;ed circulari, circa centrum, quod terminat mediam proportionalem totam inter & dimi­diam, ita vt major quantitas &longs;it versùs illam extremitatem, cui potentia motrix applicata e&longs;t.

Augu&longs;tin. Licèt fortè in parergum incidamus, tantulum &longs;chematis de­&longs;idero, vt rem à te &longs;olo auditam meliùs intelligam.

Antim. Non opus e&longs;t alio &longs;chemate: Supponamus enim cylindrum BC (in Fig. pag.45.) innatantem humido, pul&longs;um in B, &longs;itque vt BC ad BK, ita hæc ad BA, & ex K ducantur arcus BG, CN &longs;imiles, duca­turque GKN; cylindrus pul&longs;us, vt dixi ex B, de&longs;cribit &longs;uo motu duos &longs;ectores BKG, CKN, quia &longs;cilicet &longs;patium vtroque contentum e&longs;t om­nium po&longs;&longs;ibilium minimum, &longs;uppo&longs;ito quolibet alio arcu, non minore BG, & duobus radiis, qui &longs;imul coniuncti &longs;int æquales toti BC, quod aliàs demon&longs;traui, nempe à &longs;ectoribus &longs;imilibus ad triangula propor­tionalia, & ab his ad &longs;implicem lineam gradum faciens, reduxi rem ad hoc problema, datam quantitatem ita &longs;ecare, vt maius &longs;egmentum &longs;it ad minus, vt hoc ad tertium, & compo&longs;ita ex duabus extremis &longs;it om­nium po&longs;&longs;ibilium minima; vel &longs;ic Datæ quantitati vnam partem detra­here, & aliam addere, vt re&longs;idua &longs;it ad detractam, vt detracta ad addi-tam, & compo&longs;ita ex re&longs;idua, & addita &longs;it omnium po&longs;&longs;ibilium minima; &longs;ed his omi&longs;&longs;is & &longs;uppo&longs;itis, eo motu hic cylindrus, atque adeò cœteris paribus, quodlibet corpus movetur, &longs;ive ab intrin&longs;eco, &longs;ive ab extrin­&longs;eco, quo faciliùs moveri pote&longs;t; idem ob&longs;ervamus in &longs;agittis alii&longs;que corporibus oblongis, &longs;i vel aliquando &longs;ponte &longs;ua cadunt, vel projiciun­tur; &longs;ed luculentum exemplum omittere non po&longs;&longs;um, globi &longs;cilicet per planum declive de&longs;cendentis, cùm enim duobus modis deor&longs;um ferri po&longs;&longs;it. Primò vno dumtaxat motu centri, quo &longs;ingulæ partes per lineas plano inclinato parallelas eant. Secundo motu rotationis, mixto &longs;cilicet ex motibus centri & orbis; hoc &longs;ecundo modo movetur, non verò pri­mo, quem multus partium affrictus maximoperè retardaret.

Augu&longs;tin. Hæc concedere non po&longs;&longs;um; ideò enim movetur hoc motu, quia cùm centrum gravitatis globi &longs;it extra perpendiculum, quid mirum, &longs;i eò inclinet, vnde motus orbis nece&longs;&longs;ariò &longs;equitur; vt facilè etiam &longs;ine figura quivis intelligat?

Antim. Nonnihil tamen figuræ adhibeo, vt maximam difficultatem, quam ego quidem &longs;entio, in eo, quod dicis, mihi excutias.

Sit planum inclinatum DH, & in eo globus gravis, tangens planum in D, per­pendicularis AF, à centro globi ducta; &longs;intque aliæ duæ lineæ BAG, CI, plano parallelæ, de&longs;cendit globus A, vt dixi, non quidem primo modo, ita vt punctum C &longs;equatur lineam CI, & punctum D lineam DH. Sed per rotationem, vt aiunt, ita vt circa centrum A, aliæ par­tes moveantur, quia, inquis, centrum globi A e&longs;t extra perpendiculum; de quo amabò perpendiculo intelligis an de BD ducto à puncto contactus, an verò de AF.

Augu&longs;tin. Vtrumque intelligo; vt enim globus &longs;u&longs;tineatur in plano DH, perpendiculum, quod ducitur a puncto contactus B, per centrum A ite deberet; vnde certè planum e&longs;&longs;et horizonti parallelum; quando verò vnum perpendiculum cum alio non concurrit, vt in hoc ca&longs;u, tunc planum e&longs;t inclinatum; igitur cùm centrum A per lineam perpendi­cularem AE non &longs;u&longs;tineatur à plano, vlteriùs enim ad F pertingit, de&longs;cen­dat nece&longs;&longs;e e&longs;t, cùm de&longs;cendere po&longs;&longs;it; in aliis omnibus corporibus, per­fectam analogiam habes. Sit enim planum horizontale CN, & in eo

rectangulum CB, cuius centrum gravitatis F, ita inclinetur rectangulum CB, donec perveniat ad &longs;itum DI, exi&longs;tente centro gravitatis in H, ac proinde cùm perpendiculam HL cadat extrà punctum contactus D, deor&longs;um tendit, & to­tum rectangulum ruit. Idem prorsùs de globo dicendum e&longs;t.

Antim. Crede mihi, Augu&longs;tine, multi &longs;æpè ac &longs;æpiùs paralogi&longs;mis, & fal&longs;is præoccupatio-nibus abripi &longs;e &longs;inunt, quod in præ&longs;enti ca&longs;u, meo &longs;altem iudicio, acci­dit; vt enim in tua &longs;i&longs;tamus figura; non negabis, opinor, centrum H minimè de&longs;cen&longs;urum, &longs;i fortè propiùs ad planum CN accedere non po&longs;­&longs;et, cùm ex ip&longs;is terminis idem &longs;it de&longs;cendere, & propriùs ad planum DN accedere; At verò centrum A (in Figura perultima) propiùs ad planum in cli­natum DH accedere non pote&longs;t, à quo æquali &longs;emper di&longs;tantiæ men&longs;ura di&longs;tat, &longs;cilicet radio, vnus autem radius alteri æqualis e&longs;t; hinc nunquam di&longs;cedit à linea AG parallela Plano DH, & quodlibet perpendiculum ad planum terminatum à centro A ductum lineæ AF æquale e&longs;t.

Chry&longs;oc. Proptereà globus de&longs;cendit, quia eius centrum A non &longs;u&longs;tinetur in puncto contactus, cùm &longs;u&longs;tineri non po&longs;&longs;it ni&longs;i in perpen­diculo AF.

Antim. Rectè, Proptereà globus de&longs;cendit; &longs;ed profectò non pro­pterea globus volvitur, &longs;ive enim volvatur deor&longs;um, &longs;ive de&longs;cendat iux­ta primum modum in &longs;itu, in quo e&longs;t, centrum A per eandem lineam AG, deor&longs;um tendit, nec vnquam ab ea di&longs;cedit, aut di&longs;cedere pote&longs;t; cur igitur cum vtroque modo, per eandem lineam de&longs;cendere po&longs;&longs;it, hoc &longs;ecundo potiùs, quàm illo primo de&longs;cendit? quod enim dicis, Augu&longs;ti­ne, centrum gravitatis A e&longs;&longs;e extra perpendiculum, ac proptereà de&longs;­cendere, id totum verum e&longs;t, & à me admittitur, vndè reverà de&longs;cen­dit; &longs;ed per lineam AG, infrà quam de&longs;cendere nequit ; &longs;ed cùm per eam vtroque modo ire po&longs;&longs;it, ac proinde de&longs;cendere, cur, quæ&longs;o, vno potiùs quàm alio? Sed hoc alio exemplo fortè luculentiore clari&longs;&longs;imè o&longs;tendo.

Sit planum inclinatum AB, &longs;it rectan­gulum C in eo collocatum; certè &longs;i &longs;up­ponatur vtrumque lævigatum, de&longs;cen­det rectangulum, per dictum planum, ibitque centrum gravitatis C per CP parallelam plano; nec enim aliter per &longs;e de&longs;cendere pote&longs;t, nec volvi circa angu­lum D, quod fieri deberet, vt iueret; alioquin centrum C in revolutione a&longs;cen­deret, quod dici non pote&longs;t; Sit enim CD perpendiculum, & CN horizontalis, haud dubie &longs;i C volvatur circa D, radio DC, tangens decta à puncto C, perpendicularis in CD, ibit &longs;uprà horizontalem CN, vt patet ad oculum: Dixi per &longs;e, nam per accidens, cùm à plani &longs;cabutie impediri po&longs;&longs;it, latus AD, &longs;u­perior po quæ libera e&longs;t, impetus vi acqui&longs;iti, prævalens, deor­&longs;um circum volvitur circa angulum D ; &longs;ed hoc per accidens fit. Sit autem aliud rectangulam F in eodem plano inlinato, perpendiculum, FH, ho­rizontalis FO; certè &longs;i ducatur tangens FK perpendicularis MF; &longs;i centium F circa M radio MF volvatur, ibit infra FO, igitur non a&longs;cen­det &longs;ed de&longs;cendet. itaque vt ad no&longs;t globum redeat oratio cùn. nec circa punctum D volvi po&longs;&longs;it centrum A, (in Figura antipeima) ni&longs;i in-frà rectam AG de&longs;cendat, nec ab hac po&longs;&longs;it di&longs;cedere; certè non ideò globus volvitur, vt centrum A de&longs;cendat, cùm de&longs;cendere po&longs;&longs;it, etiam&longs;i non volvatur; igitur ideò volvitur, &longs;eu rotatur, quia cum vtroque modo de&longs;cendere valeat centrum A, per eandem &longs;cilicet lineam AG, & cùm pri­mo modo difficiliùs de&longs;cendat, propter affrictum partium; ideò &longs;ecundo modo de&longs;cendit, quia &longs;ic faciliùs de&longs;cendit; &longs;ic enim corpus grave non mo­do determinatum e&longs;t ad motum, &longs;ed etiam ad faciliorem, cæteris paribus, motum.

Augu&longs;tin. Audivi hactenus, in rotis valere rationem vectis; e&longs;t enim vectis quidam perpetuus; vnde manife&longs;ta petitur ratio, cur majoribus rotis currus in&longs;truantur; nempe inde cre&longs;cit mechanicæ potentiæ mo­mentum.

Antim. Quis negat, in rotis haberi rationem vectis in vecte tamen &longs;up­ponitur aliquod punctum qua&longs;i immobile, quod in ip&longs;o Hypomoclio col­locatur; quod vt meliùs intelligatur.

Supponatur planum DH e&longs;&longs;e horizon­tale, in quo &longs;it rota, eaque trahatur fune AG, in&longs;erto &longs;cilicet axe per centrum illius A, haud dubiè &longs;i æquè facile vtraque extre­mitas diametri rotæ DC adduci po&longs;&longs;et à potentia trahente per AG vtraque extre­mitas, ac proinde reliquæ omnes partes rotæ per parallelas AG adducerentur, & omnes æquè citò moverentur, vt reverà fit, &longs;i rota humido innatet; at cum propter af­frictum planirota; detur D, ac proinde difficiliùs accedatpunctum C longè faci­liùs accedit; item A. &c. ac proinde citiùs accedunt, ex quo inæquali acce&longs;&longs;u, propter partium nexum, motus orbis nece&longs;&longs;ariò &longs;equitur: Iam vero &longs;uppo­ne planum inclinatum, & nullam potentiam extrin&longs;ecam applicatam e&longs;&longs;e centro A, &longs;ed &longs;olam ine&longs;&longs;e gravitatem rotæ, quæ à centro A exeritur ab intrin&longs;eco, eodem pror&longs;us modo, quo ante à potentia, fune applicata in plano horrizontali, & vt potentia extrin&longs;eca movet rotam eo motu, quo faciliùs moveri pote&longs;t, mixto &longs;cilicet ex motu centri & orbis, in hoc plano, ita & propria rotæ gravitas in inclinato; quid clarius? maneat igitur illud principium, quòd &longs;cilicet corpora eo motu moveantur, cæteris paribus, quo faciliùs moveri po&longs;&longs;unt.

Augu&longs;tin. Do manus, & rem optimè capio, &longs;ed antequam vlteriùs per­gas, vnum ex te, Antime; re&longs;cire velim, circa ca, quæ in he&longs;terno con­gre&longs;&longs;u à te accepi. Illico probavi, vbi di&longs;ce&longs;&longs;i&longs;ti, pulcherrimum illud expe­rimentum tubi vitrei, in quo aqua per &longs;piras de&longs;cendit, dum &longs;ur&longs;um extru­dit, eo, quo dixi&longs;ti, modo inclu&longs;am illam aëtis portionem; ob&longs;ervavi enim. illam aëris portionem in cylindrum priore contractiorem, vt labenti aquæ &longs;ecus tubi &longs;uperficiem locus detur, conformari, ita vt tamen &longs;upicma pars &longs;it convexa &longs;phærica infima verò ba&longs;is, omnino plana, &longs;altem provt oculo &longs;ubjicitur.

Chry&longs;oc. Memini me legi&longs;&longs;e vel audii&longs;&longs;e præclari&longs;&longs;imam huius Phæno­neni rationem, nempe illa portio aëtis, aqua levior, vt in a&longs;cen&longs;u aquæ vim & re&longs;i&longs;tentiam faciliùs frangat & &longs;uperet, huiu&longs;modi qua&longs;i cuncatam figu­ram induit.

Antim. An fortè pro demon&longs;tratione hoc venditares? Sed vnde, quæ&longs;o, & qua vi, &longs;eu virtute aër in hanc formam &longs;e&longs;e fa&longs;tigiat? Certè &longs;i ad per­rumpendum &longs;ur&longs;um faciliùs, mucronem illum nimis obtu&longs;um, &longs;phæricum &longs;cilicet, in acutiorem conicum attenuare & acuere debuerat, cunei enim eò validiores &longs;unt, quò acutiores. Deinde æquè facilè aqua &longs;uperficiem &longs;phæricam aëris dividere pote&longs;t ac planam: præterea cur minor aëris portio aquæ re&longs;i&longs;tentiam citiùs perrumpit, & &longs;ur&longs;um emergit? Nempe vt corpus grave majus gravitatem &longs;uam potentiùs exerit, ita & leve majus &longs;uam le­vitatem; &longs;ed cur aqua &longs;imiliter cuneum cuneo minimè opponit? an fortè in ratione gravis corporis aëri cedit, quatenus hic corpus leve e&longs;t? itaque alia omnino rati; cùm enim aqua tendat vt: sùs latera tubi, per quæ deinde &longs;uas &longs;pagens, vt dixi, de&longs;cendit, eo certè ex medio tubo, &longs;en&longs;im ruere non pore&longs;t, ni&longs;i quoquo versùm cylindri aeris &longs;uperiorem marginem qua&longs;i excutiat, & qua&longs;i &longs;e&longs;e in novam cunei formam induat, e&longs;t enim cuneus latior in &longs;ummo, in imo acutior; neque in hoc vlla e&longs;t difficul­tas; multa &longs;anè eaque &longs;citu digna &longs;uper hoc experimento inihi dicenda e&longs;­&longs;ent, &longs;ed omitto, ne in parergis toti &longs;imus; inferior verò portio, &longs;eu ba&longs;is plana e&longs;t; quia nullum aquæ pondu illam emarginat.

Augu&longs;tin. Sed quid &longs;i oleum aquæ loco adhibeas; aut certè non aëris, &longs;ed olei portionem tubo includas, aut demum oleum &longs;imul & aëra?

Antim. Si oleum loco aquæ, idem fiet; quanquam paulò lentiùs aëris portio &longs;ur&longs;um evadet; &longs;i verò aëris loco, eodem modo, & &longs;ub eadem forma, &longs;ed multò lentius; quia &longs;cilicet oleum e&longs;t longè gravius aëre: &longs;i demum &longs;imul vtrumque, aër oleum longè po&longs;t &longs;e relinquet; &longs;i tamen dum olei patricula mediam tubi altitudinem decurrit, po&longs;tquam aër iam emer­&longs;it tubum inverta;, aër certè oleum facilè a&longs;&longs;equitur, nec non per medium oleum perrumpit, &longs;ervata eadem figura; quanquam tunc oleum &longs;e&longs;e non pa­rum dilatat, vt &longs;ur&longs;um aëra extrudat; aut &longs;altem vt eidem, vtpote leviori, tran&longs;itum cedat.

Chry&longs;oc. Aliquando accidit in eo conflictu, vt aëris bullula &longs;upremæ olei &longs;uperficiei adhæ&longs;erit & qua&longs;i captiva reman&longs;erit; tunc verò, vt fidelis ob&longs;ervator refert, paulo citiùs oleum emer&longs;it, aër enim addidit alas.

Antim. Oleum, vt probè tenetis, &longs;ua vligine particulam aëris intra buliam continere potuit, nempe bullæ ex materia vligino&longs;a tornantur; quod autem totum illud corpus ex aëre & oleo con&longs;tans, paulò faciliùs ab aqua &longs;ur&longs;um extrudatur, vel à levitate viribus auctis feratur, mirum e&longs;&longs;e non debet: de levitate hoc loco non di&longs;puto, aio tamen, ex hoc experi­mento, minime probari, immo potiùs, vt patet, ex iis, quæ dicta &longs;unt, impugnari. Sed ad alia principia ex doctrina motuum accer&longs;enda pergen-dum e&longs;t, Dico igitur tertio loco, in tantum corpus vnum ab alio moveri, præ&longs;cindendo à magneticis, & electricis, in quantum illud aliquem mo­tum impedit; &longs;i enim id quod movetur nullo modo ab alio impeditur, nullam vim pror&longs;us contra illud retorquet; & hoc nemo negaverit, qui hu­ius doctrinæ peritus &longs;it; &longs;ic directus ictus vegetior e&longs;t, obliquus verò debi­lior; in globulis, qui adhiberi &longs;olent in ludo minoris tudiculæ, res e&longs;t om­nino per&longs;picua.

Augu&longs;tin. Videtur e&longs;&longs;e quoddam paradoxum, quod dicis cau&longs;am &longs;cilicet potentiùs agere, quando magis impeditur, erit fortè quædam antiperi&longs;ta&longs;is; &longs;ic ignis calidior e&longs;t.

Antim. Ita e&longs;t, paradoxum e&longs;&longs;e videtur; &longs;i quis tamen rectè perpendat, impetum eum dumtaxat finem, vel effectum habere, ac præ&longs;tare immo­bili, cui ine&longs;t, vt hoc moveatur, tali &longs;cilicet motu & modo, qui offectus &longs;i non impeditur ab alio. fru&longs;tra certè contra illud vim &longs;uam exerit, &longs;i v. g. corpori dum movetur, à tergo manum admoveas, aut certè à frontè, ea ea tamen lege, vt manum admotam æquè citò moveas, nullam vim, nullum impetum manui tuæ imprimi &longs;enties; quia hæc nullo modo impedit illius corporis motum; &longs;i verò mobile in aliud corpus impinga­tur, quod motui obe&longs;t, in illud agit, impre&longs;&longs;oque impetu, illud amovet, vnde, vt dixi, finis primarius impetus e&longs;t mobilis, cui ine&longs;t, motus; &longs;ecundarius verò, & quem dumtaxat propter primum ponit, e&longs;t motus alterius cor­poris, quod dictum motum impedit; nec mirum, &longs;i impetus alium impetum producit, in eo &longs;cilicet, quod proprij mobilis motum impedit: Hinc &longs;i Phi­lo&longs;opho in verbis ludere liceret, dici à me po&longs;&longs;et impetus, qua&longs;i impedi­tur, cùm nunquam agat, & &longs;uam vim exerat, ni&longs;i impediatur. His præ­mi&longs;&longs;is, ad rem venio, Augu&longs;tine; Repetamus figuram Sextam, & primo quidem loco vnum dicam, quod vix apud vos fidem inveniat, licèt cer­ti&longs;&longs;imum &longs;it, geometrica &longs;cilicet demon&longs;tratione confirmatum; illud autem ad incredibilem proportionem inæqualitatis motus rotæ, in diver&longs;is illius punctis con&longs;iderati pertinet; dico iterum incredi­bilem.

Chry&longs;oc. locaris, Antime: quis Auriga, Rhedarius, Carpentarius hoc ne&longs;cit? quis oculos figens non videt, &longs;uperius rotæ punctum à plano, in quo rota volvitur, tota rotæ diametro di&longs;tans, velociùs agi, quàm infimuru, in quo &longs;cilicet rota planum tangit.

Antim. Serio loquor, Chry&longs;ocome, non iocor; vident omnes e&longs;&longs;e quidem inæquales motus, &longs;ed nemo crederet tantam inæqualitatis propor­tionem.

Augu&longs;t. Quanta porrò illa erit? fac &longs;upremum illud punctum moveri duplo citiùs infimo, aut etiam triplo, quadruplo, decuplo, vt voles; quid tandem erit?

Antim. videbis paulò po&longs;t; &longs;ed amabo te, Augu&longs;tine, cogita maximam quam potes proportionem inæqualitatis; & videbis vtrùm illa, quam e&longs;&longs;e con&longs;tat in rigore geometrico, &longs;it incredibilis.

Augu&longs;tin. Si centuplam e&longs;&longs;e dixero, vera haud dubiè longè maior erit, & vix vllus tantam e&longs;&longs;e crediderit.

Antim. At &longs;i maiorem centupla, immo & millecupla, & centena mille­cupla e&longs;&longs;e dicerem, omnem fidem omnino detrectares? &longs;i dicerem majorem e&longs;&longs;e quacumque de&longs;ignabili, illico iocari me diceres, Chry&longs;ocome, vt tamen verbo dicam, res ita &longs;e habet, vt facilè demon&longs;tratur.

Chry&longs;oc. Sed quæ&longs;o te, noli nos vltra in geometrica retia & Labyrinthos deducere, hæc enim totam congre&longs;&longs;ui gratiam & amœnitatem &longs;enticeta eri­piunt.

Antim. Si quando illis retibus aliquam veritatem nos fœliciter expi­&longs;cari contingat, crede mihi Chry&longs;ocome, illa retia non &longs;unt adeò inamœna, &longs;ed vt tibi morem geram, nihil ferè dicam quod etiam ab A geometris facilè intelligi non po&longs;&longs;it.

Sit ergo Rota D, quæ volvitur in plano FG, punctum E &longs;upre­mum, F infimum, ita autem moveatur, vt motus orbis, &longs;eu rotæ circa centrum D, &longs;it æqualis motui eiu&longs;dem centri D ; ac proinde eodem tempore, quo E v.g. integrum &longs;uum orbem circa D decurrit, centrum D. lineam rectam decurrat æqualem peripheriæ eiu&longs;dem rotæ, vel circuli, mo­vetur autem E motu illo mixto per lineam curuam EQV, quam haud improprio nomine cycloidem vocatis, cuius &longs;ubduplam dumtaxat figuram delineavi; nam petinde e&longs;t, &longs;ive punctum Rotæ ab E &longs;upremo perveniat ad infimum V per curvam EQV, &longs;ive ab imo V ad &longs;upremum E per VQE.

Augu&longs;tin. Hæc e&longs;t cyclois illa, quæ tot ac tanto excitavit tumultus, de qua etiam opu&longs;culum geometricum edidi&longs;ti; &longs;ub nomine Antimi Parbij.

Antim. Non agno&longs;cerem pro in ea lucubratiuncolam illam, ni­&longs;i me gratim animi ratio &longs;timularet; enim verò facere non po&longs;&longs;um, quin hoc loco in&longs;ignem pro&longs;ectò Geometram Stephanum De An­gelis digni&longs;&longs;imum magni illius Cavalerij di&longs;cipulum appellem, ei­que gratias, quam po&longs;&longs;um maximas agam, pro iis laudibus, qui­bus liberaliùs certè quàm par fui&longs;&longs;et, cùm iis longè inferior &longs;im, pro &longs;ua humanitate, me alioquin pror&longs;us incognitum, ratione præfati opu&longs;culi cu­mulavit; &longs;ed ad rem no&longs;tram. Comparemus vtriu&longs;que puncti motus, &longs;u­premi &longs;cilicet atque infimi; quod vt clariùs &longs;uccedat, &longs;it arcus EP. trigin­ta grad. punctum E, dum prædictum arcum decurrit, deferturque à cen­tro D &longs;ini&longs;tror&longs;um, &longs;cilicet versùs V, acquirit &longs;ini&longs;tror&longs;um ratione vtriu&longs;­que motus, totum &longs;patium OQ, &longs;cilicet ratione motus orbis, rectam OP, id e&longs;t &longs;inum rectum EP, quem &longs;uppono e&longs;&longs;e 30. grad. & ratione motus centri, rectam PQ æqualem ip&longs;i arcui ER, tantumdem enim Spatij cen­trum decurrit, ergo ratione vtriu&longs;que totum &longs;patium OQ Iam verò &longs;it FR arcus æqualis 30. &longs;cilicet grad. punctum R eodem tempore motu or­bis acquirit dextror&longs;um &longs;patium RS, & motu centri &longs;ini&longs;tror&longs;um &longs;patium FT æquale arcui FR. exi&longs;tis autem duobus motibus re&longs;ultat R T. Iam compa­remus hæc duo &longs;patia, &longs;cilicet. EQ, & RT, vel OQ, & differentiam SR, FT, &longs;it DE 100000. OP, &longs;ubdupla DE erit 50000. vt autem 7. ad 11.ita DE ad arcum EI, id e&longs;t ad 157143.cuius terti ars &longs;cilicet 52381. erit æqualis arcui EP, vel rectæ PQ igitur tota OQ, addito vno nume­ro alteri, erit 102381. ducatur deinde per punctum R, &longs;ecans DR, haud dubiè cadet vltra punctum T, versùs V, nempe tangens, quæ terminatur ad dictam &longs;ecantem e&longs;t &longs;emilatus polygoni circum&longs;cripti; igitur major arcu FR; igitur &longs;egmentum illud &longs;ecantis &longs;eu differentia &longs;ecantis, & &longs;inus totius e&longs;t maior &longs;patio RT; igitur &longs;i &longs;upponamus æqualem, faciemus mo­tú R maiorem vero; accipio igitur &longs;ecantem arcus FR, & in canone inve­nio 115470. ex quo numero detraho &longs;inum totum 100000. re&longs;iduum erit 15470. hæc e&longs;t RT, qùæ ferè e&longs;t vna 7.igitur motus puncti E ad motum puncti R toto tempore quo decurritur arcus FP, vel RS e&longs;t vt 7. ad 1.

Chry&longs;ocom. Sed vbinam illa tua millecupla inæqualitatis proportio? ad populum phaleras; vos &longs;anè Mathematici, multa promittitis, pau­ca præ&longs;tatis; totum orbem movetis, & vix murum in ruinam præcipitem &longs;u&longs;tinetis.

Antim. Parciùs i&longs;ta viris, Chry&longs;ocome, nam fortè aliquando incides in manus cuiu&longs;piam ex iis, quos puros Geometras vocant, à quo immi&longs;ericor­diter vapulabis, iis arma profectò non de&longs;unt, &longs;agittæ &longs;cilicet, &longs;ecantes, &longs;ecures, cunei, ro&longs;tra & vngues; expecta igitur parumper, nam pedeten­tim cum i&longs;ta rota progredimur, accipe arcum 15. grad. id e&longs;t &longs;ubduplam PQ, erit æqualis 26190. cui &longs;i addas &longs;inum rectum eiu&longs;dem arcus, &longs;cili­cet.25038. erit compo&longs;ita ex vtraque 51228. rejecta minutia, hic erit mo­tus punctE, eo tempore, quo decurrit arcum 15.grad. iam verò accipe &longs;ecantem eiu&longs;dem anguli 103290. ex qua, &longs;i &longs;ub&longs;trahas &longs;inum totum, re&longs;i­duum erit 3290. hic e&longs;t motus puncti F, eodem tempore, qui ad priorem habet rationem iam verò &longs;i accipias arcum 3. grad. &longs;cilicet 5238. eiu&longs;­dem &longs;inum rectum 5233. compo&longs;ita ex vtraque erit 10471. differentia ve­rò &longs;ecantis & &longs;inus totius eju&longs;dem anguli 137. Cùm igitur motus E per arcum 3. grad. &longs;it ad motum F per arcum æqualem vt 10471. ad 137. erit vt 75.ad 1.&longs;it motus per arcum 1.grad.erit compo&longs;ita ex arcu & &longs;inu 3491. differentia &longs;ecantis & &longs;inus totius 15.igitur ratio maioris motus ad mino­rem . Accipe arcum 30.minutorum, erit &longs;umma, arcus & &longs;inus recti 1746. differentia 4. igitur ratio accipiamus 15. erit, &longs;umma 872. differentia 1. igitur ratio . Si vltra progredimur, &longs;ecantes ce&longs;&longs;ant in canone Pi­ti&longs;ci, et&longs;i veniamus ad vnum minutum, quid tandem erit? quid &longs;i ad vnum &longs;e­cundum, aut tertium &c. immo quantumvis parvum arcum accipias, erit maior proportio ex triplici capite. Primò, quia curva EQ e&longs;t maior rectâ OQ, &longs;ed per EQ movetur punctum E, idem de aliis arcubus. Secundò, quia differentia &longs;ecantis & &longs;inus recti e&longs;t major RT, igitur, hic accipitur maior, illic verò minor motus, quàm reverà &longs;it. Tertiò quia E à puncto oppo&longs;itionis versùs Q continuò retardat motum &longs;uum; igitur movetur velociùs in primo gradu, quam in &longs;ecundo & in hoc citiùs, quàm in ter­tio, atque ita deinceps 5 cum tamen F à puncto oppo&longs;itionis ver&longs;us R mo­tum &longs;uum continuò acceleret; ac proinde moveatur citius in &longs;ecun­do gradu quàm in primo & in tertio quàm in &longs;ecundo, atque ita dein­ceps; con&longs;tat igitur: quod initio à me propo&longs;itum fuit, majorem e&longs;&longs;e proportionem motus &longs;upremi puncti rotæ; quæ in plano volvi­tur, ad motum infimi, qualibet a&longs;&longs;ignabili; hinc paradoxum egre­gium, ita moveri duo extrema eju&longs;dem lineæ finitæ, vt vnum alio infi­nities velociùs moveatur, infinities, inquam, Syncategorematicè, nec e&longs;t par ratio rotæ, quæ motu tantùm orbis movetur, quia centrum illius &longs;upponitur immobile, nec vllum punctum a&longs;&longs;ignari pote&longs;t, in radio mobili, circa alteram extremitatem, cujus motus ad motum alterius ex­tremitatis certam & finitam proportionem non habeat; denique huc etiam plurimùm, immo totum facit angulus contingentiæ, quem prædictus circu­lus cum plano facit eo &longs;anè minorem, quo circulus major e&longs;t, cùm enim quolibet angulo rectilineo, quamtumvis minimo, minor &longs;it, id que in infini­tum; motus puncti infimi rotæ, &longs;eu contactus, eo ip&longs;o incipit, quò tangere planum de&longs;init, intercepto dumtaxat dicti anguli contingentiæ cu&longs;pide, omni rectilineo minore.

Augu&longs;tin. Quid &longs;i aliquis diceret, punctum illud aliquantulum quie&longs;cere, ad in&longs;tar cuiu&longs;dam polygoni infinitorum laterum? Sic enim polygonum in plano volvitur, vt circa &longs;ingulos laterum angulos totum polygonum &longs;uc­ce&longs;&longs;ivè volvatur.

Antim. Scio, à viro docti&longs;&longs;imo hæc iam olim fui&longs;&longs;e dicta, &longs;ed Geome-triæ repugnat, vt circulus polygonum dicatur, nam omnes radij circuli æquales &longs;unt, &longs;ecus Polygoni; deinde Polygonum in plano moveri non pote&longs;t, ni&longs;i eius centrum modò a&longs;cendat, modò de&longs;cendat, vt patet; at centrum circuli ab eadem linea plano, in quo volvitur parallela; nunquam de&longs;cendit; igitur circulus polygonum dici non pote&longs;t.

Chry&longs;oc. Cùm illa inæqualitatis proportio ina&longs;&longs;ignabilis, ac &longs;uo modo infinita, vt dicis, in minutis tantummodò primis, &longs;ecundis, tertiis lo­cum habeat, non verò in arcubus paulo majoribus, vt con&longs;tat ex iis quæ dixi&longs;ti, nihil &longs;anè obe&longs;&longs;e pote&longs;t, ac proinde parum, aut nihil nobis curan­da, qui ad illa in&longs;en&longs;ibilia, in Phy&longs;ica præ&longs;ertim, minimè attendimus.

Antim. In digitalem rotam, &longs;i fortè trahatur à te&longs;tudine, i&longs;thæc opti­mè quadrant, &longs;ecus tamen in telluris globum, cujus &longs;ingula minuta 5000. pedes continent; & motus adeò velox e&longs;t, vt habita tantùm ratione motus orbis, quodlibet punctum circuli æquatoris, quolibet &longs;ecundo minuto, vt iam dixi &longs;uprà conficiat pedes 1250.circiter. Con&longs;tat igitur de illa incre­dibili motuum inæqualitate in partibus certè &longs;en&longs;ibilibus tum &longs;patij, tum mobilis, etiam in &longs;ecundis & tertiis minutis, &longs;i terre&longs;tris globus moveatur; con&longs;tat item maxima velocitas, quam ne quidem globi ex majoribus, vel minoribus tormentis emi&longs;&longs;i adæquant.

Augu&longs;tin. Quantus apparatus, Deus bone, contra Copernicanam hypo­the&longs;im; vereor tamen vt &longs;ufficiat.

Chry&longs;oc. Cave, Antime, ne tibi tritum illud occinamus, parturient mon­tes; tantò fortè apparatu terrere i&longs;tos volui&longs;ti, de me nihil dico, quia re­verà tecum &longs;entio; aut fortè tam multis & variis initio nos fatigare, &longs;eu potiùs obruere volui&longs;ti, vt &longs;cilicet, ea quæ oppones minus alacriter retun­damus; age igitur, nam prælu&longs;um &longs;atis; illos Oratores imitari mihi vi&longs;us es, qui toti &longs;unt in exordiis; ita vt finito orationis exordio, ad aliud tran&longs;eant exordium, & ab hoc &longs;ecundo ad aliud, & nunquam ad punctum, quod probandum &longs;u&longs;ceperant, de&longs;cendunt, proloqui duntaxat & magnifica ex­ordia fabricare contenti.

Antim. Ludis, Chry&longs;ocome, &longs;ed profectò non impunè feres; nemo non videt, ea quæ præmi&longs;i, non e&longs;&longs;e exordia, &longs;ed iacta principia, ex quibus de­inde meum ratiocinium deducam; ni&longs;i enim hoc facerem, ingenuè di­cam, ratiocinari non po&longs;&longs;em; Vt vt &longs;it, Galilæus ve&longs;ter, Augu&longs;tine, eo va­lebat ingenio, in hac præ&longs;ertim motuum doctrina, in qua, ne quid di&longs;&longs;i­mulem, parem non habuit, immo neque hoc di&longs;&longs;imulabo, quam primus ip&longs;e invenit, vt tam audacter pronunciarit, ex dicta motuum terre&longs;tris globi inæqualitate, Oceani huc illuc excur&longs;ionem &longs;equi; & &longs;i fortè hoc cum principiis eju&longs;dem doctrinæ non con&longs;entit et, nunquam revera tanta a&longs;&longs;everatione hoc dixi&longs;&longs;et. Ilus ergo major propo&longs;itio vera e&longs;t, &longs;cilicet aquarum motum &longs;equi ex prædicta motuum inæqualitate, nec illius inge­nium in hoc falli potuit, qui alios ferè omnes doctrinam motuum docuit; erravit tamen in minore, in qua &longs;anè illius ingenium non de&longs;idero, &longs;ed majorem diligentiam, nec non æ&longs;tus marini peritiam; itémque maiorem fidem, periti&longs;&longs;imis Naucleris adhibendam; optimè docuit ex dicta inæ-qualitate aquarum motum &longs;equi in &longs;ua hypothe&longs;i ; &longs;ed malè intulit, mari­num æ&longs;tum qualis nunc e&longs;t, ex ea &longs;equi; de marino æ&longs;tu, quod &longs;it, & ta­lis &longs;it, res certa e&longs;t; oculi dumtaxat applicandi; de terræ motu, quod re­verà &longs;it, nequidem Galilæus ip&longs;e certum e&longs;&longs;e pronunciavit; dubium igitur etiam apud vos; cùm igitur rectè componamus Telluris quietem cum eo maris æ&longs;tu, qui modò e&longs;t, nec eum ob&longs;ervemus, qui reverà e&longs;&longs;et, &longs;uppo&longs;ito terræ motu; quidni nece&longs;&longs;ariò, ni fallor, concludam; terram nor moveri, cùm id nullo modo &longs;it, quod reverà e&longs;&longs;et, &longs;i terra moveretur?

Augu&longs;tin. Tecum &longs;entio, Antime, in hoc Galilæum, in re motuum ver­&longs;ati&longs;&longs;imum, falli non potui&longs;&longs;e, eiu&longs;que autoritatem longè pluris in hoc faciendam e&longs;&longs;e, quàm multorum aliorum, qui tantum molo&longs;&longs;um, catelli &longs;anè, allatrare non ce&longs;&longs;ant; ne tamen hoc tuum argumentum non tantùm &longs;it ad hominem, &longs;ed pariter omnibus rem i&longs;tam per&longs;uadeat; &longs;epone, quæ­&longs;o, autoritatem Galilæi, & de&longs;cende ad illas conclu&longs;iones, quas ex iactis &longs;upra principiis deducere, opinor, meditaris.

Antim Faciam, quod &longs;uggeris; Supponamus igitur globum D Terram e&longs;&longs;e & ita moveri, vt &longs;upra dicebam, circuli, Æquatoris v.g. partes, inæ­qualiter, vt longè tardiùs punctum, quod &longs;pectat ad Solem, & velociùs oppo&longs;itum moveatur, id e&longs;t F, quàm E, in hoc enim &longs;chemate &longs;i&longs;tere po&longs;­&longs;umus, nec declinatio æquatoris ab Eclyptica, nec perpetuus axis paralle­li&longs;mus, nec motus centri quinquies circiter major motu orbis, ad hanc rem quidquam faciunt, puncta I & H ita moventur, vt motui centri ni­hil detrahant, nihil addant; ab H ad E ita additur vt crementum acce&longs;&longs;io­nis &longs;emper augeatur, donec tandem in E maximum &longs;it: hoc porrò cremen­tum acce&longs;&longs;ionis fit iuxta progre&longs;&longs;um &longs;inuum ver&longs;orum: ab E ad I; ita ad­ditur, vt crementa acce&longs;&longs;ionum &longs;emper minuantur, donec tandem in I nullum &longs;it crementum; hoc verò crementum fit iuxta priorem progre&longs;&longs;io­nem, &longs;ed inver&longs;am ac proinde iuxta progre&longs;&longs;ionem &longs;inuum rectorum: Ab I ad F ita detrahitur motui, centri, vt crementa detractionis &longs;emper ma­jora &longs;int, donec tandem in F &longs;it maximum, idque iuxta progre&longs;&longs;ionem &longs;i­nuum ver&longs;orum; denique ab Fin H ita etiam detrahitur, vt crementa de­tractionis &longs;emper minora &longs;int, idque iuxta progre&longs;&longs;ionem &longs;inuum recto­rum, donec tandem in H nullum &longs;it crementum: Accipe igitur punctum circuli v.g.H, ab H movetur motu accelerato, per impetum &longs;cilicet, à quocunque tandem producatur; igitur vbi pervenit ad E inten&longs;i&longs;&longs;imum impetum habet, cur ergo tam cito de&longs;truitur, cùm fru&longs;trà non &longs;it, effe­ctumque &longs;uum in mobili præ&longs;tare queat?

Chry&longs;oc. Minimè verò, cùm enim punctum E &longs;it pars globi, eandem cum aliis partibus di&longs;po&longs;itionem retinere debet, quod certè vt fiat, illius motus retardari debet; &longs;i autem motus retardatur, pro rata de&longs;truitur impetus.

Antim. Nunquid in mea & tua hypothe&longs;i, hic vel ille Oceani tractus æquè pars e&longs;t terre&longs;tris globi, atque in Copernicana?

Chry&longs;oc. Fru&longs;tra interrogas; nullum enim dubium e&longs;t.

Antim. Rectè; at po&longs;tquàm modica vis venti prædicto aquarum tractui motum & impetum impre&longs;&longs;it, nunquid etiam ce&longs;&longs;ante vento, adhuc per aliquod tempus aquarum motus & agitatio non durat? quis hoc neget? idem in latiore concha videbis; vbi enim aqua infu&longs;a plena fuerit, acce­dente minimo motu, a qua illa libratur ver&longs;us latera conchæ; ita vt huiu&longs;­modi librationes diutiùs durent, etiam po&longs;tquam omnis motus extrin&longs;e­cus ce&longs;&longs;avit; Vnde porrò hoc? rationem ex no&longs;tro primo principio facilè deduces; durat enim aliquandiu impetus priùs impre&longs;&longs;us; quia non e&longs;t fru&longs;tra, &longs;altem quoad aliquam portionem, cùm aliquid motus præ&longs;tare po&longs;&longs;it; codem pror&longs;us modo, tractus Oceani circa punctum E, cum velo­ci&longs;&longs;imè moveatur, impetum impre&longs;&longs;um aliquandiu retinet, &longs;ecundùm ali­quem gradum, vi cujus excurrit ver&longs;us Ortum; nam perinde &longs;e habet, atque &longs;i in va&longs;ti&longs;&longs;ima concha contineretur.

Chry&longs;oc. Movetur igitur totus ille aquarum tractus, &longs;ecundùm totam profunditatem.

Antim. Non dico hoc, neque nece&longs;&longs;e e&longs;t, neque fieri pote&longs;t; quia vt Conchæ &longs;upremus circulus longè major e&longs;t, quàm alij paralleli, versùs imum conchæ, ita longè faciliùs libratur aqua, intra majorem circulum, quàm intra minorem; quia &longs;cilicet in majore, habet liberiorem campum, in quo excurtat, quod facilè demon&longs;trari à me po&longs;&longs;et, &longs;i hoc etiam paret­gum vobis arri&longs;erit.

Augu&longs;tin. Mihi opus non e&longs;t; quis enim hoc ne&longs;cit? Sic videmus in con­chis angu&longs;tioribus, aquam difficiliùs librari, in majoribus verò faciliùs.

Chry&longs;oc. Ita e&longs;t, hoc videmus, quamobrem verò, non ita forte qui&longs;piam dixerit.

Augu&longs;tin. Quid faciliùs dictu, Chry&longs;ocome; &longs;i vas angu&longs;tum e&longs;t, latera minus di&longs;tant, hinc aqua nece&longs;&longs;ariò minùs excurrit, vtpote quæ à vicinis lateribus continetur; &longs;i vas amplum &longs;it &longs;ecus accidit; quia &longs;cilicet illius la­tera à &longs;e&longs;e invicem magis di&longs;tant, nec vllo &longs;chemate opus e&longs;t ad exponen­dam vim hujus rationis.

Choy&longs;oc. Non agitur hoc loco, vtrum librationes aquæ intra vas angu­&longs;tum contentæ citiùs perficiantur, quam illæ quæ fiunt in majore va&longs;e; nempe huiu&longs;modi librationes, funependulorum librationes imitantum, quæ citò fiunt in brevi funependulo, tardiùs verò in longiore; &longs;ed alia pror&longs;us e&longs;t difficultas, cur &longs;cilicet illa vis motus, quæ &longs;ufficit ad huiu&longs;mo­di librationes in va&longs;ta concha excitandas, non &longs;ufficiat &longs;i vas angu&longs;tum &longs;it, nec ad majores, quæ reverà in angu&longs;to va&longs;e fieri non po&longs;&longs;unt, nec ad mi­nores, quas alioqui major vis motus excitaret; hîc tuam opem, Antime, &longs;ed breviter, quæ&longs;o.

Antim. Brevi&longs;&longs;imè, neque hoc facerem, ni&longs;i ve&longs;tro ju&longs;&longs;u; Sit concha

DCG laxior, & alia ECF angu&longs;tior, vtraque ferè plena; aqua longè faciliùs pote&longs;t librari in arcu DCG, quàm in ECF; hic enim magis ar­duus e&longs;t, ille vetò longè mollior, &longs;eu mitior; mi­nùs enim recedit à plano horizontali ; hinc &longs;u­perficies aquæ DBG a&longs;cendere pote&longs;t per arcum GA, etiam cum modi­co impetu, &longs;ecus vetò per arcum FI, propter adductam rationem.

Augu&longs;tin. Hæc plu&longs;quàm &longs;ufficiunt, redeamus ad rem, pro qua circa ea, quæ à te dicta &longs;unt, hoc præ&longs;ertim opponendum mihi occurrit.

Quod &longs;cilicèt omnes partes terre&longs;tris globi, vel &longs;ingulæ &longs;e&longs;e moveant, vel ab extrin&longs;eco moveantur; &longs;ed ita temperatè, vt omnes inter &longs;e primam, di&longs;po&longs;itionem retineant; vnde non mirum e&longs;t, &longs;i tractus idem maris circa E velociùs, circa I tardius moveatur.

Antim. Hoc ni fallor &longs;ummum caput e&longs;t hujus difficultatis, quod tamen ex dictis facilè di&longs;&longs;olvi pote&longs;t; nempe &longs;ive tractus ille maris moveat &longs;e&longs;e, &longs;ive ab alio, fieri non pote&longs;t, vt &longs;ine impetu moveatur; igitur impetum illum acquirit proportionatum motui, quo movetur in E, vel circumcir­ca; &longs;ive illum in &longs;e producat, &longs;ive ab alio recipiat; &longs;ed impetus &longs;emel pro­ductus à quacunque tandem cau&longs;a, tamdiu remanet, quamdiu fru&longs;tra non e&longs;t, tandiu verò fru&longs;tra non e&longs;t, quamdiu aliquem effectum præ&longs;tare pore&longs;t in mo­bili, non alium certè quàm motum; quantumvis autem temperatè producatur novus impetus, hoc certè non facit, vt is, qui jam productus e&longs;t de&longs;truatur; quandiu &longs;cilicet fru&longs;tra non e&longs;t: & vt res illa novis exemplis magis per&longs;picua fiat; &longs;i aqua in canali declivi motu accelerato de&longs;cendat, qui deinde per mol­liorem deflexionem &longs;ur&longs;um &longs;ub æquali, vel in æquali inclinationis angulo at­tollatur, vbi aqua ad imum canalis pervenerit, non &longs;i&longs;tet hauddubiè, &longs;ed per aliud canalis planum inclinatum a&longs;cendet, de&longs;cendétque denuo, mul­tis qua&longs;i librationibus repetitis, hic tamen impetus productus e&longs;t ab in­trin&longs;eco, Quando animal currit per declivem collem, gradum profectò &longs;i&longs;tere nequit, quantumvis contranitatur, &longs;cilicet propter impre&longs;&longs;um ante impetum; in vibratis librati&longs;que corporibus innumera ferè &longs;uppetunt exempla. Quid mirum igitur, &longs;i prædictus maris tractus impetum ante impre&longs;&longs;um retineat & excurrat in Ortum; neque hoc impedit connexio partium eju&longs;dem globi, ni&longs;i hæ &longs;clidæ &longs;int ac duræ, nec non ita inter &longs;e connexæ, vt vna ab alia &longs;eparari non po&longs;&longs;it; tunc enim moventur iuxta leges novi impetus de&longs;tructò priore; nec mirum, cùm fru&longs;tra &longs;it; fru&longs;tra au­tem e&longs;t, quia motum alium habere 1. on pote&longs;t, præter illum, quem novus impetus exigit.

Chry&longs;oc. Si ergo in puncto E e&longs;&longs;et corpus &longs;olidum & durum, totum priorem impetum a mitteret accedente novo.

Antim. Minimè verò, ni&longs;i arctè cum aliis corporibus duris connexum e&longs;&longs;et, &longs;it enim v.g.globus lævigati&longs;&longs;imus in E, &longs;upra &longs;uperficiem &longs;olidam etiam lævigati&longs;&longs;imam, vitream puta, haud dubiè curreret prædictus glo­bus versùs Ortum, præ&longs;ertim cùm ad hunc motum nullo a&longs;cen&longs;u opus &longs;it, ac proinde nulla pror&longs;us inclinatio contraria ob&longs;tet.

Chry&longs;ocom. Igitur ille globus ita &longs;emper moveretur in &longs;uperficie tetræ; nihil enim de&longs;trueretillum impetum; quod modò ex tuis principiis deduco, &longs;ed ex trito Mathematicorum dicto.

Antim. Hoc certè ex meis principiis non &longs;equitur, immo contrarium; novus enim, qui præfato globo accederet, impetus ad motum oppo&longs;itum, vel qua&longs;i oppo&longs;itum determinatus, priorem illum &longs;en&longs;im de&longs;trueret. v. g. impetus novus accedens in P, (in anteriori Schemate) partim per PQ, id e&longs;t, versùs ortum, ratione motus centri, partim per tangentem punctum P e&longs;t determinatus; mixta autem linea &longs;eu determinatio ex vtraque illa &longs;equitur, vt con&longs;tat ex doctrina motuum. Quod verò &longs;pectat ad tritum illud Mathematicorum dictum, etiam in terræ immobilis hypothe&longs;i locum habet, &longs;ed pro&longs;ectò nullum planum ita lævigari pote&longs;t, quin aliquot Sa­lebris a&longs;peretur; quod reverà &longs;ufficeret, ad illum impetum de&longs;truendum; qualis &longs;it terræ &longs;uperficies, vides; ille porrò aquæ excurrentis tractus &longs;en&longs;im fine &longs;en&longs;u conceptum motum remittit, propter impetum contrarium impre&longs;­&longs;um, vbi enim pervenit in R v.g.cum motus centri &longs;it contrarius motui orbis, haud dubiè inde aqua aliquo modo regredi cogitur; hinc conflictus; adde mutationem determinationis lineæ motus in &longs;ingulis punctis &longs;emi­circuli EIF; denique adde aquæ divi&longs;ionem, quæ non parum re&longs;i&longs;tit motui, præ&longs;ertim alterius aquæ; quæ libet autem re&longs;i&longs;tentia impetum &longs;en&longs;im de&longs;truit.

Augu&longs;tin. Iam mentem tuam intelligere mihi videor; vis enim quod­libet punctum terre&longs;tris globi, ratione duplicis motus, centri &longs;cilicet, atque orbis, duas determinationes habere, quæ in tertiam mixtam de­inde abeunt, perinde atque &longs;i duplex impetus impre&longs;&longs;us e&longs;&longs;et ad motum mixtum; finge globo, eodem tempore, duplicem impetum imprimi alterum versùs Boream, alterum versùs Occa&longs;um, hæc gemina determinatio in eandem motus mixti lineam coale&longs;cit, vnde &longs;uppo&longs;ita vtriu&longs;que impe­tus æqualitate, globus ver&longs;us Corum ibit, id e&longs;t, Boream inter & Occa-&longs;um. Ita que in puncto E vna eademque e&longs;t vtriu&longs;que motus determinatio, &longs;cilicet per tangentem versùs Ortum; in F verò, altera determinatio alteri ex diametro opponitur; nam determinatio motus centri e&longs;t tangens ducta in Ortum; nempe hîc motus determinationem in vna &longs;altem revolutione non murat; at verò determinatio motus orbis e&longs;t tangens ducta in Occa&longs;um; in aliis punctis inter EI, & IF, in diver&longs;as partes tendunt; v.g.in puncto I de­terminatio centri e&longs;t DI producta versùs Ortum; determinatio orbis per­pendiculariter cadit versùs GF. pari modo habentur aliæ in tangentibus; & provt vna magis aut minùs con&longs;entit cum alia, velocior aut tardior e&longs;t motus; Sed dic mihi. &longs;odes Antime, po&longs;ito quod &longs;it globus in E, cur per tangentem non projicitur ver&longs;us Ortum?

Antimus. Cur me tentas, Augu&longs;tine, ne&longs;cire non potes, hoc jam à Galilæo &longs;olutum fui&longs;&longs;e, in quo certè, more &longs;uo maximam ingenij vim o&longs;tendit. Nullum corpus grave per horizontalem projicitur, quod &longs;tatim ip&longs;o initio de&longs;cendere non incipiat; &longs;emiparabolam à &longs;ummo vertice &longs;uo motu de&longs;cribens; &longs;ed quælibet parabola ex E vertice ducitur infra Cycloi­dem EQV, vi Geometræ demon&longs;trant; itaque dictus globus projicitur quidem, &longs;ed ita, vt cùm a&longs;&longs;urgere non po&longs;&longs;it, in &longs;uperficie terræ volvatur, vt alij globi volvuntur.

Chry&longs;ocom. Quid dicam ad hæc, ne&longs;cio, certa tamen e&longs;&longs;e non puto; alioquin actum e&longs;&longs;et de hy pothe&longs;i Copernicana; aliunde illud principium certum e&longs;&longs;e videtur, quòd &longs;cilicét impetus aliquamdiu duret modò fru&longs;tra non &longs;it, & aliquem motum præ&longs;tare queat, videmus enim globum proje­ctum moveri, etiam à projicientis manu ab&longs;tractum; rotam item in quo­cunque &longs;itu collocatam, vbi tantulus impetus initio impre&longs;&longs;us &longs;uerit; in funependulis, res e&longs;t plu&longs;quam per&longs;picua, itemque in motibus, qui per repercu&longs;&longs;ionem fiunt; commune igitur principium e&longs;&longs;e videtur, ex quo, ni fallor, rectè deducis tractum matis, qui e&longs;t circa E, versùs Ortum deinde excurrere; quod enim de globo dixi&longs;ti in eodem puncto E &longs;ito, ex hypothe&longs;i dumtaxataccipio, non verò ab&longs;olutè dictum.

Antim. Immò ab&longs;olutè dictum e&longs;&longs;e velim; non ratò quippe accidit vt globi lævigati&longs;&longs;imi in planis etiam lævigati&longs;&longs;imis collocentur, &longs;eu marmo­reis, &longs;eu vitreis; lævigata glacie nihil ferè lævius inuenio; & &longs;upra glaciem glaciata fru&longs;tra citò & facilè currunt; itaque &longs;i aqua movetur, excurritque, modò Ortum, modò Occa&longs;um, versùs, non video quare globus lævigati&longs;­&longs;imus in plano lævigati&longs;&longs;imo &longs;itus, vel &longs;upra lævigatam glaciem, propter eandem motus inæqualitatem moveri non debeat; & hoc etiam ad homi­nem, contra tuam hypothe&longs;im militat; vnde ruitetiam illa re&longs;pon&longs;io iam &longs;upra indicata; quod &longs;cilicet terræ motus æ&longs;tus quidem matini cau&longs;a &longs;it, &longs;ed non adæquata, vt aiunt; nempe quidquid tandem motus in aquas traducat, in globulum eo modo &longs;itum, quo dictum e&longs;t, etiam traducere deberet, cùm æquè facile traduci queat; accipio enim globulos tam fa­cilè mobiles, vt nihil mobilius excogitari po&longs;&longs;it, tornatos &longs;cilicet ex Mer­curio.

Augu&longs;tin. De puncto E fortè &longs;atis dictum, & plu&longs;quàm &longs;atis; de aliis quid cen&longs;es? Non dubito enim, quin de iis aliquid dicturus &longs;is; ad quid enim duo alia principia præmi&longs;i&longs;&longs;es?

Antim. Etiam &longs;i nihil aliud dicerem, an fortè illa, quæ de puncto E dixi non &longs;ufficiunt ad tuam &longs;ententiam impugnandam? Sed agedum, quandoquidem me &longs;timulas, etiam de aliis punctis nonnulla dicenda &longs;unt, eaque ex duobus aliis principiis, quæ &longs;upra data opera præmi&longs;i eruenda. Si terræ globum quoquo versùm obtegeret aqua, ita vt v.g.ex 8. partibus &longs;emidiametri, octava, &longs;uprema &longs;cilicet, aquea e&longs;&longs;et, extremaque &longs;uperfi­cies terræ convexa, cui &longs;uperficies aquæ incubat, lævis e&longs;&longs;et, nullis mon­tibus, nullis &longs;alebris a&longs;pera; Iam verò quàm celerrimè interior ille & in aquis latens terræ globus circa &longs;uum centrum immobile volvatur; an for­tè putas, tunc motum in portionem aqueam traductum iri?

Chry&longs;oc. Traducendum e&longs;&longs;e omnino crederem; terra enim illam etiam aquam &longs;u&longs;tineret; igitur &longs;ecum vna deferret.

Augu&longs;tin. At ego &longs;ecus &longs;entio; hic enim ca&longs;us no&longs;tro &longs;imilis e&longs;t; &longs;i enim vas probè tornatum aqua plenum in &longs;itu horizontali circa axem verticalem accurati&longs;&longs;imè & citra vllam inclinationem erectum, etiam ce­lerrimè vertatur, immotam pror&longs;us aquam videbimus; Quid vis tibi di­cam, Chry&longs;ocome, oculos meos te&longs;tes appello, & &longs;i fidem detrectes, vel in &longs;cutella &longs;tannea, quamvis imperfectè tornata, hoc ip&longs;um videbis.

Chry&longs;ocom. Aqua igitur non &longs;u&longs;tinetur à va&longs;e, alioquin &longs;i vas illam &longs;u­&longs;tineret, &longs;ecum illam circumferret, &longs;ic librum hunc, quem manu teneo, manus ip&longs;a, quocumque fertur, traducit.

Augu&longs;tin. Standum e&longs;t experimentis; tu fortè quid, Antime? qui litem movi&longs;ti, & cautè &longs;ubrides.

Antim. Dicam quod &longs;entio, & quod verum e&longs;t; Aqua certè quie&longs;cit, dum vas pernici&longs;&longs;imè volvitur; & &longs;i vas probè tornatum e&longs;&longs;et, & circa axem minimè inclinatum volveretur, eaque demum e&longs;&longs;et cava &longs;uperficie, quam nulla pror&longs;us ruga, nulla &longs;alebra, quantumvis in&longs;en&longs;ibilis a&longs;peraret, dico nunquam fore, vt cum va&longs;e aqua moveretur; & hîc applico princi­pium &longs;upra iactum, &longs;cilicet nunquam motum, vel impetum ab aliquo mo­bili imprimi alteri, ni&longs;i hoc motum illius impediat, aut retardet: in hoc autem ca&longs;u, aqua va&longs;e contenta motum va&longs;is nullo modo impedit, non per &longs;uam molem, &longs;eu molis pondus; quia moles &longs;eu pondus re&longs;i&longs;tit tan­tummodo motui, &longs;ur&longs;um; &longs;ed nulla pars va&longs;is, in hoc motu a&longs;cendit; nulla igitur aquæ pars attollenda e&longs;t; præterea nulla pars ob&longs;i&longs;tit motui va&longs;is, quia id tantùm per contactum fieret; &longs;ed nulla pars tangens ob&longs;i&longs;tit, cùm nulla pars cavæ va&longs;is &longs;uperficiei extare, & dam movetur, in aquam impin­gi &longs;upponamus; vt tamen dicam, quod res e&longs;t, cùm & axis ab&longs;que aliqua inclinatione erigi, & &longs;ic &longs;tare vix po&longs;&longs;it, & quod caput e&longs;t, nullum &longs;it corpus durum, quantumvis lævigatum, &longs;ine poris, rugis, & &longs;alebris, hinc fit, aquam dicto va&longs;e contentam tantulùm ob&longs;i&longs;tere motui va&longs;is, ac proin­de non mirum videri, &longs;i initio quidem immota maneat, quia tamen &longs;en&longs;im &longs;ine &longs;en&longs;u vires acquirit, circumferri tandem cum &longs;uo va&longs;e cernitur, & hoc adjicere debueras, Augu&longs;tine, vt &longs;emper &longs;uus &longs;it veritati locus.

Chry&longs;oc. Quid verò fieret, &longs;i vas in circulo verticali verteretur?

Antim. Eadam &longs;uppone; vas &longs;cilicet cylindricum, aut &longs;phæricum ca­vum, lævigata intus &longs;uperficie, circa axem plano horizontis planè paral­lelum; idemque &longs;ucce&longs;&longs;um iri puta; cùm eadem ratio vtrimque & æquè militet.

Chry&longs;ocom. Immo ex alio tuo principio, quo dicis, eo motu moveri mobile, quò faciliùs moveri pote&longs;t, colligo, ni fallor, longè potiori iure pro i&longs;to vltimo ca&longs;u rationem militare; cùm enim faciliùs aqua illa à &longs;uo va&longs;e, dum in plano horizontali volvitur, moveri po&longs;&longs;it, quàm ab eodem in hoc &longs;ecundo ca&longs;u; quia vt imprimo illo moveatur aqua, ne latum quidem vnguem attollenda e&longs;t, nullam igitur difficultatem, &longs;eu re&longs;i&longs;tentiam ex hoc capite vas &longs;entit; cùm tamen in &longs;ecundo ca&longs;u, illa portio aquæ, quæ con­tinetur in inferiore parte dolij, &longs;eu cylindri, ad &longs;uperiorem partem cylin­dri locum attollenda &longs;it; vnde difficultas & re&longs;i&longs;tentia; igitur cùm mobi­le eo motu moveatur, quo facilius moveri pote&longs;t, longè facilius e&longs;t, vas moveri &longs;ine aqua in &longs;ecundo ca&longs;u, quàm in primo

Antim. Plurimùm &longs;anè me tibi ob&longs;trinxi&longs;ti, mi Chry&longs;ocome, cogita­bam &longs;tatim principium illud iam &longs;upra iactum, ac fusè non &longs;ine querela expo&longs;itum, huc accer&longs;ere; &longs;ed ab hoc pen&longs;o me libera&longs;ti, ita e&longs;t; cùm vas vtrumque faciliùs moveri po&longs;&longs;it, quie&longs;cente aqua, vt patet, etiam ab&longs;que vlla penitus &longs;ui motus iactura; ita &longs;anè ex illo quoque principio probatur, va&longs;a &longs;ine aqua contenta moveri; quod autem addis, longe facilius in &longs;ecundo ca&longs;u quam in primo, pace tua dixerim; quia &longs;cilicet æquè facilè vtrimque aqua cum &longs;uo va&longs;e movetur, nec ob&longs;tat inferiorem aquæ partem in &longs;ecundo ca&longs;u ab imo ad &longs;upremum va&longs;is locum attolli, ac proinde illius pondus ob&longs;tare ac re&longs;i&longs;tere; nam ita attollitur, vt eodem tempore, æqualis portio deprimatur, e&longs;t enim perfectum æquilibrium, vt vides; &longs;ic vbi libra in æquilibrio ver&longs;atur, &longs;i vel minimam vim alteri lancium &longs;ur&longs;um impre&longs;&longs;e­ris, illa &longs;tatim &longs;ur&longs;um attollitur; an fortè illa vis minima impre&longs;&longs;a ad hoc &longs;ufficit? Minimè vero; &longs;ed minima illa acce&longs;&longs;ione tollitur æquilibrium: quid mirum ergo, fi portio præponderans, deor&longs;um eat, & oppo&longs;itam at­tollat? Sic æquè facilè rota volvitur in &longs;itu horizontali ac verticali.

Augu&longs;tin. Hæc veri&longs;&longs;ima e&longs;&longs;e, non diffiteor, ita enim à natura compa­ratus &longs;um, vt compertæ veritati numquam non me &longs;ubjiciam; movetur autem aqua cum &longs;uo va&longs;e, vt dicis, per accidens non per &longs;e, nimirum, propter a&longs;peritatem & inæqualitatem interioris &longs;uperficiei; at numquid non po&longs;&longs;et ab hoc vitio liberari, obducto &longs;cilicet oleo, vel alio quopiam vliginis genere?

Antim. An fortè putas, oleum &longs;uis rugis & &longs;triis, nec non filaminibus carere? Vidi&longs;ti, ni fallor, aliquando, majores illas guttas &longs;ive butyro, &longs;eu va&longs;ibus vnctis oleo adhære&longs;cere, an fortè in plani&longs;&longs;ima &longs;uperficie adhæ­rete po&longs;&longs;ent?

Augu&longs;tin. Sed vnde quæ&longs;o, i&longs;tæ guttulæ; rem illam &longs;æpè ob&longs;ervavi, cu­jus tamen rationem vix ac ne vix quidem mente a&longs;&longs;equor.

Antim. Sunt quædam &longs;uperficies ita di&longs;po&longs;itæ inter &longs;e, vt in earum rimas &longs;eu rugas, aqua &longs;ubire non po&longs;&longs;it, aut &longs;i reverà &longs;ubeat, &longs;tatim effluar, in pennis avium aquatilium v.g. An&longs;erum, Anatum, aliarumque &longs;imilium, hoc ip&longs;um ob&longs;ervamus, immo in multis foliis, vt bra&longs;&longs;icæ, in quibus hu­ju&longs;modi aquæ guttulæ, qua&longs;i totidem liquatas gemmas, po&longs;t pluviæ vel roris lap&longs;um &longs;æpè vidi&longs;ti; quia &longs;cilicet laxioribus rugis &longs;eu &longs;triis in longum & rectam lineam ductis con&longs;tant, per quas aqua &longs;tatim de&longs;cendit, atque effluit, ni&longs;i aliqua fo&longs;&longs;ula in&longs;it, in qua major gutta ex reliquis longè mi­noribus eò per rugam declivem confluentibus, componitur; in &longs;uperficie butyri rectas huiu&longs;modi &longs;trias tantùm non videmus; nec fortè mirum; nempe vligino&longs;a ex multis filaminibus con&longs;tant; fila autem in longum ducuntur; iunge &longs;imul multas acus, & aliquid fortè &longs;imile a&longs;picies; cur verò guttæ illæ majores in iis fo&longs;&longs;ulis tornatæ deinde non cadant, etiam &longs;i vas vnctum, cui adhærent, ever&longs;o &longs;itu &longs;tatuatur, eadem ratio e&longs;t, propter quam na&longs;o, pa­leæ, ligno, alií&longs;que corporum extremitatibus gutta adhæret, ac de illis pen­det quam certè hoc loco explicare non po&longs;&longs;um, cùm inde va&longs;ti&longs;&longs;imus allis experimentis ad &longs;uas veras cau&longs;as phy&longs;icas reducendis campus ape­riatur.

Augu&longs;tin. Auguror rem grati&longs;&longs;imam fore, & fortè altero congre&longs;&longs;u dignam, quandoquidem tam latè patere dictitas; &longs;ed ad propo&longs;itum, qùæ&longs;o, redea­mus: Con&longs;tat igitur, illum terræ globum ver&longs;um iri, licèt aqua circum­po&longs;ita nullo modo moveretur; huc enim faciunt duo illa tua principia, quæ libenter admitto, vtpote quæ cum experimentis mirabiliter con&longs;en­tiant; &longs;i verò terræ globum con&longs;ideremus, provt modò e&longs;t, & aquarum congeries &longs;tagnat in va&longs;ti&longs;&longs;imis illis terrarum conchis; &longs;i terræ glo­bus volvatur, nunquid non &longs;uo motu aqueam illam molem &longs;ecum abri­piet?

Antim. Abripiet &longs;anè majorem partem, eam &longs;cilicet, quàm arctiùs &longs;uis brachiis &longs;tringit, & quæ à &longs;uperficie conchæ intror&longs;um &longs;atis &longs;uperque di&longs;tat; huc facerent exempla concharum, quibus vulgò vtimur; &longs;ed ne dicta repetam, libens omitto, atque &longs;uppono. Vt vt &longs;it, &longs;i motum orbis con&longs;ide­remus haud dubiè facilior e&longs;t &longs;i aliqua portio aquæ retroagatur, ea &longs;cilicet, quæ à &longs;uperficie parum di&longs;tat, cum tantula elevatione, ratione cujus in &longs;u­perficiem oppo&longs;itam excurrit, & in litora occidua deinde impingi, &longs;eu po­tiùs elevari, excurrere & in litus impingi videtur, eo quippe litus ip&longs;um fer­tur, & in aquam vel immobilem vel tardiorem impingitur, nempe quoad effectum & phænomerum perinde e&longs;t, &longs;ive caput in &longs;axum, five &longs;axum in ca­put incurrat: hoc autem potiori iure in terræ globo duplici illo motu, de quo jam &longs;upra, locum habet, nempe à puncto H ad E cre&longs;cit motus per HE, non tantùm ratione motus orbis, verùm etiam motus centri; idque per cre­menta majora & majora, vt iam o&longs;tendi; Igitur, aqua, iuxta &longs;uperficiem &longs;al­tem tantulùm ex currit in partem oppo&longs;itam, &longs;cilicet in occa&longs;um, &longs;i enim hoc fiat, motu æquali &longs;uppo&longs;ito, potiori iure &longs;uppo&longs;ito inæquali, ac &longs;emper cre&longs;­cente: itaque ex iis. quæ diximus huc v&longs;que, nec non meo judicio probavimus, facilè defini: i po&longs;&longs;et æ&longs;tus marini ratio, in dicta hypothe&longs;i ; nempe aqua à puncto E ad punctum I, id e&longs;t à media nocte ad Solis Ortum (&longs;up-pono enim circulum Æquatoris) excurreret aquæ &longs;uperficies versùs ortum; ab I ad F, id e&longs;t ab ortu ad meridiem, nullo modo excurreret, &longs;altem &longs;en&longs;ibiliter; &longs;i enim tantulùm, hoc motui centri prævalenti cedet; igitur versùs Occa&longs;um, id e&longs;t, ab F, versùs R. quanquam determinatio mixta hoc etiam compen&longs;at; pari modo ab F ad H nullo modo excurrit, &longs;altem &longs;en­&longs;ibiliter; &longs;i enim tantulùm, cedit motui centri, quanquam etiam determi­natio mixta hoc ip&longs;um compen&longs;at; igitur à Solis ortu v&longs;que ad occa&longs;um, nulla fit &longs;en&longs;ibilis excur&longs;io; ab occa&longs;u ad mediam noctem, fit in occa­&longs;um, à media nocte ad ortum Solis, fit in ortum: mixtam illam determi­nationem facilè qui&longs;piam intelliget, &longs;i dividat æqualiter angulum, qui fit à tangente datum aliquod punctum, & à linea motus centri, quæ &longs;emper e&longs;t parallela HI, linea enim dictum angulum æqualiter dividens e&longs;t deter­minatio motus mixti. Iam verò, &longs;i mihi non creditis, oculis ve&longs;tris credite, & probate experimenta à me expo&longs;ita, in navi &longs;cilicet velorum dumtaxat impul&longs;u acta, in aliquo tranquillo lacu, &longs;eu flumine; &longs;i enim &longs;tatuatur in media navi, concha aquâ plena, pauio laxios in &longs;uperiore labro, &longs;ed mo­dicæ profunditatis, ad in&longs;tar illius, in qua cera liquari &longs;olet, ad cereos tor­nandos, videbitis haud dubiè, &longs;i navis motum acceleret, conchæ aquam versùs puppim ire; verò retardet, ire versùs proram; in hoc Ga&longs;&longs;endo fides detrahi non debet, nec fortè mihi, nec aliis, qui hujus experimenti oculati te&longs;tes fuerunt: & hæc de prima ratione contra tuam hypothe&longs;im, Augu&longs;tine, jam ad alias de&longs;cendam.

Augu&longs;tin. Sentio difficultatem, inficiari non po&longs;&longs;um; illud &longs;altem con­&longs;equi videor quod Galileus no&longs;ter à vero minime aberrarit, quando a&longs;&longs;e­ruit, prædictos motus ex hypothe&longs;i terræ mobilis, nece&longs;&longs;ariò &longs;equi.

Antim. Ita e&longs;t; in eo tamen deceptus, quòd eo&longs;dem motus pro Marino æ&longs;tu venditarit, licèt omnino di&longs;&longs;imiles &longs;int. Iam verò vt ad alia tran&longs;eam ar­gumenta, è terra nobis migrandum e&longs;t, in qua profectò nihil aliud invenio ex quo &longs;olidum argumentum ducere valeam &longs;altem, quod mihi faciat &longs;atis.

Chry&longs;oc. Ludis, opinor, Antime; nunquid enim ex diver&longs;is motibus, tum naturalibus, tum violentis docti&longs;&longs;imi viri ducunt in&longs;olubilia pror&longs;us argumenta, contra præfatam hypothe&longs;im, in qua nequidem corpus grave per lineam rectam de&longs;cenderet, nec accelerationis, nec retardationis, nec percu&longs;&longs;ionis ratio explicari po&longs;&longs;et.

Augu&longs;tin. Ridere &longs;oleo quorumdam hominum &longs;implicitatem, vt &longs;ic loquar, qui cum Galileo no&longs;tro de motu contendunt, qui cerrè doctrinæ motuum primus Autor & inventor fuit; nemo quippe alius hanc laudem &longs;ibi arroget; Crede mihi, Chry&longs;ocome, &longs;uarum rerum & inventionum vir ille amantior erat, quàm vt aliquem inter eas conflictum pateretur, vidit, haud dubiè, vidit, motus accelera­ti progre&longs;&longs;ionem Geometricam, ita cum hypothe&longs;i Copernicana con­&longs;entive, vt in ea æquè facilè atque in tua explicari & ad &longs;ua princi­pia reduci po&longs;&longs;it; equidem in primis &longs;uis Dialogis de vtroque &longs;y&longs;tema­te, dubius aliquantulum hæ&longs;i&longs;&longs;e vi&longs;us. e&longs;t, qua&longs;i motus gravium non e&longs;&longs;et per &longs;e acceleratus, &longs;ed tantùm per accident; at in illo mirabili certè libro, quem de motu naturali accelerato edidit, ita de hoc argumen­to &longs;crip&longs;it, vt nullum po&longs;t &longs;e dubium reliquerit.

Chry&longs;ocom. Hic lapis te petit, Antime, vtpote qui, &longs;i rectè memini, contra Galileum &longs;crip&longs;i&longs;ti, aliamque induxi&longs;ti motus naturaliter accele­rati progre&longs;&longs;ionem.

Antim. Contra Galileum nihil me vnquam &longs;crip&longs;i&longs;&longs;e memini; è qui­dem Mon&longs;nerius meus tractatum de motu locali, ex meis prælectionibus excerptum edidit, nihil tamen in eo contra Galileum.

Augu&longs;tin. Immò ex profe&longs;&longs;o Galileum, &longs;ub Mon&longs;nerij nomine, im­pugnas, nec tibi, opinor, è memoria excidit? nempe Galileus docet, &, ni fallor, demon&longs;trat, motum gravium accelerari iuxta progre&longs;&longs;ionem geo­metricam, &longs;ecundùm quam decur&longs;a &longs;patia &longs;unt vt temporum quadrata, ac proinde &longs;i primo tempore decurrat &longs;patium 1. &longs;ecundo æquali decurrit 3. tertio 5. quarto 7. atque ita con&longs;equenter &longs;ecundum &longs;eriem numerorum imparium, tu verò, Antime, vis, hanc &longs;eriem fieri &longs;ecundùm progre&longs;&longs;io­nem Arithmeticam &longs;impliorem numerorum 1.2.3.4.&c.

Chry&longs;oc. Si rectè memini, Antime, omnibus experimentis hypothe&longs;is tua repugnat; nam etiam &longs;umma quandoque altitudo &longs;umpta fuerit, Flo­rentiæ, Romæ, Bononiæ, & vt audio, in Gallia pa&longs;&longs;im, quantum tamen periti&longs;&longs;imorum hominum oculis credendum e&longs;t, prima progre&longs;&longs;io illa Ga­lileana in decur&longs;is æquali tempore &longs;patiis &longs;emper apparuit.

Antim. Summoperè lætor & gaudeo, quod &longs;ive ca&longs;u, &longs;ive &longs;tudio, hu­ju&longs;ce rei mentio à vobis facta fuerit; dico igitur, iterumque atte&longs;tor, ac tertiò, nec meam hypothe&longs;im experimentis repugnate, nec à Galileana di&longs;crepare in communi &longs;ententia quantitatis, tum continuæ, tum di&longs;cretæ; nempe, vt probè &longs;citis, res quantitatis eas difficultates continet, quas huc v&longs;que nemo ita &longs;olvit vt &longs;olutio vel omnibus arri&longs;erit, vel etiam illius a&longs;­&longs;ertoribus difficilis vi&longs;a non fuerit, in tempore præ&longs;ertim explicando; &longs;unt enim qui capere nequeunt, vt quidquid temporis e&longs;t, ab eo, quod non e&longs;t, &longs;ed fuit, vel erit, omnino di&longs;tinctum, in&longs;tans indivi&longs;ibile non &longs;it; &longs;ic enim divi&longs;ibile e&longs;t in plura, ergo plura temporis &longs;imul exi&longs;tunt, quod di­ci nequit ; &longs;i autem ea in quæ e&longs;t divi&longs;ibile, non &longs;unt quidem, &longs;ed vel fue­runt, vel erunt; ergo id quod e&longs;t, quidquid &longs;it, ab iis omnino di&longs;tingui­tur; cùm repugnet, idem &longs;imul e&longs;&longs;e & non e&longs;&longs;e, igitur illud quod e&longs;t, ab omni alio, quod non e&longs;t, di&longs;tinctum, in&longs;tans e&longs;t, indivi&longs;ibile e&longs;t: nec ju­vat à nonnullis dici, tempus e&longs;&longs;e fluenter; nempe fluenter e&longs;&longs;e; nihil e&longs;t aliud, quàm vnum e&longs;&longs;e, &longs;eu fluere po&longs;t aliud, nec-plura &longs;imul e&longs;&longs;e po&longs;&longs;e; &longs;i quid dicatur aliud, multorum captum & mentem &longs;uperat.

Augu&longs;tin. Ad quid hæc: Galileus enim docet, componi tempus ex in­&longs;tantibus ii&longs;que Mathematicis.

Antim. Sat &longs;cio; &longs;ed cùm alij huiu&longs;modi in&longs;tantia minimè admittant, partibus dumtaxat in infinitum divi&longs;ibilibus, vel &longs;initis contenti in&longs;tan­tibus, &longs;cilicet phy&longs;icis, dico hypothe&longs;im Galilei circa progre&longs;&longs;ionem mo­tus accelerati, habere quidem locum in hypothe&longs;i in&longs;tantium infinitorum, vel partium infinitarum, non ramen in hypothe&longs;i finitorum in&longs;tantium phy&longs;icorum; hîc non di&longs;cutio cau&longs;æ merita, ne &longs;altem extra chorum; id vnum dumtaxat dico, illam progre&longs;&longs;ionem alteri præferendam e&longs;&longs;e, quæ & vtrique quantitatis hypothe&longs;i &longs;atisfacit, & ip&longs;is experimentis non repu­gnat: quòd autem progre&longs;&longs;io Galileana in hypothe&longs;i finitorum in&longs;tan­tium non &longs;ub&longs;i&longs;tat, per&longs;picuè demon&longs;tro; Sit enim motus qui&longs;piam natu­ralis, qui duret per 4. in&longs;tantia, in quorum primo, mobile acquirat &longs;pa­tium 1. in &longs;ecundo 3. in tertio 5. in quarto 7. cùm velocitas cre&longs;cat, vt tempus, in &longs;ecundo in&longs;tanti velocitas erit dupla, quomodo igitur acquiri­tur triplum &longs;patium?

Augu&longs;tin. Nihil facilius triangulo Galileano, in quo res i&longs;ta clari&longs;&longs;i­

mè demon&longs;tratur: Sit enim triangulum AEI, &longs;it tempus divi&longs;um in 4.partes æquales, & primo tempo­re AB, &longs;patium acqui&longs;itum &longs;it triangulum ABF, & velocitas acqui&longs;ita BF, &longs;ecundo tempore erit veloci­tas acqui&longs;ita CG, cre&longs;cit enim, vt tempus, & vt AB ad BF, ita AC ad CG ; idem dico de quolibet alio temporis puncto accepto inter BC ; igitur &longs;patium ac­qui&longs;itum erit trapezium BCGF, triplum trianguli ABF, nempe cum velocitate BF æquabili motu, tem­pore BC, acquireret rectangulum BM, &longs;ed virtute ve­locitatis acqui&longs;itæ tempore BC æqualis velocitati BF, acquiritur triangu­lum FMG æquale ABF; igitur &longs;ecundo tempore triplum &longs;patium prioris.

Antim. Hæc omittere poteras, quæ iam trita &longs;unt, nec à me negantur; nempe velocitas BF acquiritur &longs;ucce&longs;tivè tempore AB, quod &longs;i &longs;uppona­tur e&longs;&longs;e in&longs;tans phy&longs;icum, accipienda e&longs;t velocitas. BF tota &longs;imul, re­&longs;pondeo enim toti in&longs;tanti, ac proinde tota &longs;imul e&longs;t, non verò &longs;ucce&longs;&longs;i­vè acqui&longs;ita, igitur &longs;patium debet accipi in rectangulo, non verò in trian­

gulo; v.g. Sit tempus AE 4. in&longs;tantiam, &longs;it pri­mus gradus velocitatis AG, & &longs;patium acqui­&longs;itum rectangulum AV; &longs;ecundo in&longs;tanti ve­locitas acqui&longs;ita erit BH, dupla &longs;cilicet AG; nempe tota prior remanet, & tantumdem ab ea­dem cau&longs;a, æquali tempore ponitur; igitur &longs;pa­tium e&longs;t duplum prioris, ac proinde erit rectan­gulum CH duplum prioris.

Augu&longs;tin. Duo ab&longs;urda ex his mihi deducere videor; primò enim, pri­mo tempore AB, duplum &longs;patium trianguli Galileani a&longs;&longs;umis; nempe re­ctangulum AV duplum e&longs;t trianguli ABV, cùm tamen æquale primum tempus a&longs;&longs;umi debeat, ad perfectam comparationem; &longs;ecundò longè majus &longs;patium decurritur &longs;ecundùm tuam progre&longs;&longs;ionem, quàm &longs;ecundùm Ga­lileanam, in qua &longs;patium decur&longs;um tempore AE continet 16. triangula æqualia triangulo ABV, in tua verò continet 10. rectangula æqualia AV; igitur 20. triangula æqualia ABV, igitur &longs;patium Galileanum erit ad tuum vt 16. ad 20. &longs;eu vt 4. ad 5. igitur majus vna quarta parte, quod &longs;anè omnibus experimentis repugnat, quæ cum &longs;patio Galileano pror&longs;us con&longs;entiunt.

Antim. Nemo vnquam hujus rei periculum fecit in 4. in&longs;tantibus, &longs;ed tantùm in 4. temporibus &longs;en&longs;ibilibus, nempe in&longs;tantia &longs;ub &longs;en&longs;um non cadunt; at &longs;upponuntur hoc loco 4.in&longs;tantia. iuxta &longs;ingularem illam tem­poris hypothe&longs;im ; equidem &longs;i tempus AE ex quatuor partibus temporis &longs;en&longs;ibilibus componas &longs;ecundùm communem, aut etiam Galileanam tem­poris hypothe&longs;im, & dividas AE in 8. tempora æqualia; in progre&longs;&longs;ione Galilei, tempore AE, idem &longs;patium decurritur; at verò in mea decurritur &longs;patium, quod complectitur 18.triangula æqualia ABV; igitur &longs;patium in mea decur&longs;um majus erit Galileano, vna octava; & &longs;i adhuc tempora bi­fariam dividas, majus erit vna decima &longs;exta; atque ita deinceps decre­&longs;cent exce&longs;&longs;us iuxta hanc &longs;eriem 1/4. &c. igitur. &longs;i vel in­&longs;tantia infinita &longs;unt, vel partes infinitæ, differentia &longs;patiorum in mea progre&longs;&longs;ione & Galileana decre&longs;cit in infinitum; ac proinde Illa &longs;patia æqualia cen&longs;enda &longs;unt, quorum vnum aliud &longs;uperat, exce&longs;&longs;u, minore quo­libet a&longs;&longs;ignabili: Hæc &longs;i non nemo paulò attentiùs con&longs;idera&longs;&longs;et, meam progre&longs;&longs;ionem tam citò vt fal&longs;am & experimentis omnino repugnantem minimè rejeci&longs;&longs;et, nec adeò dubita&longs;&longs;et de vera hujus accelerationis cau&longs;a, quæ in eo po&longs;ita e&longs;t, quod prioribus gradibus impetus novi gradus conti­nuè accedant, idque &longs;i quodlibet tempus ex infinitis con&longs;ter, vel etiam ex finitis, &longs;ed innumerabilibus, in triangulo; &longs;i verò ex paucis finitis, in rectangulis, iuxta figuram AEF di&longs;po&longs;itis; nec alia &longs;uper hoc, meo judi­cio, difficultas re&longs;tat; vnde concludo, meam progre&longs;&longs;ionem alteri præfe­rendam e&longs;&longs;e, quia &longs;cilicet vtrique hypothe&longs;i facit &longs;atis; quanquam ad v&longs;um. Galileana omnino adhibenda e&longs;t, cùm in eam mea re&longs;olvatur, vt verò ad cau&longs;am phy&longs;icam accelerationis res reducatur pro vtraque hypothe&longs;i, mea certè non modò præferenda e&longs;t, verùm etiam nece&longs;&longs;ariò tenenda; &longs;ed tam multa de hac re &longs;crip&longs;imus, vt de his plura &longs;cribere operæ pretium non &longs;it.

Chry&longs;ocom. Ne&longs;cio, quomodo dicas, nullam &longs;upere&longs;&longs;e difficultatem, cùm in&longs;uperabilis adhuc re&longs;tet; nempe &longs;i primo in&longs;tanti mobile acquirit AV, & &longs;ecundo, &longs;patium CH, duplum, igitur, cùm mobile e&longs;&longs;et ih &longs;pa­tio AV tanquam in loco adæquato erit in CH duplo &longs;cilicet, tanquam in loco adæquato majore.

Antim. Hæc maxima e&longs;t difficultas, fateor, & in communi temporis

hypothe&longs;i, &longs;i rèm ip&longs;am, non verba con&longs;ideremus, ferè in&longs;uperabilis; immò & in Galilei opinione, qui vult, tempus ex infinitis in&longs;tantibus Mathematicis componi, in&longs;olubilis nodus e&longs;t; &longs;i enim in tempore AE accipiantur duo in&longs;tantia, &longs;cilicet B & C, nem­pe vt linea AE repræ&longs;entat tempus, ita quodlibet illius punctum repræ&longs;entat vnum in&longs;tans, porrò mobile, quod movetur tempore AE, in&longs;tanti B e&longs;t in &longs;pa­tio BF, in&longs;tanti C in &longs;patio CG duplo prioris; quia vt arca trianguli AEI repræ&longs;entat, totum &longs;patium, quod mobile acquirit, tempore AE, ita linea BF repræ&longs;entat &longs;patium, in que fuit in&longs;tanti B; & CG, &longs;patium, in quo fuit in&longs;tanti C &c. In hypothe&longs;i in&longs;tantium phy&longs;icorum hæc difficultas omnino ce&longs;­&longs;at; &longs;ed ne huc accer&longs;am integram, & benè longam tractationem, in qua natura temporis & motus explicanda e&longs;&longs;et, con&longs;ule, &longs;i vis, Chry­&longs;ocome, tractatum no&longs;trum, de motu locali; itemque Metaphy&longs;icam non vno loco, ibi enim hoc munere perfuncti &longs;umus, quo certè in præ­&longs;enti congre&longs;&longs;u perfungi non vacat. Addo tantùm, hypothe&longs;i Coperni­canæ nihil ob&longs;tare motum acceleratum, vt dicebas, &longs;icuti eidem mo­tui non ob&longs;tat navis motus, vt plu&longs;quam mille experimentis comproba­tum e&longs;t.

Augu&longs;tin. Rectè omninò, nempe corpus grave de&longs;cenderet, motu quodam mixto, ex æquabili, & accelerato; in navi exemplum luculen­tum e&longs;t, immò & in di&longs;co projecto per inclinatam &longs;ur&longs;um, qui non mo­dò per curvam &longs;ur&longs;um a&longs;cendit, verùm etiam per curvam deor&longs;um ruit & licèt æqualia &longs;patia in dicta curva æqualibus temporibus omnino de­currat, &longs;altem ad &longs;en&longs;am, hoc tamen non ob&longs;tat, quin ratione perpen­dicularis, in quam vi motus naturalis inclinat, & in qua majora &longs;pa­tia decurrit. eodem pror&longs;us modo quo fieret, &longs;i motus naturalis cum alio horizontali conjunctus non e&longs;&longs;et; hoc inquam non ob&longs;tat, quin ratio­ne perpendicularis, dictum corpus grave motu accelerato moveatur; &longs;ed &longs;i motus acceleratus e&longs;t, cre&longs;cit. impetus; hinc major ictus &c. Non cre&longs;cunt &longs;patia, inquies; Re&longs;pondeo: non cre&longs;cunt in horizontali, con­cedo: vnde ratione horizontalis, e&longs;t motus æquabilis; non cre&longs;cunt in per­pendiculari, nego; &longs;ed profecto &longs;i non cre&longs;ceret impetus, in perpendicula­ri &longs;patia non cre&longs;cerent.

Antim. Omitte quæ&longs;o hæc argumenta, à motu gravium, vel levium petita, quæ &longs;anè multiplicem paralogi&longs;mis materiam nonnullis præ­buerunt, quos aliis, amabo di&longs;cutiendos linquamus, præ&longs;ertim, cùm mediocriter doctis, & i&longs;tarum rerum peritis cuncta hæc per&longs;pecta &longs;int; vnum tantùm: in quo non nemo maximam vim facit, obiter indico; &longs;i moveatur terra, inquit, explodaturque catapulta, vel quodlibet aliud projectionis organum, versùs polum directè, globus projectus incidet in planum oppo&longs;itum obliquè; igitur vis ictus longe minor erit, quàm &longs;i explodatur versùs ortum, vel occa&longs;um; quod tamen expe­rimentis repugnat: Sed facilè re&longs;pondeo, dicti globi explo&longs;i motum mixtum e&longs;&longs;e ex duobus, altero communi aliis partibus terræ, versùs ortum, altero impre&longs;&longs;o à machina versùs polum; vterque totum effe­ctum habet, qui &longs;ibi competit; e&longs;t enim reverà duplex impetus, quo­rum vnus independenter ab alio id totum præ&longs;tat, quod præ&longs;tare po­te&longs;t; clari&longs;&longs;imum exemplum habemus in navi; vnde argumentum illud facilè &longs;olvitur, nempe ictus per lineam obliquam minor e&longs;t, quando vnus tantùm impetus ine&longs;t, ad talem lineam determinatus; at verò quan­do duplex impetus ine&longs;t, & alter per directam lineam determinatus e&longs;t, &longs;ive alius in&longs;it, five non, æqualis ictus infligitur.

Chry&longs;ocom. Sed, quæ&longs;o te, Antime, quandoquidem alia non &longs;up­petunt argumenta in terre&longs;trl globo, ad confutandum illius motum pro­fer amabo, locos illos ex quibus alia erui po&longs;&longs;int.

Antim. Nullus globus terre&longs;tri vicinior e&longs;t, quàm Luna; in Lunari globo nonnihil habeo, quod fortè non minùs negotij tibi face&longs;&longs;et, Augu­&longs;tine, quàm Marinus æ&longs;tus.

Augu&longs;tin. Immò in Iove mobili, circa quem moventur quatuor Ioviales Lunæ, clari&longs;&longs;imam analogiam habemus terræ mobilis, circa quam Luna volvitur; nonnihil &longs;imile in Saturno habemus, circa quem etiam &longs;ua Stella, &longs;eu Luna Saturnia circumfertur; Luna igitur no&longs;træ hypothe&longs;i non obe&longs;t, immò no&longs;tra hypothe&longs;is Lunari &longs;y&longs;temati favet, quod &longs;cilicet, & à deformibus &longs;piris, & à motu raptus versùs Occa&longs;um liberat.

Antim. Negari non pote&longs;t, quin ex ip&longs;i&longs;&longs;imis, non illorum modò, qui communem A&longs;tronomorum &longs;ententiam tenent, verùm etiam prin­cipium Copernicanæ &longs;ententiæ defen&longs;orum principiit, Planetarum mo­tus reales, vt vocant, æquales &longs;int, quamvis inæquales nobis appa­reant; hanc realium motuum inæqualitatem Antiqui omnes, ad vnum, vt A&longs;tronomiæ pe&longs;tem ac mortem relegarunt; ex recentioribus verò Copernicus ve&longs;ter, illam humano intellectui horrori e&longs;&longs;e dixit, Cla­vius &longs;ummæ dementiæ; Reinholdus imperitæ imaginationis; alij deni­que, vt Tycho, æqualem motum, in cœle&longs;tibus Sphæris, pro certo & indubitato axiomate po&longs;uerunt: Scio, Keplerum, quem deinde pauci alij &longs;ecuti &longs;unt, inæqualitatem motuum realium ad&longs;truxi&longs;&longs;e, in id dum­taxat ab ip&longs;a de&longs;peratione inductum extremi&longs;que angu&longs;tiis, in quas illum multa phænomena redegerant, quæ &longs;cilicet &longs;uppo&longs;itis motibus realibus in &longs;ua hypothe&longs;i explicare non poterat; hæc vnica huius con&longs;ilij cau&longs;a fuit, quod certè penitus ruit, &longs;i po&longs;itis motibus æqualibus, cuncta phænomena explicari po&longs;&longs;unt.

Augu&longs;tin. In hac parte tecum facilè &longs;entio, & verò à Ptolemæo alii&longs;que antiquis A&longs;tronomis, itemque à Tychone, Longomontano, Copernico, Galileo, Lansbergio, Clavio, Magino, alii&longs;que rei A&longs;tro­nomicæ Principibus, in hoc di&longs;cedere, vix au&longs;im ; nec ratio dee&longs;t, quæ meo &longs;altem iudicio, rem conficit; nempe omnis motus per &longs;e inæquabi­lis vel acceleratus, vel retardatus e&longs;t, neutrum de cœle&longs;tibus motibus dici pote&longs;t; cùm enim eadem &longs;emper e&longs;&longs;et accelerationis vel retardatio­nis cau&longs;a, certè in infinitum acceleraretur, vel retardaretur; quod vel ab&longs;urdum dictu e&longs;t; omitto certi&longs;&longs;imam totius A&longs;tronomiæ ruinam ac de&longs;tructionem, cùm inæqualitas certis ac perpetuis regulis minimè &longs;ubjaceat; incerta &longs;cilicet, varia, ignota; cùm enim vna dumtaxat fit æqualitas, infinitæ &longs;unt ac variæ inæqualitates; cur hæc potiùs quam illa?

Chry&longs;ocom. Multas tamen apud Autorem Neotericum de re A&longs;tro­nomica optimè meritum, rationes legi, quibus probare conatur, inæ­qualitatem realium motuum, quantum porrò conjicio, in &longs;ingula-rem hanc opinionem de&longs;cendit, eò quòd putarer, æqualitatem realium motuum &longs;alvari non po&longs;&longs;e, ni&longs;i in hypothe&longs;i Copernicana, in qua &longs;cilicet &longs;pectantis hominis oculus extra orbitarum cœle&longs;tium centrum collocatur.

Augu&longs;tin. Scio, quem intelligas, Chry&longs;ocome, rationes illæ de­bili&longs;&longs;imæ &longs;unt, & eadem facilitate de&longs;truuntur, qua ad&longs;truuntur; præ­&longs;ertim in hypothe&longs;i hujus no&longs;tri Antimi, in qua, motus realis vnicus &longs;implex & æquabilis e&longs;t ab ortu in occa&longs;um; reliqui tantùm apparentes, hos quidem inæquales e&longs;&longs;e do vltrò, &longs;ecus tamen realem & phy&longs;icum, qui &longs;anè ita æqualis e&longs;t, vt æqualibus temporibus, æqualia &longs;patia in &longs;uis &longs;piris &longs;eu revolutionibus Planeta decurrat.

Antim. Non e&longs;t etiam, quod aliquis timeat, ne præ&longs;ata æqualitas hy­pothe&longs;i Copernicanæ &longs;uffragetur; ex illa enim poti&longs;&longs;imum contra i&longs;tam argumentum duci pote&longs;t, vt paulò po&longs;t evincam.

Augu&longs;tin. Vnum omi&longs;eram, quod &longs;cilicet in Luna maximè rea­lium motuum inæqualitas ponenda e&longs;&longs;et, quia &longs;cilicet Men&longs;es tum Sy­nodici, tum Periodici inter &longs;e inæquales &longs;unt; at etiam in mea hypothe­&longs;i, Luna &longs;pectatur ex eo centro, circa quod &longs;uos orbes agit; igitur ideò æqualitas abigenda non e&longs;t, quod in hypothe&longs;i terræ mobilis, &longs;al­vari tantùm po&longs;&longs;it; cùm & in alia hypothe&longs;i fortè &longs;alvetur, & in illa, Lunæ motus quamvis ex &longs;uo centro &longs;pectati, valde inæquales appa­reant.

Antim. Ne dicas, fortè &longs;alvetur, dele illud fortè; quia profectò æqua­litatem illam optimè & facilè &longs;alvo; vt probè, ni fallor, intelligis ex iis, quæ in proximo congre&longs;&longs;u de meo Solis &longs;y&longs;temate obiter expo&longs;ui.

Augu&longs;tin. De Sole non abnuerim, &longs;ed de Luna quid? In qua non­nulli ex tuis, etiam in tua hypothe&longs;i, motuum realium inæqualitatem admittunt, propter vnam dumtaxat inæqualitatem men&longs;ium; nempe li­cèt motus inæqualitas in hoc, vel illo arcu orbitæ in meram apparen­tiam, &longs;alva &longs;emper æqualitate reali, refundi po&longs;&longs;it, &longs;i tamen brevior &longs;it vna integra revolutio, quàm alia, realis profectò erit, non verò apparens inæqualitas, &longs;ed hoc non vrgeo contra te, quia eadem vterque difficultate laboramus.

Antim. Nullo negotio præfatam men&longs;ium inæqualitatem in mea hy­pothe&longs;i explico; Cùm Lunæ æquè ac Soli motum &longs;implici&longs;&longs;imum attri­buam ab ortu ad occa&longs;um, cum gemina illa inclinatione, de qua &longs;upra, & hac vna &longs;ingulari differentia, quòd terminus &longs;ecundæ inclinationis in Sole &longs;it Æquator, in Luna verò &longs;it Ecliptica; longioris operæ res e&longs;&longs;et, i&longs;ta fu&longs;iùs pro&longs;equi, præ&longs;ertim cùm appellata men&longs;ium inæqualitas alioquin facilè in hac mea hypothe&longs;i intelligatur: fac enim, v. g. Solem e&longs;&longs;e cir­ca Apogæum, Lunæ conjunctum; Sol tardiùs &longs;uos orbes diurnos ab­&longs;olvit: igitur breviore intervallo Lunam po&longs;t &longs;e relinquit versùs or­tum; vnde nece&longs;&longs;ariò &longs;equitur, copulam deinde tardiùs fieri; vnde men&longs;em illum periodicum longiorem e&longs;&longs;e, nece&longs;&longs;e e&longs;t; contra verò breviorem illum, qui Sole in perigæo exi&longs;tente currit; quod verò &longs;pectat ad men&longs;em periodicum, eam &longs;cilicet temporis periodum, qua Luna ab Occa&longs;u ad Ortum totum Zodiacum decurrere videtur; modò longior, modò brevior e&longs;t, pro diver&longs;o Nodorum &longs;itu; &longs;i enim Nodi exi&longs;tant, in punctis Eclipticæ Æquinoctialibus, haud dubiè Luna &longs;uas &longs;piras agens longiùs versùs Polos excurrit, minùs verò longè Nodis in punctis Sol&longs;titialibus exi&longs;tentibus; &longs;ed quò longiùs excur­rit, plus temporis ponit; Major igitur e&longs;t periodus; quid clarius &longs;upet hoc dici, vel excogitari po&longs;&longs;it, vereor &longs;anè vt qui&longs;piam videat.

Chry&longs;ocom. Mirum mihi accidit, Antime, cur adeò in motuum rea­lium inæqualitatem inveharis, cùm tamen motum vtriu&longs;que inclinatio­nis inæqualem in tuo &longs;y&longs;temate &longs;tatuas; acceleratum &longs;cilicet & retar­datum.

Antim. Hanc in&longs;tantiam facilè &longs;olvere, vel; vt veriùs dicam, eludere po&longs;&longs;em, &longs;i dicerem, e&longs;&longs;e motus rectos, qui ex natura &longs;ua accelerati &longs;unt, vel retardati; nempe vel ad &longs;uum naturalem terminum tendunt, vel ab eo recedunt; &longs;i primum, acceleratos; &longs;i alterum, retardatos e&longs;&longs;e, oportet; &longs;ed hi re verà motus non &longs;unt, qui tantùm con&longs;iderantur in decur&longs;i &longs;patij linea, in qua æqualibus temporibus æqualia &longs;emper &longs;patia à Planeta de­curruntur, licèt inæqualia nobis appareant: & verò æquabilem mo­rum e&longs;&longs;e, nece&longs;&longs;e e&longs;t, cuius æqualis eademque cau&longs;a &longs;emper manet, idem &longs;cilicet impetus, vel initio impre&longs;&longs;us, vel eo, quo dixi modo, acqui­&longs;itus.

Chry&longs;ocom. Nunquid tantulùm &longs;altem retardat medij re&longs;i&longs;tentia, vt in projectis, immò & deor&longs;um cadentibus fieri videmus?

Antim. Certè non retardat, &longs;i medium &longs;imul & Planeta eodem motu moveantur; Sed hoc ad&longs;truere non cogimur, cùm nulla ratio­ne nitatur; medium enim commune e&longs;t; Re&longs;pondeo igitur, cladem illam à re&longs;i&longs;tentia medij acceptam à Planeta continuo re&longs;arciri, vel, vt meliùs dicam, impediri; vt enim iuxta optimum Naturæ in&longs;titutum, impetum non auget, ne &longs;cilicet obtinendo fini adver&longs;etur, ita nec eun­dem impetum minui &longs;init, quod non minùs eidem repugnaret in­&longs;tituto.

Augu&longs;tin. Sed ne totus &longs;is in præludiis, ad tuum illud argumentum con­tra meam hypothe&longs;im à Luna petitum veniendum e&longs;&longs;et.

Antim. His præmi&longs;&longs;is, ad illud venio, ac dico, in tua hypothe&longs;i, realem Lunæ motum, eum &longs;cilicet, qui nobis æqualis ferè apparet, adeò inæqualem fore, vt aliquando infinities tardior aut velocior e&longs;&longs;et.

Augu&longs;tin. Somnia narras, Antime, quis vnquam hoc dixit, vel cogita­vit? Luna circa terram iret, quamvis mobilem, inæquali certè motu, quoad apparentiam, re ip&longs;a tamen ferè æquali; cùm arcus vno die decur&longs;us paucis minutis arcum alio die decur&longs;um &longs;uperet; hæc e&longs;t trita illa anomalia, eaque multiplex in Luna, quam no&longs;tri per excentricos, vel epicyclos, vel circellos explicant; &longs;ed hæc inæqualitas præterquàm quòd apparens, non verò rea­lis e&longs;t tanta, non &longs;tatuitur, ne dum infinita.

Antim. Non &longs;omnio, Augu&longs;tine; nihil dixi, quod demon&longs;trare non po&longs;&longs;im.

Sit enim centrum vniver&longs;i A, in quo Solem &longs;tatuitis; &longs;it arcus magni orbis DB, 29. circiter grad. quem &longs;cilicet terra decurrit, toto illo tempore; quo Luna ab vna copula, ad aliam ve­nit; Sit AD. 2000.Semidiam. terræ DH 60. DB 508.circiter; vnde HD in DB octies fere continetur. Sit au­tem primùm Lunain copula H, vt deinde tran&longs;eat per oppo&longs;itionem G ad &longs;equentem copulam I eo tempore, quo terra decurrit arcum DCB: divi­datur arcus DC in 4.partes æquales DELMC: ita progreditur terra cum Luna, vt terra &longs;itin D, Luna in H ; terra in E, Luna in O; terra in L, Luna in E; terra in M, Luna in P ; terra in C, Luna in G ; codem pro­gre&longs;&longs;ionis ordine terra à C tendit in B, & Luna à G tendit in I. En tibi veram ac germanam lineam Lunaris motus in tua hypothe&longs;i ; eodem por­rò tempore Luna &longs;egmenta HE & EG conficit; vnde vides, quàm &longs;it inæ­qualis motus; & multò majorem inæqualitatis proportionem invenies, &longs;i compares &longs;egmentum HO cum &longs;egmento EP, vel PG; & vt &longs;egmentum HO decurrit Luna, eo tempore, quo primum octantem &longs;uæ periodi, ap­parenti motu decurrere videtur, id e&longs;t 45. grad. &longs;i accipiamus minorem arcum v. g. 12. grad. paulò plùs, qui e&longs;t arcus illius ferè diurnus, et&longs;i com­paremus &longs;patium, quod acquirit intereà, reali motu, tum circa Novilu­nium H, tum circa Plenilunium G, longè maior erit inæqualitatis propor­tio inter illa duo &longs;patia, æqualibus temporibus decur&longs;a, licèt quoad appa­rentiam æqualia &longs;patia videantur. Vnde nece&longs;&longs;ariò &longs;equitur, Lunam inæ­quali motu moveri, reali &longs;cilicet & phy&longs;ico, atque in tanta inæqualitatis pro­portione, vt qualibet a&longs;&longs;ignabili major &longs;it.

Augu&longs;tin. Si nihil aliud habes, hæc minimè nos vrgent; nam &longs;uppo­nimus Lunam moveri in epicyclo, cujus terra centrum e&longs;t, ac proinde Luna movetur motu mixto ex motu orbis & motu centri, vtroque certè æquabili; &longs;ed ex duobus motibus æquabilibus, motum mixtum minimè æquabilem re&longs;ultare mirum dictu non e&longs;t; immo ne&longs;cire non potes, cuili­bet hypothe&longs;i, quæ epicyclos ad&longs;truit, hoc e&longs;&longs;e commune.

Antim. Non dubitabam, quin hæc dicturus e&longs;&longs;es, &longs;ed antequàm vlteriùs progrediar, non admittis, opinor, in Luna realem epicyclum; &longs;i enim realis Epicyclus e&longs;&longs;et, haud dubiè cum &longs;uperficie terræ intra 24.horas &longs;uum orbem ab&longs;olveret, quod certè ab&longs;urdum dictu e&longs;t; cùm decurrat tantùm eo tempo­re 12.gradus paulò plus.

Augu&longs;tin. Accipe quæ&longs;o, totum Sy&longs;tema telluris globi, quod non modò &longs;ublunarem omnem tractum, verùm etiam Lunarem complectitur; finge totum illud ad modum vnius Epicycli, ita tamen, vt globus terræ, & por­tio vicinior circumfu&longs;i ætheris volvatur ab occa&longs;u ad ortum &longs;patio 24.hora­rum, &longs;uperior verò multò tardiùs, & Lunaris tantum gradus eo tempore acquirat, in tanta enim di&longs;tantia, vis rapicis terræ, &longs;i non pror&longs;us evane&longs;­cit, &longs;altem plurimùm remittitur.

Antim. Ingeniosè pror&longs;us; vis enim vim illam motricem à terre&longs;tri glo­bo, ad Lunarem traduci, eamque valde remi&longs;&longs;am, propter di&longs;tantiam, cujus rei analogiam petes in mea quoque hypothe&longs;i, a Iove, qui quatuor Lunas &longs;ecum ita volvit, immò & à Sole qui Venerem & Mercurium &longs;ecum in or­bem agit; &longs;ed vt duo &longs;unt motus in terre&longs;tri globo, centri &longs;cilicet, atque or­bis, cur debilitatur vis motrix in Lunam traducta à motu orbis, intacta re­manente traducta à motu centri, vtramque enim, vel neutram di&longs;tantia æquè debilitat.

Augu&longs;tin. Si fingas totum illud Sy&longs;tema vtroque motu moveri, fieri non pote&longs;t, quin motus centri toti &longs;y&longs;temati communis &longs;it, atque adeò omnes &longs;y&longs;tematis partes per &longs;e illo motu æquè moveantur, licèt aliquæ plus, aliæ minùs propter motum orbis.

Antim. Fingo facilè totum illud &longs;y&longs;tema ad in&longs;tar &longs;phæræ, cujus majo­rem tantùm circulum accipio, qui &longs;it ad in&longs;tar epicycli ; &longs;ed cùm retardetur motus orbis propter di&longs;tantiam, non video, cur propter eandem non re­tardetur etiam motus centri; & verò, &longs;i &longs;olida quæpiam e&longs;&longs;et partium hu­jus &longs;y&longs;tematis inter &longs;e connexio, optimè intelligerem, quomodo vterque motus omnibus communicetur; &longs;ed hoc po&longs;ito, æquè citò omnes motum orbis ab&longs;olverent; &longs;ed cùm hæc &longs;olida connexio non &longs;it, quid mirum. &longs;i vter­que motus tum orbis, tum centri communicetur.

Chry&longs;oc. Vnum tibi facilè &longs;uggererem, quod ad rem præ&longs;entem pluri­mùm facit; nempe &longs;i motus orbis à globo terre&longs;tri in Lunarem traducitur; igitur hic motus Lunæ versùs ortum iret per arcus parallelos circulis diur­nis, &longs;imilis enim terræ motus &longs;imilem produceret; cùm tamen orbita Lu­næ non modò Æquatori parallela non &longs;it, &longs;ed nequidem Eclipticæ; ac­cedit quod totum illud &longs;y&longs;tema modò ad Au&longs;trum, modò ad Boream cum terre&longs;tri globo librari deberet, hoc enim &longs;it in terre&longs;tri globo ad retinen­dum axis paralleli&longs;mum; quare cùm non videatur quomodo Lunæ motus à telluris motu profici&longs;ci, vel traduci queat dicerem potiùs, (in ante­riori Schemate) Lunam ab Angelo ita moveri ab&longs;que epicyclo; quia revera nullum videmus epicyclum, idque per lineam curvam HE PGFI.

Augu&longs;tin. Ab Angelo igitur inæquali motu reali movetur; & hoc ip&longs;um e&longs;t, quod ip&longs;e Antimus intendit, & opponit contra meam hypothe&longs;im ; hoc autem argumentum eju&longs;dem pror&longs;us e&longs;t energiæ, &longs;ive dicatur Luna moveri ab Angelo per lineam HPG, &longs;ive à &longs;e ip&longs;a.

Antim. Cùm ergo ita reverà moveatur per lineam HPG, motus illius, realis &longs;cilicet, omnino inæqualis e&longs;t, vt iam dixi.

Augu&longs;tin. Ille motus, qui fit per lineam HPG mixtus e&longs;t ac proinde inæqualis, &longs;ed ex duobus æquabilibus, vt iam dixi.

Antim. Vnde porrò &longs;unt illi duo motus æquabiles' à quo principio? & quo tandem organo traducuntur?

Augu&longs;tin. Affulget novæ lux re&longs;pon&longs;ionis; &longs;uperficies terræ inæquali­ter movetur, etiam in eodem circulo majore ; nempe ille arcus, qui ad Solem convertitur, tardi&longs;&longs;imus e&longs;t, oppo&longs;itus verò veloci&longs;&longs;imus, quid mi­rum igitur, &longs;i hic Lunam longiùs promovet, &longs;cilicet circa Plenilunium, ille verò longè minùs, &longs;cilicet circa Novilunium.

Antim. Non negarim, acutam, & non nemini fortè inexpectatam re­&longs;pon&longs;ionem; &longs;ed præterquam quod &longs;ub&longs;i&longs;tunt alia &longs;upra oppo&longs;ita; quia nec in arcubus, diurnis circulis parallelis Luna movetur, non videtur, cur mo­tus centri in Lunam traductus debilior non exi&longs;tat.

Augu&longs;tin. Miror, hæc à te dici, cùm vterque debilior exi&longs;tat, vt mani­fe&longs;tum e&longs;t; &longs;ic enim ab H ad O parum progreditur, tum motu centri, tum motu orbis; igitur à puncto terræ oppo&longs;ito &longs;uam vim accipit, majorem &longs;cilicet, cùm velociùs illud movetur, quamvis alioquin motu mixto; mi­norem verò cùm tardiùs, quid ad aliud de arcubus parallelis re&longs;pondeam, non habeo, ni&longs;i fortè dicam, Lunam à &longs;e ip&longs;a, vel ab Angelo per illam or­bitam moveri: Sed cur per illam movetur inæqualiter? deinde hæc orbita re&longs;pectum habet ad terram, quæ in &longs;ua libratione diver&longs;am periodum ha­bet, malim ergo ingenuè fateri, me ne&longs;cire, quid ad hoc re&longs;pondeam.

Antim. Re&longs;umo quod &longs;upra dicere cœperam; præter illa argumenta, inquam, quibus allata re&longs;pon&longs;io non congruit, dico aliam eamque in&longs;o­lubilem re&longs;tare difficultatem; admi&longs;&longs;a enim prædicta re&longs;pon&longs;ione, fateris in puncto G majorem vim impetus à puncto terræ oppo&longs;ito Lunam ac­cipere, minorem verò à puncto H, cur ergo Luna impre&longs;&longs;um impetum deinde non retinet? cum nihil &longs;it à quo de&longs;truatur; nec enim ob&longs;tat, à novo puncto terræ oppo&longs;ito ad aliam tangentem determinari, quia cùm hoc fiat per novi impetus acce&longs;&longs;ionem, hic aditus priori majorem vim facit; igitur nulla e&longs;&longs;et ratio, cur deinde motus retardaretur versùs Qua­draturas.

Chry&longs;oc. Vereor, vt inde qui&longs;piam cau&longs;am deducat, rei mi&longs;&longs;ionis marini æ&longs;tus in Quadratoris; nempe, vt in Oppo&longs;itione vegetior e&longs;t, ita in Quadra­turis minor e&longs;t & flaccidior; quia, inquiet, cùm à Luna procedat, Lunæ motus in plenilunio maior e&longs;t, minor in Quadraturis; minorem igitur in his, majorem in illo motus effectum producit.

Augu&longs;tin. Sed in Novilunio Lunaris motus adhuc minor e&longs;t, quam in Quadraturis, & tamen nemo ne&longs;cit, æ&longs;tum in Novilunio majorem e&longs;&longs;e; alia igitur ratio prædictæ differentiæ inve&longs;tiganda e&longs;t.

Chry&longs;ocom. Aliud in mentem venit, quod expromendum e&longs;&longs;e puto; nempe &longs;i &longs;upponam Lunam 24. horarum &longs;patio orbem &longs;uum circa terram ab&longs;olvere, illius velocitas ad velocitatem puncti æquatoris in &longs;uperficie terræ erit vt 60.ad 1.&longs;unt enim motus vt circuli, hi vtrò, vt &longs;emidiametri; igitur non mirum e&longs;t, cùm motus tardus velocem producere nequeat, &longs;i Luna longè tardiùs à terre&longs;tri globo circumagitur.

Antim. Neque hoc &longs;ufficit; quia cùm vnus motus alium æqualem ad &longs;ummum producere po&longs;&longs;it, e&longs;to terræ motus æqualem Lunæ imprimat, hic erit illius quo Luna 24.horarum tempore ab&longs;olveret circulum con­&longs;ectis 360. grad. igitur erit tantùm 6. graduum; &longs;ed e&longs;t 12.grad. diurnus &longs;cilicet; aliunde igitur cau&longs;a hujus motus petenda e&longs;t: &longs;ed nulla e&longs;&longs;e po­te&longs;t, ni&longs;i hic motus inæqualis &longs;upponatur; igitur ex hoc etiam capite i&longs;ta hypothe&longs;is terræ mobilis non &longs;ub&longs;i&longs;tit, quia &longs;cilicet in ea motus realis in­æqualis per&longs;o e&longs;&longs;et.

Augu&longs;tin. Eadem difficultate tua laborat hypothe&longs;is, in qua Lunaris motus &longs;ine vno &longs;altem epicyclo explicari nequit.

Antim. Nullum Epicyclum pono n pro reali motu explicando; pro ap­parenti verò vtcumque, &longs;implicem dumtaxat motum admitto, ab ortu ad occa&longs;um, longè tamen tardiorem motu Solis, ita vt &longs;ingulis men&longs;ibus Sy­nodicis Sol Lunam a&longs;&longs;equatur, atque adeò h num integrum circulum &longs;u­pra illam acquirat; adde vtramque inclinationem, quâ &longs;cilicet tum ab Apogæo ad Perigæum & vici&longs;&longs;im, tum à Borea ad Au&longs;trum, & vici&longs;&longs;im Planeta librari videtur; vtriu&longs;que tamen periodus in Luna diver&longs;a e&longs;t à Solari; vnde Lunæ Apogæum recurrit frequentiùs; præterea Lunæ &longs;ecun­da inclinatio habet pro termino Eclipticam, vt jam dixi; anomaliæ primæ, &longs;eu periodicæ ratio eadem e&longs;t, quæ anomaliæ Solaris; neque hîc repeto, quæ jam dixi in alio congre&longs;&longs;u; quod verò pertinet ad aliam inæqualita­tem, vel anomaliam &longs;ynodicam, vt vocant. in mea hypothe&longs;i, facilè ratio redditur multiplicis inæqualitatis, quam huc v&longs;que, vt verum fatear, non­dum accuratè indagarunt A&longs;tronomi, nedum &longs;tatuerunt; hinc vnus negat, quod alius ad&longs;truit; &longs;cilicet eò qui&longs;que dumtaxat &longs;pectat, vt ob&longs;ervatio­nes ad Sy&longs;tematis excogitati formam accommodet; &longs;ed hæc fu&longs;iùs di&longs;cu­tere huius loci non e&longs;t; hoc tantùm indica&longs;&longs;e contentus, ex diver&longs;o Lu­næ &longs;itu, multiplicem inæqualitatem, apparentem &longs;cilicet, eamque variam &longs;equi po&longs;&longs;e: vtrùm verò Lunæ apogeæ di&longs;tantia maior &longs;it in quadraturis, quàm in copulis, & perigeæ minor, non de&longs;unt, etiam inter principes A&longs;tromos, qui negent: & verò punctum ac momentum veræ ac germa­næ quadraturæ vix di&longs;cerni pore&longs;t, maximè intra &longs;patium duorum vel qua­tuor graduum; de Latitudine Lunæ nihil dico; cùm eam nullo negotio explicemus; itemque Nodorum motum in antecedentia; quia citiùs &longs;ecun­dæ inclinationis motus perficitur, quàm motus in Zodiaco; vnde nece&longs;­&longs;ariò &longs;equitur motus Nodorum apparens contra &longs;eriem Signorum; motus apogæi etiam apparens eodem modo explicatur, quo jam in Sole illum explicuimus; itemque eorundem motuum inæqualitas, &longs;uppo&longs;ito motu reali æquabili&longs;&longs;imo; & vbi certæ omnino & in omnibus con&longs;entientes ob&longs;ervationes aliquando definientur, nullus dubito, quin ex jactis princi­piis facilè in hac no&longs;tra hypothe&longs;i explicentur, quod tamen modò fieri ne­quit, cùm multa etiamnum incerta maneant, & vix de Apogæo con&longs;tet, vbi &longs;it, & qualis &longs;it excentricitas, an hæc &longs;emper eadem &longs;it; di&longs;tantia verò Lunæ maxima, etiam incerta e&longs;t.

Augu&longs;tin. Probè intelligo tuum &longs;y&longs;tema Lunare; vis enim Lunam &longs;im­plici motu moveri ab Ortu ad Occa&longs;um, &longs;ed longè tardiùs, quàm &longs;tellas; ita vt intra tempus vnius men&longs;is periodici Luna à Stellis retro relicta ver­sùs Ortum, videatur totum Zodiacum percurrere, & ad idem punctum redire; & quia Sol toto eo tempore versùs Ortum relictus e&longs;t, qua&longs;i 27. grad. antequam ad copulam Luna redeat, duobus diebus & aliquot horis opus e&longs;t: hunc men&longs;is Synodicus longior periodico; addis vtriu&longs;que incli­nationis motum, ita vt &longs;ecundæ terminus &longs;it Eclyptica; & quia motus &longs;e­cundæ ab&longs;olvitur paulò ante finem periodici, hinc motus Nodorum ver­sùs Occa&longs;um, itemque Apogæi versùs Ortum; quia periodus intra quam Luna redit ad Apogæum, paulò longior e&longs;t men&longs;e periodico: inæqualitas &longs;implex eodem modo à te explicatur in Luna, & in Sole; aliæ ex diver&longs;a combinatione vtriu&longs;que inclinationis na&longs;cuntur: Latitudinem per motum &longs;ecundæ inclinationis facilè omninò explicas, Vtrùm verò major &longs;it Lati­tudo in Quadraturis, quàm in Copulis, incertum putas, itemque multa alia incerta, quæ &longs;upra obiter recen&longs;ui&longs;ti; optimè demum explicas, quomodo men&longs;es Periodici modò majores &longs;int, modò minores, itèmque Synodici, men&longs;es enim Periodici majores &longs;unt, quando Nodi &longs;unt circa Æquato­rem, minores verò, quando &longs;unt circa Tropicos; Synodici autem majores &longs;unt, dum Sol e&longs;t circa Apogæum, dum verò circa Perigæum minores; neque in his vlla re&longs;tat difficultas; vnum tantùm ex te re&longs;cire velim, Anti­me, quid cen&longs;eas de libratione illa Lunari, qua &longs;it, vt quædam interdum maculæ ad margines di&longs;ci Lunaris propiùs accedant, aliàs, ab iis longiùs recedant.

Antim Hevelio fideli&longs;&longs;imo & accurati&longs;&longs;imo Lunarium Phænomenon ob&longs;ervatori, in his detrectari fidem, non au&longs;im ; hic autem vult, Lunam ita librari, vt cùm maximè ab Æquatore declinat, versùs Boream, macu­læ Boreales in ejus di&longs;co recedant à margine, Au&longs;trales contra ad margi­nes accedant; & vici&longs;&longs;im cùm maximè declinat versùs Au&longs;trum, au&longs;tra­les recedant, accedant verò Boreales. Nonnulli ex ve&longs;tris, Augu&longs;tine, &longs;ta­tuunt ad hunc finem, Lunarem axem &longs;ibi ip&longs;i parallelum, & Axi mundi; &longs;ed meo judicio perperam &longs;atis, dum enim versùs Tropicum Cancri acce­dit Luna, extremitas Borealis axis attolleretur, vt patet, igitur & Semicir­culus di&longs;ci Borealis, & Au&longs;tralis de primeretur; ex quo contraria Phænome­na &longs;equerentur; Malim dicere Lunarem Globum magnetica for&longs;an virtute pellere, ac proinde habere duos polos magneticos; igitur codem pror&longs;us modo &longs;e&longs;e componit ad terre&longs;trem Globum, quo terrella quæpiam, vel acus magnetica; igitur quando Luna versùs Boream tendit ab Æquatore, extremitas borealis axis deprimitur, Au&longs;tralis verò attollitur, & vici&longs;&longs;im; cùm Luna ab Æquatore versùs Au&longs;trum excurrit; Au&longs;tralis deprimitur, Borealis attollitur, ex quo prædicti effectus nece&longs;&longs;ariò con&longs;equuntur.

Chry&longs;ocom. Parum admodùm abe&longs;t, quin hoc apprimè capiam; nonni­hil &longs;chematis de&longs;iderarem, vt hoc meliùs inculcetur

Augu&longs;tin. Id mihi præ&longs;tandum &longs;u&longs;cipio: &longs;it meridianus Lunaris SBTK, Axis magneticus BK, &longs;emicirculus ad terram conver&longs;us BSK, qui in di&longs;co Lunari apparet projectus in BK; lineæ vi&longs;uales BO, SP, KR, quas exhibeo parallelas, propter anguli tenuitatem; &longs;it A in Æquatore,

Axis BK &longs;ecat Æquatorem ad an­gulos rectos; &longs;i verò A &longs;it in Tro­pico Cancri, punctum B deprimitur in G, & K attollitur in H ; Hinc ante depre&longs;&longs;ionem macula E videbatur in C, igitur vicina margini, N verò in L. remota igitur à margine; at verò po&longs;t depre&longs;&longs;ionem dicti Axis Macula E erit in F, ac proinde vide­bitur in D: igitur recedit à margi­ne; at verò N erit in M ; igitur vi­debitur in I; accedit igitur ad mar­ginem; hæc adeò per&longs;picua &longs;unt, vt nihil clariùs dici, vel excogitari po&longs;&longs;e videatur. Vnum tamen dubium re­&longs;tat de fide &longs;cilicet Hevelij, cùm non defuerit, qui dictam fidem pror&longs;us elevarit, adductis ob&longs;ervationibus omnino contrariis.

Antim. Scio, non defui&longs;&longs;e; Hevelio tamen adhærendum, eique fi­dem habendam e&longs;&longs;e, putarem, præ&longs;ertim cum nonnulla ex iis, quæ con­tra illum adducuntur, minimè &longs;ub&longs;i&longs;tant; Sed hæc di&longs;cutere non vacat; Vt vt &longs;it, &longs;uppo&longs;ita veritate dictorum Hevelij. con&longs;tat rationem huius librationis à me allatam per&longs;picuam e&longs;&longs;e; &longs;i res &longs;ecus &longs;e habeat, vt mihi, Augu&longs;tine, non nocet, ita tibi nullo modo prode&longs;t. Sed iam ad alias ratio­nes veniamus.

Chry&longs;oc. Re&longs;tat, Antime, vt ad alios cœle&longs;tes globos gradum facias, in quo lepidi&longs;&longs;imum itineris extatici autorem imitari cuipiam fortè videberis; quod ne&longs;cio an Copornicanis metuendum &longs;it.

Antim. Ne timeas, Chry&longs;ocome, &longs;i&longs;temus gradum in terra, nec de Ve­nere quidquam a&longs;truam, ni&longs;i quod omnes facilè probare po&longs;&longs;int; Dico igitur iuxta Copernicanam hypothe&longs;im, Venerem tam propè ad nos acce­dere, circa conjunctionem &longs;cilicet ve&longs;pertinam, & tam procul abe&longs;&longs;e, circa matutinam, vt eius diameter vna vice &longs;eptuplo ferè major, quàm alia videnda &longs;it; quod vt in facili Schemate o&longs;tendam.

Sit (in &longs;eq.Fig.) Sol in A immobilis; &longs;it magnus orbis, in quo movetur terrá BCDE, &longs;int diametri BD, CE, &longs;itque angulus ABC grad 47. & &longs;uppo­natur maxima digre&longs;&longs;io Veneris à Sole; ducatur AF perpendicularis in BC, & &longs;ub radio AF de&longs;cribatur circulus FGHIK, hic erit orbis Veneris; igitur Perigæum Veneris erit in K, po&longs;ito quod terra &longs;it in B; Apogæum verò in H cuncta hæc pro conce&longs;&longs;is habeo; licèt Perigæum aliquando propiùs accedat ad B, tum quia interdum major e&longs;t Veneris digre&longs;&longs;io; tum etiam quia moveri cen&longs;etur in excentrico,; igitur cum &longs;imul e&longs;t in aphelio & Perigæo, propiùs ad B haud dubiè accedit. Sit ergo in K, citra acura-tiores calculos, dico, KB e&longs;&longs;e totius BH, paulo plus; igitur propter parvitatem anguli, cùm linea recta pro arcu accipi po&longs;&longs;it, Veneris diame­ter in K videtur Sexcupla illius, quæ videtur in H &longs;unt enim anguli vt di&longs;tantiæ permutando, acuti&longs;&longs;imi &longs;cilicet, qualem hoc loco con&longs;idera­mus: &longs;ed profectò nemo vnquam vidit Venerem perigæam quadragecu­plam apogææ.

Augu&longs;tin. Miror, hæc à te dici, qui per&longs;picillorum majorum &longs;atis, opi­nor, peritus es; illius &longs;altem amicus & familiaris, qui præ cæteris optima & longi&longs;&longs;ima fabricat; Galileus &longs;uo tubo&longs;picillo in&longs;tructus, argumentum à te propo&longs;itum jam olim diluit, vt pote qui omnino comperit, Venerem perigæam quadragecuplam apogææ, etiam mediocris tele&longs;copij operâ vi­deri, vt non &longs;emel ip&longs;e typis mandavit.

Antim. Sciò, hoc a&longs;&longs;ertum ab eo fui&longs;&longs;e; &longs;ed miror, à nemine, &longs;altem quod &longs;ciam, in dubium vocatum.

Augu&longs;tin. Quis amabò hac de re dubitaret, & fidem huic homini detre­ctaret, qui tam multa in cæle&longs;ti regione à &longs;e primùm explorata &longs;ub a&longs;pe­ctum mortalium adduxit, quique &longs;uo tempore, optima omnium vitra tor­nari & componi curavit.

Antim. De his non di&longs;puto, nec quidquam de cuiu&longs;piam laude velim detractum, dico tamen, me optimis alioquin tele&longs;copiis v&longs;um, nunquam Venerem perigæam quadragecuplam apogææ vidi&longs;&longs;e; Non nego per&longs;pi­cilla Galilei eximia fui&longs;&longs;e, &longs;ed longè iis breviora, quibus v&longs;us &longs;um; negari profectò non pote&longs;t, quin vir præ&longs;tanti&longs;&longs;imus Eu&longs;tachius Divinus prædi­ctam fabricandorum tele&longs;copiorum artem eò adduxerit, quò illam nemo hactenus adduxit; itaque optimo vtor tele&longs;copio, quò Venerem perigæam majorem quidem apogæa video, non tamen quadragecuplam; ad omnium oculos provoco.

Chry&longs;ocom. In qua proportione majorem diametrum perigææ vides?

Antim. Plu&longs;quam &longs;excuplam videre deberem; at non dicam &longs;excuplam, aut quintuplam triplá non video; & hinc nece&longs;&longs;aria con&longs;equutione deduco, Copernicanam hypothe&longs;im corruere, in qua nece&longs;&longs;e e&longs;t, diametrum Vene­ris perigeæ plu&longs;quam &longs;excuplam videri diametri eiu&longs;dem apogeæ.

Chry&longs;oc. Tantulum &longs;chematis de&longs;iderarem; licèt enim multam fidem tibi habeam, mens tamen maximè recreatur, &longs;i eadem quæ aure accepimus oculorum etiam te&longs;timonio confirmentur.

Augu&longs;tinus. Antimum ab hoc onere levabo; Sit AF radius partium 100000. & angulus ABF 47. graduum, tanta enim e&longs;t plerumque maxima Veneris digre&longs;&longs;io; erit &longs;ecans AB 136733. igitur tota BH 236733. & KB 36733. igitur KB e&longs;t ad BH vt vnum ad 6. paulò plus.

Sit autem quælibet linea P. ad MQ, vt vnum ad a&longs;&longs;umatur quæli­bet diameter PN quæ videatur et M &longs;ub angulo NMP, tum eadem &longs;ta-tuatur in QL ducaturque ML &longs;ecans PN in D, haud dubiè erit PO, ad QL, vel PN, vt MP ad MQ, id e&longs;t vt 1.ad 6. &longs;ed angulus LML, vel OMP e&longs;t ad angulum NMP, vt PO, ad PN, nempe in acuti&longs;&longs;imis angu­lis, qualis &longs;upponitur is, &longs;ub quo videtur Veneris diameter, arcus &longs;unt ad &longs;en&longs;um vt tangentes; igitur angulus OMP e&longs;t ad angulum NMP vt 1. ad 6. cùm igitur Veneris di&longs;tantia minima &longs;it ad maximam, vt vnum ad 6 ejus diameter apparens in ininima e&longs;t ad apparentum in maxima vt NP ad PO, id e&longs;t vt 6 paulò plus ad igitur di&longs;cus Veneris perigeæ appatens e&longs;t ad di&longs;cum apogeæ vt 40.ad 1.& re ip&longs;a talem e&longs;&longs;e Coperni­canæ &longs;ententiæ defen&longs;ores pronunciant.

Chry&longs;oc. Cur appellas Copernicanæ &longs;ententiæ defen&longs;ores? alios etiam appellare debueras, cùm etiam ex Tychonico &longs;y&longs;temate eadem pror&longs;us diametrorum apparentium ratio, &longs;eu proportio con&longs;equatur.

Fac enim terram e&longs;&longs;e immobilem in B, Solemque per orbem ANML ire, ac &longs;ecum deferte centrum epicycli Veneris; hauddubie Venus erit perigæa in K, apogæa in H.

Antim. Hoc ip&longs;um in primo no&longs;tro congre&longs;&longs;u à quo aberas, Chry&longs;oco­me, indicatum à me &longs;uperat, vt videte e&longs;t, in V.figura, & ideò non circularem epicyclum de&longs;crip&longs;i nec etiam ellipticum, &longs;ed &longs;pital: quadam, &longs;eu qua&longs;i pa­rabolica linea terminatum ab apogæo ad maximam digre&longs;&longs;ionem, & hinc ad perigæum alia curva ad rectam proxime accedente: porrò no&longs;tro &longs;y&longs;temati quælibet diametrum apparentium proportio convenire pote&longs;t.

Augu&longs;tin. Habe bis omnes A&longs;tronomos tibi refragantes, non &longs;olùm illos, qui Copernico adhærat, verùm etiam omnes propemodùm alios, immo ex tuis non de&longs;unt viri docti&longs;&longs;imi, & cœle&longs;tium ob&longs;ervationum periti&longs;&longs;imi, qui non modò Veneris perigææ dictum quadragecuplo, &longs;ed etiam quinquagecuplo & vltra majorem e&longs;&longs;e, quàm apogææ liberè pro­nunciant.

Antim. Quid faceres? meis oculis fidem detractam non po&longs;&longs;um, optimum tele&longs;copium adhibui; longè tamen minorem proportionem inæqualitatis e&longs;&longs;e comperi, quanquam &longs;ententiarum diver&longs;itas etiam inter Principes A&longs;tronomiæ multam mihi hac de re &longs;u&longs;picionem injicit, quorum aliqui Veneria perigææ diametrum 7.minut.e&longs;&longs;e volunt, alij 4. alij 3.2.alij demum 1. eadem diver&longs;itas diametrorum apparentium Mercurij, Martis & Iovis apud eo&longs;dem Autores ob&longs;ervatur. Sed, inquiet aliquis, ob&longs;er­vationes meæ accuratiores &longs;unt, idem alius de &longs;uis &longs;entiet; Vt vt &longs;it ad om­nium oculos provoco, nam &longs;æpè ac &longs;æpiùs Venerem a&longs;pexi, non procul à perigæo, &longs;cilicet paulo ante, vel paulò po&longs;t conjunctionem ve&longs;pertinam, diver&longs;is etiam modis adhibitis, nunquam tamen illius di&longs;cum quadrage­cuplum comperi, illius quem in eadem non procul ab apogæo &longs;ita ob&longs;er­varam, &longs;ed longè minorem; idem de Mercurio perigæo, quem nunquam octuplum apogæi, idem de Marte, quem nunquam &longs;exagecuplum, multò minùs octoge cuplum aut nonagecuplum ob&longs;ervare potui, Nihil &longs;anè docti&longs;&longs;imorum hominum ob&longs;eruationibus & fidei detractum velim; &longs;ed igno&longs;cant, &longs;i oculis meis plus tribuam; vereor autem vt aliqui, vt &longs;y&longs;temati á &longs;e fabri­cato, aut reformato meliùs con&longs;ulant, ex paucis ob&longs;ervationibus, ii&longs;que præ­&longs;ertim, quoad minuta &longs;altem &longs;ecunda, fallaciæ haud parum obnoxiis, ea nonnunquam ad&longs;truant, quæ dubito, an reliquis deinde ob&longs;ervationibus &longs;ubjaceant. Vnum deinde in Venere notatu dignum e&longs;&longs;e puto, eam &longs;cilicet, cùm circa perigæum vel apogæum ob&longs;ervatur, non procul abe&longs;&longs;e ab ho­rizonte, ac proinde non modicam radios vi&longs;uales refractionem pati. quæ hauddubie apparentem illius diametrum variabit; de&longs;iderandum, vt Ve­nus &longs;ub Solis di&longs;cum aliquando veniret, tunc enim exceptis trajecti&longs;que radiis &longs;olaribus tele&longs;copio, nec non projectis in planum directè oppo&longs;itum, vel ip&longs;is oculis ratio diametrum Veneris ad diametrum Solis &longs;ub­jiceretur.

Augu&longs;tin. Libenter ex re re&longs;cirem vtrùm &longs;it aliquod Veneris phœnome­non; quod in tua hypothe&longs;i explicari non po&longs;&longs;e putes.

Antim. Vix crediderim vllum e&longs;&longs;e; de certis enim loquor & indubi­tatis; nempe: modò &longs;upponam. Venerem &longs;implici motu moveri ab ortu ad occa&longs;um, eoque æquabili&longs;&longs;imo, cum illa duplici inclinatione, itus ac re­ditus reciproci, ad in&longs;tar motus accelerati & retardati; prima quidem ab Apogæo ad di&longs;tantiam mediam, eandem curn di&longs;tantia media Solis, & hinc ad Perigæum, ita vi Venus infra mediam di&longs;tantiam orbem &longs;uum i&longs;ochro­non cum Sole perficiæ ; Secunda verò ab eo latitudinis puncto, in quo fuit, antequam motu circulari moveretur ad Eclipticam, eo modo, quo iam &longs;upra dictum e&longs;t.

Augu&longs;tin. Qua quæ&longs;o linea, curva an recta? deinde an perpen­diculariter cadente in planum Eclipticæ? an verò in planum Æqua­toris?

Antim. Ad vtrumque re&longs;pondeo; ad primum quidem, per curvam fieri;

vt dixi de Sole v.g. per arcum D. F, vt eandem retineat à centro mundi di&longs;tantiam, vi &longs;cilicet hujus motus, &longs;eu inclinationis; quænam verò &longs;it accelerationis ratio à D ver­sùs F, iam &longs;upra indicavi. Suppone horizontale planum AF & &longs;uperfi­ciem &longs;phæræ inclinatam DF, in qua de&longs;cendat corpus grave motu accelerato, hæc e&longs;t accelerationis progre&longs;&longs;io; quæ in &longs;ecundam incli­nationem apprimè quadrat; quænam porrò & qualis &longs;it hæc progre&longs;&longs;io motus accelerati, altioris e&longs;t indagi­nis; Licèt enim eadem non &longs;it cum illa, quam &longs;ervant funependula in de­&longs;cen&longs;u, ab ea tamen petenda e&longs;t; Vt vt &longs;it, hæc di&longs;cu&longs;&longs;io hujus no&longs;tri in&longs;tituti non e&longs;t, ad &longs;ecundum re­&longs;pondeo, Lineam illam cadere per­pendiculariter in planum Æquato­ris, nempe determinatur à Plano cir­culi parallelo Plano Æquatoris, eius tamen terminus e&longs;t Ecliptica, vt di­xi; nempe Plánetæ hinc terram a&longs;pi­ciunt, cui &longs;erviunt, lumenque refun­dunt; inde verò Solem, &longs;ub primo re&longs;pectu, &longs;uos orbes agunt circa­terram, tanquam circa &longs;uum centrum; &longs;ub alio verò, Solis &longs;equun­tur ve&longs;tigia, qui cùm ab Ecliptica nunquam di&longs;cedat, hic &longs;olus circulus &longs;ecundam inclinationem Planetarum tanquam terminus determinat. Ex his autem per&longs;picuas rationes reddo, in mea hypothe&longs;i, acceleratio­nis, retardationis, retrogre&longs;&longs;ionis, &longs;tationis, Nodorum motus, itemque Apogæi & Perigæi, variæ digre&longs;&longs;ionis & latitudinis, vt jam &longs;upra indicavi­mus.

Chry&longs;oc. Antequam alia argumenta expromas, per te mihi liceat, Antime, vnum quidpiam, quod jam in mentem venit, breviter expo­nere; &longs;cilicet in Copernicana hypothe&longs;i, cuncta fetè gratis, vt aiunt, & ad nutum con&longs;truentis ad&longs;trui, id e&longs;t &longs;ine vlla cau&longs;a, vel ratione, quæ hoc, vel illud fieri po&longs;tulet; v.g. terram moveri volunt in excentrico; cur amabò circa illud centrum potiùs quàm circa aliud? Cur non circa Solem, qui e&longs;t in Mundi centro? aut &longs;i vis, moveri in Eclip&longs;i, cur hanc adhibes po­tiùs quàm aliam? cur Sol in hoc. vmbilico, non verò in alio, vel in ip&longs;o ellip&longs;eos centro? deinde cur & vnde movetur Apogæum? cur in con&longs;equentia potiùs quàm in antecedentia? cur terra ab occa&longs;u ad ortum, tum motu centri, tum etiam orbis &longs;ecundùm hemi&longs;phærium à Sole aver&longs;um? cur per Eclipticam cum tanta declinatione ab Æquatore? vnde etiam motus orbis annuus diurno contrarius? denique vnde ip&longs;a vertigo Solis? cur tanta, non major aut minor? Cuncta hæc, aliaque ; fortè &longs;imilia &longs;ine vlla ratione vel cau&longs;a exi­gente Copernicana hypothe&longs;is habet, eo tantùm nomine, quod ad &longs;alvan­da phænomena, nece&longs;&longs;aria e&longs;&longs;e credantur, quæ tamen alio modo &longs;alvari po&longs;&longs;unt.

Augu&longs;tin. Par pari haud dubiè referre po&longs;&longs;um: nunquid enim hæc ead&etail;m in ve&longs;tra hypothe&longs;i ad &longs;alvanda phænomena gratis & ab&longs;que alia cau&longs;a non a&longs;truuntur? nunquid non poniti sex centricos, epicyclos, Apogæi Nodorum­que motum?

Chry&longs;ec. Scio, à multis in no&longs;tra hypothe&longs;i, hæc gratis ad&longs;trui; Anti­mus tamen no&longs;ter, vt jam non &longs;emel audii&longs;ti, vno &longs;implici motu æqua­bili, & gemina inclinatione illa omnia explicat, & ad &longs;uas cau&longs;as re­ducit.

Antim. Tuo illo argumento, Chry&longs;ocome, contra Copernicum non &longs;e­mel v&longs;us &longs;um, re tamen paulò accuratiùs con&longs;iderata, illæ rationes, quæ meo &longs;y&longs;temati favent, pro explicatione illorum capitum, quæ &longs;upra recen&longs;ui&longs;ti, ad Copernicanum facilè traduci po&longs;&longs;unt, & pro illo æquè militant.

Augu&longs;tin. Magno certè beneficio me tibi ob&longs;tringes, &longs;i rem hanc me do­cueris, quæ certè quanti momenti futura &longs;it, vix dici à me pote&longs;t; &longs;i enim Keplerus pro metis nugis & fabulis, in quibus cau&longs;as phy&longs;icas cæle&longs;tium phænomenon collocabat, tantom gloriam apud omnes obtinuit; quid de illo faturum putas, qui veras eorundem cau&longs;as in hac hypothe&longs;i Copernici ad duxerit? inde &longs;altem maxima tua ingenuitas con&longs;picua & palam fiet cùm vel no&longs;ti arma porrigas, quibus &longs;e defendat.

Antim. Libenter faciam; nec enim in hi&longs;ce di&longs;&longs;ertationibus literariis, ali­quorum dolus mihi probatur, qui ea celant adver&longs;arium, quæ illius cau&longs;æ &longs;uffragantur; mihi &longs;anè &longs;ecus agendum e&longs;&longs;e puto. Itaque &longs;upponamus So­lem in centro mundi A &longs;tabulari, terram in apogæo C.circulum CHFP in plano Eclipticæ, per quem terræ centrum moveretur à C in N, quod vocamus in con&longs;equentia Signorum, &longs;i e&longs;&longs;et in mediocri, vel | connaturali di&longs;tantia; &longs;ed quia ab Apogæo ad mediocrem di&longs;tantiam tendit, &longs;en&longs;im motu accelerato accedit versùs A, &longs;imulque, tendit motu circulari ver&longs;us H, vnde non movetur per arcum CH, &longs;ed per alium CG ; &longs;upponamus autem AG e&longs;&longs;e mediocre di&longs;tantiam; in ea non &longs;i&longs;tit; &longs;ed motu retardato progreditur vltrà versus Peri­gæum; & quia rece&longs;&longs;us à mediocri' di&longs;tantia æqualis e&longs;t acce&longs;&longs;ui, æquali tem­pore decurret arcum GE, atque ita erit Perigæum in E, ex quo pari modo pervenit in I, nam AI e&longs;t mediocris di&longs;tantia, reditque per i&longs;ochronum rece&longs;&longs;um, ad Apogæum C; &longs;ive autem arcus CGE &longs;it &longs;emicirculus, vel &longs;piralis, &longs;ive etiam ellip&longs;is, cogita punctum C accedere ad R motu acce­lerato per radium AC eo tempore quo radius AC circa centrum A in eodem plano ductus pervenit in AG, ferens &longs;ecum punctum illud mobi­le, quod tunc erit in G ; deinde idem punctum moveatur motu retardato

ab R in D, dum prædictus codem motu pervenit in AE, tunc certè præ­dictum punctum erit in E &longs;cilicet in Perigæo ; quare hæc linea erit vna ex &longs;piralibus Archimedis, quæ ad &longs;emicirculum proxime accedit; quia vero differentia &longs;en&longs;ibilis nen e&longs;t, &longs;emicirculus &longs;upponi pote&longs;t, in quo cen­trum terræ motu æquabili movetur; pari modo punctum illud redit à D in R, & ab R ad A, dum idem radius ab AE redit in AC.

Augu&longs;tin. Hæc mihi &longs;ummoperè placent, cùm ex &longs;implici&longs;&longs;imis princi­piis deducantur; vna tamen difficultas &longs;e&longs;e oculis meis objicit ; nam æquali tempore, vt dicis, radius AC circumducitur in AG, vel AN, & ab AN ad AF, igitur inæqualiter movetur, cùm arcus CN minor &longs;it arcu NF.

Antim. Equidem extremitas radij AC movetur inæqualiter in cir­culo CHFP; punctum tamen C, &longs;eu centrum terræ ita movetur per CGE motu mixto ex circulari, & recto, vt hic pror&longs;us æquabilis re&longs;ul­tet: Hinc circulus CGEI e&longs;t quidem excentricus, non tamen verus, in quo &longs;cilicet terra motu &longs;implici moveatur, &longs;ed apparens; & con&longs;equen­ter centrum B, tantùm apparens; item excentricitas AB; quæ omnia ex prædicto motu mixto con&longs;equi, nece&longs;&longs;e e&longs;t; itemque anomaliam, id e&longs;t, appatentem nobis eju&longs;dem motus inæqualitatem; licet enim motus à C in G ; & à G in rvor æqualis &longs;int, inæquales tamen nobis appa­rent ; nempe dum terra decurrit arcum CG, quadratum &longs;cilicet &longs;ui Orbis, videtur nobis detumi&longs;&longs;o arcum CN minorom quadrante; & dum decurrit GE æqualem CH, videtur nobis decurrere arcum NF majo­rem, perinde quippe e&longs;t, &longs;ive terram in G a&longs;picias ex A, &longs;ive ex G Solem in A &longs;pectes; vt &longs;cilicet illum videas in puncto Eclypticæ, oppo&longs;ito, puncto G.

Chry&longs;ocom. Sed vndo Apogæi motus, i&longs;que in con&longs;equentia.

Antim. Fac terram ex C, peracto &longs;emicirculo nondum ad Perigæum perveni&longs;&longs;e, nec peracto orbe integro ad Apogæum ; inde nece&longs;&longs;ariò &longs;e­quitur, Apogæum promoveri in con&longs;equentia, &longs;cilicet à G versùs H ; in antecedentia autem moveretur, &longs;i terra ad Apogæum reditet nondum peracto orbe integro.

Chry&longs;ocom. Omitte, quæ&longs;o hæc enim faciliora &longs;unt, quàm vt longio­rem explicationem po&longs;tulent; &longs;ed vnde quæ&longs;o orbis annuus centri; vnde diurnus orbis, itemque annuus illi oppo&longs;itus?

Antim. Neque in hoc multùm laboro; &longs;i enim &longs;upponas terræ globum ita demi&longs;&longs;um fui&longs;&longs;e ex &longs;ublimi, ad acquiren dum illum velocitatis gradum, qui nece&longs;&longs;arius &longs;it, vt vna pars globi fortè præponderans, ante aliàs de­&longs;cenderit, vnde motus quidam mixtus &longs;equatur, ex motu orbis & cen­tri; &longs;i hoc &longs;upponas, inquam, vbi dictus globus ad di&longs;tantiam mediam pervenit, illico motu circulari moveri cœpit in eam partem, in quam motus Orbis prævius illum determinat; analogiam habes in globo vel di&longs;co, qui deor&longs;um præfato modo dimi&longs;&longs;us de&longs;cendit; vbi enim planum horizontale attingit, in eo movetur, &longs;eu rotatur, priore determinatione durante. v. g. &longs;it globus BCDE, (in Figura &longs;eque) centro A ita demi&longs;&longs;us per lineam perpendicularem AH, vt centrum quidem A rectam de&longs;cri­bat; aliæ verò partes etiam moveantur circa A, v.g. B in C, D, E, vbi globus attinget planum horizontale KL, in H, vi prioris determina­tionis, &longs;eu motus Orbis, F tendet in GH, I, vnde rotabitur globus in dicto plano versùs K. Idem dicendum de globo terræ tali modo de­mi&longs;&longs;o, cujus centrum movetur motu æquabili in Plano Eclipticæ cum eo velocitatis gradu, quem in primo illo de&longs;cen&longs;u acqui&longs;ivit, qui deinde &longs;emper intactus manet; pari modo motus Orbis etiam durat, cùm eadem &longs;it pro vtroque motu ratio, vt videre e&longs;t in prædicto globo.

Choy&longs;oc. Sed cur circa talem axem potiùs quàm circa alium? deinde cur libratur prædictus axis? denique cur omnes circuli diurni Æquatori &longs;unt paralleli?

Antim. Ni&longs;i orationem meam interrupi&longs;&longs;es, hæc continuò æquè facilè explicabam; Suppono terræ globum vel magnum Magnetem e&longs;&longs;e, vel &longs;al­tem magnetica virtute in&longs;tructum, vnde nece&longs;&longs;e &longs;it, duos polos magneticos ine&longs;&longs;e, & axem ad vtremque polum terminatum, quem etiam &longs;ibi ip&longs;i &longs;em-per e&longs;&longs;e parallelum oportet; igitur circa hunc, dumtaxat axem terre&longs;tris glo­bus volvitur; alioquin &longs;i circa alium ille &longs;ibi ip&longs;i parallelus non &longs;emper e&longs;&longs;et.

Ex hoc codem axis paralleli&longs;mo, &longs;equitur præfata eju&longs;dem globi inclina­tio, qua fit, vt idem globi punctum modò &longs;upra Eclipticæ planum attolla­tur, modò infra deprimatur; vnde Æquinoctia, Sol&longs;titia & quatuor anni tempe&longs;tates nece&longs;&longs;ario con&longs;equuntur; nempe, vt jam monui, &longs;upra, ille mo­tus annuus orbis e&longs;t tantùm apparens, & ex præfato axis, circa quem fit mo­tus diurnus, paralleli&longs;mo re&longs;ultat.

Chry&longs;ocom. Omnia probè intelligo; re&longs;tat, vt cau&longs;am afferas Solaris re­volutionis.

Antim. Pro hac nihil occurrit in hac hypothe&longs;i, quod &longs;olidum &longs;it, ni&longs;i fortè dicamus. Solarem globum vi motrice pollere; non &longs;anè quòd vivat, hoc enim ab&longs;urdum puto; &longs;ed quòd ea vi pollere po&longs;&longs;it, qua etiam vilia no­&longs;tra elementa pollent; ac proinde cùm jus finis &longs;it &longs;uo calore & luce alia corpora perfundere, mirum non e&longs;le, fi qua&longs;i ab aliis globis inuitatus &longs;eu determinatus, circa &longs;uum centrum immobile volvatur, vt &longs;altem illam po­tentiam quæ ine&longs;t, exerceat; alioquin per totum æternitatem hæc fru&longs;tra e&longs;&longs;et, quod dixerit.

Augu&longs;tin. Bea&longs;ti me, Antime; jam facile ad alios Planetas adductas à te rationes traducam. hoc vnum præ cæteris mihi mole&longs;tum erat, quòd in no&longs;tra hypothe&longs;i, omnia ferè aratis dici atque adduci crederem; huic &longs;anè incommodo abundè occurri&longs;ti, cùm omnia, ni fallor attigeris, nec enim mutationem obliquitatis Eclipticæ admittendam e&longs;&longs;e putarem, præce&longs;&longs;ionem Æquinoctiorum lenti&longs;&longs;imus ille &longs;tellarum motus &longs;atis ex­plicat.

Antim. Ingenuitati meæ, opinor, tribues, quòd tibi ea &longs;ugge&longs;&longs;erim, quibus mole&longs;tum illud, vt ais, argumentum refellere valeas. Vnum tibi per&longs;uadeas velim, cuncta hæc non obe&longs;&longs;e quidem ve&longs;træ hypothe&longs;i, &longs;ed non prode&longs;&longs;e; &longs;icuti no&longs;træ nec ob&longs;unt, nec pro&longs;unt; de obliquitatis Eclipticæ mutatione, idem tecum &longs;entio; præce&longs;&longs;ionem Æquinoctiorum rectè omni­no explicas per lenti&longs;&longs;imum illum fixarum motum; nec in tua hypothe&longs;i alius modus e&longs;&longs;e videtur; Licet enim Copernicus, Keplerus, aliíque ex ve&longs;tris velint fixarum motum non e&longs;&longs;e realem, &longs;ed apparentem, eo quòd, inquiunt, Æquinoctialia puncta tantulùm adducantut versùs occa&longs;um, &longs;cilicet in an­tecedentia, quia libratio terre&longs;tri globi citiùs ab&longs;olvitur, quàm motus in Zodiaco, hoc tamen, in eo &longs;altem iudicio, non &longs;ub&longs;i&longs;tit, nempe prædicta li­bratio, vt &longs;ic loquar, oritur ex motu orbis integro, circa axem axi Eclipticæ parallelum, &longs;eu ex paralleli&longs;mo axis terræ, circa quem orbes diurni erunt; hoc autem in ii&longs;dem punctis Eclipticæ Æquinoctialia puncta e&longs;&longs;e &longs;uppo­nit, &longs;ed hæc ad rem no&longs;tram nihil faciunt.

Augu&longs;tin. Expecta tantulùm, Antime, hic enim &longs;tellarum motus in tua hypothe&longs;i difficilè, &longs;altem, vt audio, explicatur; vnde for­tè meam vel hoc nomine, tuæ qui&longs;piam præferendam e&longs;&longs;e putaret.

Antim. Longè faciliùs, Augu&longs;tine, &longs;tellarum motus, quàm Planeta­rum, in qualibet hypothe&longs;i explicatur pro quo &longs;uppono 1. fixum æter­numque e&longs;&longs;e Naturæ in&longs;titutum, vt &longs;tellæ omnes eundem inter &longs;e ordinem & &longs;itum &longs;ervent. 2. Nunquam mutari illarum latitudinem: His po&longs;itis, cogita &longs;tellam quampiam in ip&longs;a Ecliptica, cogita etiam circulum quem­libet immobilem, puta meridiànum, in quo &longs;tella, primùm &longs;ita &longs;it, co­gita denique ip&longs;am Eclipticam, circa Axem mundi, &longs;uum motum ab&longs;olvere, ita vt idem punctum, quod erat in dicto meridiano ad illum redeat, orbe peracto ab ortu, in occa&longs;um 24.horis. Iam cogita &longs;tellam illam &longs;imul cum Ecliptica ab ortu in occa&longs;um ferri, & circumduci, & paulo tardiùs, vt eo momento, quo dictum punctú Eclipticæ, in quo erat, attingit meridianum, ip&longs;a tantulùm versùs ortum remaneat, non quidem extra Eclipticam, &longs;ed in ip&longs;amet Ecliptica: nec enim perfectum orbem de&longs;cribit, &longs;ed talem &longs;piram, vt &longs;emper Ecliptice re&longs;pondeat; aliæ verò, quæ &longs;unt extra Ecli­pticam, eandem &longs;emper ab illa di&longs;tantiam retineant, vnde præter circularé motum, altera &longs;altem inclinatioue opus e&longs;t, cujus terminus &longs;it æquator, non Ecliptica; ita tamen moventur, vt &longs;emper eandem ab Ecliptica di&longs;tantiam retineant: inde præce&longs;&longs;io Æquinoctiorum facilè explicatur, quæ tamen ex eo explicari non pote&longs;t, quod Sol in diver&longs;is punctis Æquatorem &longs;ecet; quia cum Sol &longs;emper Eclipticæ in&longs;i&longs;tat, licèt versùs occa&longs;um &longs;ectio Ecli­pticæ cum Æquatore, ip&longs;o Æquinoctij momento &longs;ingulis, annis promo­veatur, non tamen ex hoc &longs;equitur Æquinoctiorum præce&longs;&longs;io, ne­que propterea &longs;tulla quæpiam ab Æquinoctij puncto versùs Ortum remove-tur vt non nemo perperam exi&longs;titet, &longs;ed ideò fit Æquinoctiorum præ­ce&longs;&longs;io, quod Stellæ &longs;ingulis diebus & annis, tantulùm versùs Ortum qua­&longs;i retroagantur, id e&longs;t, non omnino diurnum orbem conficiant plenis 24. horis. Illum autem inclinationis motum lenti&longs;&longs;imum e&longs;&longs;e oportet; quod fortè propter maximam di&longs;tantiam accidit; &longs;eu veriùs propter veloci&longs;&longs;i­mum circularen motum, qui nihil ferè. prædictæ inclinationi relictum &longs;init.

Chry&longs;ocom. Sed quæ&longs;o te, Antime, ad alias rationes, &longs;i quæ tibi re&longs;tant, orationem converte, ne huc totam A&longs;tronomiam accer&longs;ere videaris.

Antim. In Venere, Mercurio, & Marte, illud præ&longs;ertim Copernicanæ hypothe&longs;i repugnare &longs;upra dictum e&longs;t, quòd Venus in Perigæo quinqua­gecuplo, Mercurius nonecuplo, Mars octogecuplo, majores videri debe­rent; quod tamen: vt dixi, meis ob&longs;ervationibus repugnat in Iove, qui &longs;e­quitur, aliquid etiam invenio; vnde tua hypothe&longs;is, Augu&longs;tine, impugne­tur: Iovem igitur, vt fortè putabas, ita propitium non habes.

Augu&longs;tin. Immò nobis præ cæteris favet, cum &longs;uis a&longs;tris medicæis quæ totidem Lunæ circa Iovem erunt, vt Luna circa terram, Venus & Mercu­rius circa Solem, & circa Saturnum Satellites.

Antim. Non ita profectò res &longs;e habet, vt jam intelligere debui&longs;&longs;es ex opu&longs;culo Diviniano, adver&longs;us Chri&longs;tiani Hugenij viri &longs;ane docti&longs;&longs;imi a&longs;­&longs;ertionem; primò enim accipiamus vnam ex præfatis Iovialibus Lunis; codem pror&longs;us modo circa Iovem &longs;uum circulum agit, quo Luna circa terram mobilem, in tua &longs;cilicet hypothe&longs;i ; ac proinde &longs;i accipia arcum

HI, &longs;imilem illi, quem Iupiter de­currit, eo tempore, quo quæpiam ex Lunis Iovialibus &longs;uum circulum ab&longs;olvit, hæc haud dubiè de&longs;cribet reali motu, ab vno Perigæo ad aliud, lineam &longs;imilem HGI, eodemque motus genere; igitur longè; tardiùs in H, quàm in G, reali &longs;cilicet mo­tu, idque in ea inæqualitatis pro­portione, quæ a&longs;ignabili qualibet minor erit, quod videtur ab&longs;urdi&longs;&longs;i­mum, & jam &longs;upra demon&longs;tratum e&longs;t; neque hic repeto, cùm &longs;it ea­dem vtrimque ratio; & ne hoc ip&longs;um paulò po&longs;t repetere cogar, hæc ca­dem ratio Lunæ Saturniæ à Chri­&longs;tiano Hugenio primùm detectæ, eo­demque modo contra tuam hypo­the&longs;im applicatur. Igitur contra illam ab a&longs;tris Medicæis & Iove, immò & Luna Saturnia eadem ratio pe­titur, quam &longs;upra ex Lunæ motu deduximus.

Secundò, vt in præfato opu&longs;culo ob&longs;ervatum e&longs;t, Stellæ Medicææ &longs;ub Iove omnino &longs;ingulis fetè diebus viderentur, præ&longs;ertim cùm per zonas &longs;ub­ob&longs;curas irent; &longs;unt enim lucidi&longs;&longs;imæ, illarumque candidi&longs;&longs;imus color à &longs;ubob&longs;curo zonatum colore adhibito præ&longs;ertim optimo tele&longs;copio, quo re­verà vti po&longs;&longs;umus, facilè di&longs;tingueretur; nempe &longs;i Stellulæ à love teguntur versùs Apogæum, intercepto &longs;cilicet Iovis di&longs;co, inter oculum & Stellam, certè in Perigæo Iovem ex aliqua parte tegent; nec qui&longs;piam celeriorem Stellæ tran&longs;itum cau&longs;ati debet, cùm &longs;ub lovis di&longs;eo, per horam ferè integram manere debeat, vt in dicto opu&longs;culo demon&longs;tratum fuit; cùm autem &longs;ub lovis di&longs;co nunquam dictas Stellas videre potuerimus, nanquam haud du­biè &longs;ub illum de&longs;cendunt, quod certè tuæ hypothe&longs;i repugnat, vt nemo negat; nec &longs;alli potuimus in ob&longs;ervando, qua&longs;i Conjunctionem Stellæ in Apogæo, à Conjunctione eju&longs;dem in Perigæo, non rectè di&longs;tinxerimus, nam di&longs;tinctu facilè fuit; illa enim Conjunctio fit in Perigæo, quæ maximam di­gre&longs;&longs;ionem Ortivam &longs;equitur, vt in Venere & Mercurio.

Tertiò cùm Iupiter lumen &longs;uum à Sole habeat, vt Mars, Venus, aliique Planetæ, Stella Medicæa &longs;altem vicinior vmbram in Iovis di&longs;cum projice­ret, quod negati non pote&longs;t ab vllo, qui rem hanc intelligat; nunquam au­tem vmbram illam videre potuimus, quamvis Stella circa Perigæum e&longs;&longs;et; Igitur Stellæ illæ &longs;ub Iovem minimè de&longs;cendunt; quod certè tuæ hypo­the&longs;i non favet.

Quartò adhibito etiam longi&longs;&longs;imo tele&longs;copio Stellas Medicæas &longs;plen­dentes &longs;emper micante&longs;que fixatum ad in&longs;tar, non verò tornatas in di&longs;cum, vt reliquos Planetas a&longs;picimus; vnde, ni fallor, deduco, ip&longs;o Iove longè al­tiores e&longs;&longs;e, quod periti Optices, opinor, minimè negabunt: Adde his, ob&longs;er­vationes non re&longs;pondere calculis factis in orbe, vel Epicyclo. Ex his, ni fal­lor, non leve contra tuam hypothe&longs;im ducitur argumentum; ac proinde, vt ante dicebas, Iupiter non adeò vobis propitius e&longs;t.

Chry&longs;oc. In tua verò hypothe&longs;i quonam pacto Stellarum Medicæarum motum explices, non intelligo, vt de&longs;cen&longs;um illarum &longs;ub Iovem &longs;alves; quid enim aliud de iis dicere potes, ni&longs;i illud ip&longs;um quod de Venere & Mercurio &longs;upra dixi&longs;t? Atqui Venus & Mercurius &longs;ub Solis di&longs;cum de&longs;cendunt.

Antim. Si ex ob&longs;ervationibus haberemus, Stellas illas &longs;ub Iovis di&longs;cum de&longs;cendere, æquè facilè illarum motum explicarem, ac &longs;upra Veneris & Mer­curij motum explicui; &longs;ed quandoquidem infra Iovem non de&longs;cendunt, non minùs facilè illarum motum explicamus, a&longs;&longs;umpta illarum mediocri di­&longs;tantia &longs;upra Iovem, ita vt in mediocri di&longs;tantia æquè citò ac Iupiter orbem &longs;uum diurnum, infra verò illam citiùs, &longs;upra demum tardiùs ab&longs;olvant, & periodus acce&longs;&longs;uum & rece&longs;&longs;uum, quibus Stella redit ad Apogæum, intra idem tempus perficiatur, quo &longs;uum orbem quælibet Stella decurrere com­muniter dicitur; &longs;ed quia in dicto opu&longs;culo hæc &longs;atis in&longs;inuata fuerunt, ne huc eadem traducam, eò vos remitto.

Augu&longs;tin. Nihil, opinor, amplius re&longs;tat, quod contra meam hypothe&longs;im afferre po&longs;&longs;is; jam enim Saturnus &longs;uam Lunam tibi &longs;uppeditavit, cujus &longs;altem intentares.

Antim. Aliud quidpiam e&longs;t, quod tibi fortè novum videbitur: Annulus ille Saturnius à Chri&longs;tiano Hugenio viro clari&longs;&longs;imo & omnigena literatura probè in&longs;tructo, ingeniosè profectò excogitatus, & quem ve&longs;tris mirum in modum placui&longs;&longs;e intelligo; &longs;i fortè verus e&longs;&longs;et, quod &longs;anè maximè percu­pio, ve&longs;træ hypothe&longs;i vltimam fetè ruinam afferret; cùm enim præfatus an­nulus plano Æquatoris &longs;emper parallelus &longs;it, haud dubiè non movetur per Eclipticam, alioquin &longs;itum acciperet, in quo Eclipticæ plano parallelus e&longs;­&longs;et; eo quippe motu movetur, quo faciliùs moveri pote&longs;t, iuxta regulam ex doctrina motuum a&longs;&longs;umptam, de qua jam &longs;upra. Et verò nemo non videt, annulum planum longè faciliùs moveri, & cum minore medij re&longs;i&longs;tentia, &longs;i in plano annuli, &longs;it ip&longs;a linea motus; igitur cùm illud planum annuli Æqua­toris plano parallelum &longs;emper &longs;it, haud dubiè in eo circulo movetur, cujus planum Æquatoris plano parallelum e&longs;t; igitur in parallelo diurno, iuxta no&longs;tram hypothe&longs;im, licèt enim &longs;piræ planum tantulùm ab Æquatoris pla­no declinet, hoc tamen &longs;ub &longs;en&longs;um non cadit: Hæc ratio &longs;ingularis e&longs;t; quia præfatus annulus e&longs;t etiam valdè &longs;ingularis, & ante Hugenium incompertus orbi, faxit Deus, vt ex futuris ob&longs;ervationibus Saturno præ&longs;ertim circa Æquatorem exi&longs;tente, ita luce nova confirmetur, vt de illo nullus vltra du­bitare po&longs;&longs;it; quod maximoperè, vt dixi, percupio, cùm in no&longs;tram hypo­the&longs;im mirificè Quadret; & hæc &longs;unt, quæ contra tuam hypothe&longs;im, Augu­&longs;tine dicenda mihi occurrunt.

Chry&longs;ocom. Addere poteras per&longs;picua Scripturæ loca, ex quibus con&longs;tat terram &longs;tare & Solem moveri iuxta literalem illorum &longs;en&longs;um, qui profecto retinendus e&longs;t, &longs;i ab&longs;que ab&longs;urdo retineri queat; adde Sanctorum Patrum auctoritatem, quæ certe maximi momenti e&longs;t, pro definiendo legitimo San­ctæ Scripturæ &longs;en&longs;u; ex his enim &longs;equitur per&longs;picua mens Eccle&longs;iæ, quæ S.Scripturæ &longs;en&longs;um ex Sanctis Patribus &longs;emper eruit; denique cùm divina potentia in &longs;acro textu laudati velit, & magni fieri, ex celerrimo illo motu, quo a&longs;tra cientur, quis hanc illi laudem jure detrahat? nemo certe, illorum præ&longs;ertim, qui &longs;acram Scripturam admittunt.

Augu&longs;tin. Licèt manus omnino dare nequeam, negati tamen à me non pote&longs;t, quin aliquid &longs;altem plau&longs;us no&longs;træ hypothe&longs;i &longs;ubduxeris, & in tuam traduxeris; &longs;ed de hac re &longs;atis.

Antim. Optimè mones; quate hic &longs;u&longs;tinendum e&longs;&longs;e iudico, ne nimia fortè huius congre&longs;&longs;us prolixitas nobili&longs;&longs;imæ coronæ tædium affetat.

Chry&longs;ocom. Prudenti&longs;&longs;imè judica&longs;ti; quare hoc vnum re&longs;tat, vt primo congre&longs;&longs;ui diem indicamus.

Augu&longs;t. Po&longs;t triduum, ni&longs;i vobis &longs;it incommodum; Sed quodnam erit di&longs;putationis argumentum?

Antim. Meam &longs;ententiam, &longs;eu veriùs hypothe&longs;im de Marino æ&longs;tu, vobis exponam; interim con&longs;ulite tabulas Nauticas, vt inde vobis &longs;uppetat, quod mihi opponatis.

DIALOGVS TERTIVS.

In quo, nova & vera cau&longs;a Marini æ&longs;tus declaratur & demonstratur.

REM magnam aggredior, Princeps Eminenti&longs;&longs;ime, adeó­que difficilem, vt Philo&longs;ophorum maximi, Stagiritæ &longs;ui principis mi&longs;erando ca&longs;u & naufragio territi, in&longs;uperabilé illam & Mortalium ingenio inacce&longs;&longs;am publicis monu­mentis in lucem editis declararint. Vnde factum e&longs;&longs;e, reor, vt quique illorum prudenti&longs;&longs;imi hunc &longs;copulum cautè prætergre&longs;&longs;i, vix extremo indice illum indicarint; cùm tamen alij certè incauti ad illum propiùs acce&longs;&longs;erint, ibique tanquam in ridicula &longs;ce­na, the&longs;es &longs;uas communi &longs;apientum ludibrio expo&longs;uerint. Et verò vix ea in &longs;omniantis animum caderent, quæ ip&longs;i excogitarunt, ad cau&longs;am Ma­rini æ&longs;tus explicandam; &longs;unt qui Soli, alij Terræ, neutri quidam præfa­tam cau&longs;am attribuunt: in Luna multiplicem virtutem, &longs;eu vim alij agno­&longs;cunt; magneticam, qua &longs;cilicet a quas adducit atque attollit; humefacti­vam, cùm &longs;it humoris vehiculum, quo humida corpora variè afficiuntur, pro diver&longs;o Lunæ a&longs;pectu; compre&longs;&longs;ivam, rarefactivam &c. Sed in Ple­nilunio, de Meridie, Luna in puncto oppo&longs;ito exi&longs;tens, qua vi, amabo, ciet æ&longs;tum? Qui ad Solem confugiunt, dicere nequeunt, quid Sol præ&longs;tet, cum bis &longs;ingulis men&longs;ibus in Novilunio &longs;cilicet & Plenilunio æ&longs;tum in media nocte, ab&longs;ente Sole habeamus. Vapores tepidos accer&longs;unt aliqui; &longs;ed vnde, à quo excitati? Quid iis cum Luna, cuius motum Marinus æ&longs;tus æmulatur? Vapores demum aquam in bullas attollunt, non verò in tu­morem; & quid nitrum ad hoc conferat, divinare, ni&longs;i fingam, profectò non po&longs;&longs;um; Terræ motum inæqualem, cui aliqui tribuunt æ&longs;tum, iam &longs;upra rejecimus; item aëris compre&longs;&longs;ionem à præterlabente Luna æquè facilè explodimus; quia Luna in Meridiano exi&longs;tente, ibi compre&longs;&longs;ionis maxima vis e&longs;&longs;et; nullus igitur æ&longs;tus. Omitto alia figmenta potiùs quàm argumenta, & ex communibus principiis rem i&longs;tam ita definio, vt ex iis, etiam ab ignaro æ&longs;tus Marini, immò qui nequidem Oceanum e&longs;&longs;e &longs;ciat, illi omnes effectus, qui &longs;en&longs;ibus no&longs;tris & ob&longs;ervationibus &longs;ubjiciuntus, deduci po&longs;&longs;int: id &longs;altem erit operæ pretium, quod hanc hypothe&longs;im meam cen&longs;uræ tuæ &longs;ubjectam, vel inde nobili&longs;&longs;imo & docti&longs;&longs;imo calculo probatam, vel ju&longs;to, à quo ab&longs;que temeritatis nota, nemo appellarit, judicio reprobatam e&longs;&longs;e, non &longs;ine voluptate intelligam: &longs;ed ad rem ve­niamus.

Augu&longs;tin. Multa &longs;anè, ac ferè omnia in memoriam revocavi, vt facilè mihi per&longs;uadeo, quæ pro ad&longs;truenda Marini æ&longs;tus cau&longs;a, dicturus e&longs;tes; &longs;ed nihil occurrit profectò, quod iam ab aliis dictum, &longs;eu fictum non fuerit: nempe, vt vel inde initium di&longs;&longs;ertationis ducamus, negari non pote&longs;t, quin Lunaris globus in hac &longs;cena &longs;uas, ea&longs;que præcipuas partes agat; quid por­rò Luna præ&longs;tare queat, quod jam excogitatum, &longs;eu fictum non &longs;it, immò & rejectum? intume&longs;cit aqua in æ&longs;tu, quod nemo peritus negare au&longs;it; cùm tantus &longs;it in quibu&longs;dam oris aquarum tumor, vt ad quinquaginta pe­dum altitudinem facilè a&longs;cendat; quibus porrò organis, &longs;eu trochleis, & qua vi Luna hunc aquis motum imprimat, præ&longs;ertim, cùm ab&longs;ente Luna aqua etiam per æ&longs;tum intume&longs;cat, conjicere non po&longs;&longs;um. Video, Lunam Marini æ&longs;tus cau&longs;am e&longs;&longs;e, cùm ex diver&longs;a Lunæ applicatione, im­mò & a&longs;pectu, diver&longs;is æ&longs;tus con&longs;equatur; quonam verò pacto, id Luna præ&longs;tet, nec video, nec alij profectò vident.

Chry&longs;ocom. Hæc vna poti&longs;&longs;imùm ex iis rebus cen&longs;enda e&longs;t, quas Deus occultas & ignotas Mortalibus e&longs;&longs;e voluit; ita vt ingeniosè iuxta atque &longs;apienter ille recentior dixerit, Marinum æ&longs;tum humanæ curio&longs;itatis nau­fragium e&longs;&longs;e; &longs;ed quid tandem tu, Antime? Modicam Augu&longs;tinus de te &longs;pem habere videtur, qua&longs;i &longs;uper hac re nihil novi afferre valeas; ego ve­ro te adeò imprudentem e&longs;&longs;e, non puto, vt fidem tuam fru&longs;tra & in ca&longs;&longs;um oppigneratis, vt antiquum, de quo jam &longs;upra, adagium in &longs;cenam revoces; parturient montes, na&longs;cetur ridiculus mus.

Antim. Parum quidem admodùm mihi arrogo; &longs;pero tamen, aliquid me adducturum, idque ex communibus principiis, quod &longs;i fortè non mul­tis, nonnullis tamen arrideat: Concedo igitur. Augu&longs;tine, id quod paulò ante dicebas, Lunam &longs;cilicet in hoc negotio &longs;uas agere partes, nempe &longs;unt qua&longs;i tres Marini æ&longs;tus periodi, diurna &longs;cilicet, men&longs;trua, annua; &longs;ingulis ferè diebus bis accedit, & affluit æ&longs;tus, bis recurrit; dico ferè, quia hic ge­minus cur&longs;us & recur&longs;us non 24. &longs;ed 25. horis, paulò minùs perficitur, &longs;ci­licet ad Lunæ motum; nempe Luna, vt redeat ad idem Meridiani pun­ctum, qua&longs;i 25. horas ponit; igitur &longs;ingulis diebus vna ferè hora tardior æ&longs;tus tumet, v.g. &longs;i hodie hora Meridiana fuit &longs;ummum æ&longs;tus, cra&longs;tina die erit ferè prima po&longs;t Meridiem hora: die verò &longs;equenti, hora po&longs;t Meri­diem &longs;ecunda; atque ita con&longs;equenter. Hic porrò Lunæ motus e&longs;t; altera periodus e&longs;t men&longs;trua; nempe pro diver&longs;o Lunæ a&longs;pectu, æ&longs;tus major, vel minor e&longs;t; v. g. in Plenilunio major e&longs;t, quàm in Novilunio, & in hoc major quàm in Quadraturis, cùm igitur ex Lunæ motu & a&longs;pectu tota il­la æ&longs;tuum varietas procedat, negari non pote&longs;t, quin à Luna pendeat. Tertia demum periodus e&longs;t annua, nam ob&longs;ervatum fuit in Æquinoctiis & Sol&longs;titiis, non modicam fieri mutationem æ&longs;tuum præ&longs;ertim in Æqui­noctiis, ita vt in Æquinoctio, v.g. Autumnali cum Plenilunio conjuncto, &longs;emper &longs;it maximus æ&longs;tus, in quo etiam Luna &longs;uo munere defungitur; &longs;i enim fiat Æquinoctium in Quadratura, modicus æ&longs;tus e&longs;t.

Augu&longs;tin. Lunam, cau&longs;am e&longs;&longs;e fateor vltrò; &longs;i autem cau&longs;a e&longs;t, aliquid agit & confert; quid porrò illud e&longs;t? fac age, me doceas, & eris mihi magnus Apollo.

Antim. Dare non po&longs;&longs;um, Lunam Marini æ&longs;tus cau&longs;am e&longs;&longs;e; &longs;i enim cau&longs;a e&longs;t, cau&longs;at, & aliquid præ&longs;tat: &longs;ed nihil penitus præ&longs;tat.

Augu&longs;tin. Ludis nos, Antime, Lunæ totum hunc effectum paulò ante tribuebas; cur igitur modò cau&longs;am e&longs;&longs;e negas? Si cau&longs;a non e&longs;t, ad æ&longs;tum nullo modo pertinet; Solve i&longs;tum nodum.

Antim. Communi di&longs;tinctione vtor, ad &longs;olvendum hunc nodum; Luna ita pertinet ad Marinum æ&longs;tum, vt &longs;ine illa hic non &longs;it, licèt revera Luna cau&longs;a non &longs;it, id e&longs;t, tumorem illum aquæ minimè attollat, vel aquas cieat; nullum enim motum aquis imprimit, nullum humorem affundit, qui &longs;cilicet ad cel&longs;um illum tumorem &longs;ufficiat; quomodo igitur ab illa æ&longs;tus pendet? Verbo dico; Luna Marini æ&longs;tus cau&longs;a non e&longs;t, &longs;ed mera Oc­ca&longs;io, qua reverà &longs;ublata, æ&longs;tus non e&longs;&longs;et.

Chry&longs;ocom. Ne quæ&longs;o ludas in verbis; &longs;olus enim verborum ludus ad res phy&longs;icas explicandas non &longs;ufficit; quid igitur illud e&longs;t, quod dicis, nam profectò non intelligo.

Antim. Faciam intelligas, Chry&longs;ocome, &longs;ed priùs illa principia jacien­da &longs;unt, ex quibus res i&longs;ta deducitur. Suppono igitur primò, illum e&longs;&longs;e fi­nem gravitatis, quæ gravibus ine&longs;t, vt &longs;ingulæ partes globi totalis versùs illiùs centrum, ni&longs;u quodam communis con&longs;pirationis tendant; quod re­verà nece&longs;&longs;arium fuit, tum ad conflandum totalem globum, tum ad eun­dem &longs;ervandum; fac enim omnes partes alicujus globi totalis à &longs;e ip&longs;is di&longs;­&longs;itas e&longs;&longs;e, illico communi dictæ con&longs;pirationis vel inclinationis, versùs idem centrum, vi, &longs;eu ni&longs;u, &longs;eu impetu &longs;e&longs;e iterum in orbem component; deinde fac partes globi totalis non contra niti vlla re&longs;i&longs;tentia; &longs;tatim mi­nima ferè ventorum, vel alterius impul&longs;us vi di&longs;&longs;ipabuntur; igitur non potuit facilior modus excogitari, tum ad conflandum, tum ad &longs;ervandum globum totalem; id e&longs;t, tum ad colligendas omnes partes, in vnum glo­bum; tum ad impediendum, ne à globo facilè avellantur, non potuit, in­quam facilior modus excogitari, quàm &longs;i partes &longs;ingulæ nativa quadam vi & inclinatione, versùs idem & commune centrum eant, &longs;eu tendant, atque nitantur.

Chry&longs;ocom. Illud commune e&longs;t principium, vt gravia deor&longs;um, levia &longs;ur&longs;um &longs;ua &longs;ponte ferantur, nec enim opinor eorum &longs;ententiam defenditis, quos tacito nomine Stagirita no&longs;ter refutavit, qui &longs;uperum, atque inferum negabant: mundi ac terræ centrum deor&longs;um e&longs;t; cælum verò &longs;ur&longs;um; hoc igitur &longs;uperum, illud inferum.

Augu&longs;tin. De iis ferè omnibus, quæ paucis complexus es, dubitarem, de eo præ&longs;ertim, quod dicis, gravia deor&longs;um, levia &longs;ur&longs;um &longs;ua &longs;ponte ferri; de gravibus vltrò concederem; nec enim illorum commentum approba­re po&longs;&longs;um, qui volunt, corpus grave à terra deor&longs;um trahi, &longs;pi&longs;&longs;i cuju&longs;dam capillitij opera; aut certè trudi à ficta ne&longs;cio qua &longs;ubtili materia, quæ &longs;en­&longs;um omnem fugit; nempe, &longs;i trudit illa materia, motum in &longs;e habet, & à &longs;e; &longs;i enim ab alio, de hoc idem dicam; Satius igitur e&longs;t dicere, corpus grave à &longs;e moveri, ac deor&longs;um ire, quod &longs;cilicet videmus atque palpamus, quàm trudi ab illa &longs;ubtili materia, mota à &longs;e ip&longs;a, quàm nullo tactu, nullo &longs;en&longs;u percipimus; is profectò, magis ridiculus non e&longs;&longs;et, qui diceret, corpus grave deor&longs;um trudi ab Angelo, quod tamen nulla ratione, nullo­que experimento probari pote&longs;t, quàm ij, qui dicunt, ab ea &longs;ubtili materia trudi, cùm nulla ratione, & nullo experimento id probare po&longs;&longs;int.

Antim. Rectè omnino; neque id ab vllo cordato viro negari pote&longs;t, gravia &longs;cilicet &longs;ponte &longs;ua deor&longs;um ire.

Augu&longs;tin. Sed non item levia, quæ ideò &longs;ur&longs;um eunt, quia &longs;ur&longs;um à graviore medio extruduntur; Supponamus enim corpus aliquod levius graviori &longs;ube&longs;&longs;e; vel gravius tantùm &longs;ua &longs;ponte deor&longs;um ibit & &longs;ur&longs;um levius extrudet; vel tantùm hoc &longs;ua &longs;ponte &longs;ur&longs;um a&longs;cendet, ac deor&longs;um ex­trudet gravius; vel &longs;imul vtrumque &longs;ua &longs;ponte ibit; quod levius tantùm nemo dixerit, & manife&longs;tæ convinci po&longs;&longs;et fal&longs;itatis.

Antim. Scio neminem e&longs;&longs;e, qui hoc dicat; &longs;ed quæ&longs;o te, fac, aliquem e&longs;&longs;e; quomodò illum convinceres; dic mihi &longs;odes.

Augu&longs;tin. In hunc modum; eo modo, quo &longs;ur&longs;um extruditur corpus leve à gravi, aër v.g. ab aqua, cui &longs;ube&longs;t, corpus grave deor&longs;um detrude­retur à levi, aqua, v. g. ab aëre, qui aquæ &longs;ube&longs;&longs;et: &longs;it ergo globus plum­beus in aëre, ideò de&longs;cendit, quia aër, qui &longs;ube&longs;t, &longs;ua &longs;ponte a&longs;cendens, illum deor&longs;um extrudit; ille autem Cylindrus aëris in globum levitat; ita mihi loqui fas &longs;it, qui à globo ad terram v&longs;que extenditur, vt patet; nec enim is, qui e&longs;t &longs;upra globum in illum levitat, &longs;ed potiùs gravitaret; corpus enim gravitat deor&longs;um, &longs;ur&longs;um verò levitat; igitur &longs;i prædictus Cylin­drus aëris primò &longs;it pedalis, ac deinde bipedalis, cùm tota vis gravitatio­nis, &longs;eu detru&longs;ionis deor&longs;um &longs;it ab aëre, qui e&longs;t infra globum, & in eum le­vitat; erit dupla vis detru&longs;ionis, &longs;eu gravitationis, quando aëris Cylin­drus plumbeo globo &longs;ubjectus erit duplus; dupla enim cau&longs;a duplum effe­ctum producit.

Antim. Id quod dicis ex hoc experimento probari pote&longs;t. Sit v. g. Scyphus vacuus &longs;ecundum perpendiculum in aquam immer&longs;us, ore præ­vio, ita vt nihil pror&longs;us aëris ante in Scypho contenti avolare po&longs;&longs;it; haud dubiè, quo profundiùs immergitur, major vis &longs;ur&longs;um illum extru­dens ip&longs;o tactu &longs;entitur; nempe totus aquæ &longs;uperpo&longs;itæ, Cylindrus cujus ba&longs;is ori va&longs;is, &longs;eu Scyphi circiter æqualis e&longs;t, in aëra Scypho conten­tam gravitat, magis autem, Cylindrus altior.

Augu&longs;tin. Igitur &longs;i prædictus Scyphus ita immergatur, vt primum vno palmo à &longs;uprema &longs;uperficie aqua di&longs;tet, ac deinde profundiùs im­mergatur, ita vt di&longs;tet ab eadem &longs;uperficie duobus palmis, dupla tunc erit vis gravitationis ; quia duplæ cau&longs;æ duplus effectus e&longs;t: igitur cùm &longs;it eadem ratio, duplus Cylindrus aëris &longs;ubjecti globo duplam vim motus in illum execet, &longs;cilicet levitationis, quod tamen fal&longs;um e&longs;&longs;e con&longs;tat.

Antim. Non dico duplam vim motus, &longs;ed tantùm dico majorem vim, quod certè ad tuum propo&longs;itum &longs;atis e&longs;&longs;e puto; cùm prædicti globi pon­dus idem &longs;it, eademque vis illa, qua deor&longs;um fertur, &longs;ive vnum, &longs;ive duos palmos altus à terra pendatur.

Augu&longs;tin. Non dicis duplam vim motus? dupla cau&longs;a duplum effe-ctum producit, cùm eadem &longs;it cau&longs;arum & effectuum proportio.

Antim. Non nego, duplum e&longs;&longs;e effectum, &longs;ed nego, duplam e&longs;&longs;e vim morus, id e&longs;t motum duplum, &longs;eu duplo velociorem, & ne diutiùs te &longs;u­&longs;pen&longs;um habeam, &longs;imili ferè experimento rem i&longs;tam explico: Sit vas quod­

libet AB; &longs;itque in&longs;erta fi&longs;tula in B, per quam, &longs;i aperiatur, effluat aqua priùs infu&longs;a; & primò quidem aqua occupet totam altitudinem AB, Tum deinde &longs;ubduplum BE, non e&longs;t dubium, quin Cylindrus BA extrudat aquam per fi&longs;tulam BC, majore vi, quàm Cylindrus EB; non ta­men duplo majore, licèt Cylindrus BA fit du­plus Cylindri BE; &longs;i enim dupla e&longs;&longs;et vis motus, id e&longs;t motus ille, quo per fi&longs;tulam aqua erumpit, duplo velocior, duplæ cau&longs;æ, quadruplus e&longs;&longs;et ef­fectus; nam &longs;i motus e&longs;t duplo velocior, eo tem­pore, quo data quantitas aquæ v.g. vncia effluit, extru&longs;a à Cylindro BE, effluent duæ vnciæ ex­tru&longs;æ à Cylindro BA; &longs;ed extrudere duas vncias, duplo motu, e&longs;t quadruplus effectus: nempe extrudere vnam duplo motu e&longs;t effectus duplus, ergo extrudere duas, duplo motu, e&longs;t quadruplus.

Augu&longs;tin. Rem capio, igitur ad effectum quadruplum, opus e&longs;t cau&longs;a qua­drupla; igitur Cylindrus BA producet duplam vim motus, comparatus cum Cylindro AF &longs;ub quadruplo. Et verò licèt in majore &longs;axo aliqua cau­&longs;a motrix eundem morum producat, quem in minore, non propterea æqua­lis effectus dicendus e&longs;t; vt patet: Vnde minùs cautè duplum illum dixe­ram motum.

Antim. Effectus igitur &longs;unt vt cau&longs;æ, cau&longs;æ vt altitudines, motus in &longs;ub­duplicata altitudinum, effectus demum in compo&longs;ita motuum & quanti­tatum; & quia motus &longs;unt vt quantitates, effectus &longs;unt in duplicata mo­tuum, vel quantitatum.

Augu&longs;t. Mihi tamen gravis &longs;uboritur difficultas; nam in &longs;cypho illo im­mer&longs;o, vna tantùm e&longs;t quantitas aëris; igitur non cre&longs;cit effectus ex quan­titate, quæ non cre&longs;cit; igitur tantùm ex motu; igitur &longs;i cau&longs;a dupla e&longs;t, motus erit duplus.

Antim. Acutè pror&longs;us: facilis tamen e&longs;t re&longs;pon&longs;io, cùm perinde gravitet Cylindrus aquæ in &longs;ubjectum aëra, atque &longs;i hic &longs;tatim extruderetur, & alius &longs;uccederet; &longs;icut Cylindrus AB primum gravitat in primam vnciam, quam extrudit, &longs;ive deinde &longs;ecundam extrudat, &longs;ive non extrudat; quia &longs;tatim clau­ditur fi&longs;tula; inde igitur vis motus extru&longs;ionis petenda e&longs;t, quod produca­tur vis motus dupla, ac proinde prima vncia duplo velociore motu extru­datur; igitur &longs;ubduplo tempore; igitur reliquo &longs;ubduplo &longs;ecunda vncia, vel extrudatur eodem motu, vel extrudi po&longs;&longs;it, licèt non extrudatur; idem dicendum de aëre immer&longs;o &longs;cypho contento, in quem Cylindrus ea vi gra­vitat, qua illum extruderet, &longs;i extrudi po&longs;&longs;et; eadem igitur e&longs;t vtrinque ratio.

Augu&longs;tin. Quem porrò effectum prædicta illa gravitatio producat, non video; cùm nec moveri, nec extrudi po&longs;&longs;it.

Antim. Manu ip&longs;a, &longs;cyphum illum ne &longs;ur&longs;um extrudatur immer&longs;um reti­nente, vim illam, impul&longs;um illum, vel impetum, vel impre&longs;&longs;ionem &longs;entimus; præterquam quod vis illa gravitantis aquæ comprimit aëra &longs;chypho con­tentum.

Augu&longs;tin. Rectè; inde petitur ratio quorumdam fontium artefacto­rum in quibus aër ab aqua compre&longs;&longs;us aliam aquam, cujus &longs;uperficiem premit, &longs;ur&longs;um extrudit; &longs;i quis verò non aquam, &longs;ed Mercurium ad comprimendum aëra adhibeat, longè major vis pre&longs;&longs;ionis &longs;equetur, & longè altiùs aqua extrudetur; &longs;ed jam hæc trita &longs;unt; vnum tantùm ob&longs;er­vo; hallucinari &longs;cilicet illum, qui in magno va&longs;e in aquas, iuxta prædi­ctum modum immer&longs;o, vivere &longs;e po&longs;&longs;e credidit, & profundum maris &longs;cru­tari; nempe aër in illo va&longs;e altè immer&longs;o vi &longs;upra gravitantis aquæ ita com­primetur, vt ducendo halitui minimè aptus e&longs;&longs;et: immo ip&longs;e aër thorace contentus & abdomine, ita comprimeretur, vt mu&longs;culi ducendo aëri &longs;er­vientes, vix ad &longs;uam functionem habiles re&longs;tarent; &longs;ed quæ&longs;o re&longs;ume alia capita, hoc enim tibi damus vltrò; &longs;cilicet corpus grave à levi deor&longs;um non detrudi, &longs;ed &longs;ua &longs;ponte de&longs;cendere.

Antim. Hoc ip&longs;um e&longs;t, quod volo, nimirum, corpus grave tantùm &longs;ua &longs;ponte deor&longs;um ire, & ab eo leve &longs;ubjectum extrudi.

Chry&longs;oc. Licèt fatear corpus grave à levi deor&longs;um non detrudi, &longs;ed &longs;ponte &longs;ua de&longs;cendere, non tamen propterea dare cogor, à gravibus de&longs;­cendentibus, levia &longs;ur&longs;um extrudi, nam & gravia deor&longs;um, ac levia &longs;ur&longs;um ire &longs;ua &longs;ponte cum Ari&longs;totele cen&longs;eo.

Augu&longs;tin. Fingamus &longs;altem, Chry&longs;ocome, corpus grave tantùm &longs;ua &longs;ponte de&longs;cendere, præci&longs;a qualibet alia virtute, &longs;eu potentia, quæ corpori levi in&longs;it; quæro ex te, vtrùm aliquid diver&longs;um ab eo, quod modò apparet, in de&longs;cen&longs;u gravium, hoc po&longs;ito, futurum &longs;it, nihil pror­&longs;us, lapis enim v.g.per medium aëra de&longs;cenderet, & &longs;ur&longs;um aëra extrude­ret, cùm aliter de&longs;cendere non po&longs;&longs;it, idemque pror&longs;us fieret, quod modò fieri videmus.

Chry&longs;oc. Eadem ratio probat, corpus leue ea vi pollere, qua &longs;ur&longs;um fe­ratur, quæ id probat, de corpore gravi; vt enim corpus grave ea pollet, vt feratur in locum &longs;uum, versùs centrum Mundi, ita & leue, vt tendat in &longs;uum ab eodem centro remotum, in hanc rem multos Ari&longs;totelis textus adducere po&longs;&longs;em; &longs;ed fru&longs;tra, cùm Philo&longs;ophi mentem tibi per&longs;pectam e&longs;&longs;e non du­bitem.

Augu&longs;tin. Quid quæ&longs;o corpori gravi cum Mundi centro? quid ab eo loco commodi refert? cur igitur illud adeò appetit? corpus verò leve, quid rixæ aut di&longs;&longs;idij habet cum illo centro? quid ab eo &longs;ibi timet? cur illud fugit, vt infe&longs;tum ho&longs;tem? Præterea &longs;i rectè memini, Stagirita ve&longs;ter lib. 4. de Cœlo textu 39. expre&longs;sè dicit aëra deor&longs;um ferri, &longs;i aqua vel terra &longs;ubtrahatur, non verò &longs;ur&longs;um, &longs;ubtracto illo corpore, cui &longs;ube&longs;t; & tamen non minùs levis e&longs;t, quàm gravis, nec minor, vt dicis, illi virtus intrin-&longs;eca ine&longs;t, vt recedat à centro Mundi, quàm aquæ, vt ad illud accedat, Denique, vt hoc vel obiter dicam, ad quem amabò finem huju&longs;modi cor­porum lationes Natura de&longs;tinavit, ni&longs;i ad rectam Vniver&longs;i di&longs;po&longs;itionem? quod nec ip&longs;e Ari&longs;toteles vnquam negavit; atqui finis ille certò obtinetur, modò graviora, quibus levia &longs;ub&longs;unt, deor&longs;um eant, & partes omnes versùs idem centrum, cùm fieri non po&longs;&longs;it, vt graviora de&longs;cendant, ni&longs;i le­viora &longs;ur&longs;um trudantur; Quod &longs;pectat ad Ari&longs;totelem, in lib.de Cœlo, multa profectò habet, quæ cum veritate minùs con&longs;entiunt in iis præ&longs;ertim, quæ &longs;crip&longs;it de motu locali; quòd enim Cœli &longs;int &longs;olidi; quòd &longs;tellæ nullum ha­beant motum, præter motum primi Mobilis, quòd Mundus &longs;it ab æterno, quòd Cœlum ortum non habuerit, nec corrumpi po&longs;&longs;it; quòd cuncta, quæ ortum habuerunt, &longs;int interitura, quòd duplo gravius duplo velociore motu de&longs;cendat, quod Deus &longs;it Agens nece&longs;&longs;arium, aliaque huju&longs;modi, non modò in iis Ari&longs;totelem non debemus &longs;equi, &longs;ed eidem apertè à nobis re­pugnari, par e&longs;t.

Antim. Addo vnum, quod in re præ&longs;enti ponderandum e&longs;t, &longs;cilicet, non agi hoc loco, vtrùm terra &longs;it ab&longs;olutè ac &longs;impliciter gravis, ignis verò ab&longs;o­lutè & &longs;impliciter levis; de aqua & aëre tantùm &longs;ermo e&longs;t; vtrumque au­tem ab&longs;olutè leve e&longs;&longs;e Philo&longs;ophus negat lib. 4. de Cœlo text. 27. ni fallor, additque text. 39. in &longs;uo loco pondus habere non levitatem; id pa&longs;&longs;im re­petit aliis locis, & expre&longs;sè fatetur, præ&longs;ertim text. 30.aëra gravem e&longs;&longs;e; adde &longs;is, quod habet lib. 3. text. 10. grave nihil aliud e&longs;&longs;e, quàm den&longs;um, & leve nihil aliud quàm rarum; Idem habet lib. 4. Phy&longs;ic. cap. 9. item lib. 8. c. 7. & alibi pa&longs;&longs;im. Non de&longs;unt etiam Autores cla&longs;&longs;ici præter Ar­chimedem, & quotquot de Statica & innatantibus humido &longs;crip&longs;erunt, quorum hac in re autoritas maximi &longs;anè momenti e&longs;t, vt Iavellus tract. 1. in 4. de Cœlo, cap. 3. concl. 3. Cabeus Tom. 4. Meteor. Tract. 14. Ru­vius lib.4.de Cœlo cap.6.quæ&longs;t. 1.Bovius lib.3.Philo&longs;oph. p. 221. & multi alij, quos facilè adducerem; &longs;ed vt jam dixi, ad rem præ&longs;entem hæc contro­ver&longs;ia non &longs;pectat, &longs;atis enim mihi e&longs;t, &longs;i aër & aqua gravia &longs;int, &longs;altem &longs;e­cundum quid; quid quid tandem &longs;it de levitate po&longs;itiva, qua levia &longs;ua &longs;ponte &longs;ur&longs;um ferantur, quam vobis quæ&longs;tionem animi gratia di&longs;putandam relin­quo; quantum enim ex iis, quæ huiu&longs;que à vobis dicta &longs;unt, alter eam ad­ftruit, alter verò de&longs;truit.

Chry&longs;ocomus. Ita e&longs;t, illam ad&longs;truo, non &longs;anè quòd ratio à priori me moveat; nullam enim e&longs;&longs;e, quæ hoc mihi certò per&longs;uadeat, vl­tro fateor; &longs;ed quia nonnulla &longs;unt experimenta, quæ id pror&longs;us evincunt.

Augu&longs;tin. Huc volo te; refer quæ&longs;o illa experimenta, iis enim, &longs;i ta­lia &longs;unt, & hoc &longs;anctè iuro, illico cedam & dabo manus.

Chry&longs;ocom. primo quidem loco, &longs;it tubus vitreus, cuius altera extre­mitas probè ob&longs;tructa &longs;it, altera verò aperta, infundatur aqua, non tamen v&longs;que ad &longs;ummum, tum admoto pre&longs;sè digito, ne aqua effluat, inver&longs;oque tubo, illa portio aëris, quæ in tubo reman&longs;it, &longs;ur-&longs;um fertur, non tamen &longs;ervata cylindri forma; licet enim ima portio cy­lyndrica &longs;it, &longs;uperior tamen habet &longs;uperficiem qua&longs;i &longs;phæricam, &longs;eu &longs;phæroidalem, hanc porrò induit aër, vt qua&longs;i cuneatim aqua perrumpat; propria igitur &longs;pontè; vi &longs;cilicet levitatis, qua pollet.

Augu&longs;tin. Si primo no&longs;tro congre&longs;&longs;ui interfui&longs;&longs;es, Chry&longs;ocome, hoc experimentum, dubio procul omni, minimè adduxi&longs;&longs;es, ob&longs;erva&longs;&longs;es enim aquam &longs;ecundùm latera tubi &longs;piratim de&longs;cendere, & ab ea &longs;ur&longs;um aëra extrudi, longè tardiore motu; quia &longs;ur&longs;um aër motu recto fertur, aqua verò deor&longs;um, non recto, &longs;ed &longs;pirali, quo rectum acceleratum im­peditum compen&longs;at; illud porro aëris fa&longs;tigium qua&longs;i cuneatum, non ab aëre vi propria induitur, &longs;ed inducitur ab aquæ pondere versùs tubi late­ra deflectente ad de&longs;cen&longs;um; alioquin &longs;i aër propria vi hanc figuram in­duit, cur non conicam, quæ ad a&longs;cen&longs;um & aquam perrumpendam lon­gè aptior e&longs;&longs;et; nec enim difficiliùs vnam quàm aliam indueret; immo fortè conicam, quæ ad cylindricam propriùs accedit. Vtinam æquè facile mihi e&longs;&longs;et, definire, quænam figura illa &longs;it, illiu&longs;que cau&longs;am afferre, quam nemo, &longs;altem quod &longs;ciam, huiu&longs;que adinvenit; hîc tuam operam, Antime; nec enim eum me reputo, qui hunc nodum &longs;olvam.

Antim. Non e&longs;t mihi dubium, quin hæc &longs;uperficies curva ab aqua ver­sùs latera va&longs;is inclinante formetur; cùm enim aqua de&longs;cendere non po&longs;&longs;it, ni&longs;i aër loco cedat, extru&longs;us &longs;cilicet ab aqua, & hic &longs;ur&longs;um extrudi non po&longs;&longs;it, ni&longs;i humor illi &longs;e&longs;e &longs;upponat, vt hoc faciat, eundem aëra qua&longs;i complexa per tubi latera &longs;piratim de&longs;cendit. An verò dicta &longs;uperficies pa­rabolica &longs;it, dubium e&longs;t; cum enim aqua versùs latera va&longs;is tendat, &longs;imul & deor&longs;um motu accelerato, inde re&longs;ultas motus mixtus, qui lineam pa­rabolicam po&longs;t &longs;e relinquit, vt jam alij demon&longs;trarunt; &longs;ed vnde erit mo­tus ille horizontalis cum perpendiculari conjunctus? an fortè dicendum e&longs;t, aquam &longs;piratim de&longs;cendere, cœpta qua&longs;i à centro &longs;pira; donec ad latera va&longs;is perveniat; ab illa autem &longs;pira deor&longs;um producta &longs;upremum illud aëris fa&longs;tigium tornari, cùm aliter &longs;piræ deor&longs;um produci non po&longs;­&longs;int: &longs;ed his omi&longs;&longs;is, cùm cylindrus aëris ab aqua &longs;tringatur, per latera delabente, tantulùm a&longs;&longs;urgat, nece&longs;&longs;e e&longs;t; vnde aqua, cui &longs;uprema illius ba&longs;is &longs;ube&longs;t, cedit locum; & cùm hæc attolli non po&longs;&longs;it, versùs latera eat oportet, vbi dumtaxat ei locus patet; &longs;cilicet inter aëra & late­ra va&longs;is, vnde linea parabolica re&longs;ultat; hinc &longs;i tubus &longs;it angu&longs;tior, vix aqua cylindrum inter aëris & latera tubi intercipi pote&longs;t; vnde prædicta &longs;upremi fa&longs;tigij forma non &longs;equitur, quæ certè minùs convexa e&longs;t, &longs;eu acuta, quò rima inter aëra & latera va&longs;is, qua perrumpit aqua, e&longs;t angu­&longs;tior: immo &longs;i tubus inclinetur, convexitas prædicti fa&longs;tigij deor&longs;um ver­sùs inferiùs tubi inclinati latus producitur; quia eò major ponderis aquæ vis fertur, ex quo etiam manife&longs;tè colligitur, hanc convexi fa­&longs;tigij figuram ab aqua versùs latera va&longs;is labente tornari. Porrò ne&longs;cio an vllus ob&longs;ervarit, quando minor e&longs;t aëris portio, tornari etiam & turbinari inferiorem aëris ba&longs;im, qua&longs;i ad in&longs;tar lentis, ino &longs;i adhuc minor &longs;it, ad in&longs;tar rotundæ gemmæ apparet; an fortè quia hæc figu­ra ab aqua ambiente inducitur, cùm inter omnes &longs;implici&longs;&longs;ima &longs;it, & inter æquales minimam &longs;uperficiem habeat; &longs;ed hæc tantulum figuræ de­&longs;iderant.

Sit tubus AD vitreus, plenus aqua, excepta por­tone aëris, quæ &longs;i innataret occuparet cylindrum FG ; primùm ita re&longs;tringitur, vt ba&longs;is diameter &longs;it TV, occupante aqua Spatia HTGV, ex cujus lap&longs;u, cùm duo corpora &longs;e&longs;e penetrare non po&longs;&longs;int, cylindrum aëris re&longs;tringi ac turbinari versùs K, vbi labens aqua versùs & &longs;ecus latera, locum illi cedit pror&longs;us nece&longs;&longs;e e&longs;t: cùm autem aqua per &longs;patia HTGV de&longs;cendens &longs;piratim, præ impetu, in aquam conten­tam cylindri portione CE altè &longs;ubeat, &longs;uperficies aquæ FE nece&longs;&longs;ariò attollitur; vnde portionem aë­ris I &longs;ur&longs;um extrudi, nece&longs;&longs;e e&longs;t; idque &longs;en&longs;im, in proportione a&longs;&longs;ignabili; detracto enim cylindro &longs;ub ba&longs;i TV, ex cylindro FG, vt re&longs;iduum ad cylin­drum FG, ita motus ba&longs;is TV ad motum aquæ la­bentis per &longs;patia HTGV, præ&longs;cindendo à &longs;pira. Iam verò &longs;it cylindrus aëris OM minor priore; at­tollitur quidem in X, & cum aqua lap&longs;a versùs N reflectatur à lateribus tubi, &longs;tatimque cum aqua inferiore mi&longs;ceatur, ita vt per &longs;piram integram minimè de&longs;cendat, qua&longs;i tondet marginem inferioris ba&longs;is cylindruli aë­ris, eamque in &longs;uperficiem convexam NPM facilè tornat; Porrò ab illa &longs;pira non integra labentis aquæ, lens aëris extru&longs;a &longs;ur&longs;um, huc illuc libratur eundo, quia cùm modò hinc, modò illinc labens aqua &longs;e&longs;e &longs;ubjiciat aëri, quid mirum, &longs;i prædicta libratio, &longs;eu tremor quidam con&longs;equatur: quod etiam accidit in cylindrulis aëris minoribus, propter eandem rationem; in majoribus enim de&longs;cendens aqua cum majore impetu aliam aquam &longs;ubit, vnde hæc &longs;ecundùm Planum horizontale &longs;en&longs;im at­tollitur.

Sit demum tubus AC in &longs;itu inclinato, cylindrus aëris EH ita conformatur, vt convexitas MFN multo longiùs producatur, quàm connexitas ME; nempe aqua gravior in latus inferius CB inclinat & versùs punctum H lateris inferioris CB de&longs;inunt &longs;piræ, quod ad oculum patet.

Augu&longs;tin. Ex iis omnibus manife&longs;tum fit, aëra &longs;ur&longs;um ab aqua extrudi, non verò &longs;ua &longs;ponte ire; alioquin cur illæ &longs;piræ? aut illa parabola? cur ini­tio a&longs;cen&longs;us, cylindri aërei fa&longs;tigium à Plano pa-rum di&longs;tat? cur &longs;i aëris portio modica &longs;it, etiam ima ba&longs;is convexa e&longs;t? cur major aëris portio tardiùs, minor citiùs a&longs;cendit? imò &longs;i idem tubus inæ­qualis &longs;it, per &longs;egmentum angu&longs;tius tardiùs aër incedit, citiùs per laxius; quia in angu&longs;tiore aër in longiorem cylindrum producitur; cur ille tre­mulus motus Lentium aëris? Cur figura Lentis, non Sphæræ? cur in tubo in­clinato longior e&longs;t convexitas aëris versùs latus interius, versùs &longs;uperius, brevior. Cuncta hæc explicari non po&longs;&longs;unt, &longs;i aër &longs;ur&longs;um &longs;ua &longs;ponte a&longs;cen­dit; &longs;cire tamen velim, cur eadem aëris portio in tubo angu&longs;tiore tardiùs, in laxiore citiùs a&longs;cendat.

Antim. Miror à te rationem non videri; in angu&longs;tiore tubo aëris por­tio in cylindrum longiorem formatur; igitur aqua per latera de&longs;cen­dens longius &longs;patium decurrere debet, antequam cum aqua inferiore conjungatur, & aëra &longs;ur&longs;um extrudat; igitur in eo plus temporis ponit.

Augu&longs;tin. Satis e&longs;t, rem intelligo, vnde etiam per&longs;picua ratio ducitur, cur modica portio aëris in eodem tubo citiùs a&longs;cendat, quàm major, quia hæc in longiorem cylindrum extenditur; quid mirum ergo, &longs;i tardiùs a&longs;­cendat?

Chry&longs;ocom. Infunde, quæ&longs;o te, in tubum aliquid olei; multa enim vi­debis, quæ tibi fortè oppo&longs;itum per&longs;uadeant: primo enim oleum tar­diùs a&longs;&longs;urgit, quia longè gravius e&longs;t aëre. Secundo eandem figuram induit quam Aër, tertio Aëris cylindrus per medium oleum citi&longs;&longs;imè &longs;ur&longs;um per­rumpit: quartò Aër nonnunquam oleum &longs;ecum longè citiùs rapit, quàm Oleum per &longs;e ip&longs;um a&longs;&longs;urgeret; nihil horum explicari pote&longs;t, ni&longs;i dicamus, aëra &longs;ur&longs;um &longs;ua &longs;ponte ferri.

Augu&longs;tin. Immo nihil horum explicari pote&longs;t, &longs;i hoc dicamus; primò igitur Aër citiùs fertur, tardiùs Oleum, cæteris paribus quia aliquando accidit, vt modica olei portio &longs;ur&longs;um citiùs avolet; tardiùs aurem æqua­lis portio; quia minus e&longs;t aquæ momentum adversùs gravitatem, &longs;eu pon­dus olei, & majus adversùs pondus aëris. Secundo de figura nihil adden­dum e&longs;&longs;e puto; ni&longs;i quòd inferior ba&longs;is ni&longs;i longior &longs;it olei cylindras, con­vexa e&longs;t. Tertio vbi aëris cylindrus ad cylindrum aëris pervenit, &longs;tatim de&longs;cendit Oleum, in libero &longs;cilicet aëre, & ab aquæ lap&longs;u circumagitur in mille orbes & &longs;piras; & verò Oleum in aëre po&longs;itum &longs;ua &longs;ponte citò de&longs;cendere, mirum non e&longs;t. Quarto Aëris bulla aliquando &longs;upremo cylin­dro olei adhæret, & tunc citiùs a&longs;&longs;urgit; quia &longs;cilicet totum illud per modum vnius attollitur; neque in hoc e&longs;t difficultas; Supponamus enim, e&longs;&longs;e vnciam aëris, & vnciam olei; certè major e&longs;t proportio momenti duarum vnciarum aquæ adversùs pondus aggregati, ex vna vncia olei, & vna aëris, quàm vnius vnciæ aquæ, adver&longs;us vnam Olei; nec ob&longs;tar aggregatum illud e&longs;&longs;e gravius alterutro; quia in comparatione duorum gravium, æqualis &longs;emper vtriu&longs;que exten&longs;io, &longs;eu moles accipitur. Sed hæc &longs;unt facilia, nec in his explicandis tua opera indigeo, Antime; in his tamen non dubito, quin alia multa à te ob&longs;ervata fuerint, quæ quia præ&longs;entis in&longs;tituti non &longs;unt, à te non po­&longs;tulo.

Antim. Negare non po&longs;&longs;um, quin multa mihi &longs;uppetant in hac ma­teria, quæ tamen quia à propo&longs;ito argumento aliena &longs;unt, in alium lo­cum tractanda & exponenda remitto.

Chry&longs;ocom. Vnde igitur motus levium &longs;ur&longs;um acceleratus? quòd certè in diver&longs;is globulis aqua levioribus probatum e&longs;t; immo in aëris cylindro per tubum a&longs;&longs;urgente, per&longs;picuè videtur; itemque in cylindro ligneo, per vim ad fundum latioris va&longs;is vel putei detento, qui &longs;ur&longs;um ita erumpit, vt longè altiùs a&longs;cendat; etiam &longs;i in imo va&longs;is fundo foramen &longs;it.

Augu&longs;tin. Ita e&longs;t; ii globuli motu accelerato a&longs;cendunt, diver&longs;o tamen à gravium motu; Supponimus enim liberum &longs;patium in ampli&longs;&longs;imo va&longs;e aqua pleno, ex quo leviora corpora, per mediam aquam a&longs;cendunt; v.g. cylindrus ligneus motu accelerato non quidem &longs;ponte, &longs;ed impre&longs;&longs;o ab aqua extrudente; nempe impetus initio productus durat deinde; quid mirum ergo, &longs;i motus inde acceleratus evadat?

Chry&longs;ocom. Igitur ad in&longs;tar gravium e&longs;&longs;et acceleratus, quod tamen omnibus experimentis repugnat;

Augu&longs;tin. Æqualibus temporibus, æqualia velocitatis momenta non accedunt, vt fit in motu gravium, &longs;ed minora &longs;emper & minora, priùs ta­men acqui&longs;itis &longs;emper remanentibus; an fortè vt in de&longs;cen&longs;u fune­penduli?

Antim. Minimè verò; cùm enim velocitates &longs;int vt motus, & hi in &longs;ubduplicata altitudinum vt &longs;upra demon&longs;tratum e&longs;t.

Sit &longs;emiparabola ABC, &longs;patium acqui&longs;itum motu naturaliter acce­

lerato erit AB, velocitas verò ac­qui&longs;ita &etail;rit BC ; &longs;it etiam AB altitu­do aquæ, intra quam corpus leve per vim intruditur & ex qua, præ­valente eju&longs;dem aquæ pondere &longs;ur­&longs;um deinde extruditur; &longs;it ergo BH æqualis BA item IN æqualis IH &longs;itque alia &longs;emiparabola NKC ita vt CI &longs;it Axi parallela; erit motus corporis levis initio extru&longs;ionis vt BC emen&longs;a verò tota aquæ altitu­dine erit vt HN: nempe vt ab A ad B acquiritur velocitas BC, & in patio DB &longs;upra DE jam acqui&longs;i­tam in &longs;patio AD, acquiritur EG ; ita in BH acquiritur IN &longs;upra jam acqui&longs;itam BC, & vt in DB acquiritur EG ita in BL acquiritur MK æqualis EG ; denique vt in AD acquiritur DE ita in LH acquiritur ON. Sed quid de foramine in fundo va&longs;is aperto, cujus &longs;upra Chry&longs;ocomus meminit?

Augu&longs;tin. De re mihi non con&longs;tat, nunquam enim hoc à me ob&longs;erva­tum e&longs;t.

Antim. Omninò di&longs;tinguendum e&longs;t; &longs;i enim tale e&longs;t, vt tantumdem aquæ per illud effluat, quantum infra cylindrum de&longs;cendit; cylindrus erit immobilis; &longs;i minùs de&longs;cendat, quàm effluat, cylindrus ip&longs;e, &longs;i de­&longs;cendere pote&longs;t, de&longs;cendet; &longs;i verò plus aquæ de&longs;cendat, quàm ex fora­mine effluat, tantulùm cylindrus a&longs;&longs;urgit.

Augu&longs;tin. Hoc ip&longs;um per&longs;picuè probat, corpus leve non attolli &longs;ua &longs;ponte; quod enim gravius deor&longs;um de&longs;cendat, non impedit, quò minùs leve &longs;ua &longs;ponte a&longs;cendat: &longs;ed accipe luculentum experimentum, iis ta­men &longs;imile, quæ jam expo&longs;ita fuere. Sit pixis quælibet, in cujus fundo he­mi&longs;phærium, vel minor Sphæræ portio accuratè & affabrè ita excavetur, vt Sphæram ligneam omninò capiat, nulla relicta intercapedine; tum pixis impleatur aqua; Sphærula lignea, quamvis levior, nullo modo a&longs;­cendit; quia &longs;cilicet cum aqua in cavitatem illam &longs;ubire non po&longs;&longs;it, ab ea Sphæra &longs;ursùm extrudi non pote&longs;t.

Chry&longs;ocom. Dicerem non a&longs;&longs;urgere Sphæram, ne detur vacuum; idem enim fieri videmus, &longs;i duo plana probè congruant.

Augu&longs;tin. Hoc dictum iri &longs;ciebam; &longs;ed fiat foramen in medio cavita­tis, quò &longs;cilicet aër ambiens facile &longs;ubeat, non propterea Sphærula a&longs;cen­dit, licèt nullum re&longs;tet vacui periculum: per vos etiam mihi liceat, hic obiter, ea &longs;altem indicare, quæ tuam illam &longs;ententiam, Chry&longs;ocome, om­ninò expugnare videntur. 1. Quandoquidem per vnum principium motus cuncta explicari po&longs;&longs;unt, quo &longs;cilicet corpus grave &longs;ua &longs;ponte deor&longs;um fertur, quod inficiatur nemo, & leve &longs;ur&longs;um extrudi pote&longs;t, fru&longs;tra ponitur aliud principium: Hæc ratio, licèt communis &longs;it, maximi &longs;anè momenti e&longs;t. Secundò, cùm ab eodem centro multæ lineæ ducantur, fi corpus levi&longs;&longs;imum e&longs;&longs;et, in centro, non po&longs;&longs;et vllo modo a&longs;&longs;urgere; cur enim potiùs per vnam lineam quam per aliam?

Antim. Facilè retorqueo argumentum, nec enim pariter &longs;ur&longs;um ex­trudi po&longs;&longs;et; cur enim potiùs per vnam lineam quàm per aliam?

Augu&longs;tin. Hoc quidem verum e&longs;t, modò ambiens gravius æqualis e&longs;&longs;et momenti; per omnes lineas; &longs;ed hoc per accidens; illud autem per &longs;e præterea, linea motus recti à termino, ad quem determinatur; cùm au­tem vnum centrum &longs;it, a&longs;&longs;umpto quolibet quncto extra centrum, ab illo ad centrum vnica tantùm linea ducitur, cùm tamen ab eodem, plures ad periphætiam duci po&longs;&longs;int; vna quidem producta ad centrum; &longs;ed quomo­do à centro determinatur hæc linea, quod neque &longs;it terminus ad quem, nec terminus à quo illius motus? Tertiò non pote&longs;t idem corpus in par­tes oppo&longs;itas &longs;imul moveri; igitur nec &longs;imul conniti, &longs;cilicet ab intrin&longs;e­co; quod vt meliùs intelligatur, &longs;it vas aqua plenum, &longs;itque pondus aquæ 40. libr. Sit fru&longs;tum ligni in fundo va&longs;is retentum pendens 5.libr. appen­datur &longs;imul vtrumque, &longs;u&longs;tinebitur à 45. libris po&longs;itis in altera lance li­bræ, eritque æquilibrium, &longs;tatimque impedimento &longs;ublato, lignum emer­git, &longs;ur&longs;umque attollitur eodem pror&longs;us æquilibrio manente; igitur hic motus &longs;ur&longs;um non e&longs;t ab intrin&longs;eco; vt patet, &longs;u&longs;tinetur ab aqua, inquies; rectè, ergo &longs;e ip&longs;um lignum non &longs;u&longs;tinet; igitur multò minùs &longs;e movet. Omitto innumera ferè experimenta, quæ rem hanc penitùs evincunt; &longs;ed ne in Parergum prolixius abeamus, cœptam di&longs;putationem à te re&longs;umi velim, Antime, præ&longs;ertim cùm hæc ad rem præ&longs;entem parùm faciant, modò enim aër gravis &longs;it, hoc tibi &longs;atis e&longs;t.

Antim. Vt igitur partes omnes terre&longs;tris globi versùs commune cen­trum nituntur, ita etiam partes aëris ambientis: Sed cùm aër &longs;ive purior, &longs;ive impurior, nam perinde e&longs;t, ambiat etiam alios totales globos, putà Lunam, globum enim totalem appello illum, qui alterius pars non e&longs;t, & &longs;eor&longs;im po&longs;itus manet, medium quoddam commune dici pote&longs;t.

Augu&longs;tin. Et cùm &longs;inguli globi totales &longs;uo centro gaudeant, versùs quod omnes illorum partes connituntur; hæc enim veri&longs;&longs;ima e&longs;t ratio, qua totales globi tornari, & figuram obtentam &longs;ervare po&longs;&longs;unt, aëris etiam, &longs;eu communis medij ambientis portio, versùs illos globos gravitat, &longs;eu nititur.

Antim. Rectè omninò; cùm enim medium commune tot v&longs;ibus nece&longs;­&longs;arium &longs;it, non minùs pertinet ad vnum globum, quàm ad alium; vnde rationiac rerum naturæ con&longs;entaneum e&longs;&longs;e videtur, vt versùs vtrumque gravitet; quota verò pars versùs vnum, & quota versùs alium, non diffi­cilè definiri pote&longs;t.

Sit enim centrum A terre&longs;tris globi CBED, &longs;it centrum Lunæ I, du­catur recta AI, connectens vtrumque centrum; con&longs;ideretur BK vt cylindrus aëris, cujus pars versùs A, & pars versùs I gravitet, tribus modis definiri pote&longs;t hujus cylindri portio, quæ versùs A, & ea; quæ versùs I gravitat; Primo divi&longs;a AI bifariam in F ; & &longs;ic FK gravitat versùs I & FB versùs A. Secundo divi&longs;a bifariam BK in M, & &longs;ic BM versùs A, & MK versùs I. gravitat. Tertiò ita divi&longs;a AI vt &longs;egmentum gravitans ver­sùs A, &longs;it ad aliud gravitans versùs I, vt globus A ad globum I. Quartus modus addi pote&longs;t, vt &longs;cilicet BK &longs;ecetur juxta dictam propor­tio nem globorum. Quidquid autem ex his dicatur, ad rem no&longs;tram perinde e&longs;t; quare majoris facilitatis gratia, primum modum accipio, & per punctum F duco GFH perpendiculariter, quæ vocetur dirimens connectentem centra, &longs;eu linea confinium. Quod dixi de AF, IF, de AN, IN dictum e&longs;to, item de reliquis lineis, &longs;eu cylindris.

Chry&longs;ocom. Multis &longs;anè, præ&longs;ertim Peripateticis, hæc tua doctrina mi­nimè probabitur, qui juxta mentem Philo&longs;ophi docent, centrum terræ idem e&longs;&longs;e cum centro Vniver&longs;i, versùs quod omnia gravia tendunt; nega­bunt igitur portionem aëris &longs;upra dirimentem GH, versùs Lunæ cen­trum gravitare.

Antim. Videtur quidem Stagirita hoc ip&longs;um, quod dicis ad &longs;truere; præ­&longs;ertim lib.2. de cœlo text. 100. Accidit autem, inquit, idem terræ medium e&longs;&longs;e, ac Vniver&longs;i, &longs;ed vt terræ centrum e&longs;t, in id ferri per accidens; per &longs;e verò ad centrum Vniver&longs;i; de hoc tamen lib. 3. text.33. dubitare videtur; vbi enim dixi&longs;&longs;et, quidquid pondus habet, ferri ad medium, &longs;eu versùs centrum, &longs;tatim &longs;ubdit hæc: vtrùm autem ad terræ medium, an Vniver&longs;i feratur, cùm idem medium &longs;it ip&longs;orum, alia ratio e&longs;t. Cùm autem Ari&longs;toteles cœlos &longs;olidos po&longs;uerit, & Sphæram ignis aëre &longs;uperiorem, & quintam e&longs;&longs;entiam, quam animatam e&longs;&longs;e indicare videtur, quid mirum, cùm ele­menta no&longs;tra, juxta illum, vltra concavum Lunæ non extendantur, & &longs;uis orbibus &longs;olidis &longs;olidi Planetæ affixi &longs;int, nihil vltra prorsùs gravitare aut levitare, ac proinde gravium & levium commune centrum in Mundi & Terræ centro collocavit. Si tamen cœlum e&longs;&longs;e fluidum puta&longs;&longs;et, & cœ­le&longs;tes Sphæras in illo communi medio moveri, & &longs;uos agere orbes; &longs;i Cometas de novo gigni & mori in ætherea regione, nec non faculas & maculas in Solis di&longs;co. Martem propiùs ad terras nonnunquam accedere quàm Solem; novas Stellas in Cœlo na&longs;ci; &longs;i demùm alia multa, quæ jam ex ob&longs;ervationibus comperta &longs;unt, &longs;civi&longs;&longs;et, non e&longs;t dubium, quin alia de Cœlo & Vniver&longs;i con&longs;tructione &longs;crip&longs;i&longs;&longs;et; quanquam cum Ari&longs;totele Dico centrum terræ Vniver&longs;i centrum e&longs;&longs;e, circa quod cœle&longs;tes Sphæræ &longs;uos orbes agunt, versùs quod illa omnia gravia tendunt, &longs;ublunaria &longs;ci­licet, quæ Ari&longs;toteles agnovit; &longs;ed cùm hoc commune medium vltra extendatur, & eadem ratione pro formatione & con&longs;ervatione militet in aliis globis; tot pono centra, in quæ partes circumpo&longs;itæ nituntur, quot &longs;unt globi totales; gravitas enim non totius, &longs;ed partium proprietase&longs;t, cujus vi quælibet pars versùs &longs;uum centrum nititur, & contranititur, ne ab eo &longs;eparet ut, & &longs;i vnquam ab eo &longs;eparetur, in illud denuò &longs;e reci­pit. Quid vero ad conmmne medium &longs;pectat, illius potio globum tendit, quæ &longs;cilicet propior e&longs;t, &longs;i quis autem ab&longs;olutè hoc neget, (quanquam non video cur ab&longs;olutè non po&longs;&longs;it ad&longs;trui) permittat &longs;altem hoc à me &longs;upponi, & ex illa hypothe&longs;i, ratiocinando, di&longs;cutere, quid ex illa &longs;equatur, & hæc qua&longs;i dicta ex hypothe&longs;i accipiat.

Auguftin. Quintam illam e&longs;&longs;entiam in cœlis nunquam probavi; cùm cœle&longs;tia corpora ex no&longs;tris elementis conflata e&longs;&longs;e communis &longs;it apud Sanctos Patres &longs;ententia, quos vide&longs;is apud Scheinerum, Ricciolum, Ce­ladam &c. immo Beda expre&longs;&longs;is verbis a&longs;&longs;erit, ahera e&longs;&longs;e &longs;uperius aëris &longs;patium in quo &longs;idera ferri perhibentur. In his autem, &longs;acræ Scripturæ &longs;an­cti&longs;que Interpretibus &longs;tandum potiùs e&longs;&longs;e duxerim; quam Peripateticis. Porrò ex &longs;uppo&longs;itione, quod cœle&longs;tia corpora ex no&longs;tris elementis con­&longs;tent, de quo po&longs;t novas ob&longs;ervationes dubitari nequit ; non video, quo­modo &longs;alvari omnia po&longs;&longs;int, ni&longs;i prædictam hypothe&longs;im ab&longs;olutè &longs;tatuamus; ita vt &longs;inguli globi totales &longs;uum &longs;ingulare centrum habeant, versùs quod partes omnes eju&longs;dem globi connituntur, cum illa communis medij, aëris &longs;cilicet portione, quæ ad illud propiùs accedit, quàm ad aliud; centrum verò terræ, præter illam centri rationem, quæ illi cum aliis globis communis e&longs;t, habet aliam rationem, quæ illi dumtaxat competit, centri &longs;cilicet Vniver&longs;i, quod certè terre­&longs;tri globo &longs;ingulare e&longs;t cui reliqui globi &longs;erviunt; nam propter ho­mines terre&longs;tris globi incolas totum corporeum mundum Deus condidit, nec aliis globis res viventes in&longs;unt, etiam, vt vocant, vegetantium vita, nihil enim hæc ad terræ incolas conferre po&longs;&longs;ent, vt patet; & quidquid &longs;uper his ad&longs;truitur, fictitium e&longs;t, & merum commentum; hinc circa ter­ram immobilem eunt cœle&longs;tes &longs;phæræ, eidem famulantes; vel diffu&longs;a luce, vt Sol, vel eadem repercu&longs;&longs;a, vt reliqui Planetæ, & &longs;tellæ veri&longs;imiliùs; adde quod diver&longs;is variorum motuum periodis tempora &longs;ignant, vt &longs;tellæ fixæ loca, propter invariabilem, quem inter &longs;e habent ordinem; &longs;ed quæ­&longs;o, perge, hæc à te &longs;uppo&longs;ita libenter admitto, etiam citra maris æ&longs;tum.

Antim. Secundo loco &longs;uppono, corpus liquidum, humidum, voca vt voles, &longs;i ab omni parte æquali ni&longs;u prematur, figuram &longs;phæricam in­duere; cùm enim corpori humido v. g aquæ figura va&longs;is facilè inducatur, nempe humidum terminis alienis facilè continetur, certè &longs;i æqualiter ab omni parte prematur, nulla e&longs;t ratio, cur potiùs hinc cedat, quàm illinc; inde igitur nece&longs;&longs;ariò figura &longs;phærica &longs;equitur: &longs;i verò minùs ab vna parte, quàm ab aliis, reliquæ haud dubiè prævalent, ac proinde hæc tantulum cedat & attollatur, nece&longs;&longs;e e&longs;t; In his, quæ per&longs;picua &longs;unt, diutiùs non hæreo.

Tertiò &longs;uppono corpus liquidum, cui corpus grave admixtum e&longs;t, inde graviùs effici; &longs;ic aqua, cui &longs;al admixtum e&longs;t, gravior evadit, item aër gravior, &longs;i multæ humoris particulæ, vt fit in nebula, admi&longs;ceantur; in hoc etiam nulla e&longs;t difficultas. His &longs;uppo&longs;itis, ad marinum æ&longs;tum explican­dum venio; & varias a&longs;&longs;ertiones ad&longs;truo ex iactis principiis deductas. Sit terra in A, vt dixi, & Luna in I, cum reliquo apparatu, vt &longs;upra, totus aèr infra lineam GFH, &longs;uppo&longs;ito vtroque globo immobili, gravitat ver­sùs centrum A; totus aër &longs;upra GH, gravitat versùs I; hic enim propriùs accedit ad I, quàm ad A; ille verò propiùs ad A, quàm ad I. Prætereà linea FB e&longs;t minor NV: itemque illæ minores, quæ propiùs accedunt ad FB; &longs;upponantur infinitæ, hinc inde, quarum maxima erit ES paral­lela dirimenti GH cum oppo&longs;ita æquali ZC: cùm autem prædictæ lineæ &longs;int totidem cylindri aëris gravitantis, haud dubiè gravitatio inæqualis e&longs;t, & con&longs;equenter pre&longs;&longs;io; igitur &longs;i &longs;upponatur globus totus aqueus, &longs;altem quo ad &longs;uperficiem, &longs;eu corticem exteriorem ex dicta pre&longs;&longs;ione inæquali, &longs;equitur figuræ &longs;phæricæ mutatio; & cùm ES, CZ &longs;int omnium maximæ in punctis E & C, maximum e&longs;t pre&longs;&longs;ionis momentum; igitur deprimun­tur C & E in Q & I v. g. igitur attollitur B in P, punctum enim B, in quo e&longs;t minimum pre&longs;&longs;ionis momentum, prævalentibus aliis, tantulùm attolli nece&longs;&longs;e e&longs;t.

Augu&longs;tin. Quàm magnum mihi campum aperis; pudet me, hæc priùs non cogita&longs;&longs;e; tam facilia, tam obvia, tam trita & communia: fac quæ&longs;o circulum DCBE volvi circa axem BD, punctum X de&longs;cribit circulum, cujus radius e&longs;t XB, in cujus tota peripheria fit æqualis pre&longs;&longs;io, &longs;cilicet vt XO, quæ e&longs;t major BF; item C de&longs;cribet peripheriam circuli radio CA, in qua tota e&longs;t æqualis pre&longs;&longs;io, &longs;ed longè major, quàm in priore; tum quia circulus major premitur, tum quia in &longs;ingulis punctis major e&longs;t pre&longs;&longs;io; in &longs;ingulis verò punctis inter CD, circuli pre&longs;&longs;ionum minores &longs;unt; quilibet &longs;cilicet &longs;ub &longs;inu recto; cùm autem pre&longs;&longs;iones &longs;int, vt præ­dicti circuli, ac proinde major &longs;it pre&longs;&longs;io in CE, &longs;equitur nece&longs;&longs;ariò de­pre&longs;&longs;io punctorum C & E & elevatio B & D, in oppo&longs;itis &longs;cilicet punctis, per quæ ducitur linea connectens centra, &longs;cilicet ID; vna tamen mihi re&longs;tat difficultas, cui &longs;olvendæ imparem profectò me &longs;entio, nempe in &longs;ingulis punctis quadrantis CD, æqualis e&longs;t vis pre&longs;&longs;ionis; cur igitur a&longs;&longs;urgit in R? cur vnum prævalet &longs;upra aliud;

Antim. Hic nodus indi&longs;&longs;olubilis e&longs;&longs;et, &longs;i tantùm pre&longs;&longs;io fieret in pun­ctis C & D, alií&longs;que eiu&longs;dem arcus CD ; &longs;ed quia æqualis radiorum, &longs;eu linearum pre&longs;&longs;io fit in circulo, v. g. in circulo radio CA, in circulo ra­dio ba, alií&longs;que parallelis, certè pre&longs;&longs;iones &longs;unt vt peripheriæ prædi­ctorum circulorum, & hæ vt radij CA, ba &c. vnde &longs;equitur, majorem e&longs;&longs;e vim pre&longs;&longs;ionis circuli, cujus radius e&longs;t CA, quàm circuli, cujus ra­dius e&longs;t Ba, deprimitur ergo aqúa in prædicto circulo CE, quem dein­ceps circulum maximæ preonis, &longs;eu depre&longs;&longs;ionis vocabo; & attollitur versùs P & R, qui &longs;unt poli prædicti circuli, &longs;eu puncta maximæ eleva­tionis: hinc ex &longs;phæra fit &longs;phærois, licèt autem pre&longs;&longs;io in b &longs;it major quam in X ; hoc tamen pro nihilo habendum e&longs;t; cùm primaria cau&longs;a elevatio­nis aquæ &longs;it à circulis pre&longs;&longs;ionis, non procul à circulo maximæ pre&longs;&longs;ionis di&longs;tantibus; accedit quod cùm non ob&longs;tante circulo pre&longs;&longs;ionia, radio ba, in­tume&longs;cat aqua in R, ac proinde in arcum Qb, oblique cylindrus incidat, pel­lit potiùs punctum b per ba quam per b A; vnde fit qu&etail;dam compen&longs;atio; nam X minùs re&longs;i&longs;tit directa pre&longs;&longs;ione per XA; quid mirum igitur, &longs;i à circulis majoris pre&longs;&longs;ionis altiùs attollatur ver&longs;us AP; itemque minùs premit per XB; b verò magis re&longs;i&longs;tit directa pre&longs;&longs;ione per bA, vnde ab aliis circulis majoris pre&longs;&longs;ionis minùs a tollitur; plus tamen per ba, quam vocare po&longs;&longs;umus obliquam pre&longs;&longs;ionem; vnde vides vnam compen&longs;ari per aliam; nempe X habet minorem pre&longs;&longs;ionem tum directam, tum obliquam; hinc ratione directæ plus attollitur, ratione obliquæ minùs, b verò habet majo­rem vtramque, ac proinde ratione directæ minùs attollitur, & plus ra­tione obliquæ; en vobis per&longs;picuam compen&longs;ationem. Denique licèt aliqua e&longs;&longs;et differentia elevationis, parum admodùm referret; de quo infra.

Chry&longs;oc. Huiu&longs;que qua&longs;i meditabundus conticui; negari tamen non pote&longs;t, quin peregrinum inventum &longs;it; modò omnia probè con&longs;entiant, ac phænomenis non repugnent; vnum tamen occurrit, quod mihi diffici­le videtur; cur &longs;cilicet pre&longs;&longs;io per vnum dumtaxat majorem circulum fiat, cujus radius e&longs;t CA; cur enim per alios non fit, quotum radij &longs;int XA, VA, BA. &c.

Antim. Rectè mones, hoc enim mihi explicandum incumbit, equi­dem fit pre&longs;&longs;io per omnes circulos majores, vt fit in circulo ma­jore, BCDE, &longs;ed quia propter pre&longs;&longs;ionem inæqualem, huju&longs;modi circuli in Ellip&longs;es, vel qua&longs;i Ellip&longs;es mutantur, con&longs;idero tantùm pre&longs;&longs;ionem in iis circulis, in quibus æqualis, vel vniformis e&longs;t pre&longs;&longs;io, inter quos vnus dumtaxat major e&longs;t, quem maximæ pre&longs;&longs;ionis &longs;upra voca­vi, in quem axis ab&longs;idum, &longs;eu maximæ elevationis, perpendiculariter cadit; aliíque minores eidem paralleli. Nempe &longs;i pre&longs;&longs;io vniformis e&longs;t, ni&longs;u quodam communi execitur, nec vnum eju&longs;dem circuli punctum ab alio attollitur; &longs;i verò difformis & inæqualis, ni&longs;us communis non e&longs;t, vt patet. Po&longs;ita igitur Luna in I, eaque immobili, terra in A, ita vt tota il­lius &longs;uperficies aquea &longs;it, terra non jam &longs;phæra, &longs;ed &longs;phærois erit ad in&longs;tar pruni, cujus major diameter e&longs;t axis ab&longs;idum, vel in linea connectente centra, minor verò e&longs;t diameter circuli maximæ pre&longs;&longs;ionis. Et &longs;i Luna &longs;it in Æquatore, prædictum Planum BCDE erit in plano Æquatoris, CE erit Meridianus, polus in C erecta CA perpendiculari ad planum Æqua­toris.

Augu&longs;tin. Quæ &longs;equuntur facilia reputo; demus enim moveri Lunam per IHS, eodem motu moveri videbitur punctum P ; & vbi Luna per­venerit in S, punctum maximæ elevationis erit in E, erítque EC linea ab­&longs;idum, & BD diameter maximæ pre&longs;&longs;ionis; atque ita prædictus aquæ tu­mor motum Lunæ omninò æmulatur, & orbe peracto, Luna redeunte ad punctum I, tumor rediret ad punctum P. Pro quo etiam fingendum e&longs;t, &longs;imul cum Luna, eodemque motu, circa centrum A, moveri lineam connectentem centra A, I, cum ip&longs;a linea dirimente GFH, &longs;ed profe­ctò hic æ&longs;tus ab eo diver&longs;us e&longs;t, quem modò habemus, vel ob&longs;ervamus in mari.

Antim. Ita e&longs;t, fateor vltro; quia totam terre&longs;tris globi &longs;uperficiem aqua non tegit; fac autem v. g. alti&longs;&longs;imum terræ tractum attolli &longs;upra aquas in V, haud dubiè eo tempore, quo tumor aquæ re&longs;ponderet radio AV, &longs;ecun­dùm eundem radium a&longs;&longs;urgit aqua per clivum montis, donec tandem Luna recedente versùs S, aqua &longs;ub&longs;idit, & refluit proprio pondere; quia pre&longs;&longs;ionis vi non &longs;u&longs;tinetur amplius; hinc fiet æ&longs;tus reciprocus, qualem modò habemus, &longs;ive, vt vocant, fluxus, & refluxus. Si verò ad occasum idem terræ tractus versùs mare inclinet; hinc inde maximus erit aquæ tumor ad vtrunque montis clivum, occiduum &longs;cilicet, atque ortivum; & Luna tendente versùs S, &longs;en&longs;im &longs;ub&longs;i­det aqua, excurrétque, hinc versùs ortum, inde occa&longs;um versùs; vt autem refluit aqua in partes oppo&longs;itas, abeunte Luna, ita Luna accedente à parti­bus oppo&longs;itis, nimirum ab occa&longs;u & ortu accurrit, vel affluit, a&longs;&longs;urgítque aqua versùs terræ tractum V, & vtrimque ad vtrumque clivum &longs;en&longs;im attolli­tur. Hinc &longs;i per medium terræ trectum, angu&longs;tum fretum perrumperet, aqua hinc inde &longs;imul a&longs;&longs;urgente, in medio freto gemini æ&longs;tus concurrerent.

Chry&longs;oc. Hæc mihi &longs;ummoperè placent; &longs;ed non intelligo, quid fiat Lu­na extra Æquatorem &longs;ita.

Antim. Faciam intelligas: finge tibi terram ad in&longs;tar &longs;phæroidis, id e&longs;t, Solidi Elliptici; cogita prunum PQRT, quod obtinebis, &longs;i ellip&longs;im hanc circa axem RP volvi iubeas. Finge autem prædictum prunum cujus &longs;ectio PQRT e&longs;t in plano Æquatoris, librari circa axem CE modò versùs Poream, modò versùs Au&longs;trum, per arcum 18. circiter graduum, hinc inde; ac &longs;imul li­neam ab&longs;idum RP volvi circa axem Mundi, in plano &longs;cilicet Æquatoris perpen­diculariter erectum, eodem pror&longs;us cum Luna motu, tum integræ revolutionis, tum etiam prædictæ librationis, en tibi germanum marini æ&longs;tus &longs;y&longs;tema.

Augu&longs;tin. Maxima difficultas &longs;e&longs;e mihi objicit ; nempe po&longs;ita linea ab&longs;i­dum extra Planum Æquatoris, Luna v.g.in Tropico Capricorni exi&longs;tente, &longs;i accipiamus quodlibet punctum extra Æquatorem, elevatio aquæ in eo puncto inæqualis e&longs;&longs;et, licèt Luna in Meridiano &longs;ita &longs;upponatur; & vt cla­riùs hanc difficultatem exponam.

Sit circulus verticalis & meri­dianus in globo terre&longs;tri ADCF, Horizon AC, Æquator FK; Tropi­cus Cancri HI, Capricorni GL, Axis mundi PM; &longs;upponatur Lu­nain G, &longs;cilicet in Tropico Capri­corni, & in meridiano &longs;upra hori­zontem; circulus maximæ depre&longs;&longs;ionis e&longs;t Bq & à terræ puncto D, quod a&longs;&longs;umptum e&longs;t extra Æqua­torem; punctum maximæ elevationis, quod e&longs;t in G, e&longs;t enim line ab&longs;idum GI, di&longs;tat toto area GD, a quo tamen circulus maximæ de pre&longs;&longs;ionis di&longs;tat tantùm arcu BM, po&longs;ita verò Luna in puncto mediæ noctis L, circulus maximæ depre&longs;&longs;ionis erit NO, Linea ab&longs;idum LH, arcus di&longs;tan-tiæ à puncto maximæ elevationis HD, maximæ depre&longs;&longs;ionis DN; igitur æ&longs;tus nocturnus longè major e&longs;t in loco D, quàm diurnus; immo &longs;i accipia­tur punctum B, in eo erit maxima depre&longs;&longs;io aquæ, Luna po&longs;ita in G ; &longs;cilicet de meridie, po&longs;ita verò in L, de media nocte, di&longs;tabit B à puncto maximæ depre&longs;&longs;ionis arcu BN; cuncta hæc repugnare videntur ob&longs;ervationibus, cùm æ&longs;tus diurnus & nocturnus æquales &longs;int.

Antim. Fateor vnum e&longs;&longs;e ex præcipuis Nodis, qui mihi &longs;olvendi &longs;unt, qui tamen facilè a me &longs;olvitur, in hypothe&longs;i facta. Nempe dato quod tota &longs;uperficies terre&longs;tris globi &longs;it aquea, cuncta hæc, vt dicis, &longs;uccederent; duo tamen ob&longs;erves, velim; primum e&longs;t, di&longs;tinguendam e&longs;&longs;e aquarum elevatio­nem, &longs;eu tumorem, ab earundem rapido cur&longs;u; vnum enim ab alio di&longs;tin­guitur, licèt vnum ex alio con&longs;equatur; vnde fieri pote&longs;t, vt cum minore ele­vatione &longs;eu tumore, rapidior cur&longs;us conjunctus &longs;it; & vici&longs;&longs;im minùs rapi­dus cur&longs;us, cum majore elevatione propter loci &longs;itum: Secundum e&longs;t, versùs Polos æ&longs;tus ferè &longs;ine legibus ire, quia cum punctum elevationis, quod non procul à Polo di&longs;tat brevem circulum, diurnum &longs;cilicet de&longs;cribat, circa axem Mundi, quid mirum, &longs;i maxima inde aquarum perturbatio na&longs;catur; & verò præ&longs;cindendo à vario terrarum &longs;itu, qui multa variat, versùs Polos, qua&longs;i vortex quidam tumentis aquæ, &longs;patio 24. horarum min 48. circa polum iret, ex quo reverà non modica aquarum perturbatio &longs;ine certa lege &longs;equere­tur. Sed de hoc infra. Porrò fateor vltro, præ&longs;cindendo à diver&longs;o partium &longs;itu & po&longs;ito quod tota &longs;uperficies terre&longs;tris globi aquea e&longs;&longs;et, in puncto D, tu­morem aquæ altiorem fore de meridie quàm de media nocte, Luna exi&longs;ten­te in Tropico Cancri, contra verò in Tropico Capricorni; immo Luna exi­&longs;tente in Cancro de meridie, vel in Capricorno, de media nocte, altiorem fore tumorem in D, quàm &longs;i Luna exi&longs;teret in Æquatore. Cur verò hoc modo non fiat, ex diver&longs;o terræ ac maris &longs;itu & à vario affluentis & refluen­tis aquæ cur&longs;u, variaque illius deflexione, reflexione, inclinatione, contra­ctione &c. de quibus infrà, omninò &longs;equitur. Itaque jam mihi &longs;ufficit, hanc veram cau&longs;am e&longs;&longs;e prædicti aquarum tumoris & motus, eju&longs;demque revo­lutionis, ad Lunæ motum diurnum ita compo&longs;it&etail; vt Luna in Meridiano exi­&longs;tente, &longs;ive &longs;upra, &longs;ive infra horizontem, præfatus tumor maximus &longs;it in lo­cis, &longs;ub eodem Meridiano &longs;itis: maxima verò ibidem depre&longs;&longs;io, Luna 90. gradibus à dicto Meridiano di&longs;tante; &longs;ic enim &longs;ingulis diebus tumor vna ferè hora tardiùs accedit; quia talis e&longs;t Lunæ motus, & jam vides, ni fallor, Chry&longs;ocome, quid ad mirabilem i&longs;tum effectum Luna conferat, & quàm providè antè dixerim, Lunam marini æ&longs;tus cau&longs;am non e&longs;&longs;e, nec enim re­verà cau&longs;a e&longs;t, &longs;ed mera occa&longs;io; cau&longs;a verò, inæqualis aëris gravitatio, eo modo, quo dixi. Ex qua po&longs;ita Luna, eju&longs;que motu ab ortu in occa&longs;um, ne­ce&longs;&longs;ariò &longs;equitur æ&longs;tus, id e&longs;t, aquarum elevatio & tumor, in dato quolibet Oceani puncto; &longs;uppo&longs;ita &longs;cilicet tota &longs;uperficie globi aquea, idque bis &longs;in­gulis diebus, &longs;cilicet de meridie, & media nocte Lunari; meridiem autem, &longs;eu mediam noctem Lunarem voco, illud temporis punctum, quo Luna e&longs;t in Meridiano, cui prædictus locus &longs;ube&longs;t; vtrùm verò tumor de meridie Lu­nari, &longs;it æqualis tumori de media nocte, jam dictum e&longs;t &longs;upra; nimirum æqualis e&longs;t, dum Luna non procul ab Æquatore exi&longs;tit; inæqualis verò, dum Luna versùs Tropicos excurrit; quid autem accidat, in hoc rerum &longs;tatu, nimirum ex diver&longs;o marium ac terrarum &longs;itu, paulò po&longs;t dicam, nec me opinor, ab onere illo eximetis.

Augu&longs;tin. Germanam ac facilem cau&longs;am habemus marini æ&longs;tus, qui &longs;ingulis diebus bis a&longs;&longs;urgeret in illa hypothe&longs;i totius &longs;uperficiei aqueæ, de qua vltra di&longs;putandum e&longs;&longs;e, non puto; quare ad aliam marini æ&longs;tus pro­prietatem venio; prima enim diurna e&longs;t, de qua huc v&longs;que; juxta illam hypothe&longs;im ; &longs;ecunda men&longs;trua, tertia denique annua. Quod &longs;pectat ad men&longs;truam, nemo ferè ne&longs;cit, æ&longs;tum maximum e&longs;&longs;e in Plenilunio, medio­crem in Novilunio, minimum in Quadraturis; Quæro igitur ex te, vtrùm in hac eadem hypothe&longs;i, ratio & cau&longs;a reddi po&longs;&longs;it huju&longs;modi varietatum.

Antim. Non e&longs;t dubium, quin po&longs;ita majore vi pre&longs;&longs;ionis, major ex illa tumoris, vel elevationis effectus con&longs;equatur, nimirum cre&longs;cente cau­&longs;a, cre&longs;cit effectus; atqui in Plenilunio major pre&longs;&longs;ionis vis e&longs;t, quàm in Novilunio; & in vtroque, quàm in Quadraturis; quia &longs;cilicet major vis e&longs;t gravitationis ; hæc verò major, quia tunc aër longè gravior.

Chry&longs;oc. Hæc probè inter &longs;e con&longs;entiunt, modò illud, quod vltimo loco a&longs;&longs;eris, &longs;ub&longs;i&longs;tat; at, vt ingenuè dicam, non video, cur aër &longs;it gravior in Plenilunio.

Antim. Aliquid fortè novi afferam; quod tamen cum reliquis experi­mentis, immo & principiis con&longs;entit; nempe certum e&longs;t circa Plenilu­nium omnibus corporibus &longs;pongio&longs;is & humidis, plus humoris & &longs;ucci ine&longs;&longs;e; vt videre e&longs;t in ovis, cancris, medulla, cerebro, alii&longs;que corpori­bus, quibus humor facilè affunditur; Hæc profectò negari non po&longs;&longs;unt ab iis, qui vel oculis in&longs;tructi &longs;unt; accedit, quod in corporibus appel­latis, non modò cre&longs;cit moles, &longs;ed etiam pondus, vt quivis probare pote­rit; quidni ergo longè plus humoris aëri circa Plenilunium in&longs;it, cùm aër facilè humorem excipiat, divi&longs;um &longs;cilicet in perexiguas, quæque omnem fugiant &longs;en&longs;um particulas. Humor autem aëri admixtus majus pondus conciliat, vt &longs;uppono ex jactis &longs;upra principiis.

Augu&longs;tin. Immo etiam fortè major e&longs;t aquæ vis circa Plenilunium; hu­mor enim humori facilè admi&longs;cetur; quod licèt nunquam expertus &longs;im, judico tamen probabile; licèt in parvis aquarum receptaculis &longs;en&longs;um omné facilè fugiat; &longs;ecus in majoribus, vt in Mari; &longs;ed cùm periculum non fe­cerim, vix affirmare au&longs;im, licèt inaudierim in quibu&longs;dam &longs;epulchris marmo­reis &longs;ubterraneis, aquam cre&longs;cere ac decre&longs;cere, pro diver&longs;o Lunæ ad&longs;pectu.

Antim. Ita e&longs;t, apud Arelaten&longs;es aliquid &longs;imile e&longs;&longs;e dicunt, &longs;ub templo Patrum S Franci&longs;ci de Paula; nempe illorum cœnobium &longs;itum e&longs;t extra vrbem, in eo loco, quem Campum Eli&longs;ium vocant, in quo innumeri vi­dentur tumuli lapidei, &longs;eu potiùs cap&longs;æ, in crypta verò &longs;ub templo, &longs;unt aliquot huju&longs;modi &longs;epulchra, in quorum vno paulo elatiore, aqua cre&longs;ce­re, ac decre&longs;cere dicitur, pro diver&longs;o Lunæ ad&longs;pectu; hoc non a&longs;&longs;ero, quia periculum non feci; mihi tamen vrna illa o&longs;ten&longs;a e&longs;t, & hoc mihi ab illis Patribus a&longs;&longs;ertum, penes quos &longs;it fides. Vt vt &longs;it, cùm circa Plenilunium plus humoris in&longs;it aliis corporibus, quæ facile humorem, &longs;ubtilem &longs;cili­cet exugunt, aëri quoque plus humoris ine&longs;&longs;e, nece&longs;&longs;e e&longs;t, cùm facillimè tenuis humor ab illo exugatur.

Chry&longs;ocom. Sed vnde amabò ille humor; an fortè Luna ex corporibus illum educit, circa Plenilunium, tunc enim major illius vis e&longs;t.

Augu&longs;tin. Si Luna humorem illum educeret, inde certè corpora humi­da &longs;icciora manerent, vt patet ex terminis, & vt mole ita & pondere im­minuta; cùm tamen &longs;ecùs accidat.

Antim. Vnde procedat hic humor, cujus major vis ine&longs;t aëri, &longs;icuti aliis corporibus, circa Plenilunium, ad præ&longs;entem effectum nihil facit, pro quo &longs;atis e&longs;t, rem ita e&longs;&longs;e, à quacumque tandem cau&longs;a &longs;it; certum e&longs;t, ta­men, Lunam cau&longs;am e&longs;&longs;e, vel occa&longs;ionem, pro cujus &longs;cilicet diver&longs;o ad­&longs;pectu, humoris affu&longs;i diver&longs;a ratio e&longs;t.

Chry&longs;ocom. Rem mihi grati&longs;&longs;imam feceris, &longs;i vel obiter &longs;altem indicâ­ris, quid &longs;entias de cau&longs;a illa; ni&longs;i enim fallor, fieri non pote&longs;t, quin aliquid apud te &longs;tatueris.

Antim. Dicam, &longs;ed ex hypothe&longs;i ; &longs;upponamus, Lunam ex no&longs;tris ele­mentis con&longs;tare, ac præ&longs;ertim ex multo humore, longè no&longs;tro &longs;ubtiliore, & puriore; nempe lympha no&longs;tra non e&longs;t pura, &longs;ed mixta ex aliis elemen­tis; quis &longs;cit, an aquæ illæ ibi &longs;int, quæ &longs;uper cœlos in &longs;acro textu e&longs;&longs;e dicuntur; nullos tamen in iis pi&longs;ces e&longs;&longs;e putes, nulla animantium, aut vegetantium &longs;emina; ibi enim fru&longs;tra e&longs;&longs;ent, cùm hæc propter hominem &longs;int terre&longs;tris orbis incolam; Sol autem, vt agit in terram, ita & in Lu­nam, & caloris vi, multum humoris rarefacti educit; cùm enim &longs;ubtilior &longs;it, longè faciliùs calore &longs;olvitur, educitúrque; hic porrò humor aëri ad­mixtus, caloris vi etiam vltra rare&longs;cit; donec tandem à Luna recedens, in conum vmbræ terræ immergatur, vbi præ frigore, den&longs;atur, & pri&longs;ti­næ gravitati re&longs;tituitur; quia verò Luna versùs occa&longs;um interim non pa­rum deflectit, ille tractus aëris, cui prædictus humor admixtus e&longs;t, pro­pior terræ fit, quàm Lunæ, atque adeò, infra lineam dirimentem, versùs ip&longs;am terram gravitat. Sed vt hoc clariùs explicetur, nonnihil &longs;chematis adhibeo: Sit centrum terræ A, (Po&longs;terioris Fig.) &longs;it Luna L, & Sol è regione op­po&longs;itus, &longs;ecundùm lineam LAK, erit Plenilunium; ac proinde hemi&longs;phætium Lunaris globi BED &longs;olaribus radiis illu&longs;tratur, quorum vi, humor ex illo educitur, &longs;ecundùm lineas eductas ex centro L, vt fit in globo terræ; cùm pariter Luna globus totalis &longs;it: Cùm autem vmbram &longs;uam terra proji­ciat &longs;ecundum lineam AL, haud dubiè &longs;i Luna &longs;it in Nodis, &longs;eu in plano Eclipticæ, in dictam vmbram immer&longs;a e&longs;t, &longs;ecus verò, &longs;i à dicto plano ab&longs;it, & quia interea Luna ab L tran&longs;it in M, K, R, aëris tractus, cui prædictus humor admixtus e&longs;t, paulò inde gravior redditus, cum iam &longs;it vicinior terræ, quam Lunæ, versùs terram tendit; vnde fit, vt redeunte Luna in L, in vmbram immer&longs;us, conden&longs;ato humore, multo gravior evadat, & cum &longs;it infra dirimen­tem, in terram magis gravitet: idem dico de reliquo aëris tractu, in orbem circa A ; acproinde major &longs;equitur pre&longs;&longs;ionis effectus, igitur major æ&longs;tus In Noerit in K, & illius Hemi&longs;phærium QPO illu&longs;tratur, educiturque vapor per lineam KP, alia&longs;que à centro K ductas; vnde prædictus vapor longiùs

recedit à terra, ac proinde vbi Luna, orbe peracto, redit in K, licèt non modica illius portio infra dirimentem de&longs;cenderit, minor tamen quàm an­te; quia versùs terram longè majus &longs;patium decurrendum fuit: hæc au­tem in terram circumquaque gravitat quidem, &longs;ed minùs; vnde minor pre&longs;&longs;io; igitur minor æ&longs;tus. At verò po&longs;ita Luna in Quadraturis M & R, &longs;uppono enim Solem in eodem loco; illu&longs;trantur Hemi&longs;phæria GIF, STV; vnde po&longs;tquam Luna, peracto orbe, redit in M, aëris tractus, cui admixtus e&longs;t eductus humor, per MI, alia&longs;que ductas à centro M, propior e&longs;t Lunæ, quàm terræ; vnde in Lunam gravitat, & cùm Lu­na tendat ab M in K, ad illum aëris tractum ip&longs;a accedit; ac proinde ma­ximam educti humoris partem colligit; immò Luna exi&longs;tente in K, Sol fe­rè lineæ AS re&longs;pondet, vnde ille aëris tractus inter MK, cui eductus hu­mor admixtus e&longs;t, majori ex parte intra vmbram à Luna projectam jacet, vnde &longs;tatim adden&longs;atur humor, & in ip&longs;am Lunam de&longs;cendit: Idem dico de Luna po&longs;ita in altera Quadratura R ; humor enim educitur per RT, alia&longs;que rectas ex centro R directas; cùm autem Lunæ motus &longs;it ab R in L, humor per RT eductus recedit ab vmbra projecta ab vtroque globo; vnde parum omninò den&longs;atur ; igitur etiam &longs;i terræ propior &longs;it, quàm Lu­næ, non tamen inde gravitatio cre&longs;cit; igitur neque pre&longs;&longs;io; igitur nec æ&longs;tus: igitur inde conveniens; ni fallor, ratio redditur, cur plus humoris Luna communicet corporibus &longs;ublunaribus, in Plenilunio; longè minùs in Quadraturis; in Novilunio demum minùs quidem quam in Plenilunio, plus verò quam in Quadraturis.

Augu&longs;tin. Hæc &longs;anè mihi &longs;ummopere placent; volvo tamen in mente nonnihil difficilè. Fingamus enim Lunam in L, vaporemque eductum attolli &longs;ecundùm altitudinem LE, quem vocemus radium Atmo&longs;phæræ Lunaris; erit prædictæ Atmo&longs;phæræ Hemi&longs;phærium BED; & in toto illo orbe LMKR, æquale Hemi&longs;phærium, vt HGI, QNO, TVX fin­gendum e&longs;t. In Novilunio verò, Hemi&longs;phærium Atmo&longs;phæræ Lunaris erit QPO, & in orbe illo diurno, TSX, BCD, HFI, in Quadratura verò M, erit GIF, PQN, SXV, CDE, denique in Quadratura R, erit STV, CBE, GHF, PON. Vnde &longs;equitur meo judicio, æqualem &longs;empet e&longs;&longs;e humoris educti copiam circumfu&longs;am, ac proinde æqualem gravitationem & pre&longs;&longs;ionem; igitur æqualem æ&longs;tum.

Antim. Fateor vltro æqualem ferè &longs;emper e&longs;&longs;e portionem humoris Lu­naris educti, admixtique aëris tractui intra Atmo&longs;phæram orbitæ Lunaris contenti, &longs;ed hic parum den&longs;atur, ac proinde vix gravior evadit, ni&longs;i intra vmbras ab alterutro globo projectas immergatur; neque hoc &longs;ufficit, ni&longs;i gravior factus propior terræ &longs;it, quàm Lunæ; hoc autem circa Plenilunium fieri con&longs;tat, in quo &longs;cilicet vmbra terræ projicitur qua&longs;i directè versùs Lu­nam; vnde magna humoris educti copia in dictam vmbram immergitur, ac proinde den&longs;atur, & gravior evadit; Lunâ autem recedente ab L, ver­sùs M, & K, humor ille tandem propior terræ fit: quid mirum igitur, &longs;i aër, cui admixtus e&longs;t magis in terram gravitet? Idem dico de Novilunio. Vbi enim Luna ex K Novilunij puncto pervenit per R in L, Sol ferè li­neæ EC re&longs;pondet, vnde vtraque vmbra tum Lunæ, tum terræ projicitur in illum aëris tractum, qui e&longs;t circa P, & cui eductus humor admixtus e&longs;t; hinc valdè den&longs;atur & gravior fit, & cùm &longs;it propior terræ, ver&longs;us illam tendit, de&longs;cenditque infra dirimentem: Si autem Luna ponatur in Quadra­tura M, vmbræ Lunæ ille aëris tractus, qui e&longs;t inter IO, & cui humor eductus admixtus e&longs;t, &longs;tatim diuque immergitur, vt patet; &longs;ive vmbra pro­jecta &longs;it à Luna, Sole po&longs;ito inter QT, & Luna inter OI, &longs;ive ab ip&longs;a terra, Sole &longs;ito paulò vltra R & Luna in K ; hinc den&longs;atur & gravior fit, & cùm Luna tunc fit propior, in eam gravitat & tendit. Denique &longs;i Luna ponatur in Quadratura R, ille aëris tractus, cui humor eductus admixtus e&longs;t, vmbræ terræ immergitur, quando Sol pervenit ferè in M ; Sed tunc Lu­na e&longs;t circa K, igitur vicinior, igitur in Lunam gravitat; pari modo, So­le po&longs;ito inter IO, Luna verò inter QT, immergitur in vmbram Lu­næ; &longs;ed tunc etiam gravitat in Lunam, cui propior e&longs;t.

Augu&longs;tin. Rem hanc probè intelligo, & nihil clarius e&longs;&longs;e videtur; duo tantùm ex te &longs;cire velim, immò tria; primum e&longs;t, vtrùm Sol æquali­ter agat in illud Hemi&longs;phærium Lunæ, quod illu&longs;trat, v.g.in BED, quan­do e&longs;t Plenilunium; Secundum e&longs;t, quid tandem fiat de humore illo ex Luna educto, terri&longs;que illap&longs;o. Tertium vtrùm ip&longs;o Plenilunij die &longs;it ma­ximus æ&longs;tus, an paulò ante, &longs;eu po&longs;t Oppo&longs;itionis momentum.

Antim. Ab hoc vltimo incipiam, in quo licèt varij &longs;int ij Autores, qui de hoc argumento &longs;crip&longs;erunt, quorum aliqui maximam vim æ&longs;tus die 17. Lunæ fieri volunt, quos arguit manife&longs;ta experientia; dico tamen etiam iuxta præmi&longs;&longs;am hypothe&longs;im, in qua totam &longs;uperficiem globi aqueam e&longs;&longs;e &longs;upponimus, maximam vim æ&longs;tus, &longs;eu quod idem e&longs;t, aquarum elevatio­nem, non fieri vbique in ip&longs;o Oppo&longs;itionis, &longs;eu Plenilunij puncto; &longs;ed tan­tùm in illo Meridiano, &longs;ub quo fit oppo&longs;itio, vel Plenilunium, idque per &longs;e, & in præfata hypothe&longs;i ; nam ratione &longs;itus, accidere pote&longs;t, vt iis omnibus, qui &longs;ub eodem Meridiano &longs;unt, eodem momento maximus æ&longs;tus non fiat, de quo infra; dixi etiam per &longs;e; nam per accidens &longs;ecus erit, vt &longs;i ex ortiva di&longs;ci Lunaris parte, plus humoris educatur, quàm ex occidua: & verò &longs;i maculæ Lunares aquæ &longs;unt, quanquam diver&longs;æ à no&longs;tris, & &longs;ine pi&longs;cibus, & virtute aliqua &longs;eminali, in parte ortiva longè plures & majores &longs;unt; Vnde &longs;equitur plus humoris educi paulò po&longs;t Plenilunium, quàm ante; quia Sol magis directè in eam partem Lunaris di&longs;ci agit, cui plus humoris educendi ine&longs;t.

Chry&longs;ocom. Ni fallor, apud aliquos Autores legi maximam vim æ&longs;tus vno vel altero die, po&longs;t Plenilunium e&longs;&longs;e; quod rectè in hanc rem Quadraret.

Antim. Legi&longs;ti haud dubiè; nam ad Diepam & alibi, vt Furnerius ob&longs;er­vat, &longs;ummum incrementum e&longs;t Die 17. Lunæ, biduo &longs;cilicet po&longs;t Plenilu­nij punctum; idem te&longs;tatur Cre&longs;centius lib. 3. Nautic. cap.2. idem Plin. lib.2. cap.97. vbi habet, maximè fervere æ&longs;tum, non in plena, aut novi&longs;&longs;i­ma, &longs;ed po&longs;tea: alibi tamen, vt in ora Gallica, te&longs;te Scaligero, exercit.52. cui &longs;ub&longs;crip&longs;it Furnerius lib.9.cap.21.in ip&longs;o Plenilunio maximè attollitur. Itaque ex diver&longs;o &longs;itu, hæc diver&longs;itas procedit; in præmi&longs;&longs;a tamen hypo­the&longs;i, eductoque vniformiter & æqualiter humore ex globo Lunari, ma­ximus æ&longs;tus fieret &longs;ub illo Meridiano, in quo fit Oppo&longs;itio; in aliis verò punctis citiùs vel tardiùs; ortiva &longs;cilicet intra Quadrantem citiùs, occidua verò tardiùs: ex illa verò hypothe&longs;i macularum Lunæ, quam tamen non ad&longs;truo, haud dubiè maximus æ&longs;tus fieret po&longs;t Plenilunium, ob rationem allatam. Sed jam ad &longs;ecundum tuum po&longs;tulatum re&longs;pondeo, mi Augu&longs;ti­ne, &longs;cilicet humorem illum, & facilè admi&longs;ceri no&longs;tris elementis, & facilè ex iis educi; nec enim cum iis mixtum quodpiam componit: ac proinde non mirum, &longs;i vt facilè educitur, atque avolat, ita facilè in Lunam redeat, cùm &longs;cilicet immergitur in vmbram, &longs;ive à terre&longs;tri, &longs;ive à Lunari globo projectam, & e&longs;t propior Lunæ, quàm terræ; in quo, meo judicio, nulla e&longs;t difficultas, nec e&longs;t quod aliquis timeat, ne hic vapor in nubes concre­&longs;cat quia nubes contexi non po&longs;&longs;unt ni&longs;i ex halitu heterogeneo; hic autem Lunatis vapor totus e&longs;t Homogeneus. Quod verò pertinet ad primum quæ­&longs;itum, dico Solem in eam globi Lunaris &longs;ectionem, &longs;eu portionem in quam radij magis directi incidunt, fortiùs agere; v. g. plus agit in arcum EY, quàm in YD, ita vt actio Solis in EY, &longs;it ad actionem in YD, vt Sinus re­ctus EY id e&longs;t LB, ad BD Sinum ver&longs;um arcus YD; & hoc in ip&longs;a &longs;e­ctione Lunæ; &longs;i enim accipiatur &longs;uperficies, actio in EY e&longs;t ad actionem in YD, in ratione compo&longs;ita, ex ratione Quadrati ab ad differentiam Quadrati BD & ex permutata Quadrati &longs;ub chorda arcus EY ad differen­tiam Quadrati &longs;ub chorda arcus ED, vel ex ratione Quadrati LB, ad Qua­dratum bD, plus bis rectangulum &longs;ub LbD, &longs;eu ad rectangulum &longs;ub bD, & aD, & Lc. ad cE &c.

Augu&longs;tin. Non intelligo hæc Geometrica, tam enim jejunè illa pro­ponis; cùm tamèn ab&longs;tru&longs;as demon&longs;trationes contineant; vix ea curtim & raptim indicata potiùs quàm expo&longs;ita qui&longs;quam mente capiat.

Antim. Suppono ea, quæ jam aliàs demon&longs;travi, &longs;cilicet circulum &longs;ub radio, æquali chordæ, æqualem e&longs;&longs;e portioni &longs;uperficiei Sphæræ, quam metitur, vel gignit arcus, cujus e&longs;t chorda, v. g. &longs;i accipiatur circulus &longs;ub radio æquali chordæ &longs;ubten&longs;æ arcui EY, erit æqualis portioni &longs;uperficiei Sphæræ, quam metitur, vel gignit arcus EY revolutus &longs;cilicet circa axem EC, hinc chorda &longs;ubten&longs;a arcui ED e&longs;t æqualis radio circuli æqualis &longs;uperficiei Hemi&longs;phærij; demon&longs;tratum e&longs;t item, portionem &longs;uperficiei genitæ ab arcu YE e&longs;&longs;e ad genitam ab arcu YD, vt Ec, ad cL; præterea lumina inci­dentia, per parallelas, &longs;unt vt ba&longs;es, &longs;i con&longs;iderentur in &longs;e; &longs;i verò con&longs;i­derentur in &longs;ubjecto, id e&longs;t in diver&longs;a &longs;uperficie, cui incidunt, &longs;i &longs;int æqualia lumina, erunt in &longs;ubjecto, vt &longs;uperficies illu&longs;tratæ permutando; v. g. &longs;i eadem vis, &longs;eu quantitas luminis, (&longs;ic enim vocare liceat) incidat in &longs;uperficiem duplam alterius, erit lumen, vel luminis inten&longs;io &longs;uperficiei duplæ ad aliam, vt 1.ad 2. Si verò &longs;uperficies &longs;unt æquales, &longs;ed lumina inæ­qualia, erunt inten&longs;iones, vt ip&longs;a lumina; &longs;i demum & &longs;uperficies inæqua­les &longs;unt, erunt inten&longs;iones in ratione compo&longs;ita luminum & &longs;uperficierum permutando; jam applica.

Augu&longs;tin. Satis e&longs;t, probe intelligo; inde autem con&longs;tat, quod jam &longs;ubindicare vi&longs;us es, vim Solis poti&longs;&longs;imum effectum habere circa Polum Hemi&longs;phærij Lunaris ab eo illu&longs;trati, v. g. circa E, intra arcum Zy, vltra verò versùs B & D parum valet; hinc etiam &longs;imilis ratio ducitur, cur Sol Oriens vel Occidens, terræ &longs;uperficiem parum afficiat, plus verò de meri­die, plus demum, quò Sol propiùs ad punctum verticale accedit; hinc vis debilior radij obliqui, non tantùm à radij reflexi carentia petenda e&longs;t; vt aliqui faciunt.

Chry&longs;ocom. Ex iis, quæ dicis, Antime, &longs;equeretur Lunaris di&longs;ci, vel Hemi&longs;phærij extremitates, minùs &longs;plendidas & illu&longs;tratas videri; nul­lum tamen ego di&longs;crimen ob&longs;ervo; oculis autem meis magis credo, quàm ve&longs;tris demon&longs;trationibus.

Antim. Demon&longs;tratio, Chry&longs;ocome, nunquam fallit, nec fallere pote&longs;t &longs;tatue igitur oculum in A; Lunam, licèt Sphærica &longs;it, vt planum di&longs;cum a&longs;picis, cujus diameter e&longs;t BD, paulò minor; & Ba, &longs;egmentum &longs;cilicet apparentis Semidiametri, vides &longs;ub angulo BAa; aL verò &longs;ub angulo aAL; &longs;ed ob parvitatem anguli BAL, qui vix e&longs;t 16.minutorum, anguli &longs;ub quibus videntur &longs;egmenta aB, aL, &longs;unt vt ip&longs;a &longs;egmenta; igitur tanta lux videtur in aB quanta in aL; quia in eadem ratione videtur contra­ctior, in qua primùm incidit di&longs;tractior; vt enim rem in plano tantùm, &longs;eu &longs;ectione lucis con&longs;ideremus, & &longs;upponamus lineam Aa, pro­pter di&longs;tantiam &longs;ecare arcum EB in Z, cùm lux incidens in &longs;e­gmentum aB, & incidens in &longs;egmentum aL, &longs;it æquè inten&longs;a; inci­dentis verò in BZ inten&longs;io; &longs;it ad inten&longs;ionem incidentis in ZE, vt aB, ad al, & cùm tota incidens in ZB, videatur contracta in aB; haud dubiè æquè inten&longs;a videbitur; & perinde atque &longs;i reverà incideret in rectam Bl: &longs;ecus autem accideret, &longs;i in arcum BZ directè radij vi&longs;uales inciderent.

Augu&longs;tin. Hæc fusiùs, quàm par &longs;it exponis; fingo ego radios ab arcu BZ profectos, à recta Ba profici&longs;ci; vnde opticè transfertur totum, id quod ine&longs;t BZ, in rectam Ba; &longs;ed in BZ tota illa luminis quantitas vi­detur, quæ, &longs;i radij liberum tran&longs;itum nacti e&longs;&longs;ent, ip&longs;i Ba incidi&longs;&longs;et; &longs;cio, ex his multa optica, eaque præclara deduci, v.g. cur flamma procul &longs;pe­ctata minùs candida appareat; cur Mars, dum minor apparet, candidior &longs;it; aliaque huju&longs;modi, quæ ad Opticam ac præ&longs;ertim rem colorum perti­nent; &longs;ed his omi&longs;&longs;is, vt ad rem no&longs;tram veniam, quæro à te, vtrùm reverà in Novilunio major æ&longs;tus &longs;it, quàm in Plenilunio.

Antim. Quibu&longs;dam in locis major e&longs;&longs;e dicitur in Novilunio; &longs;ecus ve­rò in aliis, idque vt plurimùm in Plenilunio; quod vel ex majore humoris affu&longs;i copia rectè deducitur: & verò iuxta præmi&longs;&longs;am hypothe&longs;im, nihil &longs;u­per hoc definiri pote&longs;t, ni&longs;i fortè ex &longs;uperiore aver&longs;oque Lunæ Hemi&longs;phæ­rio, plùs vel minùs humoris educatur; minùs autem educi videtur, tum quia minùs terris affunditur, tum quia ex libratione Lunæ apparet, gran­diores maculas in aver&longs;o Hemi&longs;phærio non e&longs;&longs;e; cùm demum ex fideli&longs;&longs;imâ omnium peritorum artis nauticæ relatione, maxima vis æ&longs;tus in Plenilu­nio e&longs;&longs;e dicatur, his, meo &longs;altem judicio &longs;tandum e&longs;t, quod reverà &longs;i &longs;uppo­natur, ad præmi&longs;&longs;a principia facilè reducitur: &longs;ed expectabam, Augu&longs;tine, vt quædam fortè &longs;ingularia ex iis, quæ diximus, pro ea qua vales ingenij &longs;agacitate deduceres.

Augu&longs;tin. Multa quidem animo volvi atque revolvi, &longs;ed vix temerè me committere au&longs;us &longs;um, ne the&longs;es meas ludibrio exponerem; non dubito ta­men, cùm hæc dicas, quin aliquid occurrat tibi &longs;citu dignum, quapropter te etiam atque etiam rogo, vt nobis illud participare digneris.

Antim. Illud &longs;anè te minimè effugi&longs;&longs;et; &longs;ed ad meas nugas non adeò &longs;edulò mentem applicas, quin circa alia longè fortè graviora ver&longs;eris.

Augu&longs;tin. Non ita res profectò &longs;e habet, &longs;ed cùm res i&longs;tæ tuæ novæ mi­hi accidant, vix eas primò intuitu mente complector; quomodò igitur, quid ex iis nece&longs;&longs;aria con&longs;ecutione &longs;equatur, videre po&longs;&longs;em? Mon&longs;tra quæ&longs;o viam; præ illico &longs;equar.

Antim. Illud inprimis &longs;equi videtur, aëra &longs;cilicet infimæ hujus regionis e&longs;&longs;e compre&longs;&longs;um vi ponderis innitentis.

Chry&longs;ocom. Quodnam pondus intelligis? An fortè Carte&longs;ij &longs;ententiam ad&longs;truis, qúi volebat à præter labente Luna aëra terram inter & Lunam in­terjectum comprimi?

Antim. Ab&longs;it, vt hoc dicam; licet enim fortè tantula compre&longs;&longs;io in Lunari Atmo&longs;phæra fiat, non tamen ad nos v&longs;que extenditur, vt videre e&longs;t in explo­&longs;ione majoris bombardæ, ex qua circumfu&longs;i aëris compre&longs;&longs;io &longs;equitur, quæ tamen ad modicam di&longs;tantiam producitur; intelligo igitur de ip&longs;ius aëris pondere; vt enim aquæ pondus aëra in fontibus illis artefactis, quos &longs;æpè videritis, contentum, comprimit, quidni pondus &longs;uperioris aëris alium comprimat? cogita Cylindrum plumbeum tantæ altitudinis, quanta opus e&longs;t, vt tanti ponderis vi, versùs ba&longs;im &longs;ub&longs;idat, ac dilatetur; multò magis &longs;i columnam ceream, vel ex butyro, aut charta erectam, maximæ &longs;cilicet altitudinis tibi ante oculos ponas; &longs;ub&longs;idet enim pars inferior, quanquam inæqualiter, erunt enim pre&longs;&longs;iones, vt altitudines, nimirum vt pondera; quidni ergo aër, qui certè dilatari nequit, vt butyrum, nec enim locus e&longs;t, &longs;ed tantùm comprimi, innitentis ponderis vi comprimatur? cùm perinde &longs;it, ex quacumque tandem materia pondus con&longs;tet, & mille aëris libræ eun­dem effectum gravitando habeant, quem totidem aquæ, vel alterius mate­riæ libræ haberent.

Chry&longs;ocom. Sentiremus haud dubiè ingens illud pondus, nec ferendo pa­res e&longs;&longs;emus.

Augu&longs;tin. An fortè &longs;entiunt vrinatores immer&longs;i ingens aquæ pondus illorum capiti &longs;uperfu&longs;um? Minimè verò; immò &longs;entire non debent, cùm præcipuus corporis gravitantis, liquidi &longs;cilicet, effectus &longs;it corpus &longs;ubjectum levius non deor&longs;um, at &longs;ur&longs;um extrudere; &longs;ic aqua in li­gnum immer&longs;um gravitat; equidem aqua in fundum va&longs;is lignei gravitat, deor&longs;umque pellit, &longs;i aër &longs;ubtus e&longs;t, vt patet, & &longs;imile pondus aquæ, ma­nus foramini in fundo dicti va&longs;is appo&longs;ita &longs;entiret, modò manus foramen adæquaret: at &longs;i lignum vel corpus levius aquæ immergatur, in id aqua ita gravitat, vt illud &longs;ur&longs;um extrudat, non verò deprimat deor&longs;um; &longs;i ve­rò &longs;it gravius aqua, ex parte &longs;altem illud &longs;u&longs;tentat, vnde appen&longs;um in aqua, minùs illius pondus &longs;entitur: ab illo igitur periculo immunes &longs;umus, nec timendum nobis e&longs;t, ne ab aëre obruamur: at ni fallor, ex præmi&longs;&longs;a gravitatione longè latéque aëris &longs;uperfu&longs;i, &longs;equitur egregium illud experi­mentum Mercurij in tubo vitreo contenti, & immer&longs;a alterius illius ex­tremitate, in &longs;ubjectum Mercurium, &longs;cutella contentum; &longs;u&longs;tinetur enim ad duos pedes altitudinis paulò plus reliquo tubo vacuo pror&longs;us manente, ab aëris gravitantis Cylindro.

Antim. De hoc argumento in hoc congre&longs;&longs;u agere non po&longs;&longs;umus, cùm &longs;ufficiens alterius materia e&longs;&longs;e queat; in quo præclari&longs;&longs;ima & &longs;anè mirifica phænomena explicabimus & demon&longs;trabimus, quæ tum ab aliis, tum à nobis explorata fuerunt; illud vnum vel obiter indica&longs;&longs;e &longs;ufficiat, &longs;cilicet experimentum illud nullo modo cum à te præmi&longs;&longs;a hypothe&longs;i con&longs;entire; quod ni fallor per&longs;picuè demon&longs;tro. Sit enim di&longs;tantia Lunæ à terra 50. Semidiametrorum terræ & Semidiameter terræ iuxta vulgarem calculum &longs;it pa&longs;&longs;uum Geometricorum 3436363. quem numerum &longs;i ducas in 25. quæ e&longs;t &longs;emidi&longs;tantia à terra &longs;cilicet ad lineam dirimentem, de qua &longs;upra venient 86909075. pa&longs;&longs;us, hæc e&longs;t altitudo aëris gravitantis ; &longs;i autem hunc numerum ducas in 5. venient 434544375 pedes; iam demus, aquæ gravitatem e&longs;&longs;e ad gravitatem aëris non vt 400.ad 1.vt non nemo voluit, &longs;ed vt 1000. ad 1. dividatur vltimus numerus per 1000. quotiens veniet rejecta minutia, 434544. igitur Cylindrus aëris prædictæ altitudinis adæ­quabit pondere Cylindrum aquæ altum pedes 434544. Sit autem aqua ad Mercurium, ad &longs;ummum, vt 1.ad 15. prædictus Cylindrus aëris adæquabit pondere Cylindrum Mercurij altum pedes 28969. quomodo igitur, duos tantum pedes altum adæquat & &longs;u&longs;tinet?

Augu&longs;tin. Rectè omnino; hoc enim confirmat illorum &longs;ententiam, qui volunt Mercurium &longs;u&longs;tineri ab aëre compre&longs;&longs;o, cuius vis tanta e&longs;t, vt Mercurij Cylindrum 2.pedes altum adæquet.

Antim. Hoc etiam dici non pote&longs;t, cùm enim aëris compre&longs;&longs;i vis per Cylindres æqualibus ba&longs;ibus non exeratur, &longs;icuti exeritur vis aëris gravi­tantis, certè quo major e&longs;&longs;et ba&longs;is tubi vitrei, eo minor e&longs;&longs;e deberet altitudo Mercurij ab aëre compre&longs;&longs;o &longs;u&longs;tentati; alia igitur ratio e&longs;t & cau&longs;a, quæ di­ctum Mercurium &longs;u&longs;tinet.

Chry&longs;ocom. Maxima igitur aëris no&longs;tri compre&longs;&longs;io e&longs;&longs;et ab illa imma­nis ponderis vi proveniens, ac proinde vix nobis toleranda; & vereor, vt per illam re&longs;pirare, vt aiunt, aut ducere anhelitum liceret.

Antim. Modica pror&longs;us illa vis e&longs;t; & jam olim Galileus, pro &longs;ummo, quo pollebat, ingenio, ob&longs;ervavit vim percu&longs;&longs;ionis infinitam propemo­dùm rationem habere ad vim gravitationis ; quod facilè probabis, vel vni­co ictu mallei, in glandem plumbeam impacti; illa enim ictus vi depre&longs;&longs;a ita dilatatur, vt &longs;imilis effectus vix ab immani ponderis gravitantis mole obtineri po&longs;&longs;it; omitto rationes phy&longs;icas, alioquin pulcherimas, ne à pro­po&longs;ito fine longiùs declinem; admitto igitur inferiorem aëris tractum pau­lò compre&longs;&longs;iorem e&longs;&longs;e, ac proinde parùm admodùm aut certè nihil ducen­do anhelitui obe&longs;&longs;e: licèt enim Thorax inde paulò difficiliùs explicetur, nonnihil tamen compen&longs;ationis ex eo fieri videtur, quod intra pulmones explicatos faciliùs adducatur, cùm jam &longs;ponte &longs;ua eò tendat, tum ratione gravitationis, tum ratione compre&longs;&longs;ionis, pari modo licèt aëris expul&longs;io­ni præfata compre&longs;&longs;io tantulum ob&longs;it, re&longs;i&longs;tit enim aër compre&longs;&longs;us; aliun­de tamen aër compre&longs;&longs;us ambiens thoracem, eju&longs;dem contractionem ju­vat; hinc etiam aliqua fit compen&longs;atio: prætereà e&longs;to, aër compre&longs;&longs;us tan­tulum impediat præfatam naturæ functionem; alia pariter alias impediunt; hinc motu ip&longs;o defatigamur.

Augu&longs;tin. Iam mihi venit in mentem illud Plinij dictum, lib.2.cap.98. ex Ari&longs;totele, nullum &longs;cilicet animal, ni&longs;i æ&longs;tu recedente expirare; quod inter fabulas referebam; nunc verò hujus dicti aliqua ratio affulget; nem­pe cùm accedente æ&longs;tu &longs;it minor aëris gravitatio, ac proinde minor illius pre&longs;&longs;io; contrà verò recedente; inde fit, re&longs;pirationem faciliorem e&longs;&longs;e, ac­ce&longs;&longs;us, quàm rece&longs;&longs;us tempore; cùm autem moribundi tantùm non vi­vant, & re&longs;pirandi pote&longs;tas in iis tantùm non extincta &longs;it; accedente mi­nimo illo impedimento, quod à compre&longs;&longs;ione aëris provenit, eo tempore, &longs;altem vt plurimùm, vitæ &longs;imul & anhelitus filum rumpitur.

Antim. Nihil potuit meliùs applicari, & facilè crediderim ex hac do­ctrina, non pauca Medicos in rem &longs;uam derivare po&longs;&longs;e in prædicendo ægro­rum animam agentium tran&longs;itu.

Augu&longs;tin. Vnum e&longs;t, ne quid di&longs;&longs;imulem, à me lectum, apud celeberri­mum illum Hydrographiæ &longs;criptorem Furnerium lib.9.cap.1.plus humo­ris &longs;cilicet ine&longs;&longs;e corporibus eo tempore, quo mare per æ&longs;tum intume&longs;cit; minùs verò tempore refluxus, vt vocant; illud autem, ita mihi difficilè vi­detur, vt huic nodo &longs;olvendo impar &longs;im.

Chry&longs;ocom. Ex præmi&longs;&longs;is principiis non adeò difficilè mihi videtur; cùm enim maximus æ&longs;tus &longs;it in Plenilunio, & tunc multus humor Lunari effluvio terris affundatur; quid mirum, &longs;i quo tempore maximus æ&longs;tus e&longs;t, corpora multo humore abundent.

Augu&longs;tin. Propo&longs;itæ à me difficultatis vim non capis; nec enim agi­tur de ip&longs;o æ&longs;tu Plenilunij, &longs;ed de quolibet alio. Et verò in Plenilunio fit refluxus, quo tempore minùs humoris corporibus ine&longs;t, & in Quadratu­ris etiam fit æ&longs;tus; & tunc corporibus multus humor ine&longs;t: &longs;i nobis non &longs;uccurras, Antime, animum de&longs;pondeo; ni&longs;i fortè rem ip&longs;am in dubium voces.

Antim. In dubium revocanda non e&longs;t; is enim non e&longs;t Furnerius, qui aliis imponat; & verò miror à vobis non videri, ex præmi&longs;&longs;is principiis hoc ip&longs;um &longs;equi: nempe in eo loco, in quo fit æ&longs;tus, aër minùs compre&longs;­&longs;us e&longs;t, quia minùs gravitat, vt jam diximus, nec repetendum e&longs;&longs;e du­xerim, &longs;i autem e&longs;t minùs compre&longs;&longs;us, minùs gravis e&longs;t, vt patet ex terminis; corpus enim den&longs;um &longs;eu compre&longs;&longs;um gravius evadit; igi­tur Lunatis ille humor admixtus difficiliùs, aut tardius a&longs;cendit; quo enim medium gravius e&longs;t, corpus leve eò faciliùs &longs;ur&longs;um ex­truditur; at verò tempore refluxus aër magis gravitat, in eum &longs;ci­licet tractum, in quo refluxus e&longs;t, igitur aër compre&longs;&longs;ior gravior evadit; quid mirum igitur, &longs;i Lunaris humor &longs;ur&longs;um faciliùs extrudatur? igitur tempore æ&longs;tus &longs;eu fluxus plus humoris ine&longs;t, minùs verò, tempore refluxus.

Augu&longs;tin. Libenter mihi &longs;uccen&longs;erem, qui rem ob oculos po&longs;itam non viderim; illud &longs;altem video ex dictis con&longs;tare, quæ & quanta &longs;it Lunæ vis in corpora &longs;ublunaria; multi enim effectus, in ægris præ&longs;ertim corpo­ribus ob&longs;ervantut, qui à celeberrimis Medicis Galenum &longs;ecutis Lunæ tri­buuntur; quid porrò Luna conferat, non vt cau&longs;a, &longs;ed vt &longs;ubjectum & oc­ca&longs;io, patet ex dictis huiu&longs;que; &longs;c licet majorem vel minorem humoris vim, majorem item vel minorem aëris compre&longs;&longs;ionem, gravitatem, levita­tem, gravitationem; quid etiam in malè affectis corporibus cuncta hæc præ&longs;tare po&longs;&longs;int nemo non videt; quid ad hæc diver&longs;i Lunæ a&longs;pectus, im­mò & fortè diver&longs;us Lunarium macularum &longs;itus, &longs;i fortè vt nonnullis vi­&longs;um e&longs;t, aqua &longs;it, à no&longs;tra tamen diver&longs;a; quid denique deliquium Solis vel Lunæ conferat ad diver&longs;as in &longs;ublunaribus corporibus mutationes; im­mò quid conus vmbræ ab vtroque globo projectæ, pro vario &longs;itu; nempe vapor Lunatis immer&longs;us vmbræ, den&longs;atur & gravior evadit, ferturque versùs illud centrum, cui propior e&longs;t; accedit, quòd ex Luna vmbræ im­mer&longs;a vapor non educitur, vnde nova in &longs;iccitatis aut humoris vi muta­tio &longs;equitur, immò & minor æ&longs;tus diebus, qui deinde &longs;equuntur; quia &longs;ci­licet totus ille humor de&longs;ideratur, qui toto Lunaris deliquij tempore So­lis vi eductus fui&longs;&longs;et.

Antim. Vnum omittis, quod certè dignum &longs;citu e&longs;t; &longs;it enim lagenula

quæpiam A, ex cuius ventre a&longs;&longs;urgat &longs;ur&longs;um canaliculus GF ad in&longs;tar ro&longs;tri; impleatur aqua &longs;it què &longs;uprema &longs;uperficies aquæ BC, per cana­liculum a&longs;turgit &longs;upra libellam CD ; an fortè eo tempore, quo tumet æ&longs;tus, id e&longs;t, quo Luna e&longs;t in Meridiano; minùs a&longs;&longs;urgit puta in E; plus verò, puta in F, eo tempore quo à Meridiano 90. gradibus di&longs;tat.

Augu&longs;tin. Rem magnam narras, Antime; &longs;ed fortè fabulam narras, cuipiam haud ab&longs;imilis, qui aquam Marinam in canaliculo contentam flu­xum & refluxum pati a&longs;&longs;erebat.

Antim. Seriò loquor, in his enim religioni ducerem, tibi alii&longs;que tui &longs;imilibus imponere: &longs;ed miror à te non videri; totum hoc ex præmi&longs;&longs;a do­ctrina &longs;equi; nempe aër in hoc infimo tractu compre&longs;&longs;us, vt dixi, premit &longs;uperficiem aquæ BC ; &longs;ed cùm &longs;uperficiem D minùs premat, quid mirum, &longs;i pre&longs;&longs;io in BC prævaleat? Minùs autem premitur &longs;uperficies D, quàm CF; quia compre&longs;&longs;um corpus exerit &longs;uam vim quoquo versùm per om­nes lineas, v.g. centrum ba&longs;is BC, aër &longs;uperfu&longs;us per omnes lineas premit, contentas intra conum maximè obtu&longs;um, & ba&longs;im D, per lineas contentas intra conum valdè acutum; quid mirum igitur, &longs;i pre&longs;&longs;io in BC &longs;uperet pre&longs;&longs;ionem in D, ac proinde aqua a&longs;&longs;urgat.

Chry&longs;ocom. Nunquid hoc tribui non po&longs;&longs;et Cylindro aëris gravitanti in ba&longs;im BC, qui longè gravior e&longs;t Cylindro gravitante in ba&longs;im D ; &longs;unt enim Cylindri ; vt ba&longs;es.

Augu&longs;tin. Nullo modo, nempe &longs;i habeatur ratio gravitatior. is, non a&longs;cendit aqua &longs;upra D ; quia gravitatio in perpendicularibus parallelis accipienda e&longs;t; neque in hoc vlla e&longs;t difficultas; cum &longs;it primum qua&longs;i principium Hydraulicæ, aquarum con&longs;i&longs;tentium &longs;uperficies e&longs;&longs;e ad libellam; attenta &longs;cilicet dumtaxat aquæ gravitate, &longs;ecus tamen res &longs; habet, &longs;i am­bientis pre&longs;&longs;io accedat; in hoc quippe gravitatio à pre&longs;&longs;ione di&longs;fert, quod hæc in Sphæram agat; ac proinde in idem punctum pre&longs;&longs;æ &longs;uperficiei per lineas infinitas ad illud idem punctum terminatas, illa verò per lineas parallelas deor&longs;um; ac proinde in idem punctum &longs;uperficiei vna tantùm linea gravitationis cadat; vnde ratio petitur propter quam Cylindrus major aquæ BG attollere minorem GD &longs;upra D non po&longs;&longs;it. Porrò ex te &longs;cire velim, Antimo, vtrùm in refluxu aqua altiùs a&longs;&longs;urgat quam in fluxu per canaliculum GF.

Antim. Omnia ferè complecti vi&longs;us es, & &longs;ingularem aëris compre&longs;&longs;i effectum per&longs;picuè di&longs;tinxi&longs;ti ab ip&longs;o ni&longs;u gravitationis ; &longs;i vel vnum ver-bulum addidi&longs;&longs;es, perfecta & ab&longs;oluta explicatio fui&longs;&longs;et; verbo igitur di­co; aër in æ&longs;tu &longs;eu fluxu e&longs;t minùs compre&longs;&longs;us; in refluxu verò compre&longs;­&longs;ior; quid mirum ergo fi compre&longs;&longs;ior majorem vim & ni&longs;um exerat, & fortè attollat aquam in F ; minùs verò compre&longs;&longs;us in E; dixi fortè; quia nondum periculum feci; faciam tamen brevi; quanquam &longs;i res non &longs;uc­cedat, non propterea phy&longs;ica ratio deerit.

Augu&longs;tin. Igitur pariter in Plenilunio altiùs a&longs;&longs;urget aqua; quia tunc aër gravior e&longs;t; igitur compre&longs;&longs;ior.

Antim. Gravior e&longs;t, vltrò concedo, quia multus humor admixtus; igi­tur compre&longs;&longs;ior, nego con&longs;equentiam; quia illud non comprimitur, ra­tione cujus gravior e&longs;t; cùm tamen &longs;ecus accidat, quàndo gravior e&longs;t, ra­tione altioris Cylindri: Vt vt &longs;it, in Plenilunio differentiá altitudinis aquæ ob&longs;ervare non potui, &longs;altem quæ &longs;ub &longs;en&longs;um cadat; &longs;i forte ab aliquo dein­ceps ob&longs;ervetur, ex jactis principiis ratio in promptu e&longs;t. Hîc autem aliud experimentum omittere non po&longs;&longs;um, quod dictam hypothe&longs;im æquè con­firmat; Sit vas ABG, cui tantulùm Mercurij in&longs;it, cujus &longs;uperficies EF ;

fit tubus vitreus Mercurio plenus, admotoque ori digito, inver&longs;us im­mergatur in Mercurium va&longs;e contentum; &longs;ubducto digito, ruit cum impe­tu magna pars Mercurij tubo contenti, cujus tamen portio CI &longs;u&longs;pen&longs;a manet; fui&longs;&longs;e autem ob&longs;ervatum aiunt, Luna exi&longs;tente in Meridiano, Mercurij &longs;uperficiem infra C deprimi: di&longs;tante verò à Meridiano 90. grad. &longs;upra C attolli; modica fortè vtrimque differentia; hoc experimentum, &longs;i verum e&longs;&longs;et, omnino evinceret æ&longs;tus cau&longs;am ab aliqua aëris pre&longs;&longs;ione, cui Luna occa&longs;ionem præbeat, petendam e&longs;&longs;e.

Augu&longs;tin. Immò evinceret Cylindrum Mercurij ab aëre extrin&longs;eco in &longs;uperficiem Mercurij EI gravitante &longs;u&longs;tineri, quod tamen ante negare vi&longs;us es.

Antim. Crede mihi, Augu&longs;tine, primò a&longs;pectu ita e&longs;&longs;e videtur; rem tamen penitiùs & accuratiùs in&longs;picienti &longs;ecus e&longs;&longs;e videbitur; hîc tantùm obiter indico; plus humoris ine&longs;&longs;e &longs;ublunaribus corporibus tempore flu-xus, quàm refluxus, vt jam dixi &longs;upra, ex hoc autem hujus effectus ra­tio petitur, &longs;i tamen verus e&longs;t, de quo aliàs.

Augu&longs;tin. Huc potiùs accer&longs;erem diver&longs;am pre&longs;&longs;ionem; hæc enim mi­nor e&longs;t in fluxu, in refluxu major ; quid mirum igitur &longs;i in fluxu Mercurij &longs;uperficies minùs, in refluxu altiùs &longs;upra C attollatur, premit enim aër compre&longs;&longs;us &longs;uperficiem Mercurij EF.

Antim. Vel ex hoc conjicere poteris, quàm fallax &longs;it vnum experimen­tum, & quàm facilè in errorem inducat, ni&longs;i ab aliis experimentis corri­gatur; con&longs;ulenda e&longs;t igitur tota experimentorum collectio, vt error vi­tetur, quod maximè in hoc ca&longs;u locum habet; Si enim vas A impleas

Mercurio, non jam vt ante aqua, a&longs;&longs;urgit in E vel F, per canaliculum, &longs;ed infra D &longs;ub&longs;idit: plu­ra de hoc argumento non dicam, quod reverà adeò &longs;ingulare e&longs;t & amplum, vt &longs;ingularem con­gre&longs;&longs;um po&longs;tulet; eò igitur vos remitto, præ&longs;er­tim cùm vix tempus &longs;uppetat ad reliqua pro&longs;e­quenda, quæ ad &longs;u&longs;ceptum de Marino æ&longs;tu argu­mentum pertinent.

Augu&longs;tin. Optimè mones, in proximum congre&longs;&longs;um remittamus, vt ea quæ re&longs;tant de maris æ&longs;tu pro&longs;equamur; de quo, ni fallor, illa omnia diligenter expo&longs;ui&longs;ti; quæ in præmi&longs;&longs;a hypothe&longs;i fierent, &longs;uppo&longs;ita &longs;cilicet tota &longs;uperficie aquea, quæ ad diurnam & men&longs;truam mutationem pertinent: duo re&longs;tant, opinor, primum ad mutationem annuam &longs;pectat, quæ fit in punctis anni cardinalibus, vt vocant, nimirum in Æquinoctiis & Sol&longs;titiis; alterum verò vt ex jactis principiis explices, varias æ&longs;tuum mutationes, quæ in diver&longs;is globi terraquei locis ob&longs;ervantur; &longs;uppo&longs;ita &longs;cilicet, ea globi &longs;uperficie, quæ modò e&longs;t.

Antim. Hæc duo explicanda re&longs;tant, fateor; primùm facilè expedio. Pri­mò, Luna exi&longs;tente in Æquatore, maxima e&longs;&longs;et elevatio aquarum iis, qui &longs;unt &longs;ub Æquatore, minima &longs;ub Polis; major autem vel minor pro majore vel minore loci a&longs;&longs;umpti di&longs;tantia ab Æquatore; e&longs;&longs;et autem diurnus æ&longs;tus æqualis nocturno. Secundò, Luna exi&longs;tente in Tropico Cancri, minor e&longs;&longs;et æ&longs;tus, quàm ante, iis, qui &longs;unt &longs;ub Æquatore; quanquam diurnus æqua­lis nocturno; iis verò, qui &longs;unt in Latitudine Boreali vltra Tropicum Can­cri, diurnum majorem haberent, quàm ante, minorem verò nocturnum; & vici&longs;&longs;im ij, qui &longs;unt in Latitudine Au&longs;trali, majorem nocturnum, minorem diurnum; & permutatis vicibus, exi&longs;tente Luna in Tropico Capricorni, i&longs;ti majorem diurnum, minorem nocturnum, illi verò nocturnum majorem, diurnum minorem: Porrò ad vitandam appellationum confu&longs;ionem, il­lum æ&longs;tum diurnum appello, qui fit die Lunari, id e&longs;t Luna in Meridiano &longs;upra horizontem exi&longs;tente. Tertiò, Quod pertinet ad alia loca inter Æqua­torem & Tropicos &longs;ita, &longs;ervata proportione, æ&longs;tus major aut minor definiri pote&longs;t, vt major &longs;it iis diurnus æ&longs;tus, ad quorum verticem Luna propiùs accedit. Quartò, Linea ab&longs;idum per centrum terræ &longs;emper ducitur, & cùm circa axèm Mundi moveri cen&longs;eatur, Luna exi&longs;tente in Æquatore, de&longs;cri­bit planum circuli; at verò extra Æquatorem de&longs;cribit &longs;uperficiem coni acutioris, vel obtu&longs;ioris, pro majore vel minore Lunæ di&longs;tantia ab Æqua­tore. Quintò, Maxima depre&longs;&longs;io in eo circulo &longs;emper e&longs;t, in cujus planum, & centrum, linea ab&longs;idum perpendiculariter cadit. Sextò, Diver&longs;am quoque mutationem inducere pote&longs;t diver&longs;us gradus caloris in aëre; nempe aër ca­lidior, rarior e&longs;t & levior, frigidior verò; den&longs;ior & gravior, unde varij ef­fectus gravitationis, pre&longs;&longs;ionis, Lunatis humoris, motus, &c. Hinc fortè il­lud, quod à nonnullis ad&longs;truitur, cum veritate con&longs;entit; &longs;cilicet majores cieri æ&longs;tus Luna in Aquarij Signo &longs;ita; quia Luna in Plenilunio, in quo ma­jor æ&longs;tus con&longs;ideratur, &longs;i e&longs;t in Aquario, Sol, cui opponitur, e&longs;t in Leone, tunc igitur maximè ardet æ&longs;tus ; aër igitur valdè calidus e&longs;t; igitur rarus & levis, vnde majore cum impre&longs;&longs;ione, aër Superior, humorque Lunaris gra­vitant in inferiorem tractum; &longs;ed hoc parum profectò, aut nihil ju­vat; nec cum obfervationibus con&longs;entit; & quam vis dici po&longs;&longs;it, va­rietatem, quæ ex diver&longs;is ob&longs;ervationibus habetur, ad diver&longs;um ter­ra tum tractum reduci po&longs;&longs;e; quia tamen non tantùm aër calidus, qui ad terras proximè accedit con&longs;ideratur, nec is, qui prædicto climati re­&longs;pondet, &longs;ed is totus quantus quantus e&longs;t, qui versùs terræ centrum gravi­tat, nulla fortè inde mutatio induci videtur. Hæc &longs;unt, ni fallor, quæ &longs;tando in præmi&longs;&longs;a hypothe&longs;i, de mutationibus, quæ per annum fiunt in Marino æ&longs;tu, dici po&longs;&longs;unt. Alterum re&longs;tat, quod fortè paulò difficilioris e&longs;t operæ.

Augu&longs;tin. Duo &longs;uggero, quæ mihi veniunt in mentem; primum e&longs;t, inter effectus diver&longs;æ & inæqualis gravitationis aëris, recen&longs;eri po&longs;&longs;e ventum illum, qui cum æ&longs;tu conjunctus e&longs;t, levis quidem, &longs;en&longs;ibi­lis tamen, vbi &longs;cilicet montium obices non ob&longs;tant, nec aliæ cau­&longs;æ ob&longs;unt, ab ortu versùs occa&longs;um, de quo dubium e&longs;&longs;e nequit, cùm longè faciliùs navigetur versùs occa&longs;um, quàm ver&longs;us ortum; cùm enim aër, Luna in Meridiano po&longs;ita, &longs;it minùs pre&longs;&longs;us, haud dubiè le­vior e&longs;t; igitur ab alio, qui versùs ortum e&longs;t, vtpote graviore extruditur; accedit, quòd altior e&longs;t aër in O, quàm in F ; (&longs;eque Schem.) igitur versùs f de&longs;cendere pote&longs;t.

Chry&longs;ocom. Sed cur potiùs aër, qui e&longs;t in O, de&longs;cendet in F, ab ortu &longs;cili­cet ad occa&longs;um, quà is, qui e&longs;t in N, versùs ortum; cùm eadem vtriu&longs;que &longs;it pre&longs;&longs;io, gravitas, altitudo.

Augu&longs;tin. Rem haud dubiè hoc argumento conficeres, &longs;i Luna immota in I &longs;emper e&longs;&longs;et, &longs;ed admi&longs;&longs;o illius motu versùs S aër N le­vius redditur, & aër O gravius; quid mirum ergo, &longs;i O prævaleat? Alterum fortè altioris indaginis e&longs;&longs;et; obiter tamen indicabo: nem­pe varij Autores referunt, vatias inundationes accidi&longs;&longs;e eo tempore, quo varij Planetæ Conjuncti erant; cujus ratio ex præmi&longs;&longs;is facilè, meo judicio, deducitur; Sit enim Luna I in principio Arietis, So­li conjuncta; Sint etiam Mercurius, Venus, Mars ibi conjuncti; ad-

de &longs;is Iovem; haud dubiè linea AS ad maximam di&longs;tantiam producendæ erit, antequam incidat in aliam lineam dirimentem re&longs;pectu alterius cu­ju&longs;libet globi totalis; vnde major erit circulus maximæ pre&longs;&longs;ionis, vt &longs;u­pra vocabas, Antime; igitur major illius vis atque pre&longs;&longs;io, igitur major aquæ tumor; major igitur inundatio; vt tamen de &longs;ingulis &longs;eor&longs;im aliquid definiatur; varius terrarum &longs;itus con&longs;iderandus e&longs;t; & hoc e&longs;t alterum ca­put, Antime, quod tibi explicandum re&longs;tat.

Antim. Egregia pror&longs;us ob&longs;ervatio; inde enim per&longs;picua & qua&longs;i pal­pabilis cau&longs;a & ratio multorum effectuum &longs;tatuitur, qui vulgò virtutibus occultis tribuuntur; &longs;ed vt pen&longs;um impo&longs;itum per&longs;olvam, terre&longs;tris globi Plani&longs;phærium ve&longs;tris oculis &longs;ubjicio, & antequam oculos in globum conjiciaris, nonnulla &longs;uppono ex præmi&longs;&longs;is. Primò, Vim pre&longs;&longs;ionis, quæ tum à circulo maximæ pre&longs;&longs;ionis, vt &longs;upra appellavi, tum ab aliis paral­lelis procedit, ita variari, ac perturbari po&longs;&longs;e, vt diver&longs;um æ&longs;tus effectum producat, etiam &longs;ub eodem Parallelo; variatur autem &longs;eu perturbatur ex eo quod terre&longs;tris globi &longs;uperficies tota aquea non &longs;it, &longs;ed partim aquea partim continens; nempe arcus ille circuli pre&longs;&longs;ionis, cui continens &longs;ub­e&longs;t, nullum pre&longs;&longs;ionis effectum con&longs;equitur, reliquo tamen eju&longs;dem circuli arcu, cui aqua &longs;ube&longs;t, effectum præ&longs;tante; brevitatis ergo, hunc arcum vtilem vocemus; illum verò inutilem. Secundò, Non tantùm vim pre&longs;­&longs;ionis con&longs;iderandam e&longs;&longs;e, quatenus e&longs;t ab vno arcu, &longs;ed quatenus e&longs;t etiam ab aliis; ita vt ab illo commuai qua&longs;i ni&longs;u aqua elevari cen&longs;eatur, quæ re-vera elevatio licèt aliquem aquarum motum dicat, non tamen ita acci­pienda e&longs;t, vt aqua à circulo maximæ pre&longs;&longs;ionis ad punctum maximæ ele­vationis excurrat, totumque illud &longs;patium conficiat, &longs;ed vt pars aquæ aliam partem pellat, & hæc aliam; cogita ve&longs;icam aqua plenam, quam vel ma­nu, vel fune in &longs;piras acto &longs;tringis, ac proinde temporis ferè momento tu­mor attollitur, quod certè per motum obtineri non po&longs;&longs;et. Tertiò, per motum aquam elevatam versùs litus excurrere, & aver&longs;is ire fluminibus, ad in&longs;tar majoris cuju&longs;dam dolij; vbi enim litore altior e&longs;t, in litus exun­dat; idem dico de &longs;uprema fluminum &longs;uperficie: & hæc e&longs;t ratio cur aqua, per æ&longs;tum exundet, quia cum prædictæ pre&longs;&longs;ionis vi, etiam ver­sùs oram & litus extollatur, in litus ip&longs;um, quod inferius e&longs;t, & in &longs;ub­jacentis fluminis alveum excurrit, &longs;ublata verò pre&longs;&longs;ione, aqua illa, quæ priùs exundarat in litus, cum &longs;it altius ip&longs;a maris, po&longs;tquam detu­muit, &longs;uperficie, versùs ip&longs;um mare refluit. Quartò, Majorem arcum vtilem plùs, minorem verò minùs præ&longs;tare; præ&longs;ertim cùm &longs;uo modo accedat ratio vectis, &longs;icuti brevior baculus difficiliùs curvatur, quàm longior; hinc major arcus minorem &longs;uperat, & major &longs;uperficies aquæ ex præ&longs;atis arcubus con&longs;tans vincit minorem ex arcubus etiam con&longs;tan­tem; &longs;unt autem huju&longs;modi arcus paralleli circulo maximæ pre&longs;&longs;ionis; & cum in &longs;ingulis punctis circuli vtilis, æqualis pre&longs;&longs;io cen&longs;eatur, inæ­qualitas pre&longs;&longs;ionis directæ accipienda e&longs;t in arcubus ad angulos rectos &longs;ecantibus prædictos pre&longs;&longs;ionum arcus. Quintò, Suppono ad aquam extru­dendam, per angu&longs;tiorem alveum, &longs;eu canalem, minorem pre&longs;&longs;ionis vim de­&longs;iderari, vt con&longs;tat ex doctrina motuum; nempe major mobilis, &longs;eu moven­di corporis moles motui magis re&longs;i&longs;tit.

Augu&longs;tin. Cuncta hæc &longs;atis intelligo; &longs;tatuo enim globum i&longs;tum in &longs;itu Sphæræ rectæ; ita vt axis & poli &longs;int in plano horizontis; a&longs;&longs;um­ptoque &longs;upremo globi puncto, &longs;eu vertice, illius horizon, qui per Po­los de&longs;cribitur, e&longs;tque vnus ex Meridianis & di&longs;tat à puncto a&longs;&longs;umpto 90. grad. circulus maximæ pre&longs;&longs;ionis erit, cui &longs;i omnes parallelos acci­piam, omnes circulos pre&longs;&longs;ionum habeo, & probè di&longs;tinguo arcus vtiles ab inutilibus, & portionem &longs;uperficiei ab vtilibus rectam, &longs;eu occupatam, ab alia; quæ profectò quantum varia &longs;it, cùm hinc expli­cetur, illinc contrahatur, inde versùs Ortum, hinc versùs Boream ex­currat &longs;atis patet. Vt autem majoris, vel minoris vim definiam, ratio­ne &longs;cilicet puncti a&longs;&longs;umpti, initio ducto ab horizonte, &longs;eu circulo ma­ximæ pre&longs;&longs;ionis, con&longs;idero ac metior &longs;uperficiem vtilem &longs;ic eam vo­co, quam arcus vtiles occupant) pro cujus diver&longs;o &longs;itu, & diver­&longs;a exten&longs;ione, diver&longs;a &longs;equitur pre&longs;&longs;io & elevatio in puncto a&longs;&longs;um­pto Æquatoris; Hoc &longs;at benè intelligo; vellem tantùm, vt illud quod vltimo loco ad&longs;truxi&longs;ti, de aqua in angu&longs;tias redacta paulò fu&longs;iùs ex­plicares.

Antim. Per me licet; &longs;upponamus ita extrudi per canalem ADH. vt altitudo alvei pleni &longs;it AC, latitudo verò initio &longs;it AB, &longs;ed qui retenta eadem altitudine, contrahatur &longs;ecundùm latitudinem, ac proin-de lineæ AH, BK, non &longs;int parallelæ, &longs;ed vna ad aliam accedat; jam alij demon&longs;trarunt velocitatem aquæ in AB ad velocitatem aquæ in HK

&longs;uppo&longs;ita eadem vi motrice, e&longs;&longs;e vt HE ad AD, id e&longs;t vt HK ad AB, id e&longs;t in ratione latitudinum permutando, &longs;i verò decre&longs;cat etiam altitu­do, ita vt altitudo in HK, &longs;it HI, velocitas in AB e&longs;t ad velocita­tem in HK, vt HF, ad AD vel in compo&longs;ita latitudinum & altitu­dinum permutando; hoc inquam jam alij demon&longs;trarunt; cùm enim tota aqua fluat per planum AD, & per planum HE, quæ ad in&longs;tar duo­rum foraminum con&longs;iderare po&longs;&longs;umus, &longs;uppo&longs;ita &longs;emper eadem vi motri­ce, haud dubiè velociùs fluere debet per HE, quàm per AD, idque in ea proportione, in qua AD major e&longs;t quàm HE; in hoc nulla e&longs;t difficultas, & omnibus congruit experimentis; hinc aqua quæ &longs;ur&longs;um extruditur, di­latatur, quæ verò &longs;ua &longs;ponte de&longs;cendit, contrahitur; quia hæc motu acce­lerato, illa retardato fertur.

Augu&longs;t. Hoc &longs;æpè miratus &longs;um in filo labentis olei, quod certè ad hunc effectum aptius e&longs;t, quàm aqua, propter vliginem; contrahitur enim & ex­tenuatur filum illud; &longs;ed rem grati&longs;&longs;imam faceres, &longs;i demon&longs;trares in qua proportione contrahatur.

Antim. Hoc jam alij demon&longs;trarunt; quia tamen nihil e&longs;t, quod tibi

negare au&longs;im ; &longs;upponamus e&longs;&longs;e vas CB, in cujus fundo &longs;it foramen CD, accipiatur quæcunque altitudo puta CF, &longs;it quælibet Semiparabola AFH, &longs;ub axe FA, ducanturque applicatæ CE, FH; in Parabola &longs;i accipiatur motus accelera­tus, axis erit &longs;patium, applicatæ verò tem­pus & velocitas; igitur &longs;patium acqui&longs;itum tempore CE erit ad acqui&longs;itum tempore FH, vt AC ad AF, &longs;unt enim &longs;patia, vt tempo­rum Quadrata; igitur velocitas aquæ in CD erit ad velocitatem in FG vt CE ad FH, &longs;ed tran&longs;itus aquæ &longs;unt vt velocitates, per­mutando, vt jam dixi &longs;upra; igitur vt FH ad CE, ita circulus CD ad circulum FH; igitur &longs;i vt Diameter CD ad FG, ita hæc, ad K, erit vt FH, ad CE, ita CD ad K. &longs;it vt FH ad CE, ita hæc ad L, & vt CD ad K, ita hæc ad M, &longs;itque inter KM media proportionalis N, erit vt FH ad CE, vel CD ad M, ita AF ad AC; igitur AF e&longs;t ad AC in ratione quadruplicata CD ad FG, id e&longs;t, vt CD ad M, facilè autem invenitur FG, quia vt FH ad CE, ita CD, quam habeo ad K ; inter K & D invenio mediam proportionalem FG ; item inter K & M &longs;cilicet N. Sed hæc &longs;ufficiant, jam ad &longs;u&longs;ceptum pro­po&longs;itum redeo, & quia omnia &longs;ingularia explicari non po&longs;&longs;unt; fru&longs;tra enim id fieret, mihi &longs;atis e&longs;&longs;e videtur, &longs;i vnum vel alterum &longs;ingulare ex­ponam. Accipio igitur punctum in Æquatore 345. longitudinis, vt vi­des in globo; cum circa illum tractum, celeberrimus ille fluvius, quem Amazonum vocant, ex Orientali Americæ ora in mare influat, & maxi­mum &longs;tatis horis patiatur æ&longs;tum, qui ad 300. milliaria per alveum flu­minis a&longs;cendit; huic tractui Luna oritur in Meridiano longitudinis 75. & tunc maxima e&longs;t pre&longs;&longs;io circa tractum longitudinis 545. quæ &longs;en&longs;im ver­sùs Ortum decre&longs;cit; quid mirum ergo, &longs;i versùs oram Guineæ ad Afri­cam, mare intume&longs;cat? Vbi præ&longs;ertim Luna per 30. gradus versùs occa&longs;um progre&longs;&longs;a e&longs;t, vbi verò tandem pervenit ad grad. 345. tunc ibi maxima e&longs;t aquarum elevatio; & quia longè ante aqua a&longs;&longs;urgere cœpit, ab eo &longs;cilicet momento, quo à grad.75. Luna occa&longs;um versùs progre&longs;&longs;a e&longs;t, quid mirum &longs;i a&longs;&longs;urgens aqua in apertum & &longs;atis directum fluminis alveum ex­currat? In quem tamdiu excurrit; quamdiu a&longs;&longs;urgit aqua ad illam oram; hæc autem tamdiu a&longs;&longs;urgit, quamdiu pre&longs;&longs;io decre&longs;cit; hæc demum tam­diu decre&longs;cit, quamdiu Luna ad Meridianum longit.745. accedit; vbi enim Meridianum illum attingit, maxima e&longs;t aquarum elevatio, nec vltra pre&longs;&longs;io decre&longs;cit; &longs;ed deinde cre&longs;cit pre&longs;&longs;io, progrediente ad occa&longs;um Lu­na, idque continuè donec perveniat ad nonage&longs;imum inde gradum, id e&longs;t, ad longitud. grad. 255. hinc refluit aqua, non modò proprio acta pondere, &longs;ed accedente majore vi pre&longs;&longs;ionis &longs;ollicitata, idque, quam­diu pre&longs;&longs;io cre&longs;cit, vnde per &longs;e tamdiu fluxus durat, quamdiu refluxus, & hoc vt plurimum fieri &longs;olet, licet per accidens alter altero diuturnior &longs;it, de quo infra præterea progrediente Luna à gradu 255. ad 165. in hoc puncto erit maxima elevatio; igitur circulus maximæ pre&longs;&longs;ionis &longs;ecabit Æquatorem in punctis 255. & 75. vt patet, at in ii&longs;dem punctis circulus maximæ pre&longs;&longs;ionis Æquatorem &longs;ecabat, quando Luna erat in gradu 345. igitur in eodem tractu maxima e&longs;t aquarum elevatio; &longs;en&longs;im enim ibi a&longs;­&longs;urgit aqua, vbi &longs;en&longs;im pre&longs;&longs;io decre&longs;cit; igitur dum Luna à puncto 255.ad punctum 165. progreditur, cre&longs;cit æ&longs;tus ad prædictam oram, & in fluminis alveum intrat. Denique peracto circulo Luna redit ad grad.75. & tunc e&longs;t maxima pre&longs;&longs;io in dicto tractu 345. Vides quàm facilè cuncta hæc ex præ­mi&longs;&longs;is deducta præfato tractui applicentur.

Augu&longs;t. Duo mihi occurrunt difficilia; primùm e&longs;t, &longs;ita Luna in gradu longit. 345. circulum maximæ pre&longs;&longs;ionis Meridianum illum e&longs;&longs;e, qui Æquatorem &longs;ecat in grad. 255. ac proinde per medium qua&longs;i mare paci­ficum ducitur; licèt autem hujus maris pre&longs;&longs;io aliquem effectum habere po&longs;&longs;it, non tamen vllam vim derivare pote&longs;t in oram maritimam, inquam prædictum flumen influit, cùm interjectus va&longs;ti&longs;&longs;imus Americæ tractus ob&longs;tet; &longs;ecat etiam Æquatorem in grad. Longit.75. Sed hic locus non mari &longs;ed terris incubat, ducitur enim per mediam ferè Æthiopiam & Africam ab Au&longs;tro in Boream; igitur cùm mare non premat, nullus in­de pre&longs;&longs;ionis effectus &longs;equitur.

Antim. Antequam ad &longs;ecundam difficultatem orationem convertas, hæc quam expo&longs;ui&longs;ti, mihi priùs &longs;olvenda e&longs;t; & fateor, vel nullam, vel minimam pre&longs;&longs;ionis vim à &longs;emicirculo maximæ pre&longs;&longs;ionis per mare pa­cificum ducto, ad grad Longit.255.ad o&longs;tia præfati fluminis traduci, pro­pter interjectum continentis Americæ impedimentum; dixi vel mini­mam, quia negari non pote&longs;t, traduci aliquam tum versùs Au&longs;trum per freta Magellanicum, Marium &c. tum versùs Septentrionem per freta Davi&longs;ium, Hud&longs;onium &c. Fateor etiam minimam vim traduci ad præfa­ta o&longs;tia à &longs;emicirculo ortivo maximæ pre&longs;&longs;ionis Æquatorem &longs;ecante ad grad Longit.75. cùm major illius pars &longs;it inutilis, arcus verò vtiles hinc versùs Septentrionem, indèversùs Au&longs;trum, à promontorio, quod bo­næ Spei vocant, excurrant, cùm tamen vis pre&longs;&longs;ionis non tantùm &longs;it à prædicto circulo maximo, &longs;ed etiam ab aliis minoribus parallelis, prædictæ elevationis ad illa o&longs;tia plu&longs;quam &longs;ufficientem cau&longs;am ha­bemus.

Augu&longs;tin. Cur verò ad 300. milliaria per alveum fluminis æ&longs;tus a&longs;­cendit? cùm tamen ad oram Guineæ oppo&longs;itam longè minus a&longs;cendat: & hæc e&longs;t altera difficultas.

Antim. Ex illo communi pre&longs;&longs;ionis ni&longs;u, motus quidam mixtus vel eju&longs;dem motus linea re&longs;ultat, &longs;ecundùm quam æ&longs;tus in oram excurrit; cùm igitur circuli pre&longs;&longs;ionum, qui mari Atlantico incumbunt, aquam attol­lant extrudantque qua&longs;i versùs Au&longs;trum, ac proinde versùs Borealem Americæ oram; circuli verò qui Æthiopicum premunt, extrudant aquam per fauces illas inter Bra&longs;iliam & Africam interceptas, versùs Caurum; ex vtroque ni&longs;u, mixtus quidam re&longs;ultat ver&longs;us Libycum, ac proinde in o&longs;tia præfati fluminis, qua&longs;i directè incidit æ&longs;tus; Quid mirum igitur, &longs;i longiùs excurrat? accedit quod fluminis alveus per 10. integros gradus id e&longs;t 600.milliaria, qua&longs;i &longs;ecundùm rectam lineam versùs Libycum fer­tur; quod reverà plurimùm confert ad hoc, vt æ&longs;tus per dictum alveum longius excurrat: At verò ad oram Guineæ licèt rapidi&longs;&longs;imus æ&longs;tus a&longs;­&longs;urgat torrentis ad in&longs;tar, quia in prædictam oram ad Au&longs;trum conver­&longs;am, versùs Boream extru&longs;us qua&longs;i directè fertur; non tamen per alveum fluminum longè excurrit, cùm nec &longs;int capaces alvei, nec &longs;ecundùm di­rectam lineam eant, neque, vt vides in hoc globo, Guinea magnos flu­vios habeat; equidem ad 7. grad. Latit. Au&longs;tralis magnus fluvius Zaire in Oceanum influit, &longs;ed à 6. gradu ad promontorium bonæ Spei perexiguus æ&longs;tus e&longs;t; præterquam quòd linea æ&longs;tus in eo tractu; (&longs;ic deinceps appel­labo) tendit ad Vulturnum, vel Euronotum; vnde valdè obliquè in oram illabitur; non mirum igitur &longs;i potiùs præterfluat, quàm irrumpat. Vnum omi&longs;eram, &longs;cilicet, Oceanum Æthiopicum in iis faucibus, quas in globo vides, inter Gibbum Africæ, extremumque Bra&longs;iliæ promontorium coërceri, vnde intume&longs;cat a&longs;&longs;urgatque cum impetu, nece&longs;&longs;e e&longs;t, adver­sùs oppo&longs;itam &longs;ibi, qua&longs;i aggerem, Guineæ oram.

Augu&longs;tin. Non e&longs;t dubium, quin æ&longs;tus linea ad tem hanc multùm, ne dicam totum conferat; nondum tamen &longs;atis capio, vnde & quomodò hæc linea &longs;tatuatur potiùs quàm alia; hac enim &longs;emel &longs;uppo&longs;ita, inde facilè deducam, vtrùm magnus, an parvus æ&longs;tus &longs;it, in data quali­bet ora.

Antim. Rem acu tetigi&longs;ti; hæc enim linea æ&longs;tus, &longs;eu cur&longs;us aquarum, quem &longs;i paulò vehementior &longs;it & contractior, Eurippum vocant, ab ea­dem cau&longs;a procedit, à qua æ&longs;tus ip&longs;e, vel aquarum elevatio; &longs;cilicet ab in­æquali aëris pre&longs;&longs;ione, & inæquali ni&longs;u; itaque ex pluribus capitibus hæc linea æ&longs;tus determinari pote&longs;t. Primò, in præmi&longs;&longs;a hypothe&longs;i &longs;olus e&longs;&longs;et aquarum motus ab ortu in occa&longs;um, vt jam &longs;upra dictum e&longs;t; nempe ille idem pre&longs;&longs;ionis ni&longs;us &longs;emper duraret, & tantus e&longs;&longs;et aquarum tumor, &longs;ub vno Meridiano, quantus &longs;ub alio, &longs;ub eodem &longs;cilicet Parallelo; at po&longs;ita tali &longs;uperficie terræ qualis modò e&longs;t, in &longs;ingulis ferè punctis eju&longs;­dem Paralleli, mutatur ni&longs;us; quia mutatur illius cau&longs;a; diver&longs;a e&longs;t enim arcuum vtilium ratio; hinc diver&longs;a linea &longs;equitur; &longs;i enim æqualis &longs;it ni&longs;us ab Au&longs;tro; Aquilone & Ortu, & minor, aut nullus ab occa&longs;u, in occa&longs;um linea motus ibit; &longs;i æqualis ab Au&longs;tro, Occa&longs;u & Ortu, & mi­nor in Aquilone, ad Aquilonem ibit; atque ita de aliis; & cùm infinitæ &longs;int combinationes ni&longs;uum, vt &longs;unt infinitæ diver&longs;arum pre&longs;&longs;ionum, etiam &longs;ub eodem Parallelo, quia infinitæ-mutationes &longs;uperficierum ex arcubus vtilibus con&longs;tantium, tum in magnitudine, tum in &longs;itu, inde &longs;equitur infinitas e&longs;&longs;e po&longs;&longs;e, ac reverà e&longs;&longs;e lineas æ&longs;tus, quæ ex diver&longs;o ni&longs;u na&longs;cuntur: Primum igitur caput, ex quo talis linea &longs;tatui­tur, e&longs;t talis ratio ni&longs;us, &longs;eu pre&longs;&longs;ionis. Secundò à quibu&longs;dam locorum angu&longs;tiis petitur, &longs;eu maris &longs;eu freti, quod &longs;ecundùm talem vel talem lineam excurrit; cùm enim aqua pre&longs;&longs;ionis vi extrudatur, & continen­tis vtrimque aggeres aquam contineant, quid mirum, &longs;i per freta currat, atque adeò ab alveo freti linea æ&longs;tus determinetur. Tertiò, Si vtrimque vis pre&longs;&longs;ionis in vtrumque freti o&longs;tium aquam intrudat, in­tra fretum æ&longs;tus concurrent. Quartò, quando æ&longs;tus valdè obliquè in­cidit in aliquam oram, non reflectitur, &longs;ed ip&longs;am oram præterlabitur; immò &longs;i ip&longs;a hora ad modum &longs;inus cavi e&longs;t, æ&longs;tus &longs;emiorbe peracto, ver­sùs eam partem, vnde venerat, declinat; hinc mutatio lineæ: ad hoc ca­put revoca reflexionem. Quintò, Æ&longs;tus alterius maris ex angu&longs;tis fauci­bus erumpens, & in alium incidens, lineam mutat; nempe ex vtroque qui­dam motus mixtus re&longs;ultat, ac proinde nova linea.

Augu&longs;tin. Cuncta hæc in rem hanc optimè quadrant: quare nihil aliud re&longs;tat, ni&longs;i vt fidelis & accurata Marini æ&longs;tus hi&longs;toria de&longs;cribatur, vt &longs;cia­mus quænam &longs;it linea æ&longs;tus in qualibet ora; Tu verò me tibi &longs;ummopere ob&longs;tringeres, &longs;i aliquot exempla breviter afferres, quibus ea, quæ dixi&longs;ti, meliùs con&longs;tarent.

Antim. Prædicta hi&longs;toria ad rem hanc maximè opportuna, immò & nece&longs;&longs;aria e&longs;&longs;et, in qua tamen à rei Nauticæ Scriptoribus nonnulli de&longs;i­dera&longs;&longs;ent, vt &longs;altem in præcipuis Oceani oris fideliter retuli&longs;&longs;ent de ma­ris æ&longs;tu; Primo quàm altus. Secundo quantum excurrat; Tertio quamdiu a&longs;&longs;urgat; Quarto quamdiu refluat; Quinto quâ horâ &longs;ummus æ&longs;tus &longs;it. Sexto quo die &longs;ynodalis periodi, maxima in æ&longs;tu aquarum elevatio, & quo die minima; Septimo, quo anni Plenilunio aut Novilunio &longs;it maximus æ&longs;tus. Octavo, quænam &longs;it æ&longs;tus linea, quæ fortè &longs;ingulis diebus tantulum mutatur; mutatur enim pre&longs;&longs;ionis ratio, quia mutantur &longs;uperficies ex ar­cubus vtilibus con&longs;tantes; hi porrò mutantur; quia mutatur ab&longs;idum linea, cuncta hæc in qualibet ora ob&longs;ervanda e&longs;&longs;ent.

Augu&longs;tin. Tuæ &longs;ententiæ omnino &longs;ub&longs;cribo, & hæc eadem in præfatis Hi&longs;toricis de&longs;iderarem; &longs;ed quæ&longs;o te, &longs;i me amas, profer aliquot exempla, quæ tibi haud dubiè memoria &longs;uggeret.

Antim. Hujus globi a&longs;pectus nonnulla fortè in memoriam mihi revo­cabit. Primo loco circa polum vnum occurrit; ad &longs;ummum enim pro­montorium Finnomarchiæ currit Eurippus à Cauro &longs;cilicet versùs Eu­ronotum &longs;eu Vulturnum ; &longs;unt enim angu&longs;tiæ maris inter Nieulandiam & Groelandiam, per quas mare facilè extruditur vi pre&longs;&longs;ionis, tum Oceani Tartarici, tum illius qui Americam Septentrionalem alluit, nec non ver­sùs dictam oram per dictam lineam pellitur. Secundo, A pulchra In&longs;ula, quæ novæ Franciæ Borealis e&longs;t, ad fretum Davi&longs;ium, à medio Iulio ad fi­nem Augu&longs;ti; linea æ&longs;tus tendit ad Au&longs;trum, reliquo tempore ad Occa&longs;um, quo æ&longs;tus in &longs;inum S. Laurentij irrumpit; ratio e&longs;t, quia men&longs;e Augu&longs;to glacies maris congelati liquatæ &longs;unt, ac proinde liberè fluunt, aquæ ex freti Davi&longs;ij & Hud&longs;onij angu&longs;tiis versùs Vulturnum ; itémque ex iis quæ &longs;unt Fri&longs;landiam inter & continentem Groelandiæ in Libycum; item ex iis quæ &longs;unt inter Fri&longs;landiam & I&longs;landriam in Vulturnum ; ex iis demum, quæ &longs;unt inter I&longs;landiam & Britannicas in&longs;ulas in occa&longs;um, &longs;eu Zephyro Libycum; igitur motu quodam mixto in Au&longs;trum æ&longs;tus currit, cùm tamen reliquis men&longs;ibus, concreto mari glaciali ex prioribus angu&longs;tiis æ&longs;tus vix currat, &longs;ed liberè tantùm in occa&longs;um feratur; ob&longs;tant enim in&longs;ulæ Britan­nicæ, ne in Au&longs;trum eat, ac proinde in &longs;inum S. Laurentij inde apertum &longs;u­beat; cùm tamen ex prædictorum fretorum aqua erumpens æ&longs;tum à prædicto &longs;inu S. Laurentij facilè amoveret. Tertiò, Inter promontorium floridæ & Havanam Cubæ Eurippus versùs ortum veloci&longs;&longs;imè currit, non tantùm propter multa flumina, quæ in &longs;inum Mexicanum intrant; &longs;ed quia aqua pre&longs;&longs;a circa Antillas, qua&longs;i circuitu facto, vi pre&longs;&longs;ionis, per dictum fretum versùs ortum extruditur. Et verò versùs Antillas & Mexicanum &longs;inum æ&longs;tus obliquè incidit, per lineam quæ ad Libycum tenndit; hinc parum attollitur, & frangitur illius vis ab innumeris ferè in&longs;ulis; quæ circa o&longs;tia prædicti &longs;inus qua&longs;i totidem aggeres &longs;itæ &longs;unt; addo etiam præfatum &longs;inum innumeris in&longs;ulis &longs;eminatum e&longs;&longs;e, quæ tum pre&longs;&longs;io­nem, tum æ&longs;tum impediunt. Velociter autem prædictus Eurippus fluit, quia per angu&longs;tum alveum magnum aquæ pondus aquam velo &longs;imo motu extrudit; preme vas quod piam aqua plenum, di&longs;co ligneo, vi­debi&longs;que quam cito per canalem applicatum aqua erumpat.

Augu&longs;tin. Hoc&longs;æpè probavi, & hæc veri&longs;lima cau&longs;a e&longs;t pernici&longs;&longs;imi Euripporum motus, &longs;eu cur&longs;us; immo lu&longs;i aliquando hoc experimento, plenum aqua tubum cylindricum, di&longs;co æreo apprimè tubi o&longs;tio appo&longs;ito, ex cujus centro angu&longs;tus canaliculus a&longs;&longs;urgebat, tantulùm premebam, & aqua per dictum canaliculum pernici&longs;&longs;imè a&longs;&longs;urgebat erumpebatque; vellem autem &longs;cire proportionem velocitatis, de&longs;cen&longs;um inter operculi, & erumpentis aquæ a&longs;cen&longs;um.

Antim. Velocitates &longs;unt vt ba&longs;es permutando; cùm enim illa tota por­tio extru&longs;æ aquæ per canaliculum tran&longs;eat, &longs;ub&longs;idente interim operculo, motus operculi in tubo e&longs;t ad motum aquæ in canaliculo, vt ba&longs;is canali­culi ad ba&longs;im cubi, neque in hoc e&longs;t difficultas.

Augu&longs;tin. Satis e&longs;t; optimè capio: alia difficultas occurrit; &longs;upra di­xeras, ni fallor, geminos æ&longs;tus concurrere in fretis &longs;upra appellatis; quo­modò igitur fieri pote&longs;t, vt ex angu&longs;tiis, quæ ex dictis fretis &longs;ubjiciuntur æ&longs;tus in Vulturnum eat.

Antim. Bellè; Linea fluxus versùs Caurum in dictis angu&longs;tiis, & fre­to Hud&longs;on, in freto Davi&longs;io versùs Septentrionem tendit; at verò linea refluxus, in freto Davi&longs;io versùs Au&longs;trum, in Hud&longs;onio & dictis faucibus in. Vulturnum ; &longs;ed ad propo&longs;itum redeo. Quartò, igitur à maris tractu in­ter Fortunatas & He&longs;peridum in&longs;ulas interjecto, æ&longs;tus currit versùs Oc­ca&longs;um, nempe in eam partem mare curvatur ad in&longs;tar &longs;inus immen&longs;i; &longs;ed versùs &longs;inuum extremitates vt plurimùm mare currit: ratio ex præmi&longs;&longs;is principiis nece&longs;&longs;ariò &longs;equitur; cùm enim &longs;inus versùs extremitates con­trahantur, aut &longs;altem contractiores &longs;int eo maris tractu, ex quo &longs;uo modo na&longs;cuntur &longs;inus, arcus pre&longs;&longs;ionum &longs;inui minores, reliquo tractui majores incumbunt; quid mirum ergo, &longs;i prævaleant i&longs;ti, & aqua illuc versùs ex­tremum &longs;inum extrudatur? Finge &longs;inum e&longs;&longs;e fretum, &longs;ed ob&longs;tructum; inde quoque &longs;equitur, motu velociore extrudi, quando &longs;inus e&longs;t longè contractior; hinc magnus æ&longs;tus in &longs;inu Gangetico, Per&longs;ico, Arabico, in quo longè major e&longs;&longs;et, cùm maxima vi mare ab ortu eò feratur, ni&longs;i ab In&longs;ulis circa illius o&longs;tia &longs;itis, itemque ab angu&longs;ti&longs;&longs;imo aditu, vis æ&longs;tus fran­geretur; ad de &longs;is &longs;inum Adriaticum, in quo versùs extremitatem æ&longs;tus non minimus e&longs;t, extra Quadraturas, propter rationem expo&longs;itam, quæ maxi­mè hîc locum habet.

Augu&longs;tin. Sed quæ&longs;o te, cur etiam in mari Mediterraneo, quod maxi­mi &longs;inus ad in&longs;tar e&longs;t, æ&longs;tus non attollitur.

Antim. Equidem Oceani æ&longs;tus per Gaditanum fretum influit, remi&longs;­&longs;ior tamen; quia cùm versùs Cæciam linea æ&longs;tus huic oræ illap&longs;i eat, valdè obliquè in o&longs;tra freti incidit; vnde valdè remittitur, atque adeò in oram Syriæ oppo&longs;itam vix traducitur; traducitur tamen, & &longs;en&longs;u perci­pitur in Novilunio & Plenilunio; licèt verò mare mediterraneum longi&longs;­&longs;imum &longs;it, quia tamen multis in&longs;ulis interrumpitur, & ab occa&longs;u in ortum recta excurrit, & æqualis ferè e&longs;t illius latitudo, arcus pre&longs;&longs;ionum in eo &longs;ecundùm totam illius longitudinem æquales &longs;unt; vna pars igitur non prævalet &longs;upra aliam, igitur nullus æ&longs;tus; is enim; qui e&longs;t ad oram Syriæ minimus quidem, &longs;ed jam olim à Phænicibus ob&longs;ervatus; item ad oram Provinciæ, vt Scaliger ip&longs;e ob&longs;ervavit, ab Oceano per fretum Gaditanum traducitur, non certè motu &longs;ed pre&longs;&longs;ionis vi, at verò cùm in &longs;inu Adriati­co arcus pre&longs;&longs;ionum longè minores &longs;int, quàm in reliquo mari, quid mi­rum &longs;i æ&longs;tus in eo fiat, effectus &longs;cilicet nece&longs;&longs;arius inæqualis pre&longs;&longs;ionis? mi­nor tamen propter angu&longs;tias o&longs;tij, & Corcyram ad prædictum o&longs;tium &longs;i­tam, in qua vis æ&longs;tus frangitur; item in Africæ ora prædicto maris Adtia­tici o&longs;tio, &longs;ecundum eundem Meridianum, è regione oppo&longs;ita; ibi enim mediocris &longs;altem æ&longs;tus attollitur; nempe ibi mare &longs;e&longs;e explicat, & versùs Africam qua&longs;i in &longs;inum lunatur; item in reliqua ora Africæ versùs Tune­tum, in quam vis æ&longs;tus per fretum traducta à Balearibus & Sardinia ad Bo­ream &longs;itis coërcita, impingitur; æ&longs;tus porrò ad dictam oram Africæ a&longs;&longs;ur­gentis jam olim meminit S. Augu&longs;tinus.

Augu&longs;tin. Sed vnde quæ&longs;o Eurippus ille mirabilis in freto Siculo, de quo multi multa?

Antim. Certum e&longs;t, rapidum illum motum e&longs;&longs;e ab æ&longs;tu; quia cum motu Lunæ omnino con&longs;entit; & verò vis æ&longs;tus per Gaditanum traducta, à Balearibus & Sardinia coërcita, & ab angu&longs;tiis illius tractus maris qui inter Africam & occiduum promontorium Siciliæ interjacet impedita, immo ab ip&longs;a Sicilia repre&longs;&longs;a, declinat tantulùm versùs fauces freti Siculi, in cujus angu&longs;tiis aqua velociùs currit, proptèr rationem &longs;upra explicatam; &longs;imiliter in &longs;inum Tarentinum æ&longs;tus a&longs;cendit propter eandem rationem; ad Ravennam item & Aquileiam; quia &longs;itæ &longs;unt versùs extremum &longs;inum; ad oram Dalmatiæ, ab&longs;que tumore, aqua &longs;ur&longs;um versùs extremum &longs;inum ire vi­detur; ad oppo&longs;itam verò Italiæ oram ver&longs;us o&longs;tium & fauces de&longs;cendere; &longs;ed hic motus, &longs;i tamen veritati con&longs;entit, vel ab æ&longs;tu diver&longs;us e&longs;t, vel ex eo procedit, quod æ&longs;tus in fauc&etail;s &longs;inûs irrumpat per lineam, quæ ad Boream ten­dit; & cùm &longs;inus ab extremo faucium collo, declinet &longs;ini&longs;tror&longs;um versùs Caurum, motus etiam aquæ versùs eandem partem declinat, &longs;ecundum oram Dalmaticam; in refluxu verò, qua&longs;i circuitu facto, per oram Italiæ oppo&longs;itam priori de&longs;cendit; æ&longs;tus etiam minimus ob&longs;ervatur ad Melitam, Sardiniam, Cor&longs;icam, Iluam, Cretam, &longs;ed vix ad &longs;emipedem attollitur; Ma&longs;&longs;iliæ & Tolone ad pedem integrum; quia &longs;cilicet cùm prædictæ in&longs;u­læ, tum pre&longs;&longs;ionis inæqualitatem inducant, tum etiam vim pre&longs;&longs;ionis tra­ductam &longs;i&longs;tant, quid mirum, &longs;i aliquam vim æ&longs;tus &longs;entiant; & verò ad oram occiduam Sardiniæ & Cor&longs;icæ vis pre&longs;&longs;ionis ab Oceano traducta impingitur; & magna e&longs;t maris latitudo; &longs;ub Meridiano Ma&longs;&longs;iliæ, quod &longs;anè ad pre&longs;&longs;ionis inæqualitatem multùm confert; accedit, quòd &longs;i ad oram Africæ, in qua e&longs;t Hippona &longs;entitur æ&longs;tus, quidni ad oram Provin­ciæ oppo&longs;itam? Æ&longs;tus porrò ad oram ortivam Sardiniæ & Cor&longs;icæ, item­que ad Iluam procedit à pre&longs;&longs;ionis vi traducta ab extremo mediterraneo ortivo; ad Melitam, Cretam, Siciliam, à vi pre&longs;&longs;ionis ab vtraque parte pro­veniente. In reliquo mediterraneo nullus æ&longs;tus &longs;entitur; in quibu&longs;dam oris. propter in&longs;ulas, in aliis verò, quia iis non favet pre&longs;&longs;ionis inæqualitas &longs;en&longs;ibilis, propter &longs;itum: & verò qui&longs;quis rem in hanc longo illo Medi­terranei tractu attentè con&longs;iderabit, &longs;tatim comperiet, ex præmi&longs;&longs;is princi­piis optimè explicari.

Augu&longs;tin. Hæc, quæ dicis, mirificè placent; difficilius tamen re&longs;tat; nem­pe in freto illo Siculo, diver&longs;us e&longs;t vtrimque æ&longs;tus, cùm &longs;imul & &longs;emel ab vna parte deor&longs;um, ab alia &longs;ur&longs;um ire videatur, quod nonnulli in cavitates &longs;ubterraneas rejiciunt, quas etiam volunt cum iis quæ Monti Æthnæ &longs;ub­jiciuntur, & incendio materiam &longs;uppeditant, per cuniculos e&longs;&longs;e conjun­ctas: Vnde Abbas Maurolycus, aiunt, vnum ex alio conjiciebat; &longs;cili­cet ex diver&longs;a incendij ratione, diver&longs;am rationem æ&longs;tus, & vi­ci&longs;&longs;im.

Antim. Hoc etiam &longs;pero ex ii&longs;dem principiis deductum iri; con&longs;ide­ra enim fretum Siculum qua&longs;i in meditullio Mediterranei &longs;itum, & recta directum ab Au&longs;tro ad Septentrionem, atque inde ad extremam Medi­terranei oram, ortivam &longs;cilicet, ferè numerati triginta gradus longitudi­nis; vnde certè &longs;ufficiens pre&longs;&longs;ionis vis e&longs;&longs;e videtur; accedente præ&longs;ertim maxima latitudine eju&longs;dem maris, à faucibus Adriatici ad oram Africæ oppo&longs;itam exporrecta, vt aqua per fretum ab Au&longs;tro ad Septentrionem extrudatur &longs;imiliter vis pre&longs;&longs;ionis traducta ab Oceano per Gaditanum, re­pre&longs;&longs;aque, vt jam dictum e&longs;t, à faucibus Africam inter & Sardiniam in­terjectis, ac proinde tantulùm declinans &longs;ini&longs;tror&longs;um, plu&longs;quam &longs;uffici­ens e&longs;t ad extrudendam aquam per idem fretum, à Septentrione ad Meri­diem; quamvis enim paulò obliquiùs incidat, cùm tamen priore major &longs;it, licèt frangatur ab obliquo appul&longs;u, vel potiùs &longs;uo modo reflectatur, &longs;ufficiens e&longs;t, vt dixi, ad extrudendam aquam per fretum à Septentrione ad Au&longs;trum; quid mirum igitur &longs;i agatur æ&longs;tus in contrarias partes, & gemini &longs;ibi invicem occurrant, vt jam de aliis fretis diximus? cùm autem vtrim­que aqua obliquè incidat, quid mirum &longs;i ex illius reflexione à cavo & di­ver&longs;imodè &longs;ito litore, ad Scyllam &longs;cilicet & Charybdim; diver&longs;i aquarum vortices & gyri con&longs;equantur? neque in hoc, &longs;altem meo judicio, re&longs;tat vlla difficultas; cùm enim con&longs;tet, prædictum motum ab æ&longs;tu e&longs;&longs;e, nempe accedunt & concurrunt aquæ &longs;enis quibu&longs;que horis, & cùm in aliis fretis, æ&longs;tus etiam concurrant, negari non pote&longs;t, quin primaria huju&longs;modi motuum cau&longs;a &longs;it æ&longs;tus; nempe ex tali illap&longs;u, concur&longs;u, collu­ctatione, reflexione, mirabilis motuum varietas na&longs;citur, vnde non tantum 24. vt non nemo dicebat, &longs;ed longè plures ob&longs;ervari po&longs;&longs;unt; &longs;ed jam ad Oceanum redeamus.

Augu&longs;tin. Benè e&longs;t; vnum tamen præ cæteris ex re &longs;cire velim, vtrùm prædictus æ&longs;tuum concur&longs;us in medio freto fiat.

Antim. fortè in quibu&longs;dam hoc eveniet; &longs;i tamen vis æ&longs;tus eodem tem­poris momento vtrimque ad o&longs;tia freti perveniat; quod in Siculo facilè con­ce&longs;&longs;erim, quod &longs;cilicet, &longs;ub ea linea porrigatur, quæ eidem Meridiano &longs;ub­jacet, at verò de illo æ&longs;tu, qui fit in freto Magellanico, &longs;ecus dicendum e&longs;t, quia cùm elevatio aquarum Lunæ motum æmuletur, & cùm Luna priùs ar­cum ortivum, quàm occiduum decurrat, inde fit, &longs;ummam elevationem ad o&longs;tium ortivum primùm fieri, ac deinde ad occiduum; vnde &longs;equitur concur&longs;um æ&longs;tuum, longiùs di&longs;tare ab o&longs;tio Orientali, quàm Occidentali, quod certè cum ob&longs;ervationibus omnino con&longs;entit; Nam Arnaldus Nau­clerus non ignobilis ob&longs;ervavit, concur&longs;um æ&longs;tuum fieri &longs;eptuage&longs;ima ab Orientali o&longs;tio leuca, & trige&longs;ima tantum ab Occidentali, longitudo quippe freti 100 circiter leucarum e&longs;t, accedit, quòd versùs o&longs;tium Ortivum in &longs;inum longi&longs;&longs;imum Oceanus de&longs;init; ac proinde aquam vel æ&longs;tum, qua&longs;i admo­to infundibulo in fretum pellit de freto Hud&longs;onio eadem ratio militat, cùm ab ortu in occa&longs;um eat; &longs;ecus de Davi&longs;io, qui ab Au&longs;tro ad Septen­trionem. Sed ad Eurippos redeo & lineas æ&longs;tuum; jam dixi &longs;upra, cur æ&longs;tus in oram Guineæ incidentis linea ad Cæciam tendat; in Africum verò, inci­dentis in o&longs;tium fluminis Amazonum: frequentes &longs;unt Eurippi inter Cycla­das, Maldivas, Moluccas, Iaponicas in&longs;ulas &c hoc enim &longs;olemne e&longs;t, &longs;i vis pre&longs;&longs;ionis ad&longs;it omnibus Marium angu&longs;tiis, augu&longs;tias autem in&longs;ulæ pa&longs;&longs;im &longs;eminatæ inducunt; igitur & determinationem ad talem lineam motus. Hinc per totam oram Oceani Germanici & Britannici tam diver&longs;is & contrariis lineis æ­&longs;tus illabuntur, propter in&longs;ularum obicem, locorum angu&longs;tias &c. Igitur inter Bra­&longs;iliam & Angolam &longs;ub Parallelo 10. grad. Latit. Au&longs;tralis à 20. die Aprilis ad 26. Iulij, æ&longs;tus currit versùs Cautum, item à 26. Iulij, ad 20. Ianuarij versùs partem op­po&longs;itam &longs;cilicet versùs Notapeliorem; à 20. Ianuarij ad 20. Aprilis in neutram par­tem; ratio primi e&longs;t, quia cum prædictæ angu&longs;tiæ &longs;int ferè &longs;ub Æquatore, & cum Sol à 20. Martij ad 22. Iunij ab Æquatore versùs Boream declinet, &longs;en&longs;im lique­&longs;cit Mare glaciale, quo certè glaciato, vis pre&longs;&longs;ionis minor e&longs;t; quia arcus gla­ciei incubantes inutiles &longs;unt; quid mirum ergo, &longs;i vis pre&longs;&longs;ionis Æthiopici præva­leat, & aquas per fauces trudat versùs Cautum; eò enim fauces illæ &longs;pectant: at circa 26. Iulij glaciato mari &longs;altem ex parte liquato, cre&longs;cit vis pre&longs;&longs;ionis At­lantici, prævalet igitur, & aquas per ea&longs;dem angu&longs;tias versùs Notapeliorem retrudit; reliquo verò tempore, cùm iterum Mare versùs Boream concre&longs;­cat, ac proinde vis pre&longs;&longs;ionis Atlantici minuatur, aër verò temperatæ Au­&longs;tralis rare&longs;cat, Sole præ&longs;ertim perigæo, inde vis pre&longs;&longs;ionis Æthiopici mi­nuitur, vnde per&longs;picua e&longs;t compen&longs;atio, & mare in neutram partem currit; adde &longs;is mare Au&longs;trale incognitum etiam gelu concre&longs;cere; vnde quoque mutatur pre&longs;&longs;ionis ratio.

Augu&longs;tin. Vix crediderim in alia hypothe&longs;i cuncta hæc phænomena &longs;alvari po&longs;&longs;e; &longs;ed perge quæ&longs;o.

Antim. Sexto. Inter In&longs;ulam Madaga&longs;car & Africam à 10. grad. Latit. Au&longs;tralis ad promontiorum Bonæ &longs;pei versùs Au&longs;trum it mare; habes enim angu&longs;tias, intra quas Eurippi currunt; cùm autem ab ortu in di­ctam oram æ&longs;tus veniat, obliquè omnino incidit; vnde ad Au&longs;trum li­neam motus determinari, nece&longs;&longs;e e&longs;t; &longs;ic enim ex tali aquarum illap&longs;u li­nea motus pa&longs;&longs;im determinatur, & æ&longs;tus in Eurippum, &longs;i angu&longs;tiæ ad­&longs;int, degenerat. Septimo, Ad Parallelum grad. 30. Latit. Boreal. inter Phi-lippinas & Iaponicas, re ita in ortum movetur, vt hinc paucis diebus in Californiam navigetur; quia cùm &longs;ub Zona torrida in toto mari Pacifico æ&longs;tus & aqua in occa&longs;um liberè feratur, modico circuitu facto refluit per Septemtrionalem oram Americæ, quam relegit: cujus &longs;anè mirabilis effe­ctus alia ratio e&longs;&longs;e non pote&longs;t.

Augu&longs;tin. Haud dubiè rem citiùs expedies, &longs;icut Oceanus, ita & oratio tua terrarum oras breviter & raptim ip&longs;um æ&longs;tum æmulata, præterlegat, initio ducto v.g. à Gaditano freto.

Antim. Libenter faciam & ne prolixior evadam, rem &longs;anè in pauca con­traham, præ&longs;ertim cum & Mediterraneum & maximam Oceani partem jam lu&longs;traverimus; & primo loco à prædicto freto Gaditano versùs Boream a&longs;­cendam, majorí&longs;que di&longs;tinctionis gratia numeros adhibebo.

Primò, Occurrit Ora Bæticæ in quam &longs;atis magnus æ&longs;tus incidit Cæciam versùs cùm vis maxima pre&longs;&longs;ionis ab Africo veniat; hinc quia directè in Bætim &longs;ubit, ad 30. milliaria fluvius regreditur; &longs;ecus verò Anas non pro­cul hinc di&longs;tans; quia in ejus o&longs;tia æ&longs;tus obliquè incidit; hujus enim flumi­nis cur&longs;us in Au&longs;trum recta linea tendit.

Secundo. Succedit ora Hi&longs;paniæ occidua, quæ recta ferè ad Septentrio­nem ducitur, in qua æ&longs;tus modicus e&longs;t, quia incidit per eandem lineam ver­&longs;us Cæciam; igitur obliquè; paulò tamen major e&longs;t, ad o&longs;tia Tagi, quia ille tractus qua&longs;i quoddam æ&longs;tui illabenti receptaculum & &longs;inum aperit.

Tertiò. In ora boreali Hi&longs;paniæ nullus, vel modicus e&longs;t, nempe hic quo­que fertur in Cæciam, propter rationem adductam; nempe à Septemtrio­ne In&longs;ulæ Britannicæ, & minor Britannia magnum obicem ponunt; cùm igitur æ&longs;tus in Cæciam eat, vix in prædictum litus incidit; id que ferè v&longs;que ad o&longs;tia Garumnæ, ibi enim, & ad rotam oram Aquitanicam, immo ad extremum v&longs;que minoris Britanniæ promontorium magnus æ&longs;tus e&longs;t; nem­pe ibi mare ad in&longs;tar &longs;inus in terras excurrit, & propter adductam ratio­nem in Cæciam æ&longs;tus currit: vnde &longs;atis directè illabitur, præ&longs;ertim in oram Meridionalem minoris Britanniæ.

Quartò Ad extremam oram, occiduam &longs;cilicet, minoris Britanni&etail; à fonte­navia ad promontorium Clarium, currit æ&longs;tus ab Hypotra&longs;cia, ac proinde obliquè incidit, & minùs a&longs;&longs;urgit licèt rapidi&longs;&longs;imus &longs;it in freto fontenaviæ, propter angu&longs;tias; &longs;ic autem incidit, quia ab ea parte liberiùs excurrit; con­trahitur enim Oceanus in hoc tractu versùs occa&longs;um; hinc eò currit æ&longs;tus, vt fit in reliquis &longs;inubus, ac proinde obliquè incidit, & minor e&longs;t; haud procul verò, quia lunatur mare vulturnum versùs in minorem & acu­tiorem &longs;inum, eò directè fertur æ&longs;tus, & hic maximè a&longs;&longs;urgit ad fanum &longs;cili­cet S. Maclovij, & ad Sanctum Michaelem, non procul hinc &longs;itum; inde porrò Cadomum v&longs;que currit versùs Libycum, ac proinde obliquiùs; per aliam autem lineam vix in hanc oram Neu&longs;triæ incidere pote&longs;t, vt patet ex ip&longs;a in&longs;pectione; cùm vis pre&longs;&longs;ionis à mari Germanico per fretum Gallicum eò traducatur; ad o&longs;tia Sequanæ altiùs a&longs;&longs;urgit æ&longs;tus, quia illic mare luna­tur in &longs;inum.

Quintò, Inde Gravelingam v&longs;que, per eandem ferè lineam incidit propter eandem rationem; &longs;en&longs;im tamen declinat ad Au&longs;trum, cùm à longto Maris Germanici tractu, versùs Boream ad Polum v&longs;que porre­cto, vis pre&longs;&longs;ionis Au&longs;trum versùs incumbat; ac proindo obliquè incidit in oram illam Belgicam, hinc flante Cauro, quo fit, vt æ&longs;tus directè incidat, longè major æ&longs;tus cietur, vt & in fretis, æ&longs;tuariis, &longs;inubus &c. Pro quibus nihil e&longs;t, quod addam, cùm jam &longs;upra rationem attulerim, porrò concur­runt æ&longs;tus haud procul à Freto Gallico; vis enim pre&longs;&longs;ionis ab vtro­que mari, Britannico &longs;cilicet & Germanico procedit; concurrunt autem æ&longs;tus, vt dixi extra fretum, versùs occa&longs;um; rationem jam &longs;upra adduxi, cum de Freto Magellanico.

Sextò, Ad ortivam oram Angliæ innumeris ferè &longs;inubus, fretis, æ&longs;tua­riis a&longs;peratam, tendit æ&longs;tus versùs Au&longs;trum; vnde parvus e&longs;&longs;et æ&longs;tus, propter illap&longs;um valdè obliquum, &longs;ed propter illam oræ a&longs;peritatem & inæqualitatem, nec non locorum angu&longs;tias, illap&longs;us directus e&longs;t, & altior æ&longs;tus, & multi Eurippi: ad oram verò Meridionalem, æ&longs;tus qua&longs;i ad Cæciam tendit, versùs Ortum tantulùm deflectens; cùm enim Mate Britannicum &longs;it ad in&longs;tar magni &longs;inus, na&longs;centis ex Oceano Oc­cidentali, in quo, vt &longs;upra dictum e&longs;t, fluit æ&longs;tus in Cæciam; nihil mi­rum, &longs;i in Britannico versùs eandem partem eat; ab extremo verò An­gliæ termino Occidentali, quem Lezardum vocant, deflectit æ&longs;tus ma­gis ad Ortum; hinc maximus e&longs;t ad Bri&longs;toliam, vbi Mare a&longs;&longs;urgit ad pedes 66. quia in extremis &longs;inubus, modò æ&longs;tus in eandem cum &longs;inu plagam excurrat, mare plurimùm a&longs;&longs;urgit; deflectit autem tantulum ad Ortum, propter obicem Hiberniæ versùs Septemtrionem &longs;itæ. Denique inter Angliam & Hiberniam non parum &longs;ævit æ&longs;tus propter fretorum locorumque angu&longs;tias; vnde multi na&longs;cuntur Eu­rippi.

Septimò, Suprà Scotiam liberiùs æ&longs;tus excurrit, ac ferè &longs;ine lege; item ad oram Norvegiæ inter Bergam & Stadem, propter Eurippos valde in­&longs;ignes, ob in&longs;ulas è regione &longs;itas: ad oram Finnomarchiæ & Lappiæ æ&longs;tus à Cauro fluunt, vnde vis major pre&longs;&longs;ionis e&longs;t; hinc ad extremum Lappiæ &longs;inum, Ortum versùs, in quem æ&longs;tus directè incidit, in&longs;ignis æ&longs;tus e&longs;t: Ad Fretum Na&longs;&longs;ovium concurrunt æ&longs;tus, traducta ab vtroque mari vi pre&longs;&longs;ionis, Tartarico &longs;cilicet & Septemtrionali: De Nieulandia jam &longs;upra dictum e&longs;t; quanquam facilè crediderim, illo Ma­ri per Brumam glaciato, diver&longs;am in vicinis oris æ&longs;tuum rationem & li­neam &longs;equi.

Augu&longs;tin. Iam ferè dixi&longs;ti de reliquis oris, quas Oceanus alluit, præter­lectis &longs;upra litoribus Americæ & Africæ; re&longs;tat vt ad alia tran&longs;eamus, non­dum enim hoc argumentum probè exhau&longs;tum e&longs;t, Ante omnia &longs;cire velim, cur æ&longs;tus alicubi major, alicubi minor a&longs;&longs;urgat.

Antim. Hoc facilè deducere poteras ex iis, quæ dicta &longs;unt; multis au­tem nominibus cre&longs;cit; Primò, ex majori vi pre&longs;&longs;ionis quæ ex duplici ca­pite cre&longs;cit: primum petitur à majore &longs;uperficie, quam occupant vtiles arcus pre&longs;&longs;ionis, re&longs;pectu alicujus loci, qui prædictorum arcuum qua&longs;i Po­lus e&longs;t; ex hoc capite maximus æ&longs;tus fit ad Indi O&longs;tia, ad Guineam, ad O&longs;tia fluminis Amazonum, ad oram Peruviæ. Secundum caput e&longs;t major aëris gravitas, quæ oritur ab humore admixto, vel aëre den&longs;o, & compre&longs;&longs;o.

Augu&longs;tin. Tertium caput omittis, nempe quando Luna altior e&longs;t, altior quoque e&longs;t aëris gravitantis tractus, & linea dirimens à centro terræ lon­giùs di&longs;tat.

Antim. Hoc mihi reverà exciderat, quod exqui&longs;ita ob&longs;ervatione con­firmare po&longs;&longs;um; quando enim Luna in Apogæo exi&longs;tit, tunc æ&longs;tus minor e&longs;t: itaque vis pre&longs;&longs;ionis alia major e&longs;t exten&longs;ivè, alia inten&longs;ivè; exten&longs;ivè à majore &longs;uperficie, cui arcus pre&longs;&longs;ionis incumbunt, idque cæteris pari­bus; modò &longs;cilicet inæqualem pre&longs;&longs;ionem inducant; inten&longs;ivè autem à majore aëris gravitatione, quæ vel e&longs;t à majore altitudine aëris, vel à ma­jore humoris copia admixta; hinc major æ&longs;tus in Plenilunio, minorverò Luna Apogæa. Secundò, Cre&longs;cit æ&longs;tus ex illap&longs;u magis directo; &longs;ic enim excurrit in illam oram, præ&longs;ertim per fluminum alveos: nempe a&longs;&longs;urgit æ&longs;tus per majores vndas, doliorum in&longs;tar, quarum vna aliam &longs;equitur; vn­de fit, vt &longs;i obliquè incidat, non in oram, &longs;ed in ip&longs;um mare excurrat; &longs;i au­tem in litus impingeret, altera &longs;uperveniente, a&longs;&longs;urgeret aqua, & plus ad­huc tertiæ vndæ appul&longs;u. Tertiò, Cre&longs;cit æ&longs;tus ratione &longs;inuum, nempe, vt jam dixi, &longs;i æ&longs;tus directè in &longs;inum paulò acutiorem & breviorem incidat, mirum quantum attollatur aqua, non tantùm propter angu&longs;tias va&longs;is, &longs;ed propter directum appul&longs;um; &longs;ic ad Bri&longs;toliam, vt dixi, & ad fanum Sancti Michaëlis alti&longs;&longs;imus æ&longs;tus e&longs;t, hic 70. illic 66. pedes; ad O&longs;tia fluminis Ama­zonum, ni&longs;i per alveum fluvij excur&longs;us pateret, altior for&longs;itan e&longs;&longs;et: dixi &longs;u­pra breviorem & acutiorem &longs;inum; vt enim expre&longs;&longs;ione &longs;uperficiei aquæ quolibet va&longs;e contentæ per canaliculum altiùs a&longs;cendit, quàm per majorem canalem; ita pror&longs;us æ&longs;tus in breviore & Pyramidem de&longs;inente &longs;inu; cùm enim minùs capax &longs;it, intru&longs;a per vim pre&longs;&longs;ionis aqua altiùs a&longs;cendat, nece&longs;&longs;e e&longs;t. Inter in&longs;ulas, vt plurimùm minùs a&longs;&longs;urgit aqua, tum quia vis pre&longs;&longs;ionis interrumpitur, tum quia cùm aqua per freta & angu&longs;tias di&longs;cur­rat, ac proinde effluat, tam altè a&longs;cendere non pote&longs;t.

Augu&longs;tin. Sed cur alicubi velociùs & rapidiùs, alibi &longs;en&longs;im æ&longs;tus currit?

Antim. Velocior motus, qui ab æ&longs;tu e&longs;t, à multis cau&longs;is procedit. Primò à majore vi pre&longs;&longs;ionis &longs;ic majus pondus tubi erecti & aqua pleni, eam ve­lociùs per foramen iuxta ba&longs;im apertum extrudit; major autem vis pre&longs;­&longs;ionis e&longs;t à majore &longs;uperficie ex arcubus vtilibus con&longs;tante. Secundò, ab an­gu&longs;tiis per quas aqua extrudenda e&longs;t, vi pre&longs;&longs;ionis; &longs;icut dixi &longs;upra, in Fre­tis, rapidus æ&longs;tus e&longs;t, v.g. in angu&longs;tiis ad Havanam, & alibi pa&longs;&longs;im; &longs;ic in fluminis alveo contracta aqua velociùs currit. Tertiò à breviore angu­&longs;tiarum alveo; &longs;ic per breviorem fi&longs;tulam foramini admotam, aqua velo­ciùs extruditur

Augu&longs;tin. Ne quid di&longs;&longs;imulem, hoc non capio, quanquam auguror ali­quid &longs;citu digni&longs;&longs;imum, ex hoc ip&longs;o argumento affulgere.

Antim. Faciam capias. Sit tubus AB &longs;emper aquâ plenus, &longs;it fi&longs;tula

primum GH, per quam aqua extruditur, vi ponderis AB. haud dubiè &longs;i &longs;it fi&longs;tula GI duplo longior, extrudetur aqua per GH, velociore motu, & tardiore per GI. experientia hujus rei per&longs;pecta e&longs;t; quia &longs;æpè probata; ratio verò non ita fortè cuipiam in promptu e&longs;t.

Augu&longs;tin. Iam mihi venit in mentem; nem­pe vis eadem motrix minus mobile velociùs, majus verò tardiùs movet; quid mirum igitur, &longs;i minorem aquæ molem fi&longs;tula GH contentam, vis ponderis GH faciliùs & velociùs extrudat, quàm duplò majorem contentam fi&longs;tula GI. im­mò facilè crediderim, motus e&longs;&longs;e, vt longitudines permutando.

Antim. Ab hoc vltimo incipio, quod manife&longs;tè fal&longs;um e&longs;&longs;e, demon­&longs;tro, nempe inde &longs;equeretur infinitè velociùs extrudi aquam per nudum & nulla fi&longs;tula in&longs;tructum foramen B, quàm per fi&longs;tulam quamlibet etiam bre­vi&longs;&longs;imam; prætereà cùm per fi&longs;tulam GH, aut GI aqua extru&longs;a motu æquabili moveri cen&longs;eatur, acqui&longs;ito &longs;cilicet in ip&longs;a extru&longs;ione, id e&longs;t, in ip&longs;o foramine: &longs;i in præci&longs;a vi motrice &longs;i&longs;tamus, cùm hæc æqualem mo­tum omnibus partibus extru&longs;is imprimat, quem deinde retinent per totam fi&longs;tulæ longitudinem, non videtur, cur velociùs per breviorem, tardiùs per longiorem moveatur; aliunde igitur illa motuum inæqualitas petenda e&longs;t; nimirum ab impedimento & re&longs;i&longs;tentia fi&longs;tulæ; nempe cava illa &longs;uper­ficies, non ita e&longs;t lævigata, quin aliquid &longs;cabrum, aliquæ &longs;alebræ, &longs;triæ, aut rugæ in&longs;int; cum enim aqua nullum &longs;patium liberum habeat intra fi&longs;tu­lam, vix credi pote&longs;t, quantum inde illius cur&longs;us retardetur; & verò aquæ currentis &longs;uperficies adeò plana e&longs;&longs;e non &longs;olet, præ&longs;ertim &longs;i velociore motu fluat; vt igitur &longs;uperficies aquæ convexa probè congruat &longs;uperficiei cavæ fi&longs;tulæ, id certè non &longs;ponte, &longs;ed vi quadam fieri dumtaxat pote&longs;t; vnde illius cur&longs;um retardari nece&longs;&longs;e &longs;it: cùm igitur in longiore fi&longs;tula longior &longs;it &longs;u­perficies, longius &longs;eu majus erit impedimentum; igitur per longiorem fi­&longs;tulam plus remoræ nacta, tardius aqua extruditur.

Augu&longs;tin. In qua porro proportione vnus motus alium &longs;uperat?

Antim. Hæc proportio ita inveniri pote&longs;t; comparetur aquæ quantitas extru&longs;a per nudum foramen B, factum in lamina qua&longs;i indivi&longs;ibili, cùm ea quæ per fi&longs;tulam GH extruditur, æquali tempore, motus erunt vt quanti­tates permutando; fiatque vt differentia quantitatum &longs;it ad aliam vt GH, ad GI, id e&longs;t, in ratione dupla, erit aqua extru&longs;a per GH ad extru&longs;am per GI, vt aqua extru&longs;a per nudum foramen, minus prima differentia ad ean­dem, minùs &longs;ecunda differentia; erunt autem motus vt quantitates aquæ extru&longs;æ: hic non con&longs;idero modicam illam & in&longs;en&longs;ibilem re&longs;i&longs;tentiam, quæ procedit à peripheria foraminis laminæ; quia hæc &longs;upponitur indivi­&longs;ibilis &longs;uperficies, ac proinde quælibet &longs;uperficies cava ad illam peripheriam infinitam habet rationem; igitur & re&longs;i&longs;tentia illius ad re&longs;i&longs;tentiam hujus.

Angu&longs;tin. Hoc certè callent ij, qui aquæ ex publicis fontibus di&longs;tri­buendæ præ&longs;unt, nempe æquales longitudine fi&longs;tulas omnibus aquædu­ctibus apponunt, &longs;ive tubi majores &longs;int, &longs;ive minores; vt &longs;cilicet æqualis &longs;it ratio impedimenti quod ex longitudine fi&longs;tulæ ducitur, ac proinde extru&longs;æ aquæ quantitates &longs;int vt tubi, &longs;eu tuborum ba&longs;es.

Antim. In hoc etiam errant, Augu&longs;tine, quod vt liquidò demon&longs;trem, &longs;upponantur duæ fi&longs;tulæ æqualis longitudinis GH, &longs;ed ba&longs;is inæqualis, &longs;itque exempli gratia Diameter ba&longs;is minoris vnius digiti, & Diameter majoris, duorum digitorum, cùm æquali longitudine fi&longs;tularum & al­titudine fontis BA, haud dubiè vires erunt, vt ba&longs;es, ac proinde &longs;i præcisè vis ponderis gravitantis, & aquam extrudentis con&longs;ideretur, eadem e&longs;t vtrimque ratio; nempe mobilia &longs;unt vt ba&longs;es, ba&longs;es vt vires; igitur æquales vtrimque motus; quia vires vt 4. æquè facilè movebunt pondus vt 4. ac vires vt vnum pondus vt vnum. Igitur &longs;tando præci­sè in ip&longs;a vi ponderis extrudentis, quo tempore, per majorem fi&longs;tu­lam ex appellatis, fluunt 4. libræ aquæ, vna tantùm libra per minorem effluet; &longs;ed hoc per&longs;picuis experimentis repugnat; nec demon&longs;tratio dee&longs;t; nempe vt eadem proportio maneret, impedimenta ex cava &longs;uperficie fi&longs;tu­læ petita deberent e&longs;&longs;e proportionalia; igitur cùm hæc impedimenta &longs;int, vt &longs;uperficies cavæ, &longs;uperficies cava majoris fi&longs;tulæ deberet e&longs;&longs;e quadrupla &longs;uperficiei cavæ minoris, cùm tamen &longs;it tantùm dupla; &longs;unt enim illæ vt Peri­pheriæ circulorum, & hæ vt Diametri: igitur cùm major &longs;it ratio impe­dimenti in minore fi&longs;tula, quàm in majore, quid mirum, &longs;i aquæ quantitas extru&longs;æ per majorem, &longs;it plu&longs;quam quadrupla extru&longs;æ per minorem? e&longs;&longs;et autem pror&longs;us & accuratè quadrupla, &longs;i major fi&longs;tula longitudine dupla minoris &longs;it.

Augu&longs;tin. Bellè omninò, vt hæc mihi nova, ita gravi&longs;&longs;ima pror&longs;us acci­dunt. Sed quid &longs;i aliquis æqualem in fi&longs;tulis longitudinem &longs;ervare velit, cupiat tamen apponere fi&longs;tulam majorem, per quam extrudatur, a&longs;&longs;umpta eadem fontis altitudine, quadrupla quantitas aquæ, quanta ba&longs;is fi&longs;tulæ a&longs;&longs;i­gnanda erit?

Antim. Hoc etiam facilè haberi pote&longs;t: &longs;i enim major fi&longs;tula longi­tudine dupla & ba&longs;i quadrupla extrudit præcisè quantitatem aquæ qua­druplam, &longs;it ba&longs;is majoris 16. minoris 4. ac proinde Diameter minoris 2. majoris 4. erit ba&longs;is 16. ad &longs;uperficiem cavam majoris fi&longs;tulæ, vt ba­&longs;is 4. ad cavam minoris; igitur vires majoris ad impedimentum fi&longs;tulæ majoris, vt vires minoris ad impedimentum eju&longs;dem; &longs;it minoris impe­dimentum vt vnum, erit majoris impedimentum vt 4. & &longs;i impedimen­tum vt 1. &longs;ubducit vnam partem aquæ, vel motus ex 4. impedimen­tum vt 4. &longs;ubducit partes 4. ex 16. vnde re&longs;idua erunt in eadem pro­portione, &longs;cilicet vt 3. ad 12. jam verò &longs;i longitudo dupla ma­joris fi&longs;tulæ &longs;ubducit 4. partes, longitudo &longs;ubdupla &longs;ubducet tantùm 2. igitur &longs;i major fi&longs;tula æqualis longitudine a&longs;&longs;umatur extrudet 14. partes &longs;eu libras aquæ. Vt autem inveniatur ba&longs;is fi&longs;tulæ, eju&longs;dem cum minore longitudinis, per quam quadrupla quantitas eodem tempore ef­fluat, ad i&longs;tud problema præparatorium res reducitur; dato Quadrato, cui &longs;ubtractum &longs;it &longs;ubquadruplum, id e&longs;t Quadrato &longs;emilateris, invenire Qua­dratum cui &longs;ubtracto rectangulo, &longs;ub eius latere, & quarta parte laceris prioris, re&longs;iduum &longs;it quadruplum, primi re&longs;idui, &longs;en triplum primi Qua­

drati. Supponamus CB e&longs;&longs;e latus, &longs;eu Diame­trum ba&longs;is minoris fi&longs;tulæ, & LA e&longs;&longs;e Quadra­tum quæ&longs;itum, ita vt &longs;ubtracto HE &longs;ub latere LH, & LE æquali MB, quæ e&longs;t &longs;ub quadrupla BA, re&longs;iduum EA &longs;it triplum Quadrati CA: &longs;it au­tem latus Quadrati 12 KN, quod mihi notum e&longs;t, hoc enim e&longs;t triplum Quadrati CA; &longs;it etiam KR, æqualis MB, mihi notæ, e&longs;t enim &longs;ubqua­drupla BA; his præmi&longs;&longs;is, &longs;ic formo problema decretorium: Data media proportionali, &longs;cilicet KN, & differentia extremarum, &longs;cilicet KR, invenire
extremas; dividatur RK bifariam in S & &longs;ub radio SN de&longs;cribatur &longs;emicirculus ONB, erunt KO, KP, extre­mæ quæ&longs;itæ, vt patet; igitur KO e&longs;t latus quæ&longs;itum, æquale &longs;cilicet LH. Pari modo procedam &longs;i velim ha­bere fi&longs;tulam eju&longs;dem longitudinis, ex qua eodem tem­pore tripla, vel dupla quantitas effluat.

Augu&longs;tin. Non paucæ mihi &longs;uboriuntur difficultates circa hæc, quæ à

te dicta &longs;unt; primò enim, &longs;i longitudo fi&longs;tulæ GH tale impedimentum affert, vt vnam quartam partem motus auferat; igitur dupla longitudo GI, duplum auferet; igitur quadrupla totum motum; nihil aquæ igitur ex illa efflueret, quod ab&longs;urdum e&longs;t.

Antim. Si&longs;te quæ&longs;o, neque enim huc Hydrau­lica traducenda e&longs;t, cùm &longs;it res longioris operæ; dicam igitur breviter, motum retardari po&longs;&longs;e in infinitum, vt nemo. ne&longs;cit; vnde &longs;i longitudo fi­&longs;tulæ GH. Subtrahit. velocitatis, longitudo GI &longs;ubtrahet 1/4. & dupla GI & dupla ejus totam; &longs;ed huc v&longs;que &longs;upponitur fi&longs;tula &longs;emper plena, eaque in &longs;itu horizontali ; vbi autem aqua ea tarditate, movetur, vt pars aquæ &longs;uprema proprio pondere qua&longs;i per planum inclinatum ire po&longs;&longs;it, de&longs;cendit haud dubiè, & tunc &longs;uperior fi&longs;tulæ cavitas, vacua re&longs;tat: &longs;ed quæ&longs;o te ad rem no&longs;tram redeamus, cùm hæc hujus in&longs;tituti non &longs;int.

Augu&longs;tin. Inde tantùm colligo, quantum detrimentum ij patiantur in di&longs;tributione aquarum, qui parvas fi&longs;tulas habent, & quantum vici&longs;&longs;im commodi ij, qui magnas habent; nempe illi, cui aquæ vncia competit, da­tur fi&longs;tula, cujus ba&longs;is Diameter v. g. vncia e&longs;t; alteri verò cui competunt quatuor, datur fi&longs;tula eju&longs;dem longitudinis, cujus ba&longs;is quadrupla e&longs;t prioris, &longs;ed eo tempore, quo per illam minorem fi&longs;tulam tanta aquæ quan­titas ex, major quadrupla per i&longs;tam majorem effluit, vt patet ex di­ctis; igitur vt legitimæ aquarum men&longs;uræ e&longs;&longs;ent, vel modus &longs;upra expo&longs;i­tus adhibendus e&longs;&longs;et, vel fi&longs;tularum longitudines, vt Diametri e&longs;&longs;e deberent, &longs;ed his mi&longs;&longs;is ad ae&longs;tum redi.

Antim. Iraque ex dictarum fi&longs;tularum analogia, explicabam &longs;upra, cur per breviorem freti, vel angu&longs;tiarum tractum, aqua vi pre&longs;&longs;ionis ve­lociùs extrudatur, ad proinde rapidiore motu; illud tamen di&longs;criminis intercedit, quòd in fi&longs;tulis, cre&longs;cente ba&longs;i fi&longs;tulæ, ponderis gravitantis viros cre&longs;cant vt pater ex dictis: at verò idem pondus gravitans, & eadem vis pre&longs;&longs;ionis e&longs;&longs;e &longs;upponitur, in eodem tractu, quando &longs;cilicet maxima pre&longs;&longs;io e&longs;t, re&longs;pectu illius, &longs;ive contractiores &longs;int angu&longs;tiæ freti, &longs;ive laxiores; &longs;ive longior illius tractus, &longs;ive brevior &longs;it: Vnde duplici nomine, quando brevior, e&longs;t, rapidiùs extruditur; nimirum quia arctus e&longs;t, & quia brevis; ex vtro quo enim capite aquæ extrudendæ moles minuitur.

Augu&longs;tin. Sed quæ&longs;o te, cur alicubi longè breviore tempore æ&longs;tus a&longs;­&longs;urgis, excurritque; alicubi verò plus temporis ponit?

Antim. Ita e&longs;t; nempe ad Guineam, non procul ab o&longs;tio Nigri flumi­nis 4. horis æ&longs;tus a&longs;&longs;urgit; item ad oram Cambaiæ, iuxta Indi fauces, dua­bus horis æ&longs;tus ad 30. leucas excurrit, ad o&longs;tia Garumnæ, &longs;eptem horis a&longs;&longs;urgit, quinque refluit, vt ait Scaliger exerc. 52. Sed accuratior Ob&longs;er­vator, idemque nobili&longs;&longs;imus Geometra D. Candala, expre&longs;&longs;is verbis te&longs;ta­tur, Garumnam attolli &longs;ex integris horis, deprimi verò &longs;ex horis & 24. minutis cui plus fidei habendum e&longs;&longs;e nemini dubium erit; vtpote qui ad accuratiùs ob&longs;ervanda acce&longs;&longs;us rece&longs;&longs;u&longs;que tempora, circa Garumnæ o&longs;tium, magnum horologium con&longs;trui curaverit, quod etiam minuta &longs;i­gnabat, vt ip&longs;emet te&longs;tatur in libello à &longs;e in lucem edito Ann. 1575. Quem etiam citat Furnerius. Quod ad me attinet, exi&longs;timo, æqualia vtrimque e&longs;&longs;e tempora; cùm enim æ&longs;tus initio & &longs;ub finem parum cre&longs;cat, vt dicam pau­lò po&longs;t, id e&longs;t, iuxta minimam ferè proportionem, facilè fieri potuit, vt minimum coementum primis 16. minutis & 16. vltimis &longs;ub &longs;en&longs;um & ob­&longs;ervationem v enim non potuerit; ac proinde æquè diu acce&longs;&longs;us atque re­ce&longs;&longs;us duraverit.

Augu&longs;tin. Metiri ergo æ&longs;tum debemus horis Lunaribus, divi&longs;a &longs;cilicet integra revolutione Lunæ, &longs;eu die Lunari in 24. partes, &longs;eu horas æqua­les, ita vt quælibet hora Lunatis &longs;it major hora Æquinoctiali 2. minutis; ac proinde &longs;enis &longs;emper horis Lunaribus æ&longs;tus reciproci fiunt per &longs;e, aut certè &longs;enis horis Æquinoctialibus & 12. minutis; non verò &longs;ex horis tem­poralibus, inæqualibus &longs;cilicet, iuxta formam horologij antiqui, vt vocant; & ita intelligendum e&longs;&longs;e Plinij locum lib. 2. cap. 97. per&longs;picuum e&longs;t; Vnde miror illorum errorem, qui volunt incipere æ&longs;tum vbi Luna &longs;upra Ho­rizontem vno Signo elevata fuerit, & continuo cre&longs;cere donec Luna Me­ridianum illius loci attigerit; decre&longs;cere verò ab hoc puncto, donec Luna æqualem po&longs;t Meridiem arcum decurrit terminatum &longs;cilicet ad 30. gra-dum &longs;upra Horizontem; errorem e&longs;&longs;e dico; quia Luna exi&longs;tente in maxi­mâ declinatione Au&longs;trali, arcus illius diuinus ab Ortivo puncto Horizon­tis ad Meridianum, vix e&longs;t 60. graduum; igitur &longs;i detrahantur 50. &longs;uper­&longs;unt 30. quos dum Luna decurrit, duabus &longs;cilicet horis Æquinoctialibus & 4. minutis, durat æ&longs;tus; quod apertè fal&longs;um e&longs;&longs;e con&longs;tat; tamdiu re­fluxus duraret. Prætereà, æ&longs;tus, qui fieret po&longs;t Occa&longs;um Lunæ, longè major e&longs;&longs;et priore; nempè arcus illius paralleli &longs;ub Horizonte, longè ma­jor e&longs;t alio; quem Luna &longs;ũmpta Horizontem excurrit, cuncta hæc experi­mentis repugnant. Dix i&longs;uprà, per &longs;e, cùm per accidens fieri po&longs;&longs;it, vt tem­pora fluxus & refluxus inæqualia &longs;int.

Antim. Ex præmi&longs;&longs;is principiis hoc manife&longs;tè deducitur nempè &longs;in­gulis pænè momentis, mutatur in globo punctum, &longs;eu Polus maximæ ele­vationis, ac proinde centrum circulorum & arcuum pre&longs;&longs;ionis, quorum cum diver&longs;a &longs;it ratio & proportio, propter varios continentis & Maris tractus, in &longs;uperficie globi, &longs;ine certâ lege di&longs;tinctos, inde nece&longs;&longs;ariò &longs;e­quitur diver&longs;a vis pre&longs;&longs;ionis, diver&longs;a impre&longs;&longs;io, diver&longs;a appul&longs;us, vel illa­p&longs;us linea: quod vt meliùs intelligas fige pedem circini ad Occiduum Guineæ Promontorium, non procul ab O&longs;tio Nigri, ductí&longs;que innumeris circulis ex illo centro, concentricis & parallelis, di&longs;tingue arcus vtiles ab inutilibus, &longs;en&longs;imque promoto versùs Ortum illo centro, v&longs;que ad 60. gradus, &longs;i vlteriùs illud promoveas, v&longs;que ad 90. circuli pre&longs;&longs;ionis maxima ex parte, vel continenti Africæ, Europæ, A&longs;iæ vel Indico Ocea­no incumbent, ac proinde inutiles erunt re&longs;pectu prædicti loci: quid mi­rum igitur, &longs;i 4. dumtaxat horis in eo æ&longs;tus a&longs;&longs;urgat, deprimatur verò plu­ribus? Nam promoto versùs Oceanum centro, diver&longs;a e&longs;t circulorum pre&longs;­&longs;ionis ratio. Aliquid &longs;imile ob&longs;ervabis, fixo circini pede ad litus Cam­baiæ; tanquam in centro: accedit, quòd ex multis capitibus prædicta æ&longs;tuum inæqualitas inducitur; Primò, per planum magis inclinatum, lon­giùs excurrit & velociùs, licèt plus temporis ponat in decurrendo magis inclinato, cuncta hæc ex doctrina motuum per&longs;picua &longs;unt; tantumdem temporis aqua ponit in de&longs;cen&longs;u per planum inclinatum., quantum in a&longs;cen&longs;u. Secundò, Si po&longs;t quàm aqua regredi cœpit, nova quædam fiat æ&longs;tus reflexio, versùs fluminis fauces, vel &longs;i aqua libero quidem aditu &longs;u­beat, &longs;ed exitu difficiliore, tunc acce&longs;&longs;us breviore tempore fiet quàm re­ce&longs;&longs;us. Tertiò, Si nova reflexio accedat, antequam aqua regredi incipiat, vel agger quidam appo&longs;itus ad fauces &longs;inus, aut fluminis primam vim ac­ce&longs;&longs;us retundat, vt videre e&longs;t ad fauces Sequanæ & Garumnæ, rece&longs;&longs;us bre­viore tempore fiet quàm acce&longs;&longs;us. Quartò, Pro diver&longs;o æ&longs;tus ad oram ap­pul&longs;u, vel illap&longs;u, longiùs per alveum fluviorum vel minùs longè aqua ex­currit; item pro diver&longs;a alvei inclinatione; hinc facilè crediderim, alveum illorum fluminum, in quibus ad aliquot centena milliaria æ&longs;tus excurrit, e&longs;&longs;e valde inclinatum Quintò, Dicam ampliùs, ratione eju&longs;dem loci, non modò æ&longs;tum altiùs aut minùs altè attolli, verùm e&longs;&longs;e aliquando acce&longs;&longs;um majorem, aliàs minorem e&longs;&longs;e po&longs;&longs;e; quia mutatur &longs;ingulis diebus centrum circulorum pre&longs;&longs;ionis, etiam re&longs;pectu eju&longs;dem loci; item aliquando ac-ce&longs;&longs;um æqualem e&longs;&longs;e acce&longs;&longs;ui, aliquando diuturniorem, aliàs breviorem cuncta hæc ex diver&longs;a pre&longs;&longs;ionis ratione pendent: e&longs;t autem diver&longs;a ratio pro diver&longs;o tractu &

Augu&longs;tin. Sed quaero ex te vtrùm eadem &longs;emper hora Meridiana Lunari, id e&longs;t, eo momento, quo Luna Meridianum loci attigit, &longs;ummus æ&longs;tus &longs;it?

Antim. Per &longs;e quidem &longs;ummns æ&longs;tus &longs;emper e&longs;t, exi&longs;tente Luna in Me­ridiano loci, &longs;ive &longs;upra, &longs;ive infra Horizontem; per accidens tamen &longs;ecus accidit; & Primò quidem ex diver&longs;a pre&longs;&longs;ionis ratione; Nempe fieri po­te&longs;t, vt hora decima Lunari re&longs;pectu alicujus loci, &longs;it maximus pre&longs;&longs;ionis effectus, ac proinde &longs;ummus æ&longs;tus. Secundò, Ob concur&longs;um æ&longs;tuum Ge­mini Matis tractus, vt fit in Germanico & Britannico, nempe longè ante Meridiem Lunarem, re&longs;pectu Dieppæ & O&longs;tij Sequanæ Oceanus Septem­trionalis intume&longs;cit, à quo in Germanicum vis pre&longs;&longs;ionis traducitur, & hinc per Fretum Gallicum, Dieppam, & ad O&longs;tium Sequanæ ; quò etiam cùm ex Britannico, qua&longs;i ex aver&longs;o vis pre&longs;&longs;ionis incumbat, licèt paulò tardiùs quàm ex Germanico, quod ad Ortum &longs;itum e&longs;t, vtriu&longs;que concur&longs;u &longs;um­mus æ&longs;tus Dieppæ a&longs;&longs;urgit, itémque ad O&longs;tium Sequanæ ; hîc quidem priùs vna ferè hora propter reflexionem magis directam. Hinc fieri pote&longs;t; vt a&longs;­&longs;urgat &longs;ummus æ&longs;tus in duobus locis &longs;ub diver&longs;o Meridiano &longs;itis, eodem tempore, v.g. &longs;i accipiatur alter locus di&longs;tans Dieppa 7. grad.1/2. ver&longs;us Or­tum, in quo &longs;ummus æ&longs;tus &longs;it hora vndecima Lunari; illic enim & Dieppæ eodem tempore &longs;ummus erit æ&longs;tus. Pari modo facilè dici pote&longs;t, cur mul­tis in locis &longs;ummus æ&longs;tus &longs;it po&longs;t Meridiem v, g. Burdigalæ, ad Garumnam, Antuerpiæ ad Scaldim, Hamburgi ad Albim, &longs;ummus æ&longs;tus e&longs;t hora &longs;exta Lunari po&longs;t eju&longs;dem Meridiem, quia per motum æ&longs;tus a&longs;cendit in alveo fluminum; igitur tardiùs pervenit ad loca longè di&longs;&longs;ita à fluminis faucibus: Am&longs;terodami 3. hora Lunari po&longs;t Meridiem; in ip&longs;o verò Meridie Lu­nari, Encu&longs;æ, haud procul po&longs;itæ; quia per diver&longs;os mæandros in eo maris &longs;inu, Am&longs;terodamum æ&longs;tus appellit, liberiùs Encu&longs;am; in oram Fri&longs;iæ adhuc liberiùs; hinc tertia hora Lunati ante Meridiem Luna­rem, ibi fit &longs;ummus æ&longs;tus; nempe ab Oceano Septemtrionali tantulùm versùs Ortum declinante vis pre&longs;&longs;ionis traducitur in Germanicum, & qua­&longs;i directè in oram Fri&longs;iæ; Oceanus autem Septemtrionalis propter mo­dicam Meridianorum di&longs;tantiam in eo Boreali tractu, in Germanicum incumbit, antequam Luna ad illum Meridianum perveniat; cui Ma­re Germanicum &longs;ube&longs;t, vnde prior ratio indicata plurimùm confirmatur. Itaque ex dictis con&longs;tat, &longs;ummum æ&longs;tum e&longs;&longs;e po&longs;&longs;e &longs;ub diver&longs;is Meridia­nis, eodem tempore, & &longs;ub eodem, in diver&longs;is locis, diver&longs;o, & &longs;in­gulares quo&longs;libet ca&longs;us ad præmi&longs;&longs;a & communia principia reduci, mo­do &longs;ingulares circum&longs;tantiæ habeantur, ratione quarum, vel &longs;ummus æ&longs;tus cum Lunæ motu convenit, vel tardiùs aut citiùs accidit; mihi &longs;atis &longs;it ali­quas obiter indicate.

Primò, Si nihil appul&longs;um æ&longs;tus impediat, nihil promoveat, &longs;ed mare ab incubante aëre pre&longs;&longs;um inæqualiter, liberè intume&longs;car, &longs;ummus æ&longs;tus erit &longs;emper hora meridiana Lunari, id e&longs;t, eo temporis puncto, quo Luna Meridianum illius loci attingit, &longs;ive &longs;upra, &longs;ive infra Hori­zontem,

Secundo. Si res ita compo&longs;itæ, &longs;eu di&longs;po&longs;itæ &longs;int, vt concurrant æ&longs;tus, vel in freto, vel vltra freti fauces, in quibu&longs;dam tractibus &longs;ummus æ&longs;tus erit ante meridiem, vt Dieppæ; quia &longs;cilicet aqua citiùs per freti angu&longs;tias extru­ditur; adde reflexionem quamdam, quæ &longs;equitur ex vtroque ni&longs;u maris ver­sùs fretum connitentis.

Tertio. Si mare versùs Au&longs;trum eat, &longs;en&longs;imque declinet ora versùs Boream, ad oram illam, &longs;ummus æ&longs;tus erit ante meridiem Lunarem vt in Fri&longs;iæ ora.

Quarto. Si per varios &longs;inus & mæandros mare in terras &longs;e&longs;e in&longs;inuat, &longs;um­mus æ&longs;tus erit po&longs;t meridiem Lunarem, vt Am&longs;terodami, & in iis locis, quæ &longs;ita &longs;unt ver&longs;us extremum &longs;inum.

Quinto. Si æ&longs;tus per alueos fluviorum a&longs;cendat, quò longiùs di&longs;tat ab o&longs;tio fluvij locus aliquis, eò tardiùs &longs;ummum æ&longs;tum habet, &longs;ci′icet po&longs;t meridiem Lunarem, vt Burdigala, Hamburgum, Rotomagus, An­tuerpia.

Sexto. Si aliquis terræ tractus longiùs in mare porrigatur, citiùs habet &longs;ummum æ&longs;tum, & tardiùs, vt dixi, extremitas &longs;inuum.

Septimo. Diver&longs;us litorum &longs;itus ad talem vel talem reflexionem di&longs;po­&longs;itus non parum confert; reflexionem, inquam, ni&longs;us, &longs;eu pre&longs;&longs;io­nis aquæ cuju&longs;vis ab oppo&longs;ito latere &longs;eu littore versù; aliud qua&longs;i refle­ctitur.

Octavo. Adde lineam cur&longs;us aquæ, prout &longs;cilicet vel obliquiùs, vel minus obliquè incidit.

Nono. Adde etiam diver&longs;am pre&longs;&longs;ionis rationem, qua fieri pote&longs;t, vt &longs;umma vis pre&longs;&longs;ionis non &longs;it re&longs;pectu alicujus loci con&longs;tituto centro ar­cuum pre&longs;&longs;ionis in dicto loco, &longs;ed in alio, &longs;eu versùs ortum, quo po&longs;ito, &longs;ummus æ&longs;tus erit ante meridiem Lunarem; &longs;eu versùs occa&longs;um, quo &longs;up­po&longs;ito, po&longs;t meridiem Lunarem in dicto loco erit. Ex his reliqua, ni fallor, facilè intelligetis, aut &longs;altem &longs;i quid difficile, re&longs;tet &longs;ignificare dignabi­mini.

Augu&longs;tin. Pauca haud dubiè re&longs;tant, quæ vel abundè non fuerint ex­po&longs;ita, vel ex iis, quæ à te dicta &longs;unt, facilè non intelligantur, & mihi videor rationem afferre po&longs;&longs;e illorum omnium, quæ in hac materia maxi­mam admirationem conciliare &longs;olent v.g. cur multa litora, vel nullum vel modicum æ&longs;tum patiantur, alia verò maximum; quid Luna ad æ&longs;tum con­erat, ita vt in Plenilunio & Novilunio maximus æ&longs;tus &longs;it, eiu&longs;que &longs;ummum, Luna in Meridiano exi&longs;tente, ni&longs;i per accidens &longs;ecus fiat; cur in duobus locis, &longs;ub eodem Meridiano &longs;itis diver&longs;o tempore, eodem verò, &longs;ub di­ver&longs;o Meridiano; cur in fretis gemini æ&longs;tus concurrant; cur is, qui fer­tur ab ortu intra fretum longiùs accedat, minus verò, qui venit ab occa&longs;u; cur alibi rapidi&longs;&longs;imus &longs;it, mitior alibi, cur alicubi ante meridiem Lunarem, alibi po&longs;t; pa&longs;&longs;im tamen in ip&longs;o meridie; cur in quibu&longs;dam tractibus acce&longs;&longs;us plus duret, quàm rece&longs;&longs;us; in aliis ve­rò plus rece&longs;&longs;us; quàm acce&longs;&longs;us, licèt vnus per &longs;e alteri &longs;it aquè diutur­nus; cur per &longs;e mare &longs;ex horis 12. minutis a&longs;cendat, & totidem depri­matur, cur &longs;ingulis diebus vna ferè hora, hoc e&longs;t 48.minutis æ&longs;tus tardiùs a&longs;&longs;urgere incipiat, quàm pridie, idque &longs;emper & per &longs;e, Luna in Meridia­no horæ &longs;extæ exi&longs;tente; cur in quibu&longs;dam oris ad 70. & 80. pedum alti­tudinem mare per æ&longs;tum in Plenilunio attollatur, in aliis vix ad vnum pe­dem, in multis verò nihil pror&longs;us; cuncta hæc & alia multa ex principiis à te jactis nullo negotio deducuntur; alia quædam occurrunt, quæ mihi vel dubia &longs;unt, vel eorum ratio incomperta; à dubiis initium duco. Pri­mum e&longs;t quod aliqui dicunt, in Plenilunio &longs;cilicet majorem e&longs;&longs;e vim æ&longs;tus, quàm in Novilunio ad Calecutium; cùm tamen ad indi o&longs;tia in Novilunio majores &longs;int æ&longs;tus; alterum verò quod alij referunt, quibu&longs;dam in cis per totos quindecim dies, à Novilunio &longs;cilicet, ad Plenilunium continuò æ&longs;tum cre&longs;cere; ita vt &longs;ummum crementum &longs;it in Novilunio & Plenilunio, ac totidem diebus aquam &longs;ub&longs;idere, vt ob&longs;erva tum e&longs;t, inquiunt, circa Cubam & Hi&longs;paniolam; item in fluvio Vanna vel Van&longs;one ad Pachinum Sinarum

Antim. Ab hoc vltimo incipio, quia involvit repugnantia; nempe cùm in prædictis, vt & in multis aliis Mediterranei locis, æ&longs;tus &longs;it tantùm &longs;en&longs;i­bilis in Plenilunio & Novilunio, quia cùm tunc Majores &longs;int, vt &longs;upra di­ximus, con&longs;tatque experientia; quid mirum, &longs;i tunc &longs;en&longs;ibiles &longs;int? vnde non nemo occa&longs;ionem arripuit, dicendi, cre&longs;cere continuo in iis locis per totos 15. dies, à Novilunio &longs;cilicet ad Plenilunium; quod fal&longs;i&longs;&longs;imum e&longs;t; quia &longs;ingulis diebus - bis cre&longs;cit, & bis refluit. Sed in&longs;en&longs;ibiliter, ni&longs;i paucis diebus ante & po&longs;t Novilunium ac Plenilunium; hæc autem &longs;unt inter &longs;e repugnantia, decre&longs;cere continuo à Plenilunio ad Novilunium ac proinde in Novilunio mare e&longs;&longs;e maximè depre&longs;&longs;um, cùm in eo &longs;it terminus decrementi, & toto reliquo men&longs;e nullum &longs;en&longs;ibilem æ&longs;tum apparere; fieri tamen aquarum tumorem &longs;en&longs;ibilem in Novilunio & Plenilunio. Ve­nio ad primum, & dico, de eo mihi maximum dubium e&longs;&longs;e, quanquam pro diver&longs;o Lunæ &longs;itu, non negarim fieri po&longs;&longs;e, vt major æ&longs;tus &longs;it in Novi­lunio, quàm in Plenilunio; cum enim fauces Indi &longs;int ferè &longs;ub Tropico Caneri, &longs;i &longs;upponamus Novilunium fieri in Tropico Cancri, de Meridie maximus erit ibi aquæ tumor, cùm linea ab&longs;idum eo terminetur, minor tamen erit de media nocte; quia extremitas lineæ ab&longs;idum inde di&longs;tat 47. gradibus; &longs;i verò Plenilunium fiat in Tropico Capricorni, de Meridie ma­ximus æ&longs;tus ibidem erit, quia vt linea ab&longs;idum à Tropico ad Tropicum per centrum globi tunc eat, de Meridie extremitas prædictæ lineæ, quæ ad Tropicum Cancri terminatur, re&longs;pondet lineæ Meridianæ; itaque &longs;i compatetur diurnus Plenilunij cum nocturno Novilunij, in Novilunio mi­nor æ&longs;tus erit, quàm in Plenilunio, &longs;ive diurnus Novilunijcum nocturno Ple­nilunij, major erit in Novilunio, &longs;ed profectò de&longs;unt ob&longs;ervationes, & Au­tores &longs;uper hoc in &longs;en&longs;us contrarios eunt, vtpote qui non tam ex ob&longs;erva­tionibus, quàm ex propriis conjecturis multa deducant & &longs;cribant, quæ omitto, vobi&longs;que refutanda relinquo; accedit, quòd diver&longs;a pre&longs;&longs;ionis ra­tio rem hanc plurimùm variat; immo Autores &longs;uper hoc &longs;ibi non con&longs;tant, & vnus illorum, &longs;i rectè memini, cùm docui&longs;&longs;et, incrementa matis majora fieri in Pleniluniis ad Calecutium, in Noviluniis verò ad Indi o&longs;tia, &longs;equen­ti &longs;tatim pagina dicit, alicubi majora e&longs;&longs;e in Noviluniis, vt ad Calecu­tium, alibi verò majora in Pleniluniis, vt ad Indi O&longs;tia; idem re­petit po&longs;t quintam paginam; vnde vides, cuncta hæc parum certa e&longs;&longs;e.

Augu&longs;tin. In hac re nihil aliud de&longs;idero, ni&longs;i novas & accuratas ob&longs;er­vationes, circa diurnum & nocturnum æ&longs;tum, dum Luna &longs;ita e&longs;t extra Æquatorem, ac præ&longs;ertim circa Tropicos; alia quædam de quibus certò con&longs;tat, quorum cau&longs;æ mihi compertæ non &longs;unt, ex te quærenda re&longs;tant: primum e&longs;t, cur dum æ&longs;tus a&longs;&longs;urgit &longs;ub initium & finem minoribus, crementis a&longs;&longs;urgat, majoribus verò &longs;ub me­dium.

Antim. In Sinu Tarentino dum æ&longs;tus &longs;ex horis a&longs;&longs;urgit, & fortè duo­decim minutis, quæ &longs;ub &longs;en&longs;um non cadunt, vt dixi &longs;upra, & toti­dem refluit, hæc accuratè ob&longs;ervata &longs;unt, in Novilunio v. g. prima hora lentè accedit, &longs;ecunda tantulùm intenditur motus, tertia & quarta, longè velocior evadit, quinta remittit, vt in &longs;ecunda: in &longs;ex­ta denique vt in prima: idem fit in Plenilunio: vegetior autem æ&longs;tus e&longs;t quatriduo ante & quatriduo po&longs;t Novilunium & Plenilunium, reliquo

tempore longè remi&longs;&longs;ior. Hæc literis ad me datis à viro &longs;apienti&longs;&longs;imo qui præ&longs;ens illa in&longs;piciebat, acce­pi ac fideliter retuli: Vt autem rationem, quam petis exponam, &longs;uppono ex Geometria, &longs;inus com­plementi, quo magis accedunt ad &longs;inum totum, habere minorem proportionem inæqualitatis. Sit enim quadrans MLN in quo accipiantur arcus æquales L, P, E, R, Z, & ducantur &longs;inus com­plementi XP, TE, SR, VZ, dico ML ad XP, habere minorem proportionem inæqualitatis, quàm XP ad TE, & XP, ad TE, quàm TE ad SR, atque ita deinceps quod vel ex ip&longs;is &longs;inuum Ta­bulis con&longs;tat; hoc &longs;uppo&longs;ito, cùm aqua intume&longs;cat magis vel minùs iuxta proportionem inæqualis pre&longs;&longs;ionis, & pre&longs;&longs;io inæqualis &longs;it iuxta rationem circulorum pre&longs;&longs;ionis inæqualium, hi porrò inæquales &longs;int
iuxta rationem prædictorum &longs;inuum com­plementi, mare per æ&longs;tum intume&longs;cit ad in&longs;tar pruni, vel &longs;phæroidos, vt jam &longs;upra dictum e&longs;t. Sit autem quadrans ellip&longs;eos ABD, & quadrans circuli ABY di­vi&longs;us in quotcunque arcus æquales; item quadrans circuli AGD; &longs;int anguli GAF, DAE æquales, quadrans ABY e&longs;t ad quadrantem ellipticum cum ABD, vt AY ad AD, &longs;unt enim figuræ analogæ vel homoge­neæ, vt vocare &longs;oleo; item quadrans ABD e&longs;t ad quadrantem AGD, vt AY ad AD; igitur figura YDB e&longs;t ad figuram BGD, vt AY ad AD, &longs;unt­que duæ i&longs;tæ figuræ homogeneæ; igitur vt YD ad GB, ita EO ad CI, ita HO ad CF, ita K a ad ab; &longs;ed YD, BG &longs;unt æquales, igitur OE & IC æquales, item OH & CF, item a K & ab, igitur tantum cre&longs;­cit aqua vi pre&longs;&longs;ionis à B in I, quantum ab H ad Y, vel ab E in D ; igitur &longs;ub initium & finem cre&longs;cit aqua modicis incrementis, ii&longs;que reciprocè æqualibus hinc inde, a&longs;&longs;umptis &longs;cilicet angulis æqualibus; majori­bus verò &longs;ub medium; en tibi germanam & facilem tui quæ&longs;iti ra­tionem, quæ dubito, an æquè facilè in qualibet alia hypothe&longs;i afferri po&longs;&longs;it.

Augu&longs;tin. Quid dici queat, quod in rem hanc meliùs quadret, certè non ­video; &longs;ed cur in Æquinoctiis æ&longs;tus major e&longs;t?

Antim. Iam &longs;upra ea &longs;uper hoc expo&longs;ui, quæ tibi facerent &longs;atis, &longs;i for­tè in memoriam revocares; nempe, vt jam indicavi, &longs;i Autores illos ­con&longs;ulamus, qui de hoc argumento &longs;crip&longs;erunt, nihil ferè ni&longs;i repugnan­tia inter &longs;e inveniemus; nimirum aliqui &longs;crip&longs;erunt, æ&longs;tum maximum e&longs;&longs;e in Sol&longs;titiis, minimum verò in Æquinoctiis, alij contra maximum in Æquinoctiis, minimum in Sol&longs;titiis; alij majorem in Æquinoctio ver­no; alij majorem in autumnali; alij majorem in Sol&longs;titio Brumali, mi­norem in Æ&longs;tivo; alij majorem in æ&longs;tivo, minorem in Brumali nihil af­fingo; Augu&longs;tine, hæc adeò repugnantia apud Autores invenies. De Sol­&longs;titiis nihil certi, cùm etiam in hoc Autores varient, non dubito tamen, quin, id quod e&longs;t, in no&longs;tram notitiam venire po&longs;&longs;it, fidelis ob&longs;ervatio­nis opera, in eodem &longs;cilicet loco; nempe pro diver&longs;is locis, diver&longs;a ra­tio e&longs;t, cùm diver&longs;a &longs;it pre&longs;&longs;io; &longs;ed pro eodem loco facilè ob&longs;ervari po­te&longs;t in vtroque Sol&longs;titio æ&longs;tus a&longs;&longs;urgentis men&longs;ura, tum diurni, tum no­cturni; cùm multum inter vtrumque di&longs;crimen e&longs;&longs;e po&longs;&longs;it; nulla autem re­gula certa &longs;tatui pote&longs;t, propter diver&longs;am pre&longs;&longs;ionis rationem, ob &longs;uperfi­ciem globi variis, &longs;ine lege & ordine, maris & continentis tractibus di­&longs;tinctam. Quod pertinet ad Æquinoctia; hoc vnum certò con&longs;tat, maxi­mum in iis cieri æ&longs;tum, Luna &longs;cilicet plena aut nova, &longs;altem in no&longs;tro Oceano, intra Europam; rationem hic globus tibi &longs;uggeret, in quo vides, Luna exi&longs;tente in Æquatore arcus pre&longs;&longs;ionum e&longs;&longs;e majores; vbi verò Luna declinat versùs Boream, in quo tractu, Europa no&longs;tra &longs;ita e&longs;t, vides, ni fallor, quantam prædictorum arcuum aream circulus maximæ pre&longs;&longs;ionis re&longs;cindat, traducátque ad oppo&longs;itum hemi&longs;phærium, exi&longs;ten­te Luna infra horizontem ad Meridianum; qua &longs;ita &longs;upra horizontem, de meridie &longs;cilicet Luna nova, de media nocte, in Plenilunio vides quan­tam maxima pars Americæ inutilem reddat: vbi porro Lua declinat in Au&longs;trum, eadem pror&longs;us ratio militat; po&longs;ita enim Luna in Tropico Capricorni, in Novilunio de meridie idem e&longs;t circulus maximæ pre&longs;&longs;io­nis, qui erat de media nocte dum Luna nova e&longs;&longs;et in Tropico Can­cri; in Plenilunio verò, de meridie, idem e&longs;t circulus maximæ pre&longs;&longs;ionis, qui erat de media nocte, dum Luna e&longs;&longs;et in dicto Tropico Cancri; vnde vt vides, eadem pro vtroque Sol&longs;titio ratio militat.

Augu&longs;tin. Hæc tua ratio probat, in vtroque Æquinoctio, æ&longs;tum æqualem e&longs;&longs;e; at gravi&longs;&longs;imi Autores dicunt majorem e&longs;&longs;e in Æquinoctio autumnali v.g.ad o&longs;tia Garumnæ.

Antim. Ita e&longs;t æquè pro vtroque probat hæc ratio, & ita e&longs;&longs;e nemo inficiatur. Scilicet per &longs;e; nam per accidens &longs;ecus accidere pote&longs;t; v.g.eo quod major vis humoris aëri admixta &longs;it &longs;ub Æquinoctium Autumnale, quàm &longs;ub Vernum; & verò cum &longs;it terminus æ&longs;tatis, dubium non e&longs;t, quin longè major humoris &longs;eu vaporis, in quem humor abit copia aëri ad­mixta &longs;it; vnde major evadit gravitatio, major pre&longs;&longs;io, & major æ&longs;tus: in Zona torrida & Au&longs;trali &longs;ecus dicendum e&longs;t; accedit, quod in Æquino­ctio, rarò fit Novilunium aut Plenilunium; &longs;ed tantùm aliquot ante, vel po&longs;t diebus; adde diver&longs;am venti vim, quæ ad majorem æ&longs;tum non parum confert; &longs;i hæc tibi non faciant &longs;atis, nihil habeo vltra quod tibi ex­ponam.

Augu&longs;tin. Faciunt haud dubiè; nec dubito, quin paucis aliis po&longs;tu­latis, quæ mihi re&longs;tant etiam facturus &longs;is &longs;atis; quæro igitur ex, te, vtrum vrinatores, qui profundiùs immerguntur, vim & motum æ&longs;tus &longs;en­tiant.

Antim. Ga&longs;&longs;endus hoc ip&longs;um probari curavit, invenítque non &longs;entiri æ&longs;tum pluribus pa&longs;&longs;ibus infra &longs;uperficiem maris, quod certè ex præmi&longs;&longs;is omnino &longs;equitur; nempè infra arcum BY ne minima quidem impre&longs;&longs;io aquæ accidit; in quo meo judicio, nulla e&longs;t difficultas; vnde fabulam reputo, ab ebulliente mari per æ&longs;tum, marinas belluas &longs;ur&longs;um ad &longs;uperficiem pelli, illud fortè verius, &longs;eu veri&longs;&longs;imilius, ad litus Per&longs;icum allidi pi&longs;ces ad &longs;copulos, quod aliquando vi &longs;ævi&longs;&longs;imæ tempe&longs;tatis actum e&longs;&longs;e ferunt; hinc pi&longs;ces &longs;æviente procella in maris profundum &longs;e reci­piunt.

Augu&longs;tin. Illud etiam fabulo&longs;um crediderim; quod à quibu&longs;dam Auto­ribus refertur, &longs;cilicet ad Norvegiam, e&longs;&longs;e quemdam maris tractum, in quo &longs;enis horis Naves & grandia cete &longs;orbentur à mari, & aliis Senis extrudun­tur; itémque inter Angliam & Nortmanniam e&longs;&longs;e voraginem, versùs quam naves veloci&longs;&longs;imo cur&longs;u actæ etiam vicinæ gurgiti repelluntur. Hæc meta &longs;unt Nautarum garrientium figmenta.

Antim. Idem quoque &longs;entio; quanquam prædictus gurges Angliam inter & Nortmanniam, ip&longs;e fortè e&longs;t gemini æ&longs;tus concur&longs;us, qui non di&longs;&longs;imilem effectum præ&longs;taret, vt con&longs;ideranti patebit; Ille verò tractus ad Norvegiam, qui naves votat, ac deinde evomit, dubito an &longs;it circel­lus maximæ depre&longs;&longs;ionis, quem circa Polum mundi de&longs;cribit punctum di­&longs;tans à Parallelo Lunari 90. gradibus nempe ad in&longs;tar cuju&longs;dam voraginis e&longs;t, &longs;ub&longs;idente aqua &longs;enis horis, ae totidem a&longs;&longs;urgente; &longs;ed dum res certò non con&longs;tet, quod &longs;it, fru&longs;tra quæritur, propter quid &longs;it: Non negarim tamen, versùs Norvegiam, in quo re verà tractu mare profundi&longs;&longs;imum e&longs;t, qua&longs;dam voragines e&longs;&longs;e po&longs;&longs;e, in quibus ratione &longs;itus, æ&longs;tus ip&longs;e mirificos præ&longs;tet ef­fectus.

Augu&longs;tin. Proba&longs;ine quod aliqui &longs;cribunt, in cingulis ex Lupi marini co­tio factis, per æ&longs;tum pilos erigi & &longs;tare, in refluxu verò deprimi, hoc etiam fabulam olet, ni fallor.

Antim. Vt vt &longs;it, quædam humore rige&longs;cunt, ac proinde eriguntur, vt funes ex canabe, præterea per æ&longs;tum, aër minus compre&longs;&longs;us e&longs;t, magis in refluxu; quid mirum ergo, &longs;i refluxus tempore pilos illos de­primat.

Augu&longs;tin. Sed quid cen&longs;es de iis fontibus & puteis, quorum aliqui at­tolluntur cum Oceano per æ&longs;tum, alij contra &longs;ub&longs;idunt.

Antim. Multa etiam fabulo&longs;a de his Scriptoribus promulgata fue­runt; difficile tamen non e&longs;t; rationem horum adducere; nempè altior aqua per æ&longs;tum, plus aquæ extrudit per exiguos areno&longs;æ terræ meatus; minus verò aqua &longs;ub&longs;idens; quòd &longs;i per longiores mæandros aqua tradu­cenda e&longs;t, ad putei, &longs;eu fontis recepta culum non tam citò pervenit, &longs;ed fortè &longs;ex horis tardiùs. Sic non &longs;tillant fornices, eo die, quo pluit, &longs;ed altero, immo tertio po&longs;t die, pro diver&longs;a for nicis cra&longs;&longs;itudine; nec obe&longs;t, aquam dul­cem e&longs;&longs;e; quia marina per arenam percolata dulce&longs;&longs;it: nihil dico de aliis multis fontibus, qui aliquoties per diem intume&longs;cunt, ac deinde &longs;ub&longs;i­dunt, nulla tamen temporum &longs;ervata lege, quia ad hoc argumentum non pertinent: quanquam in diver&longs;is fontibus artefactis facilè videmus, quid etiam indu&longs;trio&longs;a natura in hac materia præ&longs;tare valeat.

Augu&longs;tin. Alia Exciderant; quid enim de Mari Ca&longs;pio, de Ponto Euxino, de Mari Baltico, de Eurippo ad Eubeam, de quibu&longs;dam lacubus in Ameri­ca, in quibus æ&longs;tus fieri dicitur?

Antim. In Ca&longs;pio, Euxinio, Baltico, vel nullus, vel modicus æ&longs;tus e&longs;t cùm ab Oceano traduci non po&longs;&longs;it, & tractus aquarum breviores &longs;int, & ita &longs;iti, vt &longs;en&longs;ibilem pre&longs;&longs;ionis inæqualitatem non inducant. De lacubus Americæ memoratis, dicendum e&longs;t, vel e&longs;&longs;e tantæ longitudinis vt 700. etiam milliaria adæquent, quod &longs;ufficit, vt aliqua pre&longs;&longs;ionis inæqualitas inducatur, vel per majorem fluminis alveum ab Oceano vim æ&longs;tus eò tra­duci, quod &longs;altem meo judicio, difficultate caret. Iam de celeberrimo illo Græciæ Eurippo nunc dicam, de quo fabulo&longs;a multa narrantur; nem­pe aliàs &longs;epties &longs;ingulis diebus æ&longs;tua&longs;&longs;e dicitur, nunc verò quater in die: quod ad me &longs;pectat, fateor vltro, me nunquam vidi&longs;&longs;e; quantum tamen ex incolarum relationibus audire potui, bis &longs;ingulis diebus in præfato Eu­rippo recurrit æ&longs;tus; &longs;ed quia it reditque duodecim horis, alii&longs;que duo­decim pariter fluit, ac re&longs;init æquè rapido cur&longs;u, quater in die æ&longs;tuare vi­detur; hujus autem Eurippi eadem ratio e&longs;t, quæ aliorum, de qua jam &longs;upra; fieri taen pote&longs;t, vt quemadmodum de Siculo diximus, concur­rant in i&longs;to gemini æ&longs;tus, ab vtraque &longs;cilicet extremitate, nempe ad orti­vam vis æ&longs;tus traducitur per fauces illas, quæ &longs;unt inter Cretam & Orien­tale Peloponen&longs;i cornu, non procul ab In&longs;ula Cythere, vulgò Cerigo,præter fluente aqua Orientalem Pelopone&longs;i & Atticæ oram; ad occiduam verò per medium qua&longs;i Ægeum vis æ&longs;tus appellitur; ex præfato verò con­cur&longs;u varij vortices na&longs;ci videntur, qui vulgo ventorum vi, vel aliis cau&longs;is tribui &longs;olent; vnum dumtaxat libenter addo, anilem fabulam jam olim de Ari&longs;totele &longs;par&longs;am fui&longs;&longs;e, cum &longs;cilicet, præ de&longs;peratione, Eurippi cau&longs;am non capientem &longs;e&longs;e in medium Euripum præcipitem dedi&longs;&longs;e; quis hoc amabò credat? ni&longs;i qui nimiæ laboret vitio credulitatis? Sed quid tamdiu taciturnus fui&longs;ti, &longs;uavi&longs;&longs;ime Chry&longs;ocome? cur huc v&longs;que de argumento adeò difficili di&longs;&longs;erentem non interpella&longs;ti? An fortè res i&longs;ta tibi non pla­cuit?

Chry&longs;ocom. Placuit haud dubiè, neque hoc in&longs;iciari po&longs;&longs;um; &longs;ilui tamen, nec interpellavi vnquam, quia multa &longs;anè volvebam animo, quæ contra ea, quæ dicebas, mihi opponenda e&longs;&longs;e videbantur, quæ mihi haud parum diffi­cultatis præferre videbantur.

Augu&longs;tin. Su&longs;tine tanti&longs;per Antime, & per te mihi liceat nodos i&longs;tos à Chry&longs;ocomo contextos di&longs;&longs;olvere mentem tuam callere ap­prime mihi videor; &longs;i quid in &longs;olutione mea de&longs;ideretur facilè &longs;upplere po­teris.

Antim. Legem accepto; profer igitur, Chry&longs;ocome, illa omnia, quæ volvi&longs;ti animo adversùm nos: vtrumque di&longs;&longs;erentem libenter au­diam.

Chry&longs;ocomus. Primo quidem loco incredibile e&longs;&longs;e videtur, tantam vim ine&longs;&longs;e aëri, qua immen&longs;um propemodum aquarum pondus attollee po&longs;&longs;it.

Augu&longs;tin. An fortè putas, totam aquarum molem ab aëre gravitante attolli, aut &longs;u&longs;tineri? falleris; cùm illa tantùm aquæ portio &longs;u&longs;tineatur, quæ &longs;upra libellam maximæ depre&longs;&longs;ionis attollitur, & quæ mihi videtur per exigua, & ferè nulla, &longs;i cum tota aëris móle comparetur; & verò &longs;i tota vis prementis aëris libera e&longs;&longs;et; id e&longs;t, &longs;i omnes circuli & arcus pre&longs;­&longs;ionis vtiles e&longs;&longs;ent; id e&longs;t, &longs;i totam globi &longs;uperficiem aqua tegeret, æ&longs;tus profectò longè altiùs a&longs;&longs;urgeret: &longs;ed dic mihi, &longs;odes, quanta &longs;it altitudo aëris gravitantis in circulum maximæ pre&longs;&longs;ionis, &longs;eu depre&longs;&longs;ionis; ne ti­bi nimius videar, la&longs;&longs;umo tantùm 1000. &longs;emidiametros terræ; igitur 859000.leucas, quarum quælibet continet 4. millaria, vt quodlibet mil­liare 1000. pa&longs;&longs;us geometricos, quilibet pa&longs;&longs;us 5. pedes; &longs;upponamus au­tem aquam e&longs;&longs;e graviorem aëre millie ; igitur &longs;i cylindrus prædictæ alti­tudinis iuxta communem innatantium legem, aquæ innataret, vna &longs;ui mille&longs;ima parte immergeretur, atque adeò &longs;egmentum immer&longs;um 859. Leucarum e&longs;&longs;et; tantumdem igitur aquæ attolleret; miror igitur, illum, de quo dubitare videris, aëris gravitantis ni­&longs;um majorem non e&longs;&longs;e: immo inde facilè colligo, longè majo­rem e&longs;&longs;e gravitatis aquæ proportionem ad gravitatem aëris, & in­feriorem aëra fortè graviorem &longs;uperiore, tum propter humorem ad­mixtum, tum fortè, quia compre&longs;&longs;ior e&longs;t: ca&longs;tiga igitur præoccupatum animum, & ratiocinare ex certis principiis, & dubitationi locus non erit.

Chry&longs;oc. Hæc &longs;ententia nimiam novitatem præ &longs;e fert; ac proinde vel hoc nomine &longs;u&longs;pécta multis e&longs;&longs;e videbitur.

Augu&longs;tin. Fateor vltro, hanc &longs;ententiam novam e&longs;&longs;e, &longs;ed ex antiquis & certis principiis deducta; quòd &longs;i minimè liceat, nullus vnquam re&longs; literariæ progre&longs;&longs;us &longs;perandus e&longs;t: & verò quid damni ex hac novitate ti­meri po&longs;&longs;it, non video; &longs;upponit enim hæc &longs;ententia marinum æ&longs;tum cum iis omnibus phænomenis, quæ à rerum i&longs;tarum periti&longs;&longs;imis ob&longs;ervata fuere; docet, prædictum æ&longs;tum e&longs;&longs;e à Luna, eiu&longs;que incrementum in Novilunio & Plenilunio; decrementum in Quadraturis; maximam vim circa Æqui­noctia; agno&longs;cit aëta gravem e&longs;&longs;e; quis hoc neget? atque adeò &longs;uo ni&longs;u, &longs;ua vi pro&longs;&longs;iva pollere, quæ toties in actum exeritur, quoties major e&longs;t, quàm re&longs;i&longs;tentia; docet præterea Lunam ex no&longs;tris elementis compactam e&longs;&longs;e; & hæc communis e&longs;t Sanctorum Patrum &longs;ententia; ac proinde So­lis & caloris vi humorem educi ex Luna; denique docet commune me­dium versùs illum globum gravitare, cui propiùs e&longs;t, vnde gravitationis, ac proinde pre&longs;&longs;ionis inæqualitatem &longs;equi, nece&longs;&longs;e &longs;it, & ex hac, aqua­rum tumorem & æ&longs;tum. Cuncta hæc, etiam præ&longs;cindendo ab æ&longs;tu, ita à natura con&longs;tituta e&longs;&longs;e putarem; &longs;i vltra dubitas, ponamus ex hypothe&longs;i, nec enim, opinor, negabis ita e&longs;&longs;e po&longs;&longs;e; fingamus igitur, ita e&longs;&longs;e; & vide, vtrùm cuncta æ&longs;tus marini phænomena rectè expli­centur.

Chry&longs;oc. Si aër gravitat, cur eius pondus non &longs;entimus? deinde quomo­dò fieri pote&longs;t, vt idem aëris tractus modò versùs vnum, modò ver&longs;us aliud centrum gravitet? An fortè novit, cui proprior e&longs;t? denique, humor ille Lunaris, vbi &longs;emel terræ illap&longs;us e&longs;t, cùm hæc immobilis con&longs;i&longs;tat, non videtur, quomodò in maternum patriumque &longs;inum & globum denuò redi­re valeat.

Antim. Hæc facilè &longs;olvo; primum quidem, quia non &longs;entimus aëris pondus &longs;icuti nec vrinatores pondus aquæ; nempe ideò me­dium gravitat, vt corpus &longs;ubjectum levius &longs;ur&longs;um extrudat; nihil ergo ab eius pondere nobis timendum e&longs;t, qui aëre graviores &longs;u­mus; immo id vnum dumtaxat aëris, vel alterius medij gravita­tio in nobis præ&longs;tat, vt minùs graves &longs;imus, detracta nobis ea gravitatis, &longs;eu gravitationis parte, quæ pondus tantæ molis aëris, quan­tæ nos &longs;umus, adæquat. Secundum verò &longs;ic diluo; terminus extrin&longs;ecus determinat lineam motus gravium, ex naturæ in&longs;tito, &longs;eù præ&longs;cripto fine; nec opus e&longs;t, vt mobile cognitione, aut &longs;en&longs;u polleat; &longs;ed cum &longs;uum finem obtinere debeat, &longs;uam vim exerit ad illum obtinendum; cùm igitur corpus grave debeat con&longs;tituere vnum totum, &longs;eu vnum globum totalem, cum aliis corporibus, &longs;eu partibus eiu&longs;dem globi, vt hunc finem obtineat, ferri debet versùs commune centrum, in quo natura con&longs;tituit terminum illius latio­nis; vnde &longs;i fortè centrum illud locum mutaret, etiam corpus grave lineam motus mutaret. Res e&longs;t per&longs;picua in terræ mobilis hypothe&longs;i, quæ licèt vera non &longs;it, nemo tamen huc v&longs;que negavit, po&longs;&longs;ibilem e&longs;&longs;e. Quemadmodùm verò corpus grave determinatur à termino extrin&longs;eco, id e&longs;t, à centro, ad talem lineam gravitationis, licèt centrum illud non videat, nec cogno&longs;cat, ita determinatur ab eodem termino vel centro, cui propius e&longs;t, licèt ne&longs;ciat, cuinam propius &longs;it. Tertium denique jam &longs;upra &longs;olutum e&longs;t; nempe caloris vi, Lunaris humor longè no&longs;tro liberior ac proinde &longs;ubtilior, facilè rare&longs;cit, atque avolat, is præ&longs;ertim, qui extra vmbram terræ po&longs;itus &longs;olares radios diu excipit; in quo, meo judicio, nulla e&longs;t difficultas.

Chry&longs;ocom. In quadraturis eadem ratio pre&longs;&longs;ionis e&longs;&longs;et; quia eadem gravitationis inæqualitas, quæ e&longs;t in copulis & oppo&longs;itione; æqualis igitur æ&longs;tus, quod tamen ob&longs;ervationibus repugnat, deinde in lacubus Lunari globo &longs;ubjectis, æ&longs;tus attolli deberet; denique in Oceano Septentrionali mo­dicus æ&longs;tus e&longs;&longs;et, quia &longs;cilicet à punctis maximæ elevationis multum di&longs;tat.

Augu&longs;t. Hæc etiam facilè &longs;olvuntur; primum quidem, quia licèt in Qua­draturis eadem &longs;it ratio pre&longs;&longs;ionis, ratione altitudinis Cylindrorum aëris gravitantis, diver&longs;a tamen e&longs;t ratione medij; nempe in Quadraturis aëri versùs terram gravitanti, minus humoris ine&longs;t igitur; inde &longs;equitur, e&longs;&longs;e minùs gravem, ac proinde minorem exeri gravitationis effectum, æ&longs;tum videlicet. Secundùm jam &longs;upra dilutum e&longs;t; cùm enim lacuum &longs;uperficies paucos admodùm gradus complectatur, inæqualitas pre&longs;&longs;ionis in ea &longs;en&longs;i­bilis non e&longs;t; quid mirum ergo, &longs;i effectus illius, nimirum æ&longs;tus, &longs;en&longs;ibilis non &longs;it; hinc vbi &longs;unt majores lacus vt Americani illi, de quibus &longs;uprà, vel vbi lacus per aliquod Fretum Oceano conjuncti &longs;unt, &longs;en&longs;ibilis in iis æ&longs;tus ob&longs;ervatur. Tertium denique &longs;ic rejicio; in prima illa hypothe&longs;i, qua &longs;up­ponitur tota globi &longs;uperficies aquea; ita res &longs;e haberet; at &longs;ecundùm præ­&longs;entem rerum &longs;tatum, eáque globi terraquei &longs;uperficie &longs;uppo&longs;ita, quæ modò e&longs;t propter diver&longs;as reflexiones, pre&longs;&longs;iones, angu&longs;tias, eò currit æ&longs;tus, quo major vis, vel alia quæpiam lineæ determinatio inclinat; hinc ad eandem &longs;æpè oram etiam in locis parum di&longs;&longs;itis, adeò diver&longs;us æ&longs;tus e&longs;t.

Chry&longs;oc. Per aver&longs;a igitur flumina non a&longs;cenderet æ&longs;tus, in quorum &longs;u­perficie inæqualitatis pre&longs;&longs;ionis &longs;en&longs;ibilis non e&longs;t.

Augu&longs;tin. Non ideò a&longs;cendit per alveum fluminis, quòd fluminis &longs;uper­ficies prematur, &longs;ed quòd &longs;uperficies maris, cùm per æ&longs;tum intume&longs;cat, & &longs;it &longs;upra &longs;uperficiem fluminis, more gravium, versùs eam partem excurrat; neque in hoc vlla difficultas re&longs;tat.

Chry&longs;oc. Circuli pre&longs;&longs;ionum ad libitum à vobis accipiuntur; cur enim potiùs hi, quàm illi? vnde, ni fallor, ruit præcipua hujus ve&longs;træ &longs;ententiæ &longs;ub­&longs;tructio.

Augu&longs;tin. Nego, fingi ad libitum; nempe non fingitur linea Ab&longs;idum, vel connectens centra; neque linea confinium, &longs;eu dirimens, neque circuli paralleli, per quotum centra, Ab&longs;idum linea ducitur, cadit que perpendicu­lariter in eorum plana; nec æqualis gravitatio, &longs;eu pre&longs;&longs;io in quolibet pun­cto circuli paralleli; nec communis ni&longs;us ab omnibus punctis eju&longs;dem cir­culi; quia &longs;cilicet æqualis; &longs;i enim e&longs;&longs;et inæqualis, vna aliam &longs;uperaret; igi­tur adversùs illam ageret; igitur actio communis non e&longs;&longs;et. Hinc mani-fe&longs;ta ratio, cur ij circuli pre&longs;&longs;ionum minimè ponantur, in quorum &longs;ingulis punctis ni&longs;us inæqualis e&longs;t; cuncta hæc igitur non ad libitum &longs;tatuuntur, &longs;ed ex linea connectente centra, quæ ex globorum &longs;itu &longs;emper re&longs;ultat, ne­ce&longs;&longs;ariò con&longs;equuntur: non ruitigitur hujus &longs;ententiæ fundamentum, &longs;ed maximoperè inde confirmatur.

Antim. Verbulum addo, & con&longs;idero lineam connectentem centra; ad in&longs;tar axis coni, cuius vertex ad centrum terræ de&longs;init; Diameter verò ba­&longs;is, in quam prædictus axis perpendiculariter cadit, e&longs;t ip&longs;a linea confinium; con&longs;idero item infinitos conos, &longs;eu &longs;uperficies conicas, quarum ba&longs;es &longs;int circuli concentrici in plano prædictæ ba&longs;is, & quarum maxima e&longs;t planum circuli majoris, parallelum prædictæ ba&longs;i; minima verò præfata Ab&longs;idum linea; quælibet &longs;uperficies conica, &longs;ecat &longs;uperficiem globi terraquei in cir­culo, & omnes huju&longs;modi &longs;ectiones &longs;unt circuli paralleli, per quorum cen­tra linea Ab&longs;idum rectâ ducitur; hi &longs;unt circuli pre&longs;&longs;ionum, inæquales qui­dem inter &longs;e, ita tamen, vt in quolibet eju&longs;dem circuli puncto, æqualis pre&longs;­&longs;io fiat; vereor, vt alius modus e&longs;&longs;e po&longs;&longs;it pre&longs;&longs;ionis inæqualis, re&longs;pectu eju&longs;­dem centri. Reliqua omitto; perge Chry&longs;ocome.

Chry&longs;ocom. Si æ&longs;tus à Lunæ motu e&longs;&longs;et, ad Lunæ motum &longs;e&longs;e compone­ret; ac proinde nunquam æ&longs;tus ab occa&longs;u ad ortum excurreret, quod certè omnibus experimentis refragatur.

Augu&longs;tin. Si aqua totam globi terraquei &longs;uperficiem tegeret, tumor il­le, &longs;eu maximæ elevationis punctum, quod nunquam Lunæ non re&longs;pondet &longs;emper ab ortu in occa&longs;um ire videretur; at in hoc rerum &longs;tatu versùs litus humilius a&longs;&longs;urgens per æ&longs;tum aqua excurrit, quoquo ver&longs;um tandem &longs;pectet, idque maximè &longs;i linea cur&longs;us in oram illam directè incidat.

Chry&longs;ocom. Ventus impediret vim æ&longs;tus, cùm tamen illam augeat, aëre &longs;cilicet acto, per lineam Horizontalem, ac proinde impedito illius gravi­tationis ni&longs;u.

Augu&longs;tin. Aër, quamvis alioquin per lineam Hotizontalem actus, re­tinet tamen totam vim &longs;uæ gravitationis ; exemplum luculentum habes in ligno humido innatante, quod licèt ad in&longs;tar naviculæ per Horizontalem impellatur; totum tamen illius pondus &longs;uam vim exerit gravitando; v. g. fit vas aqua plenum 20.libr.&longs;it lignum aquæ innatans.5.libr. quod per Ho­rizontalem moveatur, haud dubiè, &longs;i vas ip&longs;um tunc appendas, 25.librarum pondus &longs;enties: &longs;ic aqua, quæ &longs;upra fundum alvei currit; in hoc &longs;uæ gravi­tatis vim totam exerit; idem dico de globo in plano Horizontali rotato: aër igitur quantumvis agitatus totius gravitationis effectum præ&longs;tat.

Chry&longs;ocom. Vix crediderim, lapidem per Horizontalem projectum, to­tius gravitationis &longs;uæ vim exerere; alio quin recta deor&longs;um iret; igitur nec aër per lineam Horizontalem à Vento actus.

Augu&longs;tin. Ex eo quod lapis totam vim &longs;uæ gravitationis exerat, non &longs;equitur, quod recta deor&longs;um ire debeat, cùm motu quodam mixto movea­tur, idque per Parabolam, vt jam multi demon&longs;tra&longs;&longs;e dicuntur: Deinde non e&longs;t par ratio lapidis & aëris; lapis enim non gravitat cum aëre gravitatio­ne communi, ni&longs;i &longs;ecundùm modicam illam ponderis portionem, quæ aëri eju&longs;dem cum lapide molis competit; at verò pars aëris, quæ in medio aëre per Horizontalem movetur, cum aliis &longs;ibi &longs;ubjectis, & impo&longs;itis, gravitatio­ne communi gravitat.

Antim. Per vos mihi liceat, breve Parergon interferete, vt hæc meliùs intelligantur. Corpus, quod e&longs;t in medio, vel eju&longs;dem e&longs;t cum medio gra­vitatis, vel majoris, vel minoris; &longs;i minoris, innatat medio; &longs;i majoris, im­mergitur; &longs;i æqualis, in quocunque loco illud colloces, ibi manet: porrò corpus humido innatans, gravitatione communi cum ip&longs;o medio gravitat; cujus rei luculentum exémplum, vel experimentum attuli&longs;ti, Augu&longs;tine; nem­pe totum illud vas appen&longs;um 25.libr.pendit, &longs;ive lignum quie&longs;cat, &longs;ive flu­ctuet; &longs;ive in fundo va&longs;is atte retineatur; &longs;ive &longs;ur&longs;um emergat; &longs;ive per Horizontalem feratur: Et verò vbi nihil propriæ & &longs;ingularis gravitatio­nis retinet, in communem gravitationem totam &longs;uam vim refundit; hinc manus ligno innatanti &longs;uppo&longs;ita nullum pondus &longs;entit, ni&longs;i fortè illud tan­tulum attollas, vel filo ex parte immer&longs;um &longs;u&longs;tineas; tunc enim vas ip&longs;um minùs pendit; v.g. &longs;i dum lignum ex parte immer&longs;um &longs;u&longs;tines, &longs;entis trium libr.pondus, vas 22.libr. tunc erit; hinc &longs;i vas dextrâ, lignum verò filo ap­pen&longs;um &longs;ini&longs;trâ &longs;u&longs;tineas, vtraque &longs;imul totum pondus, &longs;ed qua propor­tione plus ligni &longs;ini&longs;tra &longs;u&longs;tinet, eadem in va&longs;e dextera minus pondus &longs;u­&longs;tinet: porrò &longs;i corpus aqua gravius &longs;it, v.g.plumbum, haud dubiè immer­gitur, &longs;it v.g, idem vas 20.libr.&longs;it pila plumbea 10. libr. vbi hæc fundum va&longs;is attigit, totum va&longs;is pondus erit 30.libr.at &longs;i vas pendatur eo dumtaxat tempore, quo pila plumbea per aquam de&longs;cendit, &longs;upra 20.libr. illam tan­tum ponderis acce&longs;&longs;ionem &longs;enties, quam aqua, vt &longs;ic loquar, plumbo detra­hit, æqualem &longs;cilicet ponderi portionis aquæ, eju&longs;dem molis; &longs;upponamus autem gravitatem plumbi e&longs;&longs;e decuplam gravitatis aquæ, vas erit 21. libr. idem &longs;iet, &longs;i pila omnino immer&longs;a filo &longs;u&longs;tineatur. Hinc duo Paradoxa facilè deducetis; primum &longs;it, corpus leve, quod &longs;ur&longs;um per mediam aquam va&longs;e contentam emergit, magis gravitat in eum, qui vas ip&longs;um &longs;u&longs;tinet, quàm corpus grave, quod per mediam aquam deor&longs;um fertur: ac proinde corpus levius majorem vim gravitationis exerit, quàm gravius; hinc quò plus &longs;in­gularis gravitationis corpus retinet intra medium va&longs;e contentum, mino­rem vim facit adversùs illum, qui vas &longs;u&longs;tinet; & quoad vim ponderis, perin­de e&longs;t, &longs;ive prædicta pila plumbea liberè per aquam deor&longs;um eat, &longs;ive aquæ immer&longs;a & filo appen&longs;a &longs;u&longs;tineatur; contra verò quò minus &longs;ingularis gra­vitationis corpus retinet, eò magis gravitat in eum, qui præfatum vas &longs;u­&longs;tinet. Alterum Paradoxum e&longs;t: Qui&longs;quis prædictum vas portat, præter 20. libr.aquæ 1.libram plumbi &longs;u&longs;tentat, quamvis alioquin plumbum immer­&longs;um & filo appen&longs;um ab infinita potentia &longs;u&longs;tineatur; quia &longs;cilicet me­dium gravitationis plumbo detrahit, &longs;cilicet 1.libram: cùm igitur ille aëris tractus, qui à vento igitur, nihil propriæ gravitationis retineat, &longs;ed to­tam in communem conferat, quamvis per diver&longs;as lineas &longs;ur&longs;um deor&longs;um­ve, dextror&longs;um aut &longs;ini&longs;tror&longs;um à vento agatur, nullam tamen proprij pon­deris jacturam facit, &longs;ed totam illius vim ac ni&longs;um exerit gravitatione com­muniquare hoc nodo &longs;oluto, vide, an quidpiam aliud ocourrat, quod nobis opponas.

Chry&longs;ocom. Nihil prorsùs: vnicum tantùm dubium re&longs;tat; vtrùm &longs;ci­licet diver&longs;a vmbræ projectæ ratio in Novilunio ac Plenilunio aliquod di&longs;crimen in æ&longs;tu faciat.

Antim. Fator, diver&longs;am e&longs;&longs;e in vtroque, vmbræ projectæ rationem; nempe in Novilunio vmbra à globo Lunari projicitur in Hemi&longs;phærium &longs;upra Horizontem, & à terre&longs;tri in Hemi&longs;phærium infra Horizontem; in Plenilunio verò ab vtroque globo projicitur in Hemi&longs;phærium, noctu &longs;u­pra, diu infra Horizontem; &longs;ed hoc magnum di&longs;crimen in æ&longs;tu non facit; præ&longs;ertim cùm humor ille dumtaxat Lunatis ad æ&longs;tum aliquid conferat, qui terre&longs;tri globo propior e&longs;t, &longs;ive den&longs;ior &longs;it, &longs;ive rarior, ju&longs;ta enim fit com­pen&longs;atio; quippe &longs;i rarior e&longs;t, plus loci occupat, igitur illius gravitatio in plura di&longs;trahitur, ac proinde &longs;inguli Cylindri minorem vim habent; &longs;i au­tem den&longs;ior e&longs;t, deor&longs;um tendit, hinc minùs confert in gravitationem com­munem: vnde vides vnum ab alio compen&longs;ari: &longs;ed jam &longs;atis de hoc argu­mento, quod certè majorem di&longs;cu&longs;&longs;ionem po&longs;tularet, quam vobis ve&longs;tro commodo faciendam relinquo.

Augu&longs;tin. Su&longs;tine parumper, Antime, maximum dubium mihi injeci&longs;ti; &longs;i enim humor Lunaris den&longs;ior minùs confert in gravitationem commu­nem, nulla igitur ratio e&longs;t, cur in Novilunio & Plenilunio major æ&longs;tus fiat.

Antim. Multa, crede mihi, adhuc ratio re&longs;tat; nam præter eam, quæ à projectis vmbris, vt &longs;upra dictum e&longs;t, peti po&longs;&longs;et, non ignoras corpu&longs;cula etiam gravi&longs;&longs;ima tum aquæ, tum aëri innatare, ac proinde vtrumque ele­mentum inde gravius reddi; &longs;ic fœtæ nubes, & multus vapor affu&longs;us ab au­&longs;tro, aëra graviorem reddunt, vt Sal vel Sabulum aquæ admixtum; idem de præfato humore Lunari dictum puta: cur verò corpu&longs;cula illa gravi&longs;&longs;ima leviori medio innatent, non e&longs;t hujus loci di&longs;cutere, &longs;ed quæ&longs;o vos, huic congre&longs;&longs;ui finem imponamus, ne docti&longs;&longs;imorum hominum auribus & pa­tientia, immodica garrulitate abutamur.

Augu&longs;tin. Rectè mones; &longs;ed quando nobis commodum erit ad pro­ximum congre&longs;&longs;um redire?

Antim. Quando voles, diem indicendum tibi relinquo.

Augu&longs;t. Po&longs;t tridum igitur vos expecto, vt pulcherrimum illud argu­mentum de a&longs;&longs;urgente per fi&longs;tulam humido & Mercurio in eadem ab ex­teriori aëris Cylindro, vt multi volunt, ad certam altitudinem &longs;u&longs;tentato, di&longs;cutiamus.

Antim. Hoc ip&longs;um e&longs;t, quod nobis di&longs;cutiendum re&longs;tat; quare con&longs;ulite illos Autores, qui de hac materia &longs;crip&longs;erunt, vt ex variis probati&longs;que expe­rimentis, veritas tandem eluce&longs;cat; nonnihil addemus, delibando &longs;altem, de vi electrica, quam aliqui ad rem hanc nonnihil conferre putarunt.

DIALOGVS QVARTVS.

In quo, de libratis &longs;uspen&longs;i&longs;que liquoribus & Mercurio di&longs;putatur.

AMOENISSIMVM argumentum, quod tibi fortè arrideat, Princeps Eminenti&longs;&longs;ime hodierna die di&longs;cutien­dum &longs;u&longs;cepi, vtinam feliciter, quod tuis au&longs;piciis futurum &longs;pero, demon&longs;trandum. Antiquis omnino intactum fuit, & paucis ex recentioribus compertum experimentum; primùm ca&longs;u innotuit; at deinde &longs;tudio & arte, vltra promotum & perfectum; in varias porrò partes itum e&longs;t, ad illius cau&longs;am explorandam, quod vtrùm cuipiam pro votis &longs;ucce&longs;&longs;eir, vix definine au­&longs;im; &longs;ed vt meliùs di&longs;&longs;ertatione pareat, huic demus initium rejectis mutili­bus præludiis, quæ & ad rem de qua agitur, parum aut nihil conferunt, & tibi Cardinalis Eminenti&longs;&longs;ime alioquin occupati&longs;&longs;imo, nihil aliud ni&longs;i me­rum tædium afferrent.

Antim. Para&longs;ti, vt video, dulci&longs;&longs;ime Augu&longs;tine, totam illam &longs;upelle­ctilem, quæ ad ea, de quibus di&longs;putare in&longs;tituimus, experimenta pertinent; video limpidi&longs;&longs;imam in va&longs;e aquam admoto&longs;que canaliculos vitreos vtrim­que pervios; video Mercurium in va&longs;e & longiorem fi&longs;tulam vitream al­tera parte clau&longs;am; accipio vnum ex i&longs;tis canaliculis, in &longs;uperficiem aquæ immergo, humor &longs;tatim per canaliculum a&longs;&longs;urgit, ad digitalem ferè altitu­dinem, vt vides.

Augu&longs;tin. Video quidem, &longs;ed miror magis; canaliculum inclino, altiùs humor a&longs;cendit; & quod fortè mirabilius e&longs;t, breviorem canaliculum aquæ admoveo, ad tantam altitudinem minimè a&longs;cendit; longiorem adhibeo eju&longs;dem omnino ba&longs;is, altiùs humor a&longs;cendit; alterum orificium admo­to pre&longs;sè digito, claudo, non a&longs;&longs;urgit humor; digitum amoveo, illicò a&longs;&longs;urgit.

Chry&longs;ocom. Dicerem, ab illo impetu aquam attolli, quo canaliculus aquæ admovetur; &longs;ed admoto canaliculo, cujus &longs;upremum orifi­cium digito clauditur, & jam eo quie&longs;cente, cùm nullus impetus re&longs;tet, amoto digito, humor illico a&longs;&longs;urgit; vnde nece&longs;&longs;ario &longs;equi­tur, minimè a&longs;&longs;urgere, propter impetum appul&longs;us canaliculi: aliquis fortè diceret, nonnihil rarefactionis accedere; &longs;ed hoc totum inutile e&longs;t; cur enim aqua intra canaliculum potiùs rare&longs;ceret, quàm intra vas ip&longs;um? deinde æquè frigida ac calida a&longs;&longs;urgit; item æquè vinum ac oleum, &longs;altem. vt audio.

Antim. Ita e&longs;t; in his omnibus &longs;æpè probavi; item in &longs;piritu vini, & variis aquis di&longs;tillaris ; immò &longs;i canaliculum oleo immergas, paulò altiùs a&longs;&longs;urgit, qúod non ad evidentiam expertus &longs;um; &longs;ed cuncta hæc ex­perimenta luculentiora &longs;unt in &longs;cypho, vel ampulla, cujus imaginem ha­bes pag. &longs;equenti, in qua &longs;cilicet humor per canaliculum GF a&longs;&longs;urgit &longs;upra &longs;uperficiem BC, eo profectò altiùs, quo canaliculus angu&longs;tior erit.

Augu&longs;tin. An fortè dici po&longs;&longs;et, pondus aquæ contentæ in majore am­pulla, longè majus e&longs;&longs;e pondere aquæ contentæ intra minorem canalicu­lum GF, ac proinde prævalere, & inde aquam altiùs extrudi, &longs;eu attolli.

Antim. Scio, non neminem e&longs;&longs;e, cui hæc cogitatio in mentem venit, quæ tamen, meo &longs;altem judicio, legitima non e&longs;t, cùm aqua ratione pon­deris, &longs;eu gravitatis ad perfectam libellam &longs;e&longs;e componat; nempe gravi­tat per Cylindros parallelos, &longs;eu lineas parallelas, in quocunque &longs;itu cana­

les &longs;tatuantur; &longs;int enim canales ABC, IDE; infundatur aqua per Orificium AB, &longs;it libella Horizontalis ABFG; &longs;i canales æqualis &longs;int cra&longs;&longs;itudinis &longs;uperficies aquæ vtrimque &longs;i&longs;tet in ABFG, vt patet; tunc enim perfectum erit æquilibrium; &longs;i verò canalis IDE &longs;it angu&longs;tior, a&longs;&longs;urget aqua v. g. in DE, &longs;upra libellam AG, ratione tamen gravitationis, Cylindrus aquæ cujus ba&longs;is æqualis &longs;it FG, facit perfectum æqui­librium cum Cylindro aquæ æquali IG, vt patet; &longs;i enim tota moles aquæ contentæ in ABC, &longs;u­&longs;tineret contentam intra IDE, cùm illa hujus po&longs;&longs;it e&longs;&longs;e decupla, centu­pla, & in quavis data proportione majoris inæqualitatis, aqua per cana­liculum IDE ad quamcunque po&longs;tulatam altitudinem a&longs;cenderet, quod manife&longs;tè fal&longs;um e&longs;t; igitur totus Cylindrus aquæ ABC non facit æqui­librium cum Cylindro aqueo IDE, &longs;ed tantùm Cylindrus eju&longs;dem ba&longs;is DE; &longs;ed hic facit æquilibrium cum Cylindro IFG, vt patet; igitur inde per&longs;picuum fit, aquam per canaliculum IDE non a&longs;&longs;urgere in DE &longs;upra libellam, propter majorem vim ponderis ABC. Accedit quod &longs;i ba&longs;is AB Diameter &longs;it bipedalis, & ba&longs;is DE &longs;it pedalis, non a&longs;&longs;urget aqua in DE, immò ad &longs;en&longs;um &longs;i&longs;tet in FG, cùm tamen pondus aquæ ABC &longs;it quadruplum aquæ IFG; igitur in majoribus canalibus aqua non a&longs;&longs;urgit, vt in minoribus; vnde manife&longs;tè con&longs;tat, hunc effectum e&longs;&longs;e ab alia cau&longs;a.

Chry&longs;ocom. Cùm hæc nudius tertius viro cuidam ingenio&longs;i&longs;&longs;imo pro­po&longs;ui&longs;&longs;em, illico re&longs;pondit vim quandam adhæ&longs;ivam in corporibus præ&longs;er­tim liquidis, &longs;ibi compertam e&longs;&longs;e, ratione cujus, vnum alteri accedit, &longs;e&longs;e arctiùs conjungit; &longs;ic inquiebat ille, &longs;i aquæ gutta tangat aliam guttam, in vnam majorem guttam &longs;tatim mutuo qua&longs;i amplexu coale&longs;cunt; &longs;ic duo flammæ con in vnam abeunt; vnde fieri putabat, vt aquà per canalicu­lum minimè a&longs;&longs;urgeret, ni&longs;i priùs cava illius &longs;uperficies maduerit, quod vbi à me probatum e&longs;t, dicto re&longs;pondit eventus: ne&longs;cio vtrùm hæc ratio vobis arrideat.

Antim. Minimè verò, & alia ratio e&longs;t congre&longs;&longs;us guttarum & cono­rum flammæ, de qua infra. Primò, enim gratis affingitur prædicta vis adhæ&longs;iva liquidis corporibus, ex iis &longs;cilicet effectibus, qui aliis cau&longs;is tri­buendi &longs;unt. Secundò, etiam&longs;i canaliculus ante non maduerit, aqua tamen a&longs;&longs;urgit, &longs;i paulò laxior e&longs;t; centies probavi infu&longs;o in ampullam

A oleo; & ne qui&longs;piam diceret, oleum a&longs;&longs;urgere per GF, propter impetum infu&longs;ionis, infudi oleum, inclinata versùs B ampulla; ita vt &longs;uper­ficies olei per canaliculum vix a&longs;&longs;urgeretin H ; tum deinde erecta ampulla, oleum a&longs;cendit in F, licèt inferior canaliculi &longs;uperficies &longs;icca omnino e&longs;&longs;et; idem fiet admoto canaliculo &longs;uperficiei olei, &longs;i paulo major &longs;it. Tertiò, Non video cur major aquæ portio minorem potiùs ad &longs;e non adducat, quàm minor ma­jorem; &longs;i enim prædicta vi vtraque pollet, major certè majore, &longs;cilicet exten&longs;ivè, vt major flamma magis calefacit, quàm minor; accedit, quod in hoc ca&longs;u, minor longè faciliùs ad majorem accederet, &longs;cilicet de&longs;cen­dendo, quàm major ad minorem a&longs;cendendo. Quartò, in majore tubo madefacto eadem ratio militaret; nec dicas ob&longs;tare majorem vim pon­deris; quia cùm vis illa adhæ&longs;iva omnibus partibus aquæ in&longs;it, eadem e&longs;t illius proportio ad re&longs;i&longs;tentiam ponderis in majore, quæ in minore; & vt duæ partes in minore &longs;uperant duas partes ponderis; ita mille partes in majore &longs;uperabunt mille partes ponderis. Quintò, Cur oleum altiùs a&longs;­&longs;urgit, quàm aqua? Cur Mercurius ferè nihil? dico ferè, quia infra evin­cam tantulùm a&longs;&longs;urgere; Cur aliquando ip&longs;a aqua altiùs, aliàs minùs altè a&longs;cendit? Nihil horum cum illa vi adhæ&longs;iva &longs;tare pote&longs;t. Sextò, Cur aqua per canaliculum inclinatum longiùs excurrit? Cur per bre­viorem, quamvis madefactum interiùs, minùs altè, & &longs;i adhuc breviorem accipias, ferè nihil a&longs;&longs;urgit? Cur per tubulos alioquin &longs;icci&longs;&longs;imæ materiæ, vt panis bis cocti, panni, telæ &c. Ex his vides, ni fallor, Chry&longs;ocome, aliam omnino hujus effectus cau&longs;am quærendam e&longs;&longs;e.

Augu&longs;tin. Sed cur per canaliculum &longs;iccum non a&longs;&longs;urgit, atque adeò ca­va illius &longs;uperficies humectanda e&longs;t?

Antim. Si canaliculus paulò laxior &longs;it, & majoris ba&longs;is etiam per &longs;ic­cum a&longs;cendit; non a&longs;cendit, tamen &longs;i angu&longs;ti&longs;&longs;imus &longs;it, ni&longs;i &longs;en &longs;im ac lentè; quia licèt &longs;uperficies vitri lævigata e&longs;&longs;e videatur, mille tamen &longs;alebris & rugis, &longs;eu &longs;triis a&longs;peratur, quæ ni&longs;i affu&longs;o humore com­planentur, a&longs;perum iter faciunt, & modicam aquæ portionem faci­lè &longs;i&longs;tunt; cùm tamen in majore canaliculo non ob&longs;tent; quin major aquæ copia a&longs;&longs;urgat; accedit, quod &longs;i juxta Figuras præcedentes va&longs;a conformentur, aqua etiam per canaliculum &longs;iccum a&longs;cendit; cur au­tem aquæ gutta intra aliam &longs;ubeat, vel flamma intra flammam, dicemus po&longs;tea.

Augu&longs;tin. Ex his ergo con&longs;tat, totam rem i&longs;tam ab aëris com­pre&longs;&longs;ione petendam e&longs;&longs;e, vt jam indica&longs;ti in &longs;uperiore congre&longs;&longs;u, &longs;ed quia paulò fu&longs;iùs explicandum re&longs;tat, hoc tibi certè onus in­cumbit.

Antim. Rectè mones, rem hanc paulò fu&longs;iùs explicandam e&longs;&longs;e; quod ut meliùs fiat; nonnulla &longs;uppono experimenta, partim commu­nia & trita, partim &longs;ingularia. Primùm &longs;it hoc. Ampulla vitrea

DACB, cui per os D canaliculus vitreus vtrim­que pervius in&longs;eratur, & probè ob&longs;tructo ori­ficio D, exugatur ducto anhelitu per E, aër intra ampullam contentus; tum &longs;tatim, vbi removetur ab ore, immergatur in aquàm ex­tremitas E; &longs;ugitur enim aqua, dum aër intra dilatatus &longs;e&longs;e contrahit; &longs;ic demum AB &longs;uper­ficies aquæ per &longs;uctum adductæ; tum extremo E ore admoto, pul&longs;us anhelitus magna vi in­trudatur; inde &longs;it, vt aër ABD appul&longs;u novi aëris comprimatur, & compre&longs;&longs;us &longs;uperficiem aquæ AB premat, ac proinde &longs;upra &longs;uperficiem AB aqua per canalicu­lum CE a&longs;&longs;urgat; immò &longs;i &longs;it magna vis pre&longs;&longs;ionis, ad in&longs;tar jaculi erum­pat. Idem fiet opera di&longs;ci, &longs;uperficiem aquæ prementis, vt jam dixi in &longs;u­periore congre&longs;&longs;u.

Chry&longs;ocom. Certum & per&longs;picuum e&longs;t, illum aquæ jactum e&longs;&longs;e ab vna pre&longs;&longs;ione aëris va&longs;e contenti & compre&longs;&longs;i; quia &longs;cilicet aquæ &longs;uperficiem, cui incumbit, premit; & cùm nihil ob&longs;i&longs;tat pre&longs;&longs;ioni intra canaliculum, prædicta vi aqua facilè extruditur; hæc vt dixi, adeò certa &longs;unt, vt nul­lum po&longs;t &longs;e dubium relinquant. Sed quid hoc ad aquam, per canaliculum in aëre libero a&longs;&longs;urgentem? Licèt enim concedam, aëra e&longs;&longs;e compre&longs;&longs;um, cùm non minùs premat &longs;uperficiem aquæ intra canaliculum contentæ;

quàm intra majus vas, v.g. &longs;uperficiem DE, quàm AB, neque hinc, neque illine vis illa pre&longs;&longs;ionis prævalere pote&longs;t.

Antim. Fateor, maximum di&longs;crimen e&longs;&longs;e in­ter experimentum Figuræ 31. & 32. quia in hac, aër ADB novam compre&longs;&longs;ionem patitur, qua tamen aër exterior caret; vnde non modò tan­tulùm a&longs;&longs;urgit aqua per canaliculum CE, vt fit, etiam &longs;i nova compre&longs;&longs;io minimè accedat, & os ampullæ D pateat; &longs;ed magna vi, ad in&longs;tar jaculi extruditur; quem reverà effectum il­la modica vis pre&longs;&longs;ionis, quæ ine&longs;t aëri, præ&longs;tare non po&longs;&longs;et; por­rò licèt aër exterior incumbat vtrique &longs;uperficiei aquæ &longs;cilicet AB & GF, major tamen vis premit AB, quam FG, quia corpus pre&longs;&longs;um quoquo ver&longs;um pellit in orbem; igitur eò major vis e&longs;t, quo &longs;ub majori angulo incidit; v. g. a&longs;&longs;umatur centrum &longs;uperficiei AB, premitur per infinitos radios, vnde quaque illap&longs;os; cogita co­num, cujus vertex prædicto centro incumbat; igitur quò prædictus angulus, &longs;eu conus obtu&longs;ior e&longs;t, vis pre&longs;&longs;ionis major e&longs;t, & hæc eò minor, quò ille acutior; Sit autem centrum &longs;uperficiei FG canaliculo contentæ, in quod aëris prementis conus incumbat, vides, ni fallor, quàm acu­tus angulus futurus &longs;it; ac proinde vis pre&longs;&longs;ionis minor; quid mi­rum ergo, &longs;i pre&longs;&longs;io in AB prævaleat, ac proinde aqua &longs;upra FG a&longs;­&longs;urgat?

Augu&longs;tin. Quid verò fiet, &longs;i canaliculi &longs;egmentum &longs;ũmpta FG, &longs;it minus FE? an fortè aqua vi prædictæ pre&longs;&longs;ionis effluet per canaliculum? &longs;i hoc fieret, perpetuum motum haberemus.

Antim. Prævideram, te in hunc &longs;copulum impacturum; nempe, in­quis, &longs;i aqua per canaliculum majore vi pre&longs;&longs;ionis vigente in AB, a&longs;&longs;ur­

git in DE, haud dubiè &longs;i re&longs;cindatur &longs;egmen­tum canaliculi ME, effluet per os ML, cum eadem vis pre&longs;&longs;ionis aplicata &longs;it in in AB; &longs;ed reverà non effluit ex ML ; & hoc e&longs;t alterum experimentum; cùm tamen alioquin iuxta com­munes Hydraulicæ regulas faciliùs &longs;it effluere ex ML, quàm in DE attolli; ratio e&longs;t, quia vt in centrum ba&longs;is AB aëris pre&longs;&longs;io incumbit, &longs;ecundùm angulum, &longs;eu conum maximè obtu­&longs;um, ita in ba&longs;im DE, vel in ba&longs;im ML, re&longs;ecto &longs;egmento canaliculi ME, &longs;ecundùm æqualem angulum incumbit; quid mirum ergo, &longs;i neutra pre&longs;&longs;io prævaleat? At verò &longs;i non re&longs;cindatur &longs;egmentum ME, incumbit in centrum ba&longs;is ML, &longs;ecundùm angulum acutum, cujus ba&longs;is e&longs;t DE, & latus recta ducta à D, ad centrum ML. Vnde pre&longs;&longs;io in AB omnino prævalet.

Chry&longs;oc. Sed infra, pre&longs;&longs;io in AB &longs;emper major e&longs;t pre&longs;&longs;ione in ML ; etiam re&longs;ecto &longs;egmento ME; nempe vt aëris pre&longs;&longs;io incumbit centro ba&longs;is AB, idque in reliquis punctis &longs;ecundùm æqualem pre&longs;&longs;ionis angu­lum, &longs;eu conum, item in &longs;ingula puncta ba&longs;is ML, &longs;ecundùm æqualem priori angulum, refecto &longs;cilicet &longs;egmento ME; igitur pre&longs;&longs;iones &longs;unt, vt ba&longs;es; initur ba&longs;is AB, quæ longè major e&longs;t prævalet; igitur &longs;i tua pre&longs;&longs;ionis ratio &longs;ub&longs;i&longs;teret, aqua ex ML omnino efflueret; non effluit ta­men, vt fateris vltrò.

Antim. Acutè omnino paralogizas; vt enim gravitatio aquæ con­tentæ in canali AC, exerit tantùm &longs;uam vim, attollendo cylindrum IG, ad libellam v&longs;que, &longs;ecundùm cylindrum æqualem IG, vt &longs;upra o&longs;ten­&longs;um e&longs;t; ita vis pre&longs;&longs;ionis ba&longs;is AB exeritur, attollendo aquam per ca­naliculum &longs;ecundùm ba&longs;im æqualem ML, vbi autem aqua elevata e&longs;t in ML, æqualis incumbit pre&longs;&longs;io vtrimque, &longs;cilicet in ba&longs;i ML, & ip&longs;i æqua­li a&longs;&longs;umptæ in AB; &longs;i verò aquæ fuper&longs;icies &longs;upponatur in FG, haud dubiè minor e&longs;t pre&longs;&longs;io in FG, quàm in ML ; igitur quàm in æquali ML a&longs;&longs;umptæ in AB; igitur hæc prævalet; vnde a&longs;&longs;urgit aqua ex FG in ML: cogita quæ&longs;o duci totidem cylindros parallelos deor&longs;um præ­&longs;ci&longs;a gravitatione, ex &longs;ingulis punctis ba&longs;is AB, quibus totidem pre&longs;-&longs;ionis coni incumbunt; itemque ex ba&longs;i ML ; pares certè cum paribus contranituntur, &longs;inguli &longs;cilicet cylindri cum &longs;ingulis; igitur neutra pars prævalet, &longs;i verò non re&longs;cindatur &longs;egmentum ME, equidem &longs;inguli cylindri ducti ex &longs;ingulis punctis ba&longs;is ML pugnant cum &longs;ingulis ductis ex ba&longs;i AB, hi tamen victores &longs;unt; quia fortiores; cùm &longs;ingulis vis pre&longs;&longs;ionis &longs;ecundùm majorem conum, vel angulum incumbat; igitur quamvis alioquin angu&longs;ti&longs;&longs;imus &longs;it canaliculus, &longs;i tamen &longs;upra libellam AG non producatur, par vtrimque e&longs;t vis pre&longs;&longs;ionis; ac proinde neutra pars prævalet; vnde, ni fallor, tuus ille paralogi&longs;mus &longs;olutus manet.

Augu&longs;tin. Ex dictis rectè deduco, aquam attolli altiùs in longiore, ca­naliculo; nempe in longiore, angulus pre&longs;&longs;ionis acutior & minor e&longs;t, quàm in breviore v. g. angulus DFE, minor e&longs;t angulo DME, vt patet.

Antim. Hoc erat tertium experimentum; aqua enim in canaliculis longioribus tantulùm immer&longs;is altiùs a&longs;&longs;urgit: & ni&longs;i nimiæ ob&longs;tarent angu&longs;tiæ, per quas &longs;ine aliqua vi aqua traduci nequit, ad quamcumque certè altitudinem aqua a&longs;&longs;urgeret.

Augu&longs;tin. Prudenter occurri&longs;ti in&longs;tantiæ, quam tibi facere meditabar; alia tamen longè difficilior &longs;e&longs;e mihi objicit ; cùm enim &longs;inguli pre&longs;&longs;ionis cylindri &longs;ingulis contranituntur; perinde e&longs;t, five laxior &longs;it canaliculus, &longs;ive angu&longs;tior, quod tamen experimentis repugnat, cùm per canalicu­lum angu&longs;tiorem longè altiùs humor a&longs;&longs;urgat.

Antim. Haud inficior, difficultatem à te propo&longs;itam eam e&longs;&longs;e, quæ in­genio tuo digna e&longs;&longs;e videatur; quam tamen, ni fallor, &longs;atis facilè &longs;olvo: nempe aër pre&longs;&longs;us majorem vim non imprimit &longs;uperficiei majori AB quàm minori DE; Cogita di&longs;oum ligneum, quo premitur &longs;uperficies A B, motu vt vnum, itemque alium minorem, quo premitur &longs;uperficies DE, motu vt vnum; certè vterque æqualem vim imprimit &longs;uperficie, DE & AB; licèt enim alter major &longs;it, & majorem &longs;uperficiem premat; quia tamen idem aër compre&longs;&longs;us circumfu&longs;us vtramque æquè premit, æqua­lis &longs;emper pre&longs;&longs;ionis effectus &longs;equitur, id e&longs;t, eju&longs;dem quantitatis aquæ elevatio; cæteris tamen paribus: vbi enim hæc elevata e&longs;t, & ab eadem vi premente &longs;u&longs;tinetur, nullus alius effectus illi competit, cùm tota in eo exeratur; dixi cæteris paribus, id e&longs;t, &longs;uppo&longs;ita eadem proportione pre&longs;&longs;ionis aëris incumbentis &longs;uperficiei canaliculi, &longs;i enim propter bre­vitatem canaliculi prædicta proportio cre&longs;cat, vel &longs;it major canaliculus, ac proinde angulus pre&longs;&longs;ionis major, itemque major pre&longs;&longs;io, haud dubiè aqua minùs altè per canaliculum a&longs;cendit: Suppo&longs;ita autem eadem pro­portione pre&longs;&longs;ionum, altitudines aquæ elevatæ in diver&longs;is canaliculis, &longs;unt vt ba&longs;es permutando, vt pater, v.g. &longs;i ba&longs;is vnius &longs;it dupla ba&longs;is alte­riùs, altitudo ejus erit dupla altitudinis illius, vt &longs;cilicet cylindri æqua­les &longs;int.

Chry&longs;ocom. Iam optimè intelligo id, quod paulò ante capere non po­teram; quod &longs;cilicet, vt aiebas, ad quamcumque altitudinem aqua po&longs;-&longs;it attolli; modò per qua&longs;libet angu&longs;tias immitti & traduci queat; qua enim proportione decre&longs;cit ba&longs;is, cre&longs;cit, altitudo; &longs;ed quæ&longs;o te, quid fiet, &longs;i aquæ &longs;uperficies non &longs;it in AB, &longs;ed in HK.

Antim. Certum e&longs;t, minorem inde fore aquæ elevationem; quia pre&longs;­&longs;io in ba&longs;im HK minor e&longs;t quam in ba&longs;im AB; quia fit &longs;ub minore an­gulo, v.g. &longs;tante ba&longs;i in AB, a&longs;&longs;urgeta qua in DE &longs;upra libellam FG, de­pre&longs;&longs;a verò ba&longs;i in HK &longs;upra libellam HP, a&longs;&longs;urget aqua in R, eritque PR minor quàm GE. Hîc autem ob&longs;ervo aliud experimentum, reverà pulcherrimum, nempe &longs;uperficies aquæ in HK, non e&longs;t plana, nedum convexa, &longs;ed omnino concava; cùm tamen AB modo humor extet, &longs;it convexa.

Augu&longs;tin. Hoc etiam &longs;æpiùs ob&longs;ervavi, & cau&longs;am huju&longs;ce peregrini effectus curiosè per&longs;crutatus &longs;um; nec crediderim ab vllo v&longs;piam prodi­tam fui&longs;&longs;e.

Antim. Ex præmi&longs;&longs;is facilè deducitur, modò tantulum Geometriæ ac­cedat. Suppono enim AB qua&longs;i ba&longs;im trianguli, cujus vertex terminetur ad HK, cujus trianguli angulus verticis major e&longs;t, qui cadit in centrum D prædictæ ba&longs;is, quàm is, qui cadit in extremitates ba&longs;is H vel K ; vt pa­tet ex Geometria; igitur major vis pre&longs;&longs;ionis incumbit in centrum O, quàm in H vel K, & con&longs;equenter in ea puncta major, quæ accedunt propiùs ad centrum O; quid mirum igitur, &longs;i punctum O &longs;ub&longs;idat, & tota &longs;uperficies HOK cava &longs;it, propter inæqualem illam pre&longs;&longs;ionis vim.

Chry&longs;oc. Sed quæ&longs;o te, Antime, cur aquæ &longs;uperficies AB convexa e&longs;t? video enim, cur cava non &longs;it, cùm inæqualis illa pre&longs;&longs;io de&longs;ideretur; cur tamen convexa &longs;it, non plana, haud &longs;atis video.

Antim. Res &longs;atis trita e&longs;t; nempe illa humoris &longs;uperficies à centro mundi æqualiter di&longs;tat &longs;ecundùm omnes partes; &longs;i enim aliqua longiùs à præfato centro di&longs;taret, quàm aliæ, de&longs;cenderet illico; hæc certè vt ve­ritati con&longs;ona, negari ab vllo non po&longs;&longs;unt; &longs;ed profectò hæc convexitas in&longs;en&longs;ibilis e&longs;t, nempe arcus vnius minuti continet 1000. pa&longs;&longs;us geome­tricos, vnius &longs;ecundi arcus 16. pa&longs;&longs;us & id e&longs;t 83. pedes circiter arcus vnius tertij vnum pedem tubos vix habemus majoris diametri; quis porrò arcum vnius tertij minuti à linea recta &longs;en&longs;u di&longs;tinguat? Cùm igi­tur convexam &longs;uperficiem aquæ probè di&longs;cernamus, aliam omnino e&longs;&longs;e nece&longs;&longs;e e&longs;t (& hoc &longs;it aliud experimentum) nempe vbi humor extremita­tes A & B ba&longs;is attigit, non effluit aqua, &longs;ed intume&longs;cit in centro &longs;uper­ficiei; centro enim minor vis pre&longs;&longs;ionis incumbit, quàm partibus extre­mis, v.g. in centrum V vis pre&longs;&longs;ionis incumbens infra horizontalem AB non cadit, cum tamen incumbens in A & in B infra prædictam horizon­talem de&longs;cendat, vt patet, quò fit, ne aqua ex A vel B effluat & hæc vera e&longs;t & legitima triti hujus experimenti ratio.

Chry&longs;ocom. Non bene capio quid tibi velis; nonnihil, quæ&longs;o te, &longs;chematis adhibe, tunc enim oculis potiùs quàm auribus fidem ha­bebo.

Antim. Sit vas quodpiam aqua plenum AEDB, &longs;it aquæ &longs;uprema &longs;uperficies AB, & centrum illius G, premitur punctum G, non tantùm per HG perpendicularem, verùm etiam per infirmas contentas inter

HG. AG, item inter GH, GB; nulla autem e&longs;t infra AB horizontàlem per quam punctum G prematur, vt per&longs;picuum e&longs;t, at verò punctum A, versùs quod aqua effluere nititur, proptia gravitatione, non tantum premitur à perpendi­culari IA & ab aliis contentis inter IA, MA, item inter IA, AB, &longs;ed etiam ab aliis infra MA ductis, vt à PA. idem dico de puncto B, item­que de aliis in totius marginis orbe di&longs;po&longs;itis, in quibus haud dubiè pre&longs;&longs;io prævalet, vnde aquam in &longs;uperficiem con­vexam intume&longs;cere nece&longs;&longs;e &longs;it. Hinc quò major e&longs;t va&longs;is &longs;uperficies mi­nùs intume&longs;cit; quia ad tumorem æquè altum; plus aquæ, vi pre&longs;&longs;ionis attollendum e&longs;&longs;et; &longs;ic vt jam dixi, per canaliculum angu&longs;tiorem altiùs a&longs;­&longs;urgit aqua, per majorem &longs;eu laxiorem, minùs altè, e&longs;t enim eadem pror­sùs ratio.

Augu&longs;tin. Vnum mihi venit in mentem; ne&longs;cio vtrùm tuo calculo probaturus &longs;is, Antime; redeo ad primum &longs;chema & &longs;uperficiem AB, (vid. Figuram in pag.161.) &longs;upremam &longs;cilicet, quam convexam e&longs;&longs;e &longs;uppo­no; &longs;uperficiem verò ML, excurrente canaliculo v&longs;que ad DE, conca­vam; quo po&longs;ito, numquid dici po&longs;&longs;et, partes extremas A & B, quibus ma­jor vis pre&longs;&longs;ionis imprimitur, quam centro V efficere vt partes extremæ alterius ba&longs;is ML, altiùs affurgant; centrum verò minùs. Vnde vt ex hac in­æquali pre&longs;&longs;ionis vi ba&longs;is AB convexa evadit, ita & ba&longs;is ML concava.

Antim. Quàm acute paralogizas, Augu&longs;tine, &longs;upponamus enim ba&longs;im in HK majoris canalis, & in R minoris, vtraque cava per&longs;picitur; vnde, ni fallor, ruit tua ratio; quare vis illa pre&longs;&longs;ionis inæqualis, quæ incum­bit in &longs;uperficiem &longs;upremam AB, alium effectum præ&longs;tat, nimirum illum quem dixi; attollit enim &longs;uperficiem AB &longs;upra libellam, eamque tornat in convexam; ideò verò cava e&longs;t &longs;uperficies HK; quia vis pre&longs;&longs;ionis in O major e&longs;t, quàm in H vel in K, quia &longs;ub majore angulo incumbit.

Chry&longs;ocom. Hoc jam &longs;uprà dixeras, &longs;ed ne quid di&longs;&longs;imulem, non mihi &longs;tatim occurrit demon&longs;tratio illa geometrica, quam appella&longs;ti quidem, non tamen expo&longs;ui&longs;ti.

Antim. Ad prima elementa me reducis, Chry&longs;ocome, &longs;int latera va­

&longs;is AE, BF; os verò AB; &longs;uperficies aquæ EF, cen­trum C, &longs;int anguli ACB, AEB, dico ACB e&longs;&longs;e majorem, ducatur enim circulus per 3. puncta ABC, fecat BE in D ; ducatur AD, anguli ADB, ACB &longs;unt æquales quia &longs;u&longs;tinent eundem arcum AB, &longs;ed ADB e&longs;t major prædicto AEB, cùm &longs;it exterior; igitur an­gulus AEB e&longs;t minor ACB; idem de quolibet alio demon&longs;tratur: &longs;ed jam ad alia experimenta venia­mus, Sit ampulla A, de quà &longs;upra; aquæ &longs;uperfi-
cies KI in canaliculo verò &longs;it D ; volam manus admove ori BC cum modica pre&longs;&longs;ione; &longs;tatim aqua per canalicu­lum altiùs a&longs;&longs;urgit versùs F ; vbi verò repentino motu ma­nus ab ore AB, amovent, de&longs;cendit aqua præceps in G. &longs;ed &longs;tatim denuo a&longs;&longs;urgit versùs F.

Augu&longs;tin. Ex præmi&longs;&longs;is huius experimenti facilè ratio­nem afferam, nempe aër vola pre&longs;&longs;us aquæ &longs;uperficiem KI premit, ex cujus pre&longs;&longs;ione, per canaliculum nece&longs;&longs;ariò altiùs ar&longs;&longs;urgit : amota autem repente vola, aquæ &longs;uperficiem AB &longs;ecum tantulum adducit, attollítque; vnde aquam per canaliculum &longs;ub&longs;idere nece&longs;&longs;e e&longs;t.

Antim. Inde omnium huiu&longs;modi experimentorum communem ratio­nem reddo: &longs;i enim aër magis compre&longs;&longs;us aquam per canaliculum attol­lit; certè minùs altè attollit; nullo modo pre&longs;&longs;us non attollit; adductus verò, &longs;ecum versùs G aquam m canaliculo contentam adducit. Et verò, vt tandem ad rem propiùs accedam, cùm hic motus, quo aqua a&longs;&longs;urgit, non &longs;it ab intrin&longs;eco, vt con&longs;tat ex dictis, nec enim aqua &longs;pontè &longs;ua a&longs;­cendit, ab alia cau&longs;a extrin&longs;eca illum e&longs;&longs;e, nece&longs;&longs;e e&longs;t; eaque profectò applicata quænam porrò illa e&longs;t, ni&longs;i aër? quidquid tandem aër &longs;it, &longs;ive purus, &longs;ive impurus, id e&longs;t aliis corporibus admixtus; aër porrò applica­tus motum illum imprimere nequit, ni&longs;i vel gravitando, vel illo ni&longs;u, qui ex compre&longs;&longs;ione corporum &longs;equitur; primum dici non pote&longs;t, cùm enim gravitet per cylindros parallelos, æquè gravitat in minorem aquæ &longs;uper­ficiem, ac in majorem ; ac proinde vtraque, &longs;i gravitationis dumtaxat ra­tio habeatur, in eadem libella &longs;ita e&longs;t, nec vna a&longs;&longs;urgit &longs;upra aliam, re­&longs;tat igitur, vt dicamus, aëra tantulum compre&longs;&longs;um cum ni&longs;um exerere in &longs;uperficiem BC, non quidem per cylindros parallelos; &longs;ed per conos, quorum &longs;inguli vertices &longs;ingulis &longs;uperficiei punctis incumbunt; ac proin­de minorem ni&longs;um exeri adversùs &longs;uperficiem aquæ CD canaliculo con­tentæ, quia &longs;ub minoribus angulis exeritur, vt &longs;upra luculenter o&longs;ten&longs;um e&longs;t; prævalet igitur pre&longs;&longs;io incidens in &longs;uperficiem BC ; ac proinde aliam CD attollit versùs F.

Chry&longs;oc. Iam ob&longs;ervo inde germanam duci rationem, illius addu­ctionis atramenti; vbi enim atramenti guttam calami ro&longs;trum extre­mum attingit, (quod pueri facere &longs;olebamus) attramentum illico a&longs;&longs;urgit, & cavum calami ro&longs;trum implet; in alio liquore idem &longs;uc­ce&longs;&longs;um iri, certi&longs;&longs;imum e&longs;t; calamum tamen priùs humectatum fui&longs;&longs;e oportet.

Augu&longs;tin. Luculentam rationem jam attulit Antimus; &longs;ic enim com­planatur &longs;uperficies calami, alioquin multis rugis & &longs;alebris &longs;triata & a&longs;­perata, huic autem experimento communis illa ratio Antimi facilè ap­plicatur, ab inæqualis pre&longs;&longs;ionis ni&longs;u petita; nam reverà in totam guttæ &longs;uperficiem, excepto &longs;cilicet puncto illo contactus, in quo extre­mum ro&longs;trum guttæ immergitur, major e&longs;t pre&longs;&longs;ionis ni&longs;us, quàm in ca­vam ro&longs;tri &longs;uperficiem; quid mirum ergo &longs;i prævaleat illa, & humor per cavum ro&longs;trum a&longs;cendat? aliquid &longs;imile in omnibus guttis ob&longs;ervo, ad-mota &longs;cilicet tenui lamella, vel bacillo; nempe eò &longs;tatim liquor ex­currit.

Antim. Guttarum res nonnihil fortè &longs;citu dignum nobis exhibet; &longs;ed ne hoc excidar, antequam illam aggrediar; &longs;i ro&longs;trum calami longiùs &longs;it, & valde tenue, & in mucronem extenuatus, quamvis extremum ro&longs;trum guttæ immergas, nihil aut parum attramenti a&longs;&longs;urgit: ratio e&longs;t, quia par­vum, aut nullum ferè obicem ponit ad pre&longs;&longs;ionis inæqualitatem inducen­dam; nempe tenuis illa ro&longs;tri linea pauci&longs;&longs;imos pre&longs;&longs;ionis radios intercipit; nulla igitur vel modica inæqualitatis pre&longs;&longs;ionis proportio; ex hoc etiam experimento efficax, meo judicio, argumentum ducitur, quò per&longs;picuè concluditur, huju&longs;modi aquarum elevationem ab inæquali ambientis aëris pre&longs;&longs;ione procedere.

Chry&longs;ocom. Quid &longs;i cylindrus &longs;olidus immergatur, an fortè ali­quid aquæ attollitur; cùm hic obex inæqualem pre&longs;&longs;ionem in­ducat?

Antim. Aliquid omnino, quod tamen longè melius ad oculum patet, &longs;i prædictus tantulum &longs;triatus &longs;it, pro quo eadem, vt vides, ratio militat.

Chry&longs;ocom. Quid verò fieret, &longs;i canaliculus in alium paulo am­pliorem immergatur? vel duo &longs;imul quorum minor majori inclu­&longs;us &longs;it?

Antim. Pro diver&longs;a canalium & immer&longs;ionum ration, diver&longs;a &longs;ucce­dunt à me ob&longs;ervata experimenta & ad idem principium &longs;atis feliciter re­ducta.

Primò enim &longs;it canalis major HB aqua plenus; ad. moveatur, vt priùs dictum e&longs;t, minor canaliculus MN, humori illico a&longs;&longs;urgit in K, perinde atque &longs;i in quam­libet aliam aquæ, etiam majore va&longs;e contentæ &longs;uperfi­ciem immergatur; propter eandem rationem, de qua huc v&longs;que.

Secundò. Si aquæ &longs;uperficies &longs;it tantùm in C & de­mittatur canaliculus MN in C, a&longs;&longs;urget aqua v.g. in G ita tamen vt CG, &longs;it minor NK; ratio e&longs;t, quia minor e&longs;t inæqualitatis proportio in pre&longs;&longs;ionibus, quam antè, vt pa­tet; minor igitur illius effectus, minus igitur attollitur aqua: &longs;uppono enim majorem vim exeri per vacuitatem in­terceptam inter cavam majoris & convexam minoris ca­nalis &longs;uperficiem, quàm per minorem canaliculum.

Tertiò. Si &longs;ecus accidat, id e&longs;t, &longs;i cavitas canaliculi major e&longs;t prædicta vacuitate intercepta, humor per vacuitatem illam a&longs;cendet v.g. in FE, &longs;ed nullo modo per canaliculum NC a&longs;&longs;urget; quia major e&longs;t aëris pre&longs;&longs;io per canalicu­lum, quàm per vacuitatem interceptam.

Quartò. Si æqualis &longs;it vtriu&longs;que &longs;patij, id e&longs;t, cavitatis & vacuitatis ca­pacitas, & canaliculus demittatur in C, neque hinc, neque illinc humor a&longs;&longs;urgit; quia æqualis vtrimque pre&longs;&longs;io: neutra igitur præ­valet.

Quintò. Iam verò ad aliud quæ&longs;itum venio, & &longs;uppono vtrum­que canaliculum pervium, ita vt minor intra majorem, qua&longs;i intra vagi­nam conditus &longs;it, & tunc etiam pro diver&longs;a di&longs;po&longs;itione varia &longs;uccedunt;

Primò, &longs;it &longs;uperficies Aquæ AB, &longs;it carnalis major FE, & minor inclu&longs;us HD, vterque eju&longs;dem altitudinis, & &longs;imili modo immer&longs;us; &longs;i vacuitas majoris (&longs;ic de­inceps appellabo interceptum illud &longs;patium) æqualis &longs;it minori canaliculo, &longs;cilicet eiu&longs;dem cavitati, per vtramque æquè altè humor a&longs;&longs;urgit; v.g. in LK, quia vis æqualis pre&longs;&longs;ionis exeritur ; quod vt fiat ba&longs;is ma­joris FG debet e&longs;&longs;e dupla minoris IH ; dico ba&longs;im, non diametrum ba&longs;is, ne fortè &longs;chema vos deci­piat.

Secundo. Si ba&longs;is majoris &longs;it major dupla, altiùs a&longs;­&longs;urgit aqua per minorem, quàm per majorem, v.g. per minorem in LK, per majorem in MN; quia ma­jor e&longs;t proportio inæqualitatis pre&longs;&longs;ionum ad mino­rem; quàm ad vacuitatem interceptam; igitur & ef­fectum.

Tertio. Si verò ba&longs;is majoris &longs;it minor dupla, &longs;ecus accidet; & a&longs;&longs;urget humor altiùs per vacuitatem, quàm per canaliculum, ra­tio patet ex dictis.

Quartò. Si major altiùs immergatur, quàm minor, cæteris paribus, humor altiùs a&longs;cendet per minorem, &longs;uppo&longs;ita tamen ba&longs;i majoris &longs;altem dupla ba&longs;is minoris.

Quinto. Si verò canaliculus minor profundiùs demittatur, certè ex hoc capite altiùs deberet a&longs;cendere per majorem, quàm per minorem; quia tamen major e&longs;t portio renitentis aëris, ne aqua per majorem a&longs;­cendat, quæ priùs non erat, compen&longs;atio fieri videtur, & pro diver&longs;a ba&longs;ium ratione, modò altiùs, modò æquè altè, modò minùs altè a&longs;­&longs;urgit.

Sexto. Si &longs;olus major immergatur, ac proinde tantulum a&longs;cendat aqua, &longs;i deinde minor canaliculus in cum, vt priùs, immittatur, altiùs per vtrumque aqua a&longs;&longs;urget, tum quia minus &longs;patij occupandum e&longs;t, tum quia vis reni­tentis aëris minor e&longs;t.

Septimo. Si minor &longs;olus profundiùs immergatur, v.g. v&longs;que in O, minùs altè a&longs;cendet, quàm ante; per minorem quidem, quia brevius, &longs;upra &longs;uperfi­ciem aquæ &longs;egmentum extat; per majorem verò, quia cum angulus pre&longs;&longs;io­nis renitentis cre&longs;cat, minùs altè humor a&longs;&longs;urgit.

Octavo. Si verò major &longs;olus profundiùs deprimatur, retento minore in codem &longs;itu, paulò altiùs a&longs;cendit per minorem; quia vis pre&longs;&longs;ionis circa illius infimam ba&longs;im cre&longs;cit; hæc autem ratio facit, ne per majorem æquè altè a&longs;­&longs;urgat.

Nonò. Pro diver&longs;a ba&longs;ium ratione, altiùs aut minùs altè a&longs;cendit per cavitatem minoris, aut per vacuitatem interceptam inter vtrumque de­oque vno vel altero, diver&longs;a erit altitudinum ratio, &longs;ecundum regu­las &longs;upra traditas; nunquam tamen quantumvis minor deprimatur aqua per illum a&longs;&longs;urgens ex illo effluet.

Decimò, Vbi minoris convexa &longs;uperficies cum majoris cava conjungi­tur, aqua intercepta illico a&longs;&longs;urgit, & qua&longs;i quodam glutine vna cum alia conjungitur: idem ferè fiet, &longs;i duæ &longs;uperficies convexæ conjungantur. Ex his, quæ huc v&longs;que dixi, de duobus canaliculis, quorum vnus alteri immittitur, reliqua facilè conjicies.

Augu&longs;tin. Nunquam per&longs;uadere mihi potui&longs;&longs;em, in re hac minima tantam ob&longs;ervationum &longs;ylvam recondi; ex qua ego, &longs;olo ratiocinio mul­tas alias deducere po&longs;&longs;em. Sed quæro ex te, quot &longs;int capita, ex quibus humor altiùs per canaliculum immer&longs;um a&longs;cendat.

Antim. Sex aut &longs;eptem, ni fallor, recen&longs;eo. Primò, quo longior e&longs;t ca­naliculus, altiùs humor a&longs;cendit, non tamen vbi valdè producitur in pro­portione &longs;en&longs;ibili; Secundò, quo minor e&longs;t canaliculi ba&longs;is; vt patet. Ter­tiò, quo minùs altè immergitur canaliculus, altiùs a&longs;&longs;urgit aqua. Quartò, major aëris ambientis libertas, & major angulus pre&longs;&longs;ionis, vi cujus hu­mor a&longs;&longs;urgit. Quintò major vel minor aëris ambientis compre&longs;&longs;io. Sextò Minor gravitas liquoris attollendi. Septimò, major eju&longs;dem fluitas, vel humiditas, &longs;ic &longs;piritus vini altiùs a&longs;cendit quàm aqua, & metallum li­quatum nihil aut parum admodùm.

Augu&longs;tin. Quid porrò de Mercurio? nonnulla enim de illo mihi veniunt in mentem, quæ vix a&longs;&longs;erere au&longs;im ; quia nunquam illa experimento probavi.

Chry&longs;ocom. Exprome tamen, vt &longs;altem videamus vtrum rectè ratioci­neris; cùm fieri non po&longs;&longs;it, quin Antimus illa ob&longs;ervarit.

Augu&longs;tin. Primò Mercurius, aut nihil aut parum a&longs;&longs;urgere debet per canaliculum propter cra&longs;&longs;itudinem & &longs;ummam vim ponderis. Secundò, Suprema &longs;uperficies intra canalem depre&longs;&longs;a, non e&longs;t cava, &longs;altem &longs;en&longs;ibi­liter, propter eandem rationem. Tertiò, Mercurij gutta per calami ro&longs;trum non a&longs;&longs;urgit, vt reliqui humores. Quartò non a&longs;&longs;urgit, etiam &longs;i cylindrus &longs;olidus immergatur, licèt tantulùm a&longs;cendat aqua, &longs;i in ejus &longs;uperficiem immergatur.

Antim. Parum abes à &longs;copo, Augu&longs;tine, eaque tantùm non prævidi&longs;ti, quæ nonnulli in Mercurio cum &longs;ummo &longs;tupore mirantur. Primò enim &longs;i canaliculus Mercurio &longs;ecundum alteram extremitatem immergatur, non modò non a&longs;&longs;urgit per canaliculum, &longs;upra libellam exterioris &longs;uperficiei, &longs;ed tantulùm &longs;ub&longs;idit, quod hi&longs;ce oculis centies ob&longs;ervavi. Secundò, Non modo &longs;uprema illius &longs;uperficies cava non e&longs;t, &longs;ed omnino convexa; & vbi ad os tubi, in quo continetur pertingit, longè convexior, quàm &longs;uper­ficies aquæ. Tertiò, Non modò non a&longs;&longs;urgit gutta Mercurij per ro&longs;trum calami, &longs;ed ne quidem ro&longs;trum in eam &longs;ubit, &longs;ed vel cedit, non &longs;ine fo&longs;&longs;ula in puncto contactus, vel repentino motu &longs;e&longs;e &longs;ubducit. Quartò, non modo non a&longs;&longs;urgit Cylindro &longs;olido immer&longs;o; &longs;ed qua&longs;i fo&longs;&longs;ula circa illius &longs;uperficiem acta &longs;ub&longs;idit, & circa fo&longs;&longs;ulam Mercurij &longs;uperficies attollitur, idque ad &longs;en&longs;um & evidentiam.

Augu&longs;tin. Non video, ne quid di&longs;&longs;imulem, quomodo hæc ex præmi&longs;&longs;is con&longs;equi po&longs;&longs;int; ac proinde non mirum &longs;i ex iis à me non deducta.

Antim. Con&longs;equuntur tamen; nempe cùm Mercurius vitro non adhæ­reat, vt per&longs;picuum e&longs;t, in tantum enim corpus humidum aliorum corpo­rum &longs;uperficiei adhæret, in quantum in cavitates, &longs;trias & pororum o&longs;tiola &longs;ubit; certè Mercurius præ cra&longs;&longs;itudine in eas angu&longs;tias &longs;e&longs;e minimè inge­rit; vnde aëri locus vitrum inter & Mercurium relinquitur; nec enim va­

cuum datur. Sit &longs;uperficies Mercurij AB, in quam immergatur Cylindrus vitreus EC, &longs;ub&longs;idet M rcurius in fo&longs;&longs;ulam GH, quæ optimè concipitur, &longs;i tota hæc Figura circa Cylindri EC axem volvi &longs;upponatur; cùm enim non adhæreat Mercurius lateri ED, aër compre&longs;&longs;us qua&longs;i cuneatim penetrat v&longs;que ad G, & fa­cilè à latere ED Mercurium removet; hinc tantulum attolli Mercurium nece&longs;&longs;e e&longs;t; hinc circa &longs;uperficiem Cylindri EC fo&longs;&longs;ula, & circa fo&longs;&longs;ulam modicus tumor; vt enim cuneus dum &longs;ubit vnum ab alio removet, ita premens aër ad in&longs;tar cunei interceptus inter &longs;uperficiem Cy­lindri & Mercurium, hunc ab illa tantulum removet; atque ita, vt vides, quartum experimentum ad commune no&longs;trum principium reducitur.

Augu&longs;tin. Iam verò &longs;ecundum, eodem modo, te duce explicabo, nempe aër etiam &longs;e&longs;e in&longs;inuat ad in&longs;tar cunei inter &longs;uperficiem cavam canalis & Mercurium contentum, vn de illum à dicta &longs;uperficie remover, idque in orbem, ac proinde circa medium, vel centrum tantulum attollitur, atque intume&longs;cit; &longs;ed quid de primo? vix enim video, quonam pacto ad idem principium re­duci queat; idem de tertio dictum &longs;it; &longs;uggere quæ&longs;o mihi, quid &longs;entias.

Antim. Per admotum canaliculum Mercurius non a&longs;&longs;urgit; tum quia cùm longè cra&longs;&longs;ior &longs;it reliquo humore in angu&longs;tias difficiliùs intruditur; vnde per telam, &longs;eu pannum non colatur, vt aqua; quia per exigua coli fo­ramina difficilè trajicitur; tum quia prædicta fo&longs;&longs;ula exterior circa canali­culi immer&longs;i &longs;uperficiem convexam excavata vim pre&longs;&longs;ionis di&longs;trahit à &longs;u­perficie Mercurij, quæ ba&longs;i canaliculi adhæret, eam que in contrariam par­tem traducit; vnde non mirum, &longs;i vi pre&longs;&longs;ionis Mercurius per canaliculum non a&longs;&longs;urgat. Sed potiùs ex vtroque capite Mercurius intra canaliculum &longs;ub&longs;idat infra &longs;uperficiem exteriorem, cùm & vitrum &longs;uo appul&longs;u, & vis pre&longs;&longs;ionis, quæ per canaliculum exeritur, &longs;upra aliam prævalens, ob ratio­nem expo&longs;itam, Mercurium deprimant. Inde quoque ratio ducitur tertij experimenti; nempe ro&longs;trum calami propter cra&longs;&longs;itudinem Mercurij in eum non &longs;ubit, &longs;ed potiùs Mercurius ro&longs;tro cedens in fo&longs;&longs;am &longs;ub&longs;idit; cùm difficiliùs quàm aqua dividatur; vnde mutatur pre&longs;&longs;ionis ratio, ac proinde per ro&longs;trum admotum non a&longs;&longs;urgit, vt aqua.

Chry&longs;ocom. Quid &longs;i in va&longs;e compo&longs;ito iuxta formam præ&longs;criptam & delineatam in Figura &longs;equente.

Antim. Hoc ip&longs;um &longs;ubnectere meditabar; &longs;ed præveni&longs;ti; infundo igi­

tur Mercurium in AB, donec totum vas plenum &longs;it, &longs;tatue libellam AG; ob&longs;erva quantumlibet, vides Mercurium a&longs;&longs;urgere in FG ; equidem cir­ca centrum V altiùs attollitur, quàm &longs;i e&longs;&longs;et aqua, propter rationem à me &longs;upra expo&longs;itam; tantu­lum enim &longs;ubït cuneus aëris inter latera va&longs;is & Mercurium, quod inaqua non fit; vnde altiùs centrum V. attollitur; minus verò centrum &longs;u­perficiei FG, quia minor e&longs;t &longs;uperficies: vides ta­men, vix oculo di&longs;cerni po&longs;&longs;e, vtra &longs;uperficies al­tiùs a&longs;&longs;urgat; equidem &longs;i canaliculus IE angu­&longs;tior e&longs;&longs;et, difficilius per illum cra&longs;&longs;ior Mercurius a&longs;&longs;urgeret; hinc minùs altè, in plumbo, & melle idem probabis; &longs;i verò, vt hic, paulò laxior ad ean­dem &longs;en&longs;ibiliter a&longs;cendit altitudinem, & licèt tantulum a&longs;&longs;urgat, per cana­liculum id compen&longs;atur ab altiore tumore &longs;uperficiei AB. Illud porrò tan­tulum, quo a&longs;&longs;urgit ab eadem ratione inæqualis pre&longs;&longs;ionis procedit; cùm enim aquæ gravitas &longs;it ad gravitatem Mercurij ferè vt 1.ad 15.fit &longs;egmentum aquæ &longs;upra libellam AG a&longs;&longs;urgens, FL; dividatur linea FM in 15.partes æquales, vna ex illis erit altitudo &longs;egmenti Mercurij a&longs;&longs;urgentis in canali­culo ID; &longs;i tamen paulò laxior &longs;it, vt dixi; &longs;i enim angu&longs;tior, præ cra&longs;&longs;itudi­ne minùs a&longs;&longs;urgit: vides quàm facilè cuncta hæc ad commune illud princi­pium reducantur, immò ad aliud reduci nequeant; ac proinde ex præmi&longs;&longs;is omnibus experimentis idem principium etiám &longs;tatuitur & confirmatur. Sci­licet humorem attolli in canaliculo propter inæqualem aëris pre&longs;&longs;ionem.

Augu&longs;tin. Hæc mihi &longs;upra modum arrident; quid porrò fiat &longs;i canàli­culus intra alium in&longs;eratur, quando &longs;cilicet in Mercurium immergitur, ex te re&longs;cire de&longs;idero, cùm mihi dubium non &longs;it, quin cuncta hæc probaveris.

Antim. Rectè conjicis, à me probata e&longs;&longs;e: Sit ergo Cylindrus vitreus AD, cavus, &longs;ed clau&longs;us in CD, apertus in AB; in quem tantulum Mercurij infu&longs;us occupet &longs;egmentum CO, & in&longs;eratur canaliculus vtrimque pervius IE; non a&longs;&longs;urgit Mercurius &longs;upra libellam NO, &longs;ed tantulum deprimitur in canaliculo; a&longs;&longs;urgit verò in vacuitate intercepta, propter rationem jam expo&longs;itam. Si verò infundatur aqua in prædictam vacuitatem interceptam, tantulum Mercurius in præ­dicta vacuitate contentus deprimitur infra libellam NO, a&longs;&longs;urgit verò &longs;upra in canaliculo, puta in G ; quod certè fieri debet, vt &longs;it perfectum æquilibrium; cùm &longs;cilicet non modò pondus Mercurij NE attollat Mer­curium, verùm etiam pondus &longs;imul aquæ infu&longs;æ; igitur &longs;i pondus &longs;olius Mercurij &longs;u&longs;tinet &longs;egmentum Mercu­rij EE, majus pondus, vtpote compo&longs;itum ex Mercu­rio & aqua infu&longs;a, majus Mercurij &longs;egmentum &longs;u&longs;tinet, puta EG ; &longs;i autem a&longs;cendat per canaliculum &longs;upra NO, infra NO de&longs;cendat, nece&longs;&longs;e e&longs;t, in­tra vacuitatem.

Prætereà &longs;i his &longs;tantibus, attollatur canaliculus IE, v&longs;que ad imam aquæ &longs;uperficiem, puta v&longs;que ad NO, tunc de&longs;cendente Mercurio ex &longs;egmento FG, &longs;ubit aqua canaliculum impletque, tum canaliculum, tum vacuitatem, &longs;i&longs;titque vtraque aquæ &longs;uperficies, tum intra, tum extra canaliculum, in ea­dem libella, puta HM nec a&longs;&longs;urgit aqua per canaliculum altiùs contra mo­rem &longs;olitum; ratio ex eo petitur, quòd aëris pre&longs;&longs;io aquam per canaliculum attollere nequeat, ni&longs;i &longs;imul attollat Mercurium; &longs;upponitur enim canali­culus tantulum immer&longs;us in Mercurium; hunc autem, vt dixi, attollere non pote&longs;t; hinc &longs;i canaliculus ita attollatur, vt ima illius extremitas &longs;it &longs;upra &longs;uperficiem Mercurij, tunc aqua altiùs a&longs;&longs;urgit &longs;upra libellam HM, puta in I, quia tunc inæqualis aëris pre&longs;&longs;io &longs;uum effectum habet; neque ad hunc finem Mercurius, vt ante, attollendus e&longs;t, &longs;ed aqua &longs;ola; &longs;i demum ex illo &longs;itu, quo ima ba&longs;is canaliculi &longs;upremæ Mercurij adhæret, & vtra­que &longs;uperficies aquæ, tum in vacuitate, tum in canaliculo æquè a&longs;&longs;urgit in HM, deprimas canaliculum v&longs;que ad E, aquæ &longs;uperficies in vacuitate a&longs;cendit &longs;upra HM, infra quam de&longs;cendit in canaliculo; quia &longs;egmentum canaliculi immer&longs;um Mercurio ex eo loco imi va&longs;is, quem occupat, extru­dit Mercurium in vacuitatem interceptam faciliùs quàm in canaliculum, propter angu&longs;tias; quid mirum ergo, &longs;i &longs;uperficies aquæ in vacuita­te a&longs;&longs;urgat &longs;upra HM, hanc enim attollit extru&longs;us à &longs;egmento im­mer&longs;o Mercurius, in canaliculo verò &longs;ub&longs;idente Mercurio, incu­bans aqua etiam &longs;ub&longs;idit, ex his, ni fallor, reliqua facilè intelli­getis.

Augu&longs;tin. Cuncta hæc illam aëris pre&longs;&longs;ionem omnino evincunt, ad quam etiam multa alia, quæ vi cuidam tractrici vulgò tribuuntur, æquè facilè reducere po&longs;&longs;um. Sic &longs;pongio&longs;a corpora humorem dicuntur exuge­re, vt panis, præ&longs;ertim bis coctus, aut recens, &longs;pongia, pannus, terra &longs;icca, pumex, aliaque huju&longs;modi; nam pori &longs;eu meatus, quantumvis obliqui totidem canaliculos faciunt, per quos aqua facilè a&longs;&longs;urgit: Vn­de vis illa tractrix, vt omnino fictitia, rejicitur; item illa Fromondi fa­bula, qui ni&longs;i me fallit memoria lib. 5. Meteor. cap.2. art.2. Vbi Conimbri­cen&longs;ium aliorumque &longs;ententias rejeci&longs;&longs;et, recurrit ad qua&longs;dam partes aquæ tenuiores, quæ &longs;ur&longs;um a&longs;cendunt; &longs;ed illa aqua, vbi deinde &longs;pongia expri­mitur, æquè cra&longs;&longs;a e&longs;t atque alia, & aëre longè gravior; cur ergo a&longs;cen­dit? Idem Fromondus aquam frigidi&longs;&longs;imam exugi negat; &longs;ed merum men­dacium e&longs;t.

Antim. Sine quæ&longs;o i&longs;tum hominem; &longs;ufficiat à te optimè deduci, il­los effectus, qui vulgò &longs;uctioni, &longs;eu vi tractrici tribuuntur, ad idem prin­cipium no&longs;trum reduci; vt autem ad illud redeam, novum experimentum adduco, per quod, meo judicio, mirificè confirmatur: Sit vas quodlibet aqua plenum, admoveatur canaliculus, in &longs;itu perpendiculari, illico aqua a&longs;&longs;urgit; appendatur in hoc eodem &longs;itu canaliculus, fideli bilance, aqua, quæ &longs;ubit, nullum momentum addit ponderi canaliculi vitrei; quod vt accura-tè fiat, &longs;u&longs;pendatur canaliculus tenui filo pendulo ex brachio extremo bi­lancis; ita vt deor&longs;um ire non po&longs;&longs;it, &longs;ed tantùm parum immergatur in &longs;uperficiem aquæ &longs;ubjecto va&longs;e contentæ; occludaturque &longs;upremum os ca­naliculi cera, aut &longs;uilla ve&longs;ica, antequam immergatur, ac deinde immer&longs;um illius pondus accuratè appendatur, admoto &longs;cilicet iu&longs;to pondere oppo&longs;itæ lanci; po&longs;teà verò aperiatur acu &longs;upremum os prius ob&longs;tructum; a&longs;&longs;urgit illico aqua per canaliculum, licèt nihil ponderis pror&longs;us accedat: Illa igi­tur aquæ portio, quæ per canaliculum a&longs;cendit, dicto filo pendulo non &longs;u&longs;tinetur, &longs;ed ab alio principio, eoque applicato; &longs;cilicet ab aëre com­pre&longs;&longs;o; hoc experimentum, &longs;i accuratè fiat, rem i&longs;tam evincit.

Chry&longs;ocom. Sed vnde huju&longs;modi aëris compre&longs;&longs;ionem e&longs;&longs;e putares?

Augu&longs;tin. Huic tuo quæ&longs;ito faciam &longs;atis; &longs;i dixero ex duplici capite pro­venire, Primò, ex admixtione vaporis & halitus; cùm enim no&longs;ter aër purus non &longs;it, multa huju&longs;modi habet admixta, vnde illius compre&longs;&longs;io &longs;equitur. Secundò, ex pondere &longs;upremi aëris incubantis: fieri enim non pote&longs;t, quin aër &longs;ubjectus inde compre&longs;&longs;us evadat.

Chry&longs;ocom. E&longs;t quod multa opponam. Primò, totus aër gravitat gra­vitatione communi; ne igitur pars inferior in &longs;e ip&longs;um gravitare dica­tur, dicendum videtur. Superiorem aëris tractum in inferiorem non gravitare.

Augu&longs;tin. Dare non po&longs;&longs;um totum aëra gravitatione communi gravi­tare in quodlibet corporis &longs;ubjecti punctum; nec enim vllum centrum gravitatis commune habet, quod iis dumtaxat gravibus competit (de phy&longs;ico loquor) quorum tota vis gravitationis per vnicam lineam à præ­dicto centro ductam exeritur ; corpus liquidum, vt aqua, & &longs;pirabile, vt aër, ni&longs;i contineantur in va&longs;e, per Cylindros deor&longs;um, parallelos, gra­vitant; &longs;cilicet ad &longs;en&longs;um; cùm alioquin omnes Cylindri gravitationis versùs idem centrum eant; vnde paralleli e&longs;&longs;e non po&longs;&longs;unt; equidem &longs;e­cundùm eundem Cylindrum gravitatio omnium partium, quæ illum componunt, ita communis e&longs;t, vt omnes &longs;imul in corpus &longs;ubjectum gra­vitent, & &longs;ingulæ &longs;upra &longs;ingulas &longs;ubjectas immò &longs;upra eandem &longs;ubjectam omnes &longs;uperiores, in eodem tamen Cylindro; cogita lapidem lapidi &longs;uppo­&longs;itum, &longs;ubjectus enim omnes &longs;uperiores ferre cen&longs;etur.

Chry&longs;ocom. Tota igitur illa gravitatio reducitur in lineas; &longs;inguli enim Cylindri &longs;unt totidem lineæ; linea autem, aut nihil, aut parum ponde­ris habet; nulla igitur inde compre&longs;&longs;io, aut certè modica; quid enim tam parvi ponderis vis efficeret: ponamus enim Cylindrum aqueum da­tæ ba&longs;is & altitudinis pendere vnam libram; &longs;upponamus item aquæ gra­vitatem e&longs;&longs;e ad gravitatem aëris vt 1000. ad 1. haud dubiè Cylindrus aë­ris æqualis pendit tantùm vnam mille&longs;imam partem vnius libræ; igitur &longs;i 1000. huju&longs;modi Cylindros ita di&longs;ponas, vt vnus alteri imponatur, om­nes &longs;imul vnam libram pendent; cùm autem in infinitum contrahi ba&longs;is po&longs;&longs;it, & in eadem proportione cre&longs;cere altitudo, certè habebis Cylindrum petitæ cuju&longs;libet altitudinis, qui vnam libram pendat, licèt ad lineam non­dum redactus, &longs;eu contractus &longs;it.

Augu&longs;tin. Nulla e&longs;t in hoc difficultas, & valde miror, te in hoc ar­gumento diutiùs hærere; in qua enim proportione decre&longs;cit pondus, de­cre&longs;cit re&longs;i&longs;tentia; id e&longs;t, in qua proportione contrahitur ba&longs;is Cylindri comprimentis, contrahitur & Cylindri compre&longs;&longs;i: nempe, vt &longs;e habet comprimens Cylindrus, cujus ba&longs;is e&longs;t vt quatuor, ad Cylindrum com­pre&longs;&longs;um ba&longs;is vt quatuor, ita &longs;e habet Cylindrus ba&longs;is 2.ad Cylindrum ba­&longs;is vt 2.eju&longs;dem &longs;cilicet altitudinis.

Chry&longs;ocom. Quis, quæ&longs;o capiat, tantam pre&longs;&longs;ionis vim, quam haud du­biè immane pondus incubantis aëris omninò efficeret, etiam &longs;i demus, aëris gravitatem e&longs;&longs;e ad gravitatem aquæ vt 1. ad 1000. aut etiam &longs;i vis, duplo, vel triplo minorem; porrò aëra parum admodum compre&longs;&longs;um e&longs;&longs;e, vel ex eo probatur argumento, vt aiunt, ad hominem, quod tantulum aquæ dumtaxat elevet.

Augu&longs;tin. In hoc &longs;altem hallucinaris, quòd eandem aëris gravitantem vbique e&longs;&longs;e &longs;upponas, quod tamen à veritate pror&longs;us alienum e&longs;t, nempe aër inferior gravior e, quia compre&longs;&longs;ior, in quacumque voles ratione; cùm enim aëris altitudinem certam ne&longs;ciamus, &longs;uper hoc, ni&longs;i tantùm in genere, aliquid definire nequimus; quòd autem modicam vim pre&longs;&longs;ionis, &longs;eu potiùs compre&longs;&longs;ionis aëris ex eo probes, quòd modicus &longs;it illius effe­ctus, aqua &longs;cilicet per canaliculum a&longs;&longs;urgens, rectè, meo judicio, non de­ducis; cùm etiam aër exterior compre&longs;&longs;us, per &longs;upremum os canaliculi per­vij eam vim retundat; minùs tamen; vnde alia pre&longs;&longs;io prævaleat nece&longs;­&longs;e e&longs;t.

Chry&longs;ocom. Immò tu potiùs hallucinaris, Augu&longs;tine, licèt enim retun­dat, repellatque humorem per caniculum a&longs;&longs;urgentem aër compre&longs;&longs;us, per eundem &longs;cilicet canaliculum &longs;uam vim exerens; quia tamen vires pre&longs;&longs;io­nis &longs;unt vt anguli, &longs;eu coni pre&longs;&longs;ionum, de quibus ante, haud dubiè pre&longs;&longs;io intra canaliculum vix e&longs;&longs;et millecupla alterius, ac proinde mille&longs;imam tantùm effectus, &longs;cilicet elevationis partem impediret, quæ reverà &longs;ub &longs;en­&longs;um non cadit.

Augu&longs;tin. Sentio vim hujus argumenti, cui &longs;olvendo vix parem me &longs;en­tio; immò alia duo mihi veniunt in mentem, quæ non parum negotij mihi face&longs;&longs;unt; fer opem, Antime, nempe de tua cau&longs;a & &longs;ententia hîc agitur.

Antim. Citiùs quàm par e&longs;&longs;et, animum de&longs;pondes; quid quæ&longs;o hîc diffi­

cile? Repete Figuram &longs;uperiorem. Sitque &longs;uperfi­cies aquæ AB, in quam vis pre&longs;&longs;ionis exeritur ; itemque FG, in quam etiam vis pre&longs;&longs;ionis cadit, minor certè, &longs;ed in minima proportione inæqualitatis incumbit; nempe totus aër æqua­liter premit AB & FG, v&longs;que ad terminum DE, cùm æquè liber &longs;it, vt patet; illa &longs;olùm aëris portio contenta in &longs;egmento canaliculi FE inæqualitatem inducit; nimirum totus aër liberè premit FG, &longs;ed excepta portione FE; cujus angulus pre&longs;&longs;ionis contrahitur, de hoc enim angulo intelligi debent ea, quæ &longs;upra dicta &longs;unt; quo &longs;emel admi&longs;­&longs;o, vides, quàm modica &longs;it pre&longs;&longs;ionis differentia, ac proinde minimus ferè illius effectus.

Augu&longs;tin. Ea, quæ modò dixi&longs;ti, multam mihi lucem attulerunt; & jam mihi &longs;olvere po&longs;&longs;e videor illa, quæ mihi paulò ante in mentem ve­nerunt; primum erat, quod in imo aëris tractu, aqua per canalicu­lum altiùs attolli deberet, quod tamen fieri non exi&longs;timo; &longs;ed hoc facilè &longs;olvitur; quia modica illa differentia in vtroque &longs;itu &longs;ub &longs;en&longs;um non ca­dit. Alterum erat paulò difficiliùs, quod &longs;cilicet in Plenilunio & Novi­lunio longè altius attolli deberet, quia tunc aër gravior e&longs;t; &longs;ed profe­ctò cùm illa gravitas aëris ab humore admixto procedat, qui reverà non comprimitur, non &longs;equitur, aëra compre&longs;&longs;iorem e&longs;&longs;e, licèt gravior &longs;it, non quidem per &longs;e, &longs;ed per accidens, vt aiunt. Teium denique, quod jam &longs;upra indicaveras, cuipiam fortè difficillimum videbitur; nempe tempore &longs;ummi æ&longs;tus, cùm minor incubet aëris gravitatio, aër minus compre&longs;&longs;us e&longs;t; &longs;ub finem verò refluxus cùm major incubet gravitatio, ac proinde aër compre&longs;&longs;ior fit; hac hora humor per canaliculum altiùs, il­la verò minùs altè a&longs;&longs;urgeret, quod tamen, opinor, minimè &longs;uccedit; facilè tamen re&longs;ponderi pote&longs;t, immò re&longs;pondeo, hoc non facere, vt hu­mor aliùs attollatur, cùm maneat &longs;en&longs;ibiliter eadem inæqualis pre&longs;&longs;ionis proportio; &longs;ive aër compre&longs;&longs;ior, &longs;ive minùs compre&longs;&longs;us &longs;it; &longs;ed hoc jam &longs;upra indica&longs;ti, Antime; Non nego tamen compre&longs;&longs;ioris aëris alios ef­fectus e&longs;&longs;e po&longs;&longs;e; &longs;ed in hoc ca&longs;u novus effectus non e&longs;t; hæc porrò re­&longs;pon&longs;io in primum illud, quod &longs;upra expo&longs;ui, optimè quadrat, vt patet: antequam autem ad tuas guttulas & bullas orationem convertas, &longs;cire ve­lim, cur humor aliquando a&longs;&longs;urgat per canaliculum veloci&longs;&longs;imo motu, ali­quando verò tardiùs; præ&longs;ertim &longs;i canaliculus inclinetur, quod aliquando memini, à me probatum fui&longs;&longs;e.

Antim. Citò a&longs;&longs;urgit, quando humefacta &longs;uperficie cava canali­culi, nullas &longs;alebras, nulla impedimenta humor invenit; vbi tamen in dictas a&longs;peritates a&longs;&longs;urgens humor incurrit, tardiùs haud dubiè progredi­tur; cujus rei clari&longs;&longs;imam analogiam habes in aqua per &longs;iccum alveum currente, cujus cur&longs;us ab inæquali alvei &longs;uperficie &longs;i&longs;titur & impedi­tur, ac proinde lentiùs fluit; ideò porrò per inclinatum alveum prædi­cta motus tarditas ob&longs;ervatur, quia &longs;cilicet ex parte, in dictam vitri &longs;uperficiem incumbit, ac proinde in prædictas &longs;alebras magis incur­rit; &longs;ed jam ad guttas & bullas venio, & ante omnia, quæro ex te, Augu&longs;tine, vnde illam Figuram Sphæricam habeat gutta, præ&longs;ertim &longs;i pau­lò minor e&longs;t.

Augu&longs;t. Varij varia de hoc argumento, quæ quia merè commenti­tia e&longs;&longs;e puto, & fictitia, ad &longs;alvandum hoc experimentum vltro præter­mitto, præ&longs;ertim cùm ex iis, quæ huc v&longs;que à te dicta &longs;unt, veram hu­jus rei cau&longs;am, germanamque rationem conjiciam; nempe cùm ab aë­re compre&longs;&longs;o æquali ni&longs;u tota guttæ &longs;uperficies prematur, quid mi­rum &longs;i inde Sphæriea Figura inducatur. Vix obnitente, &longs;eu reluctan-te humoris gravitate, qui cùm in puncto contactus qua&longs;i &longs;u&longs;tinea­tur, & partes inter &longs;e aliquam tenacitatem habeant, & premens aër vndequaque premat, ac proinde ab ima parte qua&longs;i &longs;u&longs;tineat latera­les humoris partes, hæ minimè &longs;ub&longs;idunt; hinc vbi major e&longs;t humoris quantitas, &longs;ub&longs;idit humor, & gutta deprimitur, prævalente &longs;cilicet humo­ris pondere.

Antim. Rectè omninò mentem meam & &longs;en&longs;um a&longs;&longs;equeris; hinc multa experimenta omnibus obvia ad idem principium reduco. Primò, vbi vna gutta in aliam incidit, duæ in vnam eandemque abeunt; nem­pe in eo contactus puncto, in quo vna tangit aliam, ab externo aëre non premitur, &longs;ed in aliis omnibus; hinc cedit humor in eo puncto, atque adeò vna intra aliam intruditur. Secundò, Gutta pendula hæret aliquan­do vel in &longs;uperficie ligni, quæ deor&longs;um vergit, vel extremo na&longs;o; vnde hoc? quia premit aër ab omni parte, ea dumtaxat excepta, quæ ligno vel na&longs;o adhæret; ea autem vis e&longs;t pre&longs;&longs;ionis, quæ guttam hærentem &longs;u­&longs;tineat; &longs;i autem &longs;cire velis, quanta &longs;it hæc gutta, illico reponam, æqua­lem e&longs;&longs;e humoris portioni, quæ per canaliculum attollitur, vt &longs;æpè pro­bavi. Tertiò, Si partem inferiorem guttæ pendulæ, vel minima fe&longs;tu­ca tangas, &longs;tatim effluit per admotam fe&longs;tucam; quia in eo puncto, in quo fe&longs;tuca guttæ admovetur, aër non premit, quia non tangit; aliæ igitur partes prementes prævalent; igitur accedente præ&longs;ertim gravita­te, &longs;eu pondere guttæ pendulæ, gutta decidit. Quartò, Si verò tangas in &longs;uperiore portione laterali, & lentè fe&longs;tucam adducas, gutta &longs;equitur, non quòd vlla vis tractrix in&longs;it, quæ in hoc præ&longs;ertim ca&longs;u fictitia e&longs;t, &longs;ed quia partem illam aër non premit, &longs;ed oppo&longs;itam, illa cedit huic præ­valenti; vnde &longs;i fe&longs;tuca reducitur, vi pre&longs;&longs;ionis, in prædicta parte oppo&longs;i­ta, guttam &longs;equi nece&longs;&longs;e e&longs;t. Quintò, Guttæ humoris, plano in &longs;itu ver­ticali &longs;ito etiam adhærent, propter eandem rationem, quam non re­peto. Sextò, In guttis Mercurij id di&longs;criminis e&longs;t, quod paulò majores non adhæreant, propter majus pondus, &longs;ecus minores, pro quo e&longs;t eadem ratio, i&longs;tæ autem perfectiùs tornantur; quia Mercurius tenacior e&longs;t & cra&longs;­&longs;ior; accedit, quòd in planorum Strias & Salebras non &longs;ubit, vt aqua; igi­tur faciliùs &longs;e&longs;e &longs;u&longs;tinet.

Chry&longs;ocom. De bullis vel ampullis, idem facilè dixero; quæ &longs;ic tornan­tur ab aëre pre&longs;&longs;o tum interiore, tum exteriore: fe&longs;tucam etiam admotam ac deinde reductam &longs;equitur bulla, propter eandem rationem: in hoc certè nullam video difficultatem; &longs;ed perge quæ&longs;o, Antime, ac recen&longs;e alia expe­rimenta, quæ haud dubiè ob&longs;erva&longs;ti.

Antim. Hoc facere meditantem interpella&longs;ti. Septimò, Igitur vbi pup­pus vel extremam linguam papillæ mammæ affigit, lac &longs;tatim effluit; quia &longs;cilicet aër vndequaque mammæ &longs;uperficiem premit, excepta illa par­te extrema, cui lingua puppuli adhæret ; quid mirum igitur &longs;i lac exprima­tur? Octavò, Ni&longs;i extra chorum &longs;altare timerem, huc etiam adducerem co­nicam flammæ Figuram, ad quam inducendam aëris pre&longs;&longs;io non parum confert; cùm enim ab halitu igneo &longs;ur&longs;um extru&longs;o aër valde rare&longs;cat, & di&longs;pergatur, ab ea parte non premit, &longs;ed ab omni alia, vnde Figuram conicam &longs;equi nece&longs;&longs;e e&longs;t; &longs;ed hoc argumentum alterius loci e&longs;t; in libro &longs;ingulari de igne rem hanc fusè pro&longs;ecutus &longs;um. Nonò, Arborum trun­ci & rami, immò & pili, o&longs;&longs;a, nervi, & multa alia Figuram Cylindricam habent, cùm enim initio molliora e&longs;&longs;ent, ab aëre premente tornata fuerunt. Decimò, Si linguam vulneri admoveas, dum recens e&longs;t, illico &longs;anguis effluit, ob aëris &longs;cilicet pre&longs;&longs;ionem in circumpo&longs;itam car­nem. Omitto alia ferè innumera, quæ ex dictis facilè & nullo negotio intel­ligetis.

Augu&longs;tin. Vna difficultas re&longs;tat, eaque maxima: nempe intelligo, hu­morem etiam per canaliculum a&longs;&longs;urgere intra vas, in quo aër maximè di­latatus e&longs;t; vnde manife&longs;tè colligi videtur, non attolli propter aëris com­pre&longs;&longs;ionem.

Antim. Non nego, difficilè argumentum e&longs;&longs;e; &longs;ed quia connexum e&longs;t cum illo celebri experimento &longs;u&longs;pen&longs;i in fi&longs;tula vitrea Mercurij, vel alio recipientis vitrei, in quo aër vi emboli adducti dilatatur, quæ paulò po&longs;t di&longs;cutiemus, rem illam eò remitto; antequam porrò de præfato experi­mento agam, vnum profectò non omittam, quod viro ingenio&longs;i&longs;&longs;imo meique amici&longs;&longs;imo aliquando in mentem venit, &longs;cilicet ab ea vi humo­rem per canaliculum attolli, quàm vulgò electricam vocant, quod tamen, meo judicio, dici non pote&longs;t; cùm diver&longs;i&longs;&longs;ima &longs;int vtriu&longs;que motio­nis principia; nempe vis electrica in eo po&longs;ita e&longs;t, quod Vi&longs;cidorum fi­laminum ten&longs;orum priùs ac deinde reductorum vi, facilè mobilia &longs;imul adducantur, affiganturque &longs;uccino, ex quo prædicta filamina effluvio quo­dam perenni erumpunt; quid porrò hæc ad elevationem humoris per ca­naliculum?

Augu&longs;tin. Inaudij aliquid de hoc argumento à te fui&longs;&longs;e excogitatum, &longs;ed majori &longs;altem ex parte mihi excidit; quare rem mihi grati&longs;&longs;imam facies, &longs;i obiter &longs;altem explanes, neque hoc Parergum Chry&longs;ocomo di&longs;plicebit; im­mò inde meliùs con&longs;tabit eorum veritas, quæ huc v&longs;que de humoris per ca­naliculum elevatione nobis expo&longs;ui&longs;ti.

Antim. Per me licèt, Augu&longs;tine, &longs;ed obiter; &longs;uccinum igitur po&longs;t modicum affrictum in modica di&longs;tantia, trahit, & ad &longs;e adducit corpo­ra facilè mobilia, eaque omnis generis, excepta dumtaxat flamma, alii&longs;­que accen&longs;is, vt prunis, ferro candente, idque in omni &longs;itu, &longs;ur&longs;um, deor­&longs;um, dextror&longs;um, &longs;ini&longs;tror&longs;um, modò nihil pror&longs;us interponatur; &longs;i enim vel tenui&longs;&longs;imum chartæ folium interponatur, nihil trahit, præ­ter ip&longs;um folium; trahit autem corpora facilè mobilia omnis generis, vt dixi, & in omni corporis &longs;tatu; duro &longs;cilicet, liquido, &longs;pirabili; &longs;ic fumum trahit agitque in diver&longs;os vortices &longs;eu turbines, pulverem, aquam, oleum, &c. Videres enim guttam aquæ vel olei, cui &longs;uc­cinum admovetur extendere &longs;e&longs;e atque attolli; Videres innumera pul­veris grana tripudio quodam &longs;alientia, Atomos intra Solis ra­dium, conclavi probè clau&longs;o fluitantes, admoto &longs;uccino turmatim accurrere, fumum in mille, ductum filamina hinc & illinc &longs;uccino advolvi, acum magneticam libratam in orbem agi pernici&longs;&longs;ime; libræ lancem in perfecto æquilibrio &longs;tatutam, vel attolli, &longs;i &longs;ur&longs;um &longs;uccinum applicetur, vel deprimi, &longs;i deor&longs;um, dixi, po&longs;t affrictum &longs;uccini; quia ta­men ad diver&longs;i corporis &longs;uperficiem prædictus affrictus fieri pote&longs;t, ob­&longs;ervavi etiam, diver&longs;os inde effectus &longs;equi; nempe &longs;i affrictus fiat ad pannum omnis generis, &longs;ed præ&longs;ertim ad coactilem, tunc &longs;uccinum ma­ximè trahit; ad telam etiam, &longs;ed minus, item ad cutem, chirothecam, corium, modo pinguius non &longs;it, chartam, olo&longs;ericum, barbam, capillos, ad o&longs;&longs;a, metalla, cornu, ceram, ligna, te&longs;tam, vitrum, vel nihil, vel pa­rum admodum: item &longs;i affrictus fiat ad cutem, humore, melle, bal&longs;a­mo, atramento, adipe ferè omnis generis, therebinthina, &longs;ucco mali au­rei, &longs;apone, aquis di&longs;tillatis ferè omnis generis, dilutam &longs;eu perfu&longs;am, itemque &longs;i pulvere a&longs;per&longs;o affrictus fiat; &longs;ecus tamen &longs;i butyro, &longs;uillo adipe, oleo fere omnis generis; tunc enim &longs;altem parum trahit, ni&longs;i &longs;al oleo admixtum &longs;it, quod mihi ante aliquot annos indicavit vir acuti&longs;&longs;imi ingenij meique amanti&longs;&longs;imus Laurentius Magalottus. Accedit, quod non &longs;uccinum modò, vt vulgò dicitur, vi electrica pollet, &longs;ed alia multa corpora, vt Lacca, quàm vulgò ceram Hi&longs;panicam vocant, gagates, concretum &longs;cilicet bituminis genus, adamas, multique lapilli; non ta­men vnio; cry&longs;tallus & multa alia, nullum tamen ligni genus, te&longs;tæ, me­talli, carnis &c. Illud vnum ob&longs;ervo, corpus omne electrica virtute pol­lens e&longs;&longs;e vitrificum, vt &longs;ic loquar, id e&longs;t, quod ad in&longs;tar vitri malleo frangi &longs;eu teri, non verò duci, aut findi, aut friari po&longs;&longs;it.

Augu&longs;tin. Tam multa, tam varia in vnum conge&longs;&longs;i&longs;ti experimenta, re­ticitis tamen rationibus, vt mentem potiùs obrueris, quàm refeceris, aut recrearis; &longs;ingula quæ&longs;o te repetamus & reducamus ad certa principia, vt inde veritas phy&longs;ica eluce&longs;cat, itaque ante omnia, edi&longs;cere nobis tuam hypothe&longs;im.

Antim. In vno tantùm corpore electrico hypothe&longs;im meam &longs;tatuo, cùm &longs;cilicet pro aliis omnibus eadem ratio militet; accipio igitur Laccam &longs;eu ceram hi&longs;panicam, tum quia magis obvia e&longs;t, tum quia vi electrica maximè pollet; illamque adhibui ad omnia ferè experimenta, con&longs;tat multo igne; quippe accenditur; & multa vligine, quia ducitur &longs;eu ne­tur in filamina vi&longs;cofa; ignis autem qui ine&longs;t, perenni actione in partes vicinas agit, quas haud dubiè rarefacit, ac proinde intra pororum an­gu&longs;tias contractæ inde nituntur erumpere, qua data porta; pori enim ob­&longs;tructi &longs;unt; &longs;ublata autem huju&longs;modi ob&longs;tructione per affrictum, ma­teria intus compre&longs;&longs;a erumpit ad in&longs;tar &longs;ulphurei jaculi; & quia vi&longs;co&longs;a e&longs;t, netur in filamen tenui&longs;&longs;imum, quod præ impetu, quo erumpit, cum intus altera ejus extremitas, propter vi&longs;co&longs;itatem aliis partibus eju&longs;dem materiæ adhæreat; maximè tenditur; at &longs;tatim ce&longs;&longs;ante impetu, redu­citur vt chorda ten&longs;a, & &longs;ecum a&longs;portat corpu&longs;cula facilè mobilia, quæ occurrunt.

Chry&longs;oc. Hoc fortè gratis dicitur; quis enim filamina illa vnquam vi­dit, aut &longs;en&longs;it? quis alia multa his &longs;imilia non fingat?

Antim. Perennia corporum effluvia agno&longs;cimus omnes, quod ex odo­re, &longs;itu, &longs;iccitate ac re&longs;olutione corporum facilè probamus; accedit, quod partes ignis, eá&longs;que multas ine&longs;&longs;e con&longs;tat, quæ vi activa eaque ne­ce&longs;&longs;aria pollent; multùm item materiæ rectè di&longs;po&longs;itæ, in quam ignis agat, vligino&longs;æ &longs;cilicet & pinguis; quidni ergo effectus nece&longs;&longs;arius ex cau&longs;a nece&longs;&longs;aria? Calor &longs;cilicet & rarefactio eju&longs;dem materiæ; &longs;ed cum intra pororum angu&longs;tias comprimatur, pori enim, majore &longs;cilicet ex par­te ob&longs;tructi &longs;unt; vbi deinde affrictu, pori os ab&longs;tergitur, inde erumpit cum impetu, & cùm materia vi&longs;co&longs;a &longs;it, ducitur in filum, cujus altera ex­tremitas intra porum hæret.

Chry&longs;oc. Sed quid tandem poros ob&longs;truit? deinde vnicus affrictus &longs;uf­ficeret, cùm tamen aliquo po&longs;t affrictum tempore fortè non trahat.

Antim. Ille halitus vligino&longs;us, &longs;ic enim vocare liceat, ductus in fila­men, eo ferè modo, quo fumus; netur in fila; &longs;i enim candelam recèns extinctam a&longs;picias, &longs;itam inter oculum & Solem, vel luculentam flam­mam, incredibilem prorsùs tenui&longs;&longs;imorum filaminum vim miraberis; quia verò &longs;tatim concre&longs;cit externo frigore, ad o&longs;tium pori omnino riget, inde manife&longs;ta ob&longs;tructionis cau&longs;a, concretum &longs;cilicet ad pori os filamen.

Chry&longs;ocom. Inaudij &longs;emper, affrictum illum fieri, vt inde calor produ­catur, quem nece&longs;&longs;arium e&longs;&longs;e, dicunt, ad virtutem illam electricam exci­tandam.

Antim. Scio pro&longs;ectò, hæc vulgò dici ac doceri; non tamen res ita &longs;e­habet; Lacca enim, &longs;i nimium incale&longs;cat, nihil trahit, deinde &longs;i po&longs;t af­frictum; Laccam vel &longs;uccinum in aliqua di&longs;tantia flammæ admoveas, ac deinde ad ea corpu&longs;cula, quæ alioquin facilè trahuntur, applices, nihil prorsùs trahit, vt millies &longs;altem probavi; calor igitur vim electricam non excitat, &longs;ed potiùs impedit; equidem &longs;i denuò Laccam panno affrices, corpu&longs;cula, vt ante, illico trahit, ea porrò di&longs;tantia flammæ, vel primis lacca admovetur, qua, vt modicum &longs;altem trahat, corpu&longs;culis admo­vetur.

Chry&longs;ocom. Non video, quid flamma ad id conferat, vt tractionem im­pediat.

Augu&longs;tin. Id tamen video; licèt tu ip&longs;e longè oculatior &longs;is; nempe fi­lamina illa vligino&longs;a &longs;unt, ac proinde ignem &longs;tatim concipiunt, abeuntque in auras; &longs;ublata igitur cau&longs;a tractionis, filaminum &longs;cilicet ten&longs;ione & adductione ce&longs;&longs;at tractio ; immo licèt jam corpu&longs;culum &longs;uccino adhæ­reat, v. g. fru&longs;tum chartæ, &longs;i ju&longs;ta di&longs;tantia flammæ admovetur, eo ip&longs;o à &longs;uccino avellitur, ac deor&longs;um proprio pondere cadit; quia &longs;cilicet funicu­los illos con&longs;umit ignis, quibus affixum tenebatur.

Antim. Nihil addi pote&longs;t, adeòque i&longs;ta difficultas penitus exhau&longs;ta e&longs;t; con&longs;tat igitur non ideò affrictu opus e&longs;&longs;e, ad excitandum calorem, &longs;ed ad &longs;uperficiem ab&longs;tergendam, & purganda pororum o&longs;tiola, vt &longs;cilicet nova filamina ex iis erumpant; non negarim tamen, affrictu illo aliquid etiam caloris produci, & colligi ignis partes; calor enim congregat homoge-nea, calidi &longs;cilicet; &longs;ic affrictu manus incale&longs;cit; calor porrò auctus vbe­rioris effluvij cau&longs;a e&longs;t; perfectam, ni fallor, hujus rei analogiam habe­mus in corporibus odoratis, præ&longs;ertim durioribus; certum enim e&longs;t, odorem diffundi in halitu odorifero; affrictu autem eorundem corpo­rum major vis prædicti halitus educitur: primarius tamen affrictus finis in electricis alio &longs;pectat, &longs;cilicet ad pororum o&longs;tia expurganda: hinc pan­no potiùs, quàm tela, aut &longs;erico, prædictus finis obtinetur; quia pannus laneus a&longs;perior e&longs;t: ad id porrò quod dicebas, à nemine vnquam præ­dicta filamina vi&longs;a fui&longs;&longs;e, vt cum tua bona venia dicam, futile e&longs;t; quis enim pariter halitum odoratum vidit? aut contagio&longs;um? eumque, in quem &longs;in­gulis diebus aliqua no&longs;tri corporis pars avolat? proba &longs;is, in&longs;igni aliquo micro&longs;copio; quod ad me &longs;pectat, nonnihil videre, auribu&longs;que percipere mihi videor. Videre quidem, adhibitis divinianis micro&longs;copiis, quæ iure omnibus huc v&longs;que fabricatis anteponenda e&longs;&longs;e duxerim; audire verò admota auribus tenui&longs;&longs;ima lamina, quæ &longs;onora vi maximè polleat, cui &longs;tatim po&longs;t affrictum &longs;uccinum applicatur; minimum enim & acuti&longs;&longs;imum tinnitum audite mihi videor, qui edi non pote&longs;t, ni&longs;i à prædictorum fila­minum appul&longs;u; neutrum tamen pro certo vendito: neque id nece&longs;&longs;e e&longs;t, cùm aliundè con&longs;tet; nec enim prædicta corpu&longs;cula propria vi, &longs;eu vir­tute a&longs;cendunt; v.g. pulvis gravi&longs;&longs;imus; aliunde igitur moventur; non ab aëre; quid enim ad hoc affrictus iuvaret? quid noceret flamma? cur alia corpora ad eundem finem æquè idonea non e&longs;&longs;ent, ac electrica? à &longs;uc­cino igitur adducuntur; qua vi amabo? tractrice, inquies; cur ergo af­frictu opus? cur obe&longs;t flamma? cur major Laccæ aut &longs;uccini fru&longs;tum majus pondus non attollit? deinde &longs;uccinum vertibile accedit ad quod­libet corpus, ni&longs;i ignitum &longs;it; &longs;i ad vnum tantùm, vt magnes ad ferrum, & vici&longs;&longs;im, e&longs;&longs;et aliqua analogia, &longs;ed quod ad omnia; nativa vi ab intrin­&longs;eco, non dictu modò, &longs;ed cogitatu ridiculum e&longs;t: Itaque, cùm jam aliunde, & ex communibus principiis habeam, præ&longs;atum filaminum efflu­vium; & cum iis adductis, illi omnes motus explicari facilè po&longs;&longs;int, ad­duci verò nece&longs;&longs;e &longs;it, &longs;i priùs tendantur, tendi autem oporteat, &longs;i cum im­petu ex poro erumpant; itemque cum impetu erumpere, &longs;i priùs materia vligino&longs;a & vi&longs;co&longs;a vi partium ignis rarefacta; ob&longs;tructis poris avolare prohibita, compre&longs;&longs;a intus retineatur, ac demum erumpant prædicta fila­mina, &longs;i affrictu, obex tollatur: fru&longs;tra oculorum, quorum aciem fu­giunt, te&longs;timonium quæritur; nec ea propter meritò dici pote&longs;t, hæc à me gratis ad&longs;trui; accedit, quòd multæ ob&longs;ervationes hæc filamina pror­&longs;us evincunt. Primò, &longs;i po&longs;t affrictum, &longs;uccinum pulveri admoveatur, quo­quover&longs;um di&longs;pergitur pulvis, adducitur que. Secundò, fru&longs;tula chartæ, quibus admovetur, eodem modo di&longs;perguntur. Tertiò, vbi ad ducuntur illa in diver&longs;os gyros & &longs;piras eunt, &longs;itumque mutant, & modo hinc, mo­dò illinc trahuntur. Quartò, Nonnunquam a&longs;&longs;urgunt ex plano, in quo ja­cebant, & &longs;ic erecta manent, licèt &longs;uccinum non tangant. Quintò, Vnum alteri catenatim adhæret, quod non fit alio corpore admoto. Sextò, vidi aliquando, idque non &longs;emel, fru&longs;tum chartæ citra contactum, è &longs;uccino pendulum; dici tamen po&longs;&longs;et adhæ&longs;i&longs;&longs;e &longs;uccino per aliquod in&longs;en&longs;ibile chartæ filamentum. Septimò. Vbi fru&longs;tra illa levi digito moveo, Sen&longs;io re­&longs;i&longs;tentiam omnino illi &longs;imilem, quam &longs;entirem, &longs;i tenui&longs;&longs;imo reticulo impli­cata e&longs;&longs;et; immo po&longs;tquam loco &longs;uo mota &longs;unt, in eandem non recipiunt &longs;e&longs;e, &longs;ed huc illuc, ab aliis filaminibus abripiuntur. Octavo. Quando po&longs;t af­frictum, fru&longs;tum adducitur, qua&longs;i tripudio quodam huc illuc agitur; vix hæc aliaque multa &longs;imilia &longs;ine prædictis filaminibus explicari po&longs;&longs;unt, immo nec intelligi.

Augu&longs;tin. Perge quæ&longs;o, & alia nobis expone, quæ ad rem hanc per­tinent.

Antim. Per me licet; Nono, igitur &longs;i po&longs;t affrictum, &longs;uccinum &longs;uccu­tias, eoque tundas aliud corpus, non trahit, vel longè minùs; quia prædicta filamina &longs;uccu&longs;&longs;u illo di&longs;&longs;ipantur. Decimò. Item &longs;i valido anhelitu &longs;uccinum perfles, etiam po&longs;t affrictum; quia &longs;ic eadem filamina difflantur. Vndecimò. Idem accidit, &longs;i Aquiloni. Vel Au&longs;tro vehementi, po&longs;t affrictum, exponas. Duodecimò. Item &longs;i po&longs;t affrictum &longs;uccinum, vel humido immergas, vel humore perfundas; nempe illa filamina humor diluit; hinc ad ten&longs;ionem inepta: Analogiam habes in membrana tympani. Decimo-tertiò. Po&longs;tquam traxit, &longs;ibique affixit pulverem &longs;uccinum, licèt illud admoveas fru&longs;tulis chartæ, illa vix trahit; ab&longs;ter&longs;o tamen pulvere, citra novum affrictum, char­tulas trahit; quia filamina circa pulverem occupata, aliud quidqiam non trahunt; ab&longs;ter&longs;o tamen pulvere, fractis &longs;cilicet vinculis, nova erumpunt, quæ prædictum præ&longs;tant effectum, ad quem præ&longs;ertim præfata ab&longs;ter&longs;io plurimum confert. Pari modo, po&longs;tquàm traxit aliquot fru&longs;ta chartæ, vix pulverem trahit, propter eandem rationem. Decimo - quartò. Si po&longs;t a&longs;tri­ctum, &longs;uccinum immergas Oleo, non ob&longs;tat, quo minùs trahat, quia Oleum prædicta filamina vligino&longs;a non diluit. Decimo - quintò. Sicuti humorem affundas, & in ea &longs;uccinum frices, po&longs;t affrictum nihil trahit, quia affu&longs;us humor filamina diluit, & ten&longs;ionem impedit; idem dico de aquis di&longs;tillatis, vino, oxymo, aceto, &longs;ucco mali aurei, propter eandem rationem; idem de &longs;apone adipe, melle, bal&longs;amo, therebinthjna propter nimiam tenacitatem, quæ filamina impedit. Decimo - &longs;extò. Si perfundatur cutis oleo, po&longs;t af­frictum in ea &longs;uccini, &longs;equitur tractio ; quia vt jam dixi &longs;upra, Oleum non ob&longs;tat, ni&longs;i &longs;al Oleo admi&longs;ceatur, quia &longs;cilicet poros &longs;uccini ob&longs;truit; idem de butyro, & &longs;uillo adipe recente, propter eandem rationem. Decimò - &longs;e­ptimò. Si pulverem cuti a&longs;pergas, ac deinde frices, nihil trahit; quia pulve­ris admoti mordacitas, vel a&longs;peritas filamina &longs;ecat. Decimo - octavò. Si affri­ctus fiat in capillis, & tenera barba, tractioni non obe&longs;t; quia e&longs;t ad in&longs;tar la­næ. Ex his, ni fallor, reliqua facilè intelligetis; quare illa omitto, ne prolixior &longs;im.

Chry&longs;ocomus. Experimentorum, quæ Primò loco ad duxi&longs;ti, rationem & cau&longs;am afferre omi&longs;i&longs;ti, &longs;upple illam quæ&longs;o.

Augu&longs;tin. Non omi&longs;it, &longs;ed eam &longs;uppo&longs;uit, cùm facile ex dictis elici po&longs;­&longs;it, nam primo di&longs;perguntur grana pulveris huc illuc; quia diver&longs;a filami­na huc illuc erumpunt, & vbi reducuntur multa grana male implicata pro-prio pondere cadunt. Secundò fru&longs;ta chartæ à diver&longs;is filaminibus appul&longs;is, nece&longs;&longs;ariò agitantur, di&longs;perguntùrque, & in multos gyros & &longs;piras agun­tur, à diver&longs;is &longs;cilicet filaminibus adducta; eunt autem filamina &longs;ecundùm lineam pororum. Tertiò, quod nonnunquam a&longs;&longs;urgant citra tactum, ideò fit, quia in ea di&longs;tantia, pauciora filamina eò appul&longs;a non &longs;ufficiunt, ad tantum pondus attollendum. Quartò Corpus interceptum etiam tenui&longs;&longs;imum fila­mina &longs;i&longs;tit, ideò tractionem impedit. Vnum tamen fru&longs;tum chartæ alteri applicatum adhæret, propter filamina lateralia. Quintò. Tripudium illud fru&longs;tri chartæ adducti diver&longs;is filaminibus, per diver&longs;as lineas trahentibus, tribuendum e&longs;t: Vides, quàm facilè rationes de&longs;ideratæ deducantur; reli­quis experimentis &longs;ubjectæ fuerunt. Vnum fortè dee&longs;t, cur &longs;cilicet affrictus in quibu&longs;dam corporibus factus tractionem, vel omnino, vel ex majore parte impediat; quod tamen dictu facile e&longs;t; quia &longs;cilicet, quorumdam affri­ctu, nec excitatur calor, nec pori ob&longs;tructi ab&longs;terguntur; &longs;ic ad ter&longs;ionem charta inepta e&longs;t; tela aptior; pannus verò apti&longs;&longs;imus, præ&longs;ertim, &longs;i quid ca­loris excitandum e&longs;t: omitto vortices illos adducti fumi; con&longs;tat enim ex fi­laminibus, quæ cum aliis filaminibus agglomerantur; hic enim e&longs;t diver&longs;æ tractionis effectus; &longs;ed vnde e&longs;t? mi Antime, cinericius ille color fumi &longs;ucci­no advoluti.

Antim. Puta fuliginem qua&longs;i &longs;ublimatam, vt &longs;ic loquar, &longs;eu flo­rem quemdam fuliginis, aut fumi, in &longs;uperficie &longs;uccini concre&longs;­centem; corporum autem &longs;ublimatorum & calcinatorum color, vt ­plurimum ad album accedit, &longs;ed de coloribus hîc di&longs;putandi locus non e&longs;t.

Chry&longs;ocom. An fortè hic effectus in vacui metum referri po­te&longs;t?

Antim. Non de&longs;unt profectò, qui præ&longs;atam tractionem in Vacui me­tum reducant, &longs;ed meo judicio, perperam; quis enim amabò, & vnde hic vacui metus? dato enim prædicto effluvio, minùs loci e&longs;t, quàm opor­teat, non plus; prætereà cur aër potiùs non accurrit, vel adducitur ad fu­gam Vacui, quàm charta, vel alia corpora, quæ longè difficiliùs moven­tur quàm aër? denique e&longs;to, vacui metu vnum corpus alteri adhæreat, ac proinde hoc &longs;ine illo moveri non po&longs;&longs;it, nullum tamen à &longs;e ip&longs;o ob vacui me­tum movetur, vt luculentis experimentis o&longs;tendi à me po&longs;&longs;et, hinc etiam illo­rum &longs;ententiam rejicio, qui volunt effluvium illud in capillitium quoddam concre&longs;cere, cui fe&longs;tucæ, aliaque corpu&longs;cula facilè deinde adhæreant; quidam recentior hanc &longs;ententiam typis mandavit, &longs;ed multis ante annis, &longs;cilicet ann. 1646, in Philo&longs;ophia per propo&longs;itiones dige&longs;ta, hanc ip&longs;am, quam vo­bis expo&longs;ui, jam edideram; vnde me ab illo non accepi&longs;&longs;e per&longs;picuum fit, quanquam citra eruptionem illam, ten&longs;ionem & reductionem filaminum, &longs;i vnum vel alterum experimentum demas nullum ex reliquis explicari pote&longs;t, adhibito etiam præ&longs;ato capillitio, vt con&longs;ideranti patebit; quare vltra refutare illam &longs;ententiam operæ pretium non e&longs;t.

Chry&longs;ocom. Scite averem, vtrùm &longs;upponas tua illa filamina rumpi præ nimia ten&longs;ione & impetu.

Antim. Non negaverim, frangi aliqua; quod tamen non ob&longs;tat; cùm alterum &longs;egmentum, cujus altera extremitas poro &longs;uccini adhæret, redu­catur po&longs;t fractionem; opus tamen non e&longs;t, vt rumpantur; cùm ad præfa­tos effectus explicandos &longs;atis &longs;it filamen, ten&longs;um priùs, deinde cum im­petu &longs;uccinum versùs reduci, vt fieri videmus in chordis ten&longs;is: habetis igitur &longs;implicem iuxta atque facilem modum à me aliàs excogitatum, explicandæ virtutis electricæ; nec effluvium illud gratis, vt dicebas, à me fingitur, quod &longs;cilicet tam multa & varia experimenta evincunt; quod­que (ita &longs;altem mihi videtur) vi&longs;u & auditu percipi pote&longs;t; dicerem etiam tactu, ni&longs;i vobis ri&longs;um movere timerem; nam præter illam re&longs;i&longs;tentiam, quam digitus &longs;entit, dum fe&longs;tucam affixam removere lentè conatur, &longs;i po&longs;t affrictum &longs;uccinum validum & probè lævigatum proximè admoveam extremæ linguæ, vel oculis, vel parti cuipiam læ&longs;æ, quæ vel levi&longs;&longs;imum tactum ferre nequeat, aliquem appul&longs;um &longs;entire mihi videor; probate &longs;ulcis, &longs;ed de his fortè prolixiùs, quam par e&longs;&longs;et; jam ad Mercurij elevatio­nem veniendum e&longs;t.

Augu&longs;tin. Per vos mihi liceat vnum proferre; quod diu in mente volvo; &longs;cilicet, aëra mihi videri æquè compre&longs;&longs;um in quolibet tractu, &longs;ive ille &longs;uperior, &longs;ive inferior &longs;it: demus enim infimum pre&longs;&longs;iorem e&longs;&longs;e, vtpote cui totum pondus &longs;uperioris incumbat, quod &longs;upra innui&longs;&longs;e vi&longs;us es, Antime; igitur aër compre&longs;&longs;us intra vas, inde non erumpit, licèt vas ape­riatur: aut certè adversùs alium aëra erumpit, eique &longs;e&longs;e admi&longs;cet, & pre&longs;&longs;ionem æquè dividit; dico igitur, infimum aëris tractum equidem ma­gis comprimi, majoris ponderis vi gravitantis ; &longs;ed ita contraniti, vt tra­ctum &longs;uperiorem continuum comprimat; atque adeò communis & æqua­lis &longs;it vtriu&longs;que compre&longs;&longs;io; nempe aër in aëre compre&longs;&longs;us &longs;e&longs;e dilatat, do­nec æqualis vtrimque &longs;it compre&longs;&longs;io; & hoc, ni fallor, longè faciliùs &longs;ol­vit argumentum illud &longs;upra adductum, petitumque ab intolerabili com­pre&longs;&longs;ione, quæ ex tanta ponderis, aëris &longs;cilicet, gravitantis vi &longs;equeretur; itemque illud ex eo ductum, quod in vertice alti&longs;&longs;imi montis aqua per canaliculum minùs altè a&longs;&longs;urgeret, itemque tempore fluxus; nam vt dicam quod res e&longs;t, illæ tuæ re&longs;pon&longs;iones, licèt di&longs;&longs;imularim, mihi plenè non fe­cerunt &longs;atis.

Antim. Fateor tuam illam longè faciliorem e&longs;&longs;e, cui etiam vltro &longs;ub­&longs;cribo: neque illud, quod aliqui afferunt, de lanæ cumulo cujus pars in­ferior compre&longs;&longs;ior e&longs;t, quidquam negotij face&longs;&longs;it; nec enim lana propriè loquendo comprimitur; &longs;ed tantùm extruditur aër inter lanæ filamina contentus; neque hæc vera e&longs;t compre&longs;&longs;io, ea &longs;cilicet, ex qua tantam vim motus &longs;equi videmus: &longs;ed tandem ad Mercurij fi&longs;tulam venio.

Pulcherrimum fortè ac celeberrimum experimentum e&longs;t illorum omnium, quæ hoc currente &longs;æculo, &longs;ub mortalium venerunt ad&longs;pe­ctum: primus illius inventor fuit docti&longs;&longs;imus Torricellus, vir certè, quem inter principes hujus temporis Geometras iure annumero; qui cùm à Galilæo aliquando audii&longs;&longs;et, vel potiùs ab eo typis mandatum legi&longs;&longs;et, aquam attolli non po&longs;&longs;e in Siphone, &longs;upra altitudinem 18.cubi-torum vel pedum circiter 32. vt vir erat Totricellus profundi ratiocinij, illico prædixit, fore vt Mercurius attolli non po&longs;&longs;et &longs;upra altitudinem pedum 2 3/4 vel 1/3 circiter; quod cùm in fi&longs;tula vitrea proba&longs;&longs;et; provt præ­dixerat, &longs;ucce&longs;&longs;it eventus; in hunc porrò modum probavit; Sit vas ABG,

in quo &longs;it Mercurius EBF, &longs;it fi&longs;tula vitrea BCD probè clau&longs;a in D, apertain B, repleatur Mercurio, tum admoto pre&longs;&longs;è digito in B, immerga­tur extremitas B intra Mercurium, &longs;tatutaque fi&longs;tula in perpendiculari &longs;itu &longs;ubducatur digitus ex B, de&longs;cendit Mercurius, nullo aëre &longs;ubeunte, ita tamen, vt &longs;egmentam extantis Mercurij CI; &longs;ive longior &longs;it fi&longs;tula, &longs;ive brevior, &longs;it &longs;emper pedum 2. 1/4 circiter, &longs;ive tubus angu&longs;tior &longs;it, &longs;ive laxior.

Chry&longs;ocom. Huius experimenti primum inventorem & auctorem P. Va­lerianum Magnum fui&longs;&longs;e, accepi, immo hic, ni fallor, libellum de hoc ar­gumento in lucem edidit, in quo hoc idem atte&longs;tatur, quantum &longs;cilicet memini&longs;&longs;e po&longs;&longs;um.

Augu&longs;tin. Nihil profectò magis à veritate alienum; Torricellus haud dubiè, & citra omnem controver&longs;iam, primus inventor fuit; immo alij multi hoc idem argumentum ante Valerianum tractarunt; cujus ratio, & cau&longs;a phy&longs;ica vtinam æquè facilè & certo &longs;tatui à nobis po&longs;&longs;et, atque in­ventor; nempe res mihi difficillima e&longs;&longs;e videtur, &longs;tatuere, quid occupet &longs;e­gmentum illud fi&longs;tulæ CD, quod vacuum e&longs;&longs;e videtur; & qua vi alterum IC &longs;upra &longs;uperficiem EF, &longs;u&longs;tineatur; in his duobus enucleandis, tua de&longs;udabit, opinor, indu&longs;tria, Antime; vtinam, de quo valde dubito, fœliciter.

Antim. Tentabo &longs;altem, idque vnum operæ pretium erit, quod nec in mea, nec in alia cuju&longs;piam hypothe&longs;i, difficultatem, &longs;i quæ fortè in&longs;it, di&longs;­&longs;imulaturus &longs;im. Ab illa autem initium duco, quæ & Torricelli & mul­torum hodie num e&longs;t, in qua &longs;cilicet, præfatum experimentum in hunc modum explicatur: Cylindrus aëris gravitans &longs;u&longs;tinet, inquiunt, Mer­curium IC, eju&longs;dem &longs;cilicet cum illo ponderis; e&longs;tque perfectum inter vtrumque æquilibrium; &longs;egmentum verò fi&longs;tulæ CD omni corpore va­cuum remanet, hæc porrò hypothe&longs;is ex duplici præ&longs;ertim capite effi­caciter, vt aiunt ab a&longs;&longs;ertore probatur. Primò, ex eo quod quæcumque tan­dem &longs;it fi&longs;tulæ altitudo & latitudo, &longs;egmentum extans (&longs;ic appello IC) æqualis &longs;emper &longs;it altitudinis IC. 2. &longs;cilicet pedum, & 1/3 vel 1/4. Secundò, ex eo quod aquæ &longs;egmentum extans 32. &longs;cilicet pedum circiter eju&longs;dem &longs;it cum &longs;egmento Mercurij extante ponderis; e&longs;t enim fere gravitas Mercurij ad gravitatem aquæ vt 14. ad 1. vis ergo æqualis &longs;u&longs;tinet &longs;egmentum ex­tans Mercurij 2. pedum 1/3, & &longs;egmentum extans aquæ 32. pedum; &longs;ed illa vis alia e&longs;&longs;e nequit à cylindro aëris gravitante.

Augu&longs;tin. Accedit non leve adminiculum, ex eo quod à vitis accura­ti&longs;&longs;imis probatum fuit, in vertice alti&longs;&longs;imum montium &longs;egmentum ex­tans Mercurij e&longs;&longs;e minus IC ; quia &longs;cilicet cylindrus aëris gravitantis ac &longs;u&longs;tinentis prædictum &longs;egmentum extans, brevior e&longs;t; igitur minor illius vis & ni&longs;us. Qaod autem &longs;egmentum CD omnino vacuum &longs;it, vel ex eo con&longs;tat, quod inclinata fi&longs;tula in BK, a&longs;&longs;urgit Mercurius & totum &longs;e­gmentum CD occupat, non tamen videtur, quò abeat, aut &longs;e recipiat cor­pus illud, quod vacuitatem CD occupabat, &longs;i fortè aliquod e&longs;&longs;et; ex quo, ni fallor; nova confirmatio prioris partis ducitur; cum illa vis, quæ &longs;u&longs;ti­net &longs;egmentum Mercurij IC in perpendiculo; &longs;ufficiat ad &longs;u&longs;tinendum &longs;egmentum BK in plano inclinato, quod ex doctrina motuum facilè de­mon&longs;trarem, &longs;i res ita po&longs;tularet.

Antim. Non de&longs;unt etiam alia adminicula, de quibus infra; accedunt tamen gravi&longs;&longs;imæ difficultates; omitto leviores, ne in nugis vos deti­neam, & vt ab ea parte, quæ ad vacuum &longs;pectat, initium ducam, multa reverà, opponuntur, quæ dubito, an &longs;olvi po&longs;&longs;int. Primò, Qui&longs;quis ad&longs;truit huiu&longs;modi vacuum in &longs;egmento fi&longs;tulæ CD, de omni corpore quamvis alioquin tenui&longs;&longs;imo, negat, quod &longs;patium illud occupet; at &longs;i dixero, ibi e&longs;&longs;e vel tenuem materiam Carthe&longs;ij, vel æthera, vel &longs;ubtili&longs;&longs;imum humo­rem dilatatum, non dico certò, &longs;ed probabiliter tantùm, quo quæ&longs;o ar­gumento prædictum vacuum probare poterit? Secundò, Si vacuum e&longs;t, quomodo lumine perfunditur? Si enim lumen con&longs;i&longs;tit in effluvio quo­dam igneo; vel in motione cuju&longs;dam materiæ &longs;ubtili&longs;&longs;imæ, vt docent De­mocritici; cum vacuitatem illam &longs;ubeat, occupet, impleat, ibi certè va­cuum non e&longs;t; aut certè lumen e&longs;t meta qualitas per medium diffu&longs;a, vt docent ij, qui meliùs cen&longs;ent; atque ita cùm qualitas &longs;ine &longs;ubjecto e&longs;&longs;e non po&longs;&longs;it, eoque corporeo, &longs;egmentum CD vacuum non e&longs;t. Tertiò, Si vacuum e&longs;&longs;et, totus quantus aër & æther, qui terre&longs;tri globo vicinior e&longs;t, in dictum &longs;egmentum gravitaret ad &longs;tatuen dum æquilibrium.

Chry&longs;oc. Su&longs;tine, quæ&longs;o; dici enim pote&longs;t, æthera non e&longs;&longs;e gravem; aut certè &longs;i gravis &longs;it; incredibilem e&longs;&longs;e proportionem gravitatis aëris ad gravitatem ætheris, vtrum que de&longs;truit vim huius argumenti.

Augu&longs;tin. Immo &longs;unt, qui dicunt, atmo&longs;phæram tantùm gravitare, hoc e&longs;t aggregatum quoddam ex multiplici halitu, aqueo præ&longs;ertim, vel ex ratione texturæ ramorum & filaminum in communis ætheris, &longs;eu, vt vo­cant &longs;ubtilis materiæ medio natantium.

Antim. Fateor, multam vim halitus aëri admixtam e&longs;&longs;e; &longs;ed aqueus frigore conce&longs;&longs;it, terre&longs;tris verò partim de&longs;cendit, partim cum Atomis flui­tat in aëre, aëra autem voco illud, quod non e&longs;t vapor; hic enim totus li­que&longs;cit; vbi frigore den&longs;atur ; nec filaminum agglomeratorum cumulus, &longs;ed illud medium, in quo dicta filamina, &longs;eu filaminum ramenta, vel exuviæ fluitant & natant: fateor etiam, aëra multo humore foetum graviorem e&longs;­&longs;e, quod certè inficietur nemo: quòd autem cra&longs;&longs;iores nubes altiùs non at­tollantur, non probat, &longs;uperfu&longs;um aëra non gravitare, &longs;ed tantùm minùs gra­vitate; quod fateor vltro; æther ille ab aëre fortè non di&longs;tinguitur; aut &longs;i di&longs;tinguitur, incredibilis non e&longs;t illius gravitatis proportio ad gravitatem hujus; Vt vt &longs;it, juxta illa mea principia, quæ jam in &longs;uperioribus congre&longs;­&longs;ibus præmi&longs;i, hoc argumentum omnino inefficax non e&longs;t; &longs;ecernatur ta­men, vt vultis; ne cuiquam moveam litem; alia pro&longs;equor. Quartò, So­nus editur intra illud &longs;egmentum CD, appenditur enim filo tintinnabu­lum intra ampullam vitream, quæ ad extremitatem D facilè componitur; nec e&longs;t, quòd aliquis dicat, &longs;onum, &longs;eu tremulum motum traduci per filum in fi&longs;tulam; quia hoc fal&longs;um e&longs;&longs;e con&longs;tat, ex luculento experimento; &longs;i enim tintinnabulum appendas filo ad ferreum axem, ob&longs;tructis auribus; licèt den­tibus prædictum axem tangas, nullum &longs;onum percipies, quamvis tintinna­bulum re ip&longs;a &longs;onet; igitur filum aptum medium non e&longs;t, ad prædictum motum traducendum: deinde ita di&longs;poni pote&longs;t tintinnabulum, in&longs;erto fi­&longs;tulæ filo ferreo, ex quo pendeat, vt fi&longs;tulam nullo modo tangat, nec me­diatè, nec immediatè, vt aliquando probavi; &longs;en&longs;i tamen vt antè, &longs;onum; &longs;o­nus autem propagari non pote&longs;t, ni&longs;i per medium. Quintò, Ignis intia idem &longs;egmentum accenditur; hic porrò accendi non pote&longs;t, ni&longs;i vel parti­culæ ignis eò penetrent, vt Democriti ci dicunt; vel calor, qui, vt Peripate­tici docent, qualitas e&longs;t, eò v&longs;que ad pabulum diffundatur, per medium &longs;ci­licet; immò ignis accenditur tantùm per collectionem partium calidi, quæ certè colligi non po&longs;&longs;unt, ni&longs;i humoris interceptæ partes extrahantur, vt fit per re&longs;olutionem; rare&longs;cens enim humor avolat; vnde ignis &longs;eu calidi particulas congregari, &longs;eu colligi, nece&longs;&longs;e e&longs;t; nunquam autem partes hu­moris avolarent, &longs;i vacuum e&longs;&longs;et, vt pater.

Augu&longs;tin. Certis experimentis con&longs;tat fumum in dicto &longs;egmento non a&longs;&longs;urgere &longs;ur&longs;um, &longs;ed deor&longs;um cadere; flammam item &longs;tatim extingui; vn­de fortè vacuum e&longs;&longs;e, qui&longs;piam putaret.

Antim. Scio de quibus experimentis &longs;ermonem facias; libellum legi, & mihi nobili&longs;&longs;imi Autoris Roberti Boyle diligentia, nec non accurata indu&longs;tria &longs;ummopere placuit: Ille igitur ignem accendit in &longs;uo recipiente vitreo (&longs;ic enim vas illud vocat, ex quo anthliæ opera, maxima contenti aëtis pars exugitur & educitur) nempe in eo, & ignem ex &longs;ilice excu&longs;&longs;it, & pulverem tormentarium accendit, non tamen opera lentis v&longs;toriæ, licèt hoc aliis pro vobis &longs;ucce&longs;&longs;erit; ille autem ob&longs;ervat fumum intra recipiens ex accen&longs;a in eo materia tantulùm a&longs;&longs;urgere, & mox deor&longs;um ire, quod citra vacuum facilè explicatur; nihil enim vetat aëre dilatato intra recipiens, fumum graviorem e&longs;&longs;e; cùm etiam rarefacto gravior &longs;it; &longs;ic vbi Sol æ&longs;tivus de Meridie in os camini &longs;uis radiis paulò altiùs penetrat, vix fumus a&longs;&longs;ur­git; quia tunc aër Meridiano æ&longs;tu rare&longs;cit, & levior redditur, ac proinde minimè de&longs;cendere pote&longs;t, vt &longs;ur&longs;um extrudat fumum; immò licèt intra recipiens aër non dilatetur, fumus tamen po&longs;t aliquod tempus in infe­riorem va&longs;is tractum de&longs;cendit, vt idem Autor ob&longs;ervat; quia remitten­te caloris vi den&longs;atur, immò & ab aëre comprimitur, vnde gravior evadit; de&longs;cendat, igitur nece&longs;&longs;e e&longs;t; nihil ergo ex prædicto fumi de&longs;cen&longs;u deducitur per quod vacuum in dicto &longs;egmento CD ad&longs;truatur. Porrò quòd ignis in vacuo accendi non po&longs;&longs;it, patet; vtpote, qui tantummodò accenditur, ex collectione partium ignis, vt dixi, quæ ex eo colliguntur, quod partes hu­moris interceptæ avolent, vel per excu&longs;&longs;ionem, vt in affrictu &longs;ilicis, vel per ratetactionem, per quam &longs;cilicet redduntur leviores; &longs;ed &longs;i nullum e&longs;t medium, avolare non po&longs;&longs;unt, quamvis alioquin levi&longs;&longs;imæ evadant, quia &longs;cilicet rari&longs;&longs;imæ.

Chry&longs;ocom. Sunt, qui dicunt, non totum quidem &longs;egmentum CD va­cuum remanere, &longs;ed tantùm illius partem aliquam.

Antim. Hoc ip&longs;um in&longs;inuare videtur &longs;upra laudatus Autor; &longs;ed pro&longs;e­ctò, &longs;i quid video, hoc &longs;tare non pote&longs;t; quia &longs;i aliqua pars dicti &longs;egmen­ti vacua &longs;it, quidquid ine&longs;t &longs;ubtilis materiæ innatare illi non pote&longs;t; igitur &longs;upremus &longs;egmenti tractus vacuus e&longs;t; infimum verò &longs;ubtilis illa materia, vel aër dilatatus occupat; in &longs;upremo igitur tractu &longs;egmenti nullum obje­ctum videri, nullus &longs;onus auditi, nullus ignis accendi po&longs;&longs;et: nec e&longs;t quod dicant aliqui, di&longs;tincta e&longs;&longs;e ad in&longs;tar pororum vacuola; quia cùm ferè to­tus aër ex recipiente educatur, longè majora e&longs;&longs;ent prædicta vacuola reli­quo &longs;patio, ab aëre, vel &longs;ubtili materia occupato; ac proinde lumen conti­nuum, vel objectum continuo lumine illu&longs;tratum minimè videretur, &longs;ed di&longs;tinctum majoribus maculis nigerrimo colore tinctis; nihil enim atrius vacuo excogitari pote&longs;t.

Augu&longs;tin. Sed quæ&longs;o te, ad alias rationes orationem converte; hæc enim, meo &longs;altem judicio, exhau&longs;ta e&longs;t; quod tamen antequam facias, le­vem &longs;crupulum mihi excutias, velim, circa ea quæ de &longs;ono dixi&longs;ti; legi enim in dicto Autore, immi&longs;&longs;o Horologio rotato in recipiens, &longs;trepitum rotæ denticulatæ auditum fui&longs;&longs;e, antequam ex eo aër per anthliam educeretur; quo tamen educto, vix, ac ne vix quidem ille &longs;trepitus admotas pervenit ad aures.

Antim. Subnectere debueras, quæ apud eundem Autorem legi&longs;ti, pul­&longs;atæ campanulæ &longs;onum in dictum recipiens immi&longs;&longs;æ, etiam educto aëre auditum fui&longs;&longs;e. Fateor quidem, minimum &longs;onum vix audiri; nec enim dubium e&longs;t, quin vt nimia compre&longs;&longs;io aëris, ita nimia ten&longs;io propagationi &longs;oni tantulum ob&longs;tet; quippe qui per motum particularem eju&longs;dem medij propagetur, quas certè vt pre&longs;&longs;um medium repellit, ita ten&longs;um retinet, & qua&longs;i ad &longs;e adducit: &longs;ed jam ad alias rationes venio. Sextò, Igitur ferro candente applicato &longs;egmento CD extrin&longs;ecùs, Mercurius de&longs;cendit in­fra C, idem præ&longs;tat aër ambiens calidior; hic tamen &longs;en&longs;im, illud verò temporis ferè momento; idem dico de flamma, de lacca caloris vi molli­ta; rare&longs;cit igitur illa materia &longs;egmento CD contenta; nec enim calor in vacuum agit; premitque &longs;uperficiem Mercurij C, illamque deprimit, vt &longs;e&longs;e dilatet, quod certè cuilibet corpori rarefacto competit.

Chry&longs;ocom. Diceret fortè aliquis, vitrum ip&longs;um calore tantulum dilatari, non verò materiam &longs;egmento CD contentam, cùm nulla in&longs;it.

Antim. Hoc jam mihi venerat in mentem, &longs;ed, vt tute &longs;cis, vana e&longs;t ra­tionis vmbra, &longs;eu larva, & mera hallucinatio; quia &longs;ive fi&longs;tula ID &longs;it laxior, &longs;ive angu&longs;tior, eadem &longs;emper e&longs;t extantis Mercurij altitudo IC.

Augu&longs;tin. An fortè dici po&longs;&longs;et, calorem derivari ex vitro in Mercu­rium?

Antim. Hoc reverà dici non pote&longs;t: nam e&longs;to id fiat, ac proinde tan­tulum incale&longs;cat & rare&longs;cat Mercurius; inde &longs;equitur altiùs a&longs;&longs;urgere; quia paulò levior e&longs;t: deinde &longs;i &longs;egmento CI, in quo extans Mercurius continetur, ferrum candens admoveatur, non &longs;ubfidit &longs;uperficies Mercurij C; &longs;ed aliquot bullæ ex Mercurio &longs;ur&longs;um evolant &longs;i&longs;tunt que in &longs;uperficie C, idque &longs;en&longs;im, de quibus infra. Manet igitur illa &longs;exta ratio, adver&longs;us vacuum. Septimò, Si intra CD &longs;it acus pendula magnetica, & magnes ex­trin&longs;ecus admoveatur, illam movet adducitque ad &longs;e, vel à &longs;e repellit; igi­tur aut virtus magnetica e&longs;t pura qualitas diffu&longs;a, atque adeò per medium, ac proinde medium illud &longs;upponitur in &longs;egmento DC; igitur non e&longs;t va­cuum; aut prædicta virtus in corpu&longs;culorum effluvio po&longs;ita e&longs;t; ac proinde hæc per poros vitri &longs;ubeunt; igitur alia pariter æquè tenuis materia per eo&longs;dem poros &longs;ubire poterit; non e&longs;t igitur &longs;egmentum DC vacuum. Octa­vò, Totum vas ABG, cum fi&longs;tula ID, in hoc eodem &longs;itu, & &longs;egmento Mercurij extantis IC, immi&longs;&longs;um e&longs;t à laudato &longs;upra Autore in dictum re­cipiens, eductoque aëre de&longs;cendit Mercurius ver&longs;us I; &longs;ub&longs;i&longs;tit tamen &longs;n­pra I, licèt aër per multum temporis, Anthliæ opera, educeretur; &longs;i autem CD e&longs;&longs;et vacuum & potiori iure ip&longs;um recipiens, nulla e&longs;&longs;et ratio, propter quam &longs;upra I extaret intra fi&longs;tulam Mercurius; quod enim prædictus Au­tor dicit, aëra compre&longs;&longs;um adhuc manere intra recipiens, ac proinde, &longs;u­perficiem Mercurij EF ab eo tantulum premi, atque adeò Mercurium in fi&longs;tula &longs;upra I attolli; hoc, inquam nemo &longs;ibi per&longs;uadeat, cùm prædictus aër po&longs;t Anthliam tamdiu exercitam valde dilatatus re&longs;ter, vt multis expe­rimentis probate po&longs;&longs;um.

Augu&longs;tin. Cur igitur educto ex recipiente aëre Mercurius in fi&longs;tula de&longs;cendit, nunquam tamen v&longs;que ad I?

Antim. Aliam rationem, eamque germanam, ni fallor, affero; nempe &longs;egmentum CD aliqua materia valde ten&longs;a occupat, quæ cum pro rata re­&longs;i&longs;tat cum aëre intra recipiens contento, & cum Mercurius, &longs;emoto agen­te extrin&longs;eco, in eadem altitudine EIF e&longs;&longs;e debeat, po&longs;ito quod materia illa intra fi&longs;tulam ten&longs;a re&longs;i&longs;tat, & &longs;uperficiem Mercurij retineat, aër verò intra recipiens tën&longs;us &longs;uperficiem EF ad &longs;e adducat, corpus enim ten&longs;um alia corpora trahit ad &longs;e, prævalet quidem aër, propter Anthliæ vim, ac proinde Mercurium intra fi&longs;tulam contentum deprimit, non tamen omni­no; quia materia &longs;ubtilis intra fi&longs;tulam ten&longs;a pro rata re&longs;i&longs;tit; igitur &longs;uper­ficies Mercurij &longs;upra I, &longs;emper extat; præ&longs;ertim cùm materia illa ten&longs;a in­tra LD magis re&longs;i&longs;tat, quàm intra CD dilatata.

Chry&longs;ocom. Quid &longs;i extra recipiens extet extremitas D, ita tamen vt ad es recipientis probè agglutinata &longs;it, & educto maxima vi aëre ex recipiente perforetur fi&longs;tula in D.

Antim. Non probavit Autor, probarunt tamen alij, de&longs;cendit que Mer­curius in B. Subiitque aër tum proprio pondere, tum etiam adductus ab aë­re ten&longs;o intra recipiens; hic enim adducit &longs;uperficiem Mercurij EF, eam­que attollit; hæc autem &longs;ecum trahit, educit que Mercurium ex fi&longs;tula, quem &longs;equitur aër, qui deinde à Mercurio &longs;ur&longs;um in recipiens extruditur; cuncta hæc ex no&longs;tris principiis facilè explicantur.

Augu&longs;tin. Nonnulli capore nequeunt, &longs;eu nolunt, vim illam tractivam, qua &longs;cilicet fit, vt corpus ten &longs;um, dum &longs;e&longs;e reducit, corpus contiguum tra­hat; quo enim vinculo, quo fune illud trahit?

Antim. Hæc di&longs;cu&longs;&longs;io hujus loci non e&longs;t, vnum tamen breviter dice; &longs;ci­licet æquè facilè concipi vnum corpus ten&longs;um, &longs;eu dilatarum &longs;e&longs;e intror­sum reducere, atque concipitur, corpus compre&longs;&longs;um &longs;e&longs;e extror&longs;um exten­dere; item corpus ten&longs;um, dum &longs;e&longs;e reducit, aliud corpus, cui contiguum e&longs;t, &longs;e cum adducere, & corpus compre&longs;&longs;um, aliud corpus à &longs;e amovere; nec alio fune opus e&longs;t ad hunc finem; cùm enim juxta Naturæ in&longs;titutum om­nia corpora &longs;int partes vniver&longs;i, & partes, quæ totum aliquod componunt, conjunctæ e&longs;&longs;e debeant, alio quin patres non e&longs;&longs;ent, &longs;i &longs;eor&longs;im e&longs;&longs;e po&longs;&longs;ent; ideo vnum corpus adhæret alteri, quando &longs;cilicet hoc moveri nequit, ni&longs;i vel aliud adducatur, vel talis &longs;eparatio fiat, vt vacuum intercedat; nempe &longs;upponamus corpus dilatarum &longs;e&longs;e in pri&longs;tinum &longs;tatum reducere, ac &longs;e&longs;e contrahere, etiam &longs;i corpora contigua &longs;imul non adducantur, vnde qua que vacuum erit; ac proinde corpus illud &longs;eor&longs;im ab omnibus aliis &longs;ejunctum; igitur non e&longs;&longs;et amplius vniver&longs;i pars. Itaque cum tale &longs;it Naturæ in&longs;titu­tum, vt omnia corpora &longs;int partes vniver&longs;i, &longs;eor&longs;im e&longs;&longs;e non po&longs;&longs;unt; &longs;em­per igitur vnum aliis adhæret ; & ne &longs;eor&longs;im fiat, perinde &longs;e habent omnis, atque &longs;i vnita effent; hinc vacui fuga; hinc Naturæ vinculum & funis. Vt vt &longs;it (de his enim alibi di&longs;putavimus) quando corpus ten&longs;um &longs;e&longs;e re&longs;ti­tuit, &longs;eu contrahit, cùm perinde &longs;e habeat, atque &longs;i alteri contiguo conjun­ctum e&longs;&longs;et in ordine ad hunc finem Naturæ in&longs;tituto definitum, vt &longs;cilicet omnia corpora &longs;int parces vniver&longs;i, qui revera finis po&longs;tulat, vt vacuum ar­ceatur, quid mirum, &longs;i &longs;ecum illud adducat, vnde fateor vltro, multum cor­pus moveri metu vacui; vnum tamen alteri adhærere, non quidem imme­diatè, ad vitandum vacuum, &longs;ed ad &longs;ervandum inde omnem prædictum Natu­ræ finem.

Augu&longs;tin. Non deerunt inter Democriticos, qui fines illos & Naturæ in&longs;tituta rideant, vt à rebus phy&longs;icis planè aliena.

Antim. Sat &longs;cio: eò tamen illos, quamvis invitos, venire nece&longs;&longs;e e&longs;t: volunt enim, compre&longs;&longs;ionem aëris explicandam e&longs;&longs;e per &longs;piras, vel arcus ten&longs;os, aut certè per motum longiorum Atomorum, qui majus &longs;patium po&longs;tulet; &longs;ed ex iis quæro, cur &longs;pira illa ten&longs;a &longs;it, vel compre&longs;&longs;a; & cur in eo &longs;itu, in quam redacta e&longs;t, non permaneat; ac demum, vnde vim illam habeat, qua &longs;e reducit, &longs;eu reducere nititur.

Augu&longs;tin. Re&longs;pondebunt illico, rationem ab ip&longs;a &longs;piræ, vel aëris figu­ra petendam e&longs;&longs;e, vt videre e&longs;t in artefactis, quorum analogia &longs;atis favet.

Antim. Sed in&longs;to, & quæro, vnde habeant prædictæ aeris particulæ, vt &longs;piræ &longs;int, vel arcus, vt hanc potiùs, quàm aliam figurám po&longs;tulent, ac proinde ami&longs;&longs;a illa ac mutata, tantum ni&longs;um exerant, vt &longs;e&longs;e in eam re&longs;ti­tuant; prætereà vnde tanta vis motrix, tum in &longs;piris, vel arcubus aëris, tum etiam &longs;ecundùm aliam hypothe&longs;im, in oblongis illis particulis? ad quid enim motus ille circularis? quid quæ&longs;o hic ad illam particulam facit, aut confert? Pro his alii&longs;que &longs;imilibus, ad primum naturæ in&longs;titutum omnino confugient; cur ergo idem mihi non liceat? Quod verò &longs;pectat ad analo­giam artefactorum, non habet locum in hac controver&longs;ia; alioquin peti­tur, vt aiunt, principium: quæro enim, cur arcus ten&longs;us, vel &longs;pira ten&longs;a tan­ta vi redeat, ac &longs;e&longs;e re&longs;tituat; & dico rationem inde petendam e&longs;&longs;e, quod &longs;cilicet pori ita &longs;int di&longs;po&longs;iti, vt ex Lunatione arcus v.g. multa compre&longs;&longs;io contentæ in iis materiæ con&longs;equatur; ditis autem illam materiam ideò comprimi, &longs;eu tendi quia ex minimis &longs;piris, vel arcubus con&longs;tat; idem igi­tur probas per idem. Itaque, quidquid e&longs;t, quidquid agit, &longs;eu movetur, propter illum finem e&longs;t, ad quem à Natura de&longs;tinatur, movetur que, vt il­lud obtineat; video lapidem, & alia corpora tam recta linea, &longs;ublato im­pedimento ad idem centrum tendere, vt nunquam ab illa di&longs;cedant: quam­obrem verò? quia &longs;cilicet finis lapidis aliorumque corporum gravium e&longs;t globum totalem con&longs;tituere, &longs;eu componere &longs;imul cum aliis; vt ergo fi­nem illum vel obtineant, vel obtentum indemnem &longs;ervent, illa vi pollent, qua deor&longs;um ferantur, aut &longs;altem connitantur; finem autem retum ex ip&longs;o v&longs;u, v&longs;um &longs;en&longs;u ip&longs;o percipimus; ex his vides, non e&longs;&longs;e fortè, cur hæc Democritus rideat; &longs;ed hæc obiter, quæ hujus in&longs;tituti non &longs;unt, nec hujus loci.

Chry&longs;ocom. Hæc tamen vel obiter indica&longs;&longs;e profectò non oberit; &longs;ed quæ&longs;o te, ad alias rationes orationem ac &longs;ermonem reevoca.

Antim. Nonò, &longs;i ve&longs;icam cyprinam, vel alterius generis, aperto fora­mine priùs exhau&longs;tam aëre, eoque expre&longs;&longs;o, arcto ligamine ad foramen &longs;tri­ctam, appen&longs;amque circa extremitatem interioris fi&longs;tulæ D, tum infu&longs;o Mercurio, admotoque, ac deinde &longs;ubducto, vt ante, digito, vbi de&longs;cendit Mercurius in CI, præfata ve&longs;ica ita intume&longs;cit, vt vix immi&longs;&longs;o anhelitu, adeò tensè intume&longs;cene videatur: hoc experimentum certum e&longs;t, illudque multi probarunt.

Augu&longs;tin. Iam aliquid de illo in audieram; &longs;ed quid inde contra va­enum?

Antim. Quid inde, inquis; miror à te non videri; &longs;i enim &longs;patium CD vacuum e&longs;t; vnde quæ&longs;o hic effectus? quæ cau&longs;a hanc ve&longs;icam ita di&longs;ten­dit? non intrin&longs;eca, cùm tota aëre evacuata fuerit; extrin&longs;eca nulla e&longs;t, &longs;i &longs;patium CD vacuum e&longs;t.

Augu&longs;tin. Quid ad hæc ille recentior, quem jam &longs;upra lauda&longs;ti?

Antim. Idem pror&longs;us, quod nonnulli Pari&longs;ien&longs;es cum Pecquero; &longs;cili­cet partes aëris inter rugas &longs;eu plicas ve&longs;icæ remanere, quæ cùm liberio­res &longs;int, à prima compre&longs;&longs;ione in pri&longs;tinam exten&longs;ionem &longs;eu dimentionem re&longs;tituunt &longs;e&longs;e; quod certè priùs non faciebant, nimirum ab extrin&longs;eco aëre æquè compre&longs;&longs;o impeditæ.

Chry&longs;ocom. Hæc &longs;anè ratio &longs;ubtilis mihi videtur; &longs;ed vt ex tuo nutu conjicio, non multùm tibi arridet.

Antim. Genium meum no&longs;ti; di&longs;&longs;imulare non po&longs;&longs;um, id quod &longs;entio; & quando quidem liberè in hoc congre&longs;&longs;u, quod intus &longs;entimus, exponi­mus, fateor, rationem illam mihi non probari. Primò, enim quis &longs;ibi per­&longs;uadeat, ambientem nos aëra adeò compre&longs;&longs;um e&longs;&longs;e, vt ad mille &longs;imam &longs;uæ exten&longs;ionis partem redactus &longs;it? nempe paucæ illæ rugæ interioris ve&longs;icæ po&longs;t accuratam expre&longs;&longs;ionem, vix mille&longs;imam partem &longs;patij occupant, il­lius, quod ten&longs;a & tumida ve&longs;ica continet; tanta vis aëris pre&longs;&longs;i no&longs;tris cor­poribus valdè noceret, & vix liceret ducere anhelitum. Secundò, Si tan­tulum inclinetur fi&longs;tula BD, a&longs;&longs;urgit Mercurius &longs;upra C, &longs;en&longs;imque ve&longs;ica detume&longs;cit; antequam a&longs;&longs;urgens Mercurius eam attingat; quid ergo de­nuo aëra in ea contentum comprimit? Tertiò, Si aqua &longs;patium CD oc­cupet, provt facilè po&longs;t a&longs;cen&longs;um Mercurij illud occupare pote&longs;t, de quo infra, ve&longs;ica detume&longs;cit; &longs;ed vnde hoc? aquam enim compre&longs;&longs;am non e&longs;­&longs;e apud omnes con&longs;tat; ab illa igitur aër ve&longs;ica inclu&longs;us non comprimi­tur; dicet haud dubiè laudatus Autor aëra intra plicas exteriores ve&longs;icæ priùs contentum, vbi Mercurius de&longs;cendit in CI, &longs;e&longs;e in pri&longs;tinam exten­&longs;ionem re&longs;tituere, comprimi verò denuò ab a&longs;&longs;urgente Mercurio, vel ab aqua inducta; igitur &longs;egmentum CD non e&longs;t vacuum, quod hîc dumtaxat probare intendo; deinde, quis credat prædictum aëra e&longs;&longs;e in &longs;patio centies millecuplo illius, quod ante obtinebat intra in&longs;en&longs;ibiles plicas?

Augu&longs;tin. Fieri non pote&longs;t, quin præfatus Autor de ve&longs;icis recipiente inclu&longs;is aliqua habeat.

Antim. Habet haud dubiè; inclu&longs;a, inquit, intra recipiens ve&longs;ica, edu­ctoque deinde aëre, ve&longs;ica priùs ligata intume&longs;cit; cujus tumoris cau­&longs;am vult e&longs;&longs;e re&longs;iduum aëris intra ve&longs;icam contenti, qui cùm liberè dila­tari po&longs;&longs;it, educto &longs;cilicet externo aëre contranitente, maximè dilatatur ac &longs;e&longs;e explicat; hinc, vt vides, præviam dicti aëris compre&longs;&longs;ionem accer­&longs;it; eam &longs;cilicet, ac tantam, quæ omnem fidem &longs;uperet; ego certè di­cere malim, illud tantulum aëris intra ve&longs;icæ rugas relicti, ab extrin&longs;eco ambiente, Anthliæ vi educto dilatari, vnde &longs;i ve&longs;ica perforata &longs;it, vel minùs arctè ligata; cùm aër internus externo contiguus &longs;it, citra tumorem ve&longs;icæ adducitur, nec non tenditur; hinc &longs;i aër in recipiens inver&longs;o Epi&longs;tomij verticillo immittatur, cùm ce&longs;&longs;et dilatatio, ve&longs;ica detume&longs;cit; aliud ad­dit, &longs;cilicet ve&longs;icam ita exten&longs;am & compre&longs;&longs;am, vt nulla plica inter-na re&longs;tet; ac proinde nullus aër, quamvis deinde circa collum con&longs;tricta &longs;it, educto licet aëre ex recipiente, non tamen propterea tume&longs;cere, quia &longs;cilicet dee&longs;t materia intus dilatanda, in quo nulla e&longs;t difficultas, nulla &longs;al­tem mihi e&longs;&longs;e videtur.

Chry&longs;ocom. Quid &longs;i mediocris &longs;altem aëris quantitas intra ve&longs;icam ob­&longs;tricto valide collo, relinquatur, vt facilè fieri pote&longs;t?

Antim. Hoc &longs;anè præfatus Autor minimè omi&longs;it, &longs;ed inde validum pro &longs;ua hypothe&longs;i confirmanda, duxit argumentum; nempe; po&longs;t exhau­&longs;tum ex recipiente aëra, ve&longs;ica di&longs;cinditur, vnde &longs;tatim concludit, majo­ris quantitatis aëtis interni, &longs;ubducto externo contranitente, majorem ac liberum ni&longs;um exeri; vnde non mirum, &longs;i ve&longs;ica rumpatur; vt etiam ma­gno cum fragore di&longs;rumpitur, &longs;i jam inflata arctè &longs;tricto collo, luculento igni proximè admoveatur.

Augu&longs;tin. Hoc experimentum rem ip&longs;am conficere videtur; atque ita ex eo præfati Autoris &longs;ententia omnino demon&longs;trari.

Antim. Expecta quæ&longs;o, Augu&longs;tine, &longs;trenui pugilis non e&longs;t, tam citò deditionem facere; immò &longs;i rem attentè perpendas, no&longs;træ hypo­the&longs;i æquè favet; nempe major aëris quantitas magis dilatari pote&longs;t, quàm minor, vt patet; quid mirum ergo, &longs;i cum externa vi, aër intra ve&longs;icam contentus in majus &longs;patium explicari queat, debiliora ve&longs;icæ latera, quæ tantam dilatationem non ferunt, cedere cogantur; in parte &longs;cilicet debi­liore? illa autem analogia ve&longs;icæ igni admotæ ad rem no&longs;tram facit; nam vt aër inclu&longs;us præ calore plus æquo rare&longs;cens, ve&longs;icam di&longs;rumpit; ita & aër plus æquo externa vi acris adducti dilatatus eundem effectum præ­&longs;tat.

Augu&longs;tin. Iam mihi res clari&longs;&longs;ima videtur; in ferenda &longs;ententia nimis præceps fui; &longs;u&longs;tinendum fuerat, vt rectè monui&longs;ti; &longs;ed jam ad alias ratio­nes progredi poteris, cum hæc difficultas exhau&longs;ta &longs;it.

Antim. Decimò, Si po&longs;tquam de&longs;cendit Mercurius in fi&longs;tula extante &longs;egmento BC, digitum ori B pre&longs;sè admoveas, ne quid aëris &longs;ubeat, & fi&longs;tulam invertas, &longs;enties digiti pulpam fortiter attrahi atque intume&longs;cere, codem pror&longs;us modo, quo intume&longs;cit caro, admota cucurbitula; immò cum aliqua difficultate avellitur: deinde digitus, perinde atque &longs;i cucurbi­tula avelleretur; &longs;i autem ante quam digitus admoveatur, punctim acu, vel cultello pulpa illa configatur, vbi deinde admovetur ori B, & invertitur fi­&longs;tula, copio&longs;us &longs;anguis exugitur, eodem pror&longs;us modo, quo fieri &longs;olet in cucurbitulis.

Augu&longs;tin. Sed quid inde contra vacuum? nec enim video quò &longs;pe­ctes.

Antim. Iamjam videbis; &longs;i enim vacuum e&longs;&longs;et in &longs;egmento CD, vel inver&longs;a fi&longs;tula in &longs;egmento CD, quid quæ&longs;o digiti pulpam in tumorem at­tolleret? quid &longs;anguinem exugeret? aëris externi pondus, inquies; &longs;ed nullum pror&longs;us pondus &longs;entitur, nulla pre&longs;&longs;io in externa digiti parte; im­mò aër &longs;ubire nequit, vt pater; deinde cùm Mercurius in de&longs;cen&longs;u, pro­pter motum acceleratum primùm de&longs;cendat infra C, licèt deinde po&longs;t va-rias vibrationes &longs;ur&longs;um atque deor&longs;um, &longs;i&longs;tat in C, &longs;i dum notabili &longs;e­gmento e&longs;t, infra C, admoveatur digitus in B, ac deinde fi&longs;tula invertatur, longè majore vi & pulpa digiti in tumorem attollitur, & &longs;anguis exugi­tur; idem tamen aëris pondus gravitat: vnde igitur diver&longs;us effectus? certè à materia ten&longs;iore in &longs;egmento CD contenta; &longs;i enim ten&longs;ior e&longs;t, majore vi trahit; & digiti pulpam ad &longs;e adducit; &longs;ic arcus ten&longs;ior &longs;agittam longiùs ejiculatur: & verò amoto illo vacuo, & in ejus locum materia illa ten&longs;a &longs;ub&longs;tituta, cuncta hæc facilè explicantur.

Augu&longs;tin. Sic etiam facilè explicarem aliud experimentum prædicti Autoris, qui exhau&longs;to aëre ex recipiente, dicit, operculum illius alioquin levi&longs;&longs;imum, gravi&longs;&longs;imum &longs;entiri, propter pondus aëris externi &longs;uperimpo­&longs;itum; hic tamen effectus aëri externo tribui non debet &longs;ed aëri interno valde ten&longs;o ac dilatato, nempe cùm operculum illud attolli non po&longs;&longs;it, ni&longs;i aër internus vltra dilatetur, huic majori ten&longs;ioni valde re&longs;i&longs;tit; co­gita quæ&longs;o arcum ten&longs;um, qui non ni&longs;i longè majore vi vltra tendi pote&longs;t.

Antim. Diceret haud dubiè &longs;upra laudatus Autor, intra pulpam digiti multas e&longs;&longs;e partes, quæ &longs;emota pre&longs;&longs;ione ambientis erumperent, & liberiorem &longs;ortitæ motum, maximam inducerent mutationem; at profectò nihil tale &longs;en&longs;i; &longs;ed tumorem dumtaxat illum; nec pul&longs;us ratio mutatur; vno verbo nihil accidit, quod exuctioni validæ tribui non po&longs;­&longs;it: equidem &longs;i digitus arctè funiculo &longs;tringatur, &longs;upra illam extremita­tem, quæ ori B, affigitur, propter majorem &longs;anguinis vim in eo tractu retenti, impeditur enim circulatio, major etiam &longs;anguinis copia exugi­tur: &longs;i quis autem totam manum in &longs;egmentum CD immitteret, ita vt tamen nullus aër &longs;ubire po&longs;&longs;et, &longs;imilem quidem, majorem tamen dictæ exuctionis effectum &longs;entiret, non &longs;ine aliquo periculo manus intume&longs;­centis, vt alicui accidi&longs;&longs;e intelligo: Alligavi deinde extremo digito ve­ficam cyprinam, quæ &longs;tatim inver&longs;a fi&longs;tula intumuit; item medullam &longs;ambuci, & fru&longs;tulum &longs;pongiæ, &longs;ed in his nulla mutatio contigit, aperti enim &longs;unt laxiores pori, per quos aër educitur & dilatatur; ex præmi&longs;&longs;is igitur certum re&longs;tat, &longs;egmentum CD vacuum non re­&longs;tare; quo verò corpore plenum &longs;it, paulò po&longs;t dicam. Ad aliam partem tran&longs;eo, in qua dicebatur &longs;egmentum Mercurij IC, &longs;u&longs;tinerià Cylindro aëris eju&longs;dem ba&longs;is, ita vt perfectum &longs;it vtrimque æquibrium; contra hanc &longs;ententiam nonnulla militant, quæ &longs;incerè vobis exponam. Primò, Si appendatur fi&longs;tula BD, po&longs;tquam &longs;ubducto digito, de&longs;cendit Mercurius in IC, &longs;tatera fideli adhibita, & &longs;ignetur ponderis ratio, ac dein­de citra Mercurij de&longs;cen&longs;um, eadem fi&longs;tula cum æquali quantitate Mercu­rij appendatur, eadem ratio ponderis invenietur, paulò major ; æqualem quantitatem Mercurij intelligo &longs;egmento IC ; & dico paulò majorem ; nempe immer&longs;um &longs;egmentum fi&longs;tulæ IB ad primum pondus nihil confert; immò potiùs aliquid detrahit; quia Mercurio levius e&longs;t; &longs;ed mihi &longs;ufficit, modo vtrinque proximè æqualis &longs;it ratio ponderum, qualis reverà e&longs;t, vt &longs;æpè probavi: Ex hoc autem experimento &longs;ic mihi rectè ratiocinari videor; Si mercurius IC &longs;u&longs;tinetur à cylindro exterioris aëris, igitur cum illo perfe­ctum &etail;quilibria &longs;unt, igitur cum alio æquali pondere ad libram appen&longs;o aliud æquilibrium facere non pote&longs;t; Supponamus enim Mercurium IC, e&longs;&longs;e trium li­brarum, æquilibrium facit cum cylindro aëris etiam trium librarum; &longs;i autem aliud pondus trium librarum in altera lance appendatur, cum hoc Mercurius æquilibrium facere nequit, alioquin &longs;ex libris Mercurius Æquiponderaret quod legibus Staticæ repugnat. Et verò Mercurius CI ab aëris cylindro &longs;u­&longs;tentatus perinde &longs;e habet, atque &longs;i e&longs;&longs;et cylindrus vel embolus, qui nullo ne­gotio educi & immitti po&longs;&longs;et per fi&longs;tulam; &longs;ed prædictus cylindrus digito v.g. &longs;u&longs;tentatus fi&longs;tulæ pondus non augeret; & hæc e&longs;t &longs;ecunda ratio; aperto enim foramine in D, inductoque embolo in cavitatem BC, &longs;i eum digito tantulum attollis, clau&longs;o foramine in D, & fi&longs;tula appendatur, præfatus cylindrus nullum pondus addit fi&longs;tulæ; igitur, nec Mer­curius CI, à cylindro aëris &longs;u&longs;tentatus; cùm vtrimque par &longs;it ratio.

Chry&longs;oc. Diceret forta&longs;sè aliquis, Mercurium contentum Segmento IC gravitate in latera fi&longs;tulæ; &longs;i enim fi&longs;tula perforetur in L v.g. per foramen Mercurius effluit.

Antim. Scio, ita aliquos re&longs;pondere; &longs;ed hæc re&longs;pon&longs;io, meo &longs;altem judicio, nodum non &longs;olvit; quando enim latera va&longs;is ita non adhærent contento, quin ea liberè, &longs;ine illo moveri po&longs;&longs;int, de primi &longs;cilicet, at­que attolli, in ea certè corpus contentum non gravitat; quia non ob­&longs;tant, quo minùs illud deor&longs;um eat; hoc autem luculento experimento de­mon&longs;tro.

Sit Vas BAC oblongum, clau&longs;um in C, apertum in AB, plenum aqua, illudque ex ligno levi&longs;&longs;imo, & valde cra&longs;&longs;um; immergatur in aquam, donec &longs;it in æquilibrio, immer&longs;o &longs;egmento DC, extante verò Segmento DA, aqua contenta &longs;egmento DA, extans &longs;upra &longs;uperficiem aquæ GDF, eodem modo gravitat in latera va&longs;is CADB, quo Mercurius in latera præ­dictæ fi&longs;tulæ; &longs;i tamen appendatur vas CA, in hoc &longs;itu nullum pondus habet, quia &longs;cilicet ab aqua &longs;u&longs;ti­netur; nihilo tamen minus, &longs;i perforetur latus DB, per foramen effluet aqua, &longs;icuti Mercurius per fora­men apertum in fi&longs;tula effluit. Sed alio experimento lu­culentiore rem hanc explico: Sit vas HB continens Mercurium FB &longs;ic tu­bus ligneus oblongus, ex materia levi&longs;&longs;ima, MC, vtrimque pervius, &longs;i imponatur altera eius extremitas C Mercurio, tantulum &longs;egmentum im­mergetur; infundatur mox aqua in prædictum tubum, per os &longs;uperius M, donec proximè ad C Mercurij tubo contenti &longs;uperficies deprimatur, aqua verò tubo infu&longs;a a&longs;&longs;urgat in K ; denique appendatur tubus CM, nullam profecto ponderis vim exerit, quia &longs;cilicet &longs;u&longs;tinetur à Mercurio; immo &longs;i deprimatur infra C, &longs;ur&longs;um extruditur à Mercurio, æquali, vel potiùs eodem aquæ &longs;egmento &longs;emper extante; & &longs;i tantulum attollatur &longs;upra C,

extantis aquæ &longs;uperficies manebit in K ; atque ita &longs;i po&longs;t prædictam elevationem tubi MC hic appendatur, ex eret quidem aliquam vim ponderis; &longs;ed minimam, in qua aqua extans nullam partem habet, &longs;ed tantùm tubus ligneus, qui minore &longs;egmento, quam par e&longs;&longs;et, ad æquilibrium immer&longs;us e&longs;t: licèt, facto in tubo MC foramine inter KN, aqua tubo contenta per il­lud effluat? &longs;i autem aquam infundas in vacuitatem interceptam HCI attolletur, a&longs;&longs;urgétque Mercurius per tubum CM, nulla tamen tubo fit ponderis ac­ce&longs;&longs;io. Ex quibus, ni fallor, evidenter concluditur, corpus ab alio &longs;u&longs;tentatum, novam vim ponde­ris non exerere, quando appenditur; ac proin­de &longs;i appen&longs;um totam vim ponderis exerit, ab alio corpore non &longs;u&longs;tentari, igitur &longs;egmen­tum extantis Mercurij ab exterioris aëris cylindro non &longs;u&longs;tinetur, quia &longs;cilicet appen&longs;um totam vim ponde­ris exerit.

Augu&longs;tin. Sunt, qui dicant, &longs;i rectè memini, ab aëris cylindro, qui

ba&longs;i D incumbit, æquè deor&longs;um deprimi, ac &longs;ur&longs;um attollitur, ab alio gravitante in ba&longs;im B; mediante &longs;cilicet Mercurio.

Antim. Hoc facilè reijcitur; nempe æqualis cylindrus aëris incumbit ba&longs;i D, &longs;ive mercurio, &longs;ive aqua, &longs;ive aëre fi&longs;tula plena &longs;it, vt patet; Vnde, &longs;i quem haberet effectum, eundem &longs;emper haberet; &longs;ed hæc in&longs;tantia futi­lis e&longs;t; are in ea diutiùs minimè hærendum, vt tran&longs;eam ad tertiam ratio­nem; &longs;i enim &longs;egmentum IC Mercurij ab aëris exterioris cylindro &longs;u&longs;tinetur; igi-tur cùm cylindrus exterior eandem vim &longs;emper habeat, æquale &longs;e­gmentum IC &longs;emper &longs;u&longs;tinet; &longs;ed hoc experimento repugnat; nam &longs;i tantulum aëris antequam demittatur Mercurius in fi&longs;tula re­linquatur, Mercurius de&longs;cendet infra C; in C autem &longs;u&longs;tineri de­beret; &longs;i à cylindro aëris exterioris, &longs;u&longs;tineretur, vt patet; im­mo de&longs;cendit infra C non juxta men&longs;uram cylindruli aëris in fi&longs;tula relicti, &longs;ed juxta majorem ; vnde illum aëra multùm dilatari, nece&longs;&longs;e e&longs;t; vnde fortè aliam materiam intra fi&longs;tulam dilatatam e&longs;&longs;e di­cemus.

Augu&longs;tin. Huc recurrit hypothe&longs;is Autoris &longs;upra laudati; dicent enim illius &longs;ententiæ a&longs;&longs;ertores, illud tantulum aëris intra fi&longs;tulam relicti, po&longs;t de&longs;­cen&longs;um Mercurij liberiorem nanci&longs;ci campum, ac proinde cùm ante com­pre&longs;&longs;us e&longs;&longs;et, explicare &longs;e&longs;e ac dilatare, & premere &longs;uperficiem Mercurij, vnde hic infra C de&longs;cendit.

Antim. Tantam compre&longs;&longs;ionem aëris jam &longs;upra &longs;atis efficaciter refu­tavi; hic tantùm addo, &longs;i vacuum remanet &longs;egmentum CD, illam aëris par­ticulam &longs;atis &longs;patij habere, vt explicet &longs;e&longs;e, ac proinde non premere &longs;uper­ficiem Mercurij, ideo enim illam premere dicitur quia nititur explicare &longs;e­&longs;e, cùm plus æquo compre&longs;&longs;us &longs;it. Si verò &longs;egmentum CD non e&longs;t vacuum, &longs;ed plenum, jam videndum e&longs;t, quare plenum &longs;it; &longs;i aëre dilatato, hæc particu­la haud dubiè dilatatur, compre&longs;&longs;a igitur non manet; &longs;i æthere, vt volunt ali­qui, per poros adducto, certè illa, tantùm ætheris, vel &longs;ubtilis materiæ por­tio exugitur, &longs;eu per poros adducitur, quæ ad occupandum &longs;egmentum CD, ne vacuum re&longs;tet, nece&longs;&longs;aria e&longs;t: &longs;ed primus locus cedit intra dictum &longs;egmen­tum præfatæ aëris portioni; &longs;i demum e&longs;t alia &longs;ubtilis materia ten&longs;a, potio­ri jure prædictus aër tenditur ac dilatatur; igitur compre&longs;&longs;us non ma­net, igitur &longs;uperficiem Mercurij &longs;egmento CI contenti deor&longs;um non premit.

Chry&longs;ocom. Cur ergo Mercurias de&longs;cendit infra C? ne&longs;cio, vtrùm aliam cau&longs;am excogitare quis po&longs;&longs;it.

Antim. Non dee&longs;t alia cau&longs;a, nempe Mercurij IC pondere prædicta aëris particula dilatatur; vt enim aër Mercurij pondere comprimitur in fontibus quibu&longs;dam arte factis, ita & eodem dilatatur; quid mirum ergo, &longs;i Mercurius infra C de&longs;cendat? hoc autem novo experimento per&longs;picuè demon&longs;tro; &longs;i enim fi&longs;tulam BD & vas ABG, non Mercurio, &longs;ed aqua impleas, admotóque digito, extremum B in aquam EF immergas, di­gitúmque &longs;ubducas; fi&longs;tula plena manet; &longs;i autem non pror&longs;us aquâ fi&longs;tu­lam impleveris, admotóque digito extremum B immer&longs;eris, &longs;ubduxerí&longs;­que digitum, aqua tantulum de&longs;cendit v. g. &longs;i dum admotus e&longs;t digitus extremo B immer&longs;o &longs;uprema &longs;uperficies aquæ &longs;it in M, &longs;ubducto digito de&longs;cendit, qua&longs;i in N; hac tamen ratione, vt dum &longs;uperficies aquæ e&longs;t circa mediam altitudinem ID, puta in C &longs;egmentum de&longs;cen&longs;us prædictæ &longs;uper­ficiei majus &longs;it; minus verò, quo dicta &longs;uperficies accedit propriùs ad D vel ad I.

Augu&longs;tin. Hæc experimenta eò jucundiora mihi accidunt, quo illorum cau&longs;as ex præmi&longs;&longs;is Antime, mihi deducere po&longs;&longs;e videor; ideò enim &longs;uperficies aquæ &longs;ubducto digito de&longs;cendit, quia pondus aquæ fi&longs;tulæ contentæ re­lictam in fi&longs;tula portionem aëris dilatat; &longs;i autem dicta &longs;uperficies acce­dit propius ad D, e&longs;t quidem magnum aquæ pondus, ad majorem dilata­tionem præ&longs;tandam, &longs;ed dee&longs;t &longs;ubjectum, &longs;eu materia majoris dilatatio­nis capax; &longs;i verò propiùs ad I, e&longs;t quidem &longs;ubjectum capax majoris dila­tationis, &longs;cilicet major aëris portio; e&longs;t tamen minima vis ponderis ad il­lam præ&longs;tandam; &longs;i demum &longs;uperficies &longs;it in C, & &longs;atis magna e&longs;t vis ponderis, &longs;egmentum, &longs;cilicet aquæ IC, & &longs;ubjectum &longs;atis capax, &longs;cilicet portio aëris CD ; major igitur &longs;equitur dilatatio, majus igitur &longs;egmentum de&longs;cen&longs;us. At &longs;cire ex te velim, Antime, vtrùm idem in Mer­curio fiat.

Antim. Idem prorsùs &longs;æpiùs probavi in fi&longs;tula duos pedes alta; vt &longs;ci­licet majus &longs;egmentum e&longs;&longs;et, quo &longs;uprema &longs;uperficies Mercurij ad me­dium altitudinis fi&longs;tulæ extantis, propiùs accederet. Si autem altiorem fi&longs;tulam adhibeamus, in qua &longs;cilicet &longs;ubducto digito ex A, Mercurius de­&longs;cendat, donec extet in &longs;egmento IC duorum circiter pedum & 1/4 vel ; quo plus aëris in hac fi&longs;tula relinquetur, eò majus erit de&longs;cen&longs;ûs Mer­curij &longs;egmentum infra C; pro quo illa quam luculenter expo&longs;ui&longs;ti, Au­gu&longs;tine, ratio militat; equidem quando fi&longs;tula altior e&longs;t, vt rectè ob&longs;er­vat &longs;upra laudatus Autor, æqualis aëris portio intra fi&longs;tulam relicta, tam longum de&longs;cen&longs;us infra C &longs;egmentum non præ&longs;tat; quia prædictus aër in majore Mercurij de&longs;cen&longs;u v&longs;que ad C, magis dilatatur, quàm in minore; vnde non mirum, &longs;i deinde eundem minùs dilatet Mercurius in­fra C de&longs;cendens: hinc etiam quo major erit portio aëris in &longs;egmento CD, eò majus erit &longs;egmentum de&longs;cen&longs;us Mercurij infra C. Hinc diver­&longs;æ conjugationes &longs;eu combinationes majoris &longs;cilicet aëris &longs;egmenti, vel minoris, ante dilatationem; majoris altitudinis fi&longs;tulæ vel minoris; ma­joris &longs;egmenti Mercurij vel minoris; prædicta &longs;ex variè combinari po&longs;­&longs;unt; & &longs;ic cuncta ad præmi&longs;&longs;a principia facilè reducuntur; nempe ma­jus Mercurij &longs;egmentum &longs;eu pondus idem &longs;egmentum aëris magis di­latat; majus &longs;egmentum aëris ab eodem Mercurij &longs;egmento magis dila­tatur; denique majus de&longs;cen&longs;us &longs;egmentum à D in C eandem portionem aëris magis dilatat, quàm minus.

Chry&longs;ocomus. Hæc ratio mihi &longs;atis arridet; &longs;ed quæ&longs;o te, profer alias.

Antim. Sit igitur quarta ratio: &longs;i per compre&longs;&longs;ionem corporis liqui­di, admoto &longs;cilicet di&longs;co &longs;upremæ &longs;uperficiei, attollatur liquor in fi&longs;tula, nullum illius pondus, appen&longs;a fi&longs;tula &longs;enties; ratio in promptu e&longs;t, quia à di&longs;co admoto attollitur & &longs;u&longs;tinetur; illius ergo pondus nullam aliam vim exerit; igitur pari modo Mercurius extans in &longs;egmento IC nullam vim ponderis exerit, &longs;i vel ab exteriore aëre compre&longs;&longs;o, vel ab aë­ris cylindro &longs;u&longs;tineatur; par enim e&longs;t vtrimque ratio; & in&longs;tantia &longs;upra facta hîc etiam eodem modo refellitur; cùm non minùs liquor à pre-mente di&longs;co elevatus in fi&longs;tulæ latera gravitet, quàm Mercurius, & aper­to in extante fi&longs;tulæ &longs;egmento foramine, tam vnus effluat, quàm alius; & vt dicam &longs;uper hoc, quod &longs;upra exciderat, quonam pacto Mercurius extans in &longs;egmento fi&longs;tulæ IC gravitet in latera eju&longs;dem, facto foramini ­ in L, totum pondus Mercurij CL exerit vim &longs;uam, qua extrudit Mercu­rium &longs;ubjectum per foramen L: itaque omnes partes Mercurij gravi­tant in B vltimam &longs;uperficiem fi&longs;tulæ; hæc autem &longs;u&longs;tinetur, vt volunt à cylindro exterioris aëris; ex hac porrò gravitatione qua&longs;i repercu&longs;&longs;a &longs;eu reflexa &longs;equitur, vt illius ni&longs;u, &longs;i pars &longs;ubjecta versùs latera cedere po&longs;&longs;it, versùs illa extrudatur; hinc aperto foramine, tanta vi erumpit; igitur ni&longs;us ille non pellit fi&longs;tulam, vel illius latera deor&longs;um, &longs;ed quoquo versùm per horizontalem di&longs;trahit, in quo, meo judicio, nul­la e&longs;t difficultas; &longs;altem apud eum; qui rem i&longs;tam paulò attentiùs per­pendat.

Chry&longs;ocom. Hæc ratio ad primam facilè refertur, qua &longs;cilicet proba&longs;ti, Antime, ex eo quod fi&longs;tula cum extante Mercurio appen&longs;a totam vim &longs;ui ponderis exerat, evinci, &longs;egmentum extantis Mercurij à cylindro exte­rioris medij, &longs;cilicet aëris, minimè &longs;u&longs;tineri.

Antim. Reducitur, non inficior; cùm tamen novum &longs;it experimentum, illudque &longs;atis luculentum, novæ rationis mihi loco e&longs;t.

Augu&longs;tin. Quid &longs;i non aëris, &longs;ed aquæ &longs;egmentum in fi&longs;tulam immitta­tur, antequam Mercurius de&longs;cendat in CI?

Antim. Hoc alij jam probarunt, inveneruntque, Mercurium &longs;ub&longs;idere infra C (1/14) altitudinis &longs;egmenti aquæ immi&longs;&longs;æ, quia pondus cylindri aquej 14. pedum v. g. e&longs;t æquale ponderi cylindri Mercurij vnum pedem alti; at verò &longs;i aëra, non aquam immi&longs;eris, Mercurius &longs;ub&longs;idit infra C, &longs;patio majore ip&longs;o &longs;egmento aëris immi&longs;&longs;i, ita illi, &longs;ed pace illorum dixerim; &longs;it enim fi&longs;tula BD 4 pedum; immittatur &longs;egmentum aëris altum vnum pedem, tum Mercurius, fiatque more &longs;olito, non &longs;ub&longs;idit Mercurius in­fra C &longs;egmento vnius pedis, ne dum majore ; itaque &longs;i &longs;egmentum aëris immi&longs;&longs;i &longs;it paulo minus, non nego fieri po&longs;&longs;e, vt &longs;egmentum de&longs;cen&longs;us Mercurij infra C &longs;it majus &longs;egmento aëris immi&longs;&longs;i, quod tamen genera­tim dici nequit ; &longs;ed hæc &longs;upra jam di&longs;cu&longs;&longs;imus. Venio ad quintam ratio­nem. Segmentum fi&longs;tulæ CD non e&longs;t vacuum, &longs;ed plenum alia materia, eaque valde ten&longs;a, ten&longs;o aëri haud ab&longs;imilis, qui exhau&longs;to per anthliam multo aëre, in recipiente, de quo &longs;upra re&longs;tat.

Chry&longs;ocom. Equidem jam &longs;upra proba&longs;ti, ad evidentiam, meo &longs;altem ju­dicio, &longs;egmentum CD vacuum non e&longs;&longs;e; &longs;ed aliqua tenui materia plenum; hoc facilè conce&longs;&longs;erim, ten&longs;am tamen e&longs;&longs;e nondum à te, quod &longs;altem à me perceptum &longs;it; huc v&longs;que probatum.

Antim. Deducere facilè poteras, ex adducto experimento ve&longs;icæ cy­prinæ, quæ po&longs;t de&longs;cen&longs;um Mercurij adeò intume&longs;cit; rejecimus enim re­&longs;pon&longs;ionem vel hypothe&longs;im &longs;upra laudati Autoris, quod &longs;cilicet aër in pli­cis inclu&longs;us, compre&longs;&longs;us priùs, &longs;uæ deinde libertati relictus, &longs;e&longs;e explicet, infletque ve&longs;icam; nam & tanta compre&longs;&longs;io aëris repugnat &longs;en&longs;ui, cùm inclinata fi&longs;tula detume&longs;cat ve&longs;ica, antequàm &longs;uperficies Mercurij ad illam perveniat; vnde manife&longs;tè &longs;equitur, ideò aëra intra ve&longs;icam dilatari, & tendi, quia ab ambiente ten&longs;o quoquo ver&longs;um adducitur.

Augu&longs;tin. Ex alio experimento ten&longs;am materiam e&longs;&longs;e in &longs;egmento CD, &longs;atis efficaciter probari po&longs;&longs;e, arbitror; nimirum ex eo quòd, vt &longs;upra dixi&longs;ti, Antime, pulpa digiti valide adducatur ab illa materia; exugatur copio&longs;us &longs;anguis; caro intume&longs;cat vberis ad in&longs;tar; nec enim aëri extrin­&longs;eco hic effectus tribui pote&longs;t, vt jam &longs;upra &longs;atis inculca&longs;ti; immo &longs;i incli­netur fi&longs;tula, cujus extremum B Mercurio immergitur, po&longs;tquàm denuò pre&longs;sè admotus e&longs;t extremo aperto B, exugitur, vt antea, digitus, vber­que intume&longs;cit, denique vt res magis per&longs;picua fiat, admoto digito ex­tremo ori fi&longs;tulæ ligneæ, vtrimque perviæ, altéque immer&longs;o extremo illo, cui pre&longs;sè digitus admotus e&longs;t, ita vt nihil aquæ &longs;ubingredi queat; licet cylindrus aquæ gravitet in cylindrum aëris fi&longs;tula contenti immer&longs;um, non tamen propterea exugitur digitus, intume&longs;cit digiti pulpa, a&longs;&longs;urgit vber; ille igitur digiti admoti effectus ab aëris exterioris cylindro non procedit: cuncta hæc, ni fallor, evincunt, intra CD materiam ten&longs;am ine&longs;&longs;e; nec quid­quam in contrarium opponitur, quod expeditè &longs;olvi non po&longs;&longs;it; non dee­runt tibi, Antime, aliæ rationes.

Antim. Non de&longs;unt haud dubiè: en tibi vnam ex poti&longs;&longs;imis; &longs;i infun­datur aqua &longs;upra Mercurium EF, attollatúrque fi&longs;tula, donec extremum B &longs;uperet &longs;uperficiem EF, illico Mercurius IC a&longs;&longs;urgit tanto impetu ver­sùs D, vt quandoque præ nimia ictus vi, fi&longs;tula di&longs;&longs;iliat; idem accidit, &longs;i extremum ex Mercurio adductum in aëre &longs;tatuatur; idem etiam accidit &longs;i valde inclinetur fi&longs;tula; ingreditur enim Mercurius maximo cum impetu, & versùs fundum D impactus maxima vi nonnunquam fi&longs;tulam frangit.

Chry&longs;ocomus. Hunc effectum, dubio procul omni, exterioris aë­ris cylindro prævalenti attribuent, &longs;icut in libra, vbi alteri lan­ci majus pondus imponitur, hæc alteram lancem &longs;ur&longs;um attol­lit.

Antim. Acutè omnino, ad &longs;peciem tamen, cùm reip&longs;a hæc ratio legi­tima non &longs;it; nec enim tanto impetu pondus de&longs;cendens aliud paulo mi­nus in altum tollit; &longs;ed longè tardiore motu, quàm &longs;i pondus motu acce­lerato deor&longs;um &longs;ine impedimento ferretur; atqui cylindrus aëris, vt ip&longs;i fatentur, eju&longs;dem e&longs;t ponderis cum &longs;egmento extante Mercurij IC, ef­fluente igitur modica Mercurij particula, ip&longs;ique &longs;uccedente particula aquæ molis æqualis, minima e&longs;t ponderum differentia; igitur quamvis cylindrus aëris prævaleat, illud tamen modicum di&longs;crimen virium tantum motum ciere non pote&longs;t, quia &longs;cilicet motus acceleratus deor&longs;um circa initium tardi&longs;&longs;imus e&longs;t, &longs;ecus tamen motus ten&longs;orum, vel compre&longs;&longs;orum; nimirum corpus compre&longs;&longs;um &longs;tatim initio maxima (vid. Figuram in pag.183.) vi erumpit; præterea &longs;uppponamus tubum geminum BCA, infun­datur aqua per os B; &longs;en&longs;im hæc a&longs;&longs;urgit per canalem CA; &longs;it clavicula &longs;eu verticillus in H, ita vt &longs;egmentum HA vacuum aqua relinquat, & tamdiu infundatur per os B, donec aqua perveniat ad &longs;ummum verticem B, tum volvatur verticillus H, illico aqua a&longs;cendit in A, non tamen tanto cum impetu; idem fit, &longs;i Mercurius infundatur; ex quo deduco tantam vim motus, (vid. Figuram in pag. 184.) vel impetus a&longs;&longs;urgentis Mer­curij per CD, non e&longs;&longs;e à pondere cylindri aëris, cùm par &longs;it vtrimque ra­tio; idem probari poterit in canali tantulùm inflexo vel incurvato; nempe licèt in altero brachio prævaleat aquæ pondus, non tamen ea propter tan­ta i impetus a&longs;&longs;urgit in altero; accedit, quòd eadem vi, &longs;ur&longs;um Mercu­rius adducitur, qua digiti pre&longs;sè affixi pulpa &longs;eu caro; hæc autem à mate­ria ten&longs;a duntaxat adducitur, cùm nulla alia cau&longs;a applicata &longs;it; denique licet hic effectus æquè attribui po&longs;&longs;et cylindro aëris, ac ten&longs;æ in &longs;egmento C D materiæ, cùm tamen aliqua &longs;int in hoc ca&longs;u, quæ cylindrus aëris &longs;al­vare non pote&longs;t, licèt &longs;uppo&longs;ita illa materia ten&longs;a optimè &longs;alventur; non e&longs;t dubium, quin totus effectus huic potiùs, quàm illi cau&longs;æ attribuen­dus &longs;it.

Chry&longs;ocom. Demus igitur in &longs;egmento CD materiam ten&longs;am con­tineri; quid inde? an fortè illa Mercurij &longs;egmentum CI &longs;u­&longs;tinet?

Augu&longs;tin. Haud dubiè, cùm dilatari ac tendi vltra non po&longs;&longs;it: vnde vide­tur e&longs;&longs;e quoddam qua&longs;i &etail;quilibrium, ita vt nec materia ten&longs;a attollere po&longs;&longs;it majus pondus Mercurij, quam CI, neque hoc pondus Mercurij dilatare vl­tra materiam ten&longs;am in CD.

Antim. Non ita profectò res &longs;e habet, Augu&longs;tine; nam &longs;i hoc e&longs;&longs;et, quo altius e&longs;&longs;et &longs;egmentum materiæ ten&longs;æ CD, majore vi polleret addu­ctiva, vt ita loquar: igitur Mercurium &longs;upra C attolleret; infra C verò, quò brevius e&longs;&longs;et illius &longs;egmentum; quod omnibus experimentis repu­gnat; &longs;ive enim longior, &longs;ive brevior &longs;it fi&longs;tula, modò &longs;it paulo altior IC ; æquale &longs;emper &longs;egmentum Mercurij extat; dicerem igitur, data præfa ta hypothe&longs;i materiæ ten&longs;æ, Mercurium ip&longs;i adhærere; hanc verò fi&longs;tulæ, iuxta Naturæ in&longs;titutum, de quo &longs;upra, vnde &longs;u&longs;tinetur Mercurij &longs;egmentum IC ab illa vi, quæ fi&longs;tulam &longs;u&longs;tinet, ita pror&longs;us &longs;cyphus ex aqua non plènè eductus, &longs;ecum aquam adducit, cujus pondus is profectò &longs;entit, qui &longs;cyphum &longs;u&longs;tinet; &longs;ic Mercurius breviorem fi&longs;tulam &longs;egmento IC totam occupat, licèt immergatur in Mercurium EF ; adhæret enim Mercurius vitro, & ab eo &longs;u&longs;tinetur, qui fi&longs;tulam &longs;u&longs;tentat; vbi verò al­tior e&longs;t fi&longs;tula, & tantùm e&longs;t Mercurij pondus quantum requiritur ad ex­primendam, exugendam, educendam, eliciendam illam materiam ten­&longs;am, vndecunque tandem exugatur, de quo infra, de&longs;cendit Mercurius in CI, adhærétque materiæ ten&longs;æ, & hæc fi&longs;tulæ; ita vt fi&longs;tula &longs;u&longs;tineri non po&longs;&longs;it, ni&longs;i &longs;imul tum materia, tum Mercurius extans &longs;u&longs;tineatur. Sup­po&longs;ita igitur illa materia ten&longs;a, &longs;egmentum Mercurij CI non &longs;u&longs;tinetur à cylindro aëris, &longs;altem &longs;olo, nam illo etiam &longs;ublato, cùm pondus Mercurij CI æquale &longs;it re&longs;i&longs;tentiæ, qua materia ten&longs;a in &longs;egmento CD majori ten&longs;ioni re&longs;i&longs;tit, de&longs;cendere non pote&longs;t infra C, ni&longs;i vacuum inducatur, quod expo­&longs;ito Naturæ in&longs;tituto repugnat, vt patet.

Augu&longs;tin. Scire velim, cur particulam illam &longs;altem Solo, addi­deris, qua&longs;i fortè putes cylindrum illum aëris nonnihil con­ferre.

Antim. Dicam paulò po&longs;t; &longs;i enim materia illa ten&longs;a rarior e&longs;t aëre, exter­nus aër haud dubiè nonnihil confert, de quo infra; ne rationes contra illam hypothe&longs;im, quam impugno, interrumpam. Sit ergo &longs;enta ratio; Quan­do admovetur corpus calidum &longs;egmento CD, po&longs;t de&longs;cen&longs;um Mercurij v.g. Lacca liquata, &longs;eu ferrum candens, Mercurius &longs;ub&longs;idit infra C, igitur non &longs;u&longs;tinetur à cylindro aëris externi, quod, ni fallor, per&longs;picuè pro­bare po&longs;&longs;um; nam cùm idem maneat cylindrus aëris exterioris, eadem vis illius manet; igitur idem Mercurij &longs;egmentum IC &longs;u&longs;tinet; cur ergo de&longs;cendit Mercurius infra C? hoc autem &longs;equitur, &longs;ive &longs;egmentum CD vacuum &longs;it, &longs;ive tenui materia plenum; primum quidem, vt patet; alte­rum verò, quia cùm materia illa frigore den&longs;atur, & contrahitur, vel &longs;ecum adducit in illa contractione Mercurij &longs;uperficiem C, atque ita aër exterior &longs;egmentum Mercurij extantis non &longs;u&longs;tinet, &longs;ed hoc materiæ te­nui adhæret, & hæc fi&longs;tulæ; vel &longs;ecum non adducit, ac proinde fit vacuum; nec Mercurius &longs;upra C a&longs;&longs;urgit, cùm &longs;upra illud attolli non po&longs;&longs;it à Cylindro exterioris aëris, cujus pondus idem manet, ac proinde ii&longs;dem viribus pollet.

Augu&longs;tin. Hæc ratio, ne quid di&longs;&longs;imulem, rem mihi pror&longs;us per&longs;uadet; cylindrus enim aëris exterioris, à quo, vt nonnulli volunt, Mercurij ex­tantis &longs;egmentum &longs;u&longs;tinetur, neque plus, neque minus pote&longs;t &longs;u&longs;tinere; igi­tur &longs;i ferrum candens admoveatur &longs;egmento CD, & hoc vacuum &longs;it; nul­la e&longs;t ratio, cur &longs;uperficies C &longs;ub&longs;idat; &longs;ub&longs;idit tamen; &longs;i verò nix, vel trita glacies admoveatur CD, & hoc plenum &longs;it tenui materia, hæc quidem contrahitur, ni&longs;i tamen &longs;ecum &longs;uperficiem C adducat, attollátque, hæc haud dubiè non a&longs;&longs;urgit; cùm à cylindro aëris vltra C attolli non po&longs;&longs;it; &longs;i autem, eam materia illa &longs;e&longs;e contrahens &longs;ecum adducat, attollátque; ad &longs;u&longs;tinendum &longs;egmentum Mercurij IC adhærentis prædictæ materiæ, vt hæc fi&longs;tulæ, cylindri exterioris æquipondio non e&longs;t opus.

Chry&longs;oc. Quid &longs;i dicerem, vitrum ip&longs;um fi&longs;tulæ contrahi præ frigore, & præ calore explicari; ac proinde materiam illam ratione va&longs;is, modò con­trahi, modò explicari, ex quo etiam Mercurij &longs;uperficies &longs;ub&longs;idat, vel a&longs;­&longs;urgat?

Augu&longs;tin. Hæc re&longs;pon&longs;io nullius momenti e&longs;t vt jam &longs;upra o&longs;ten&longs;um fuit; &longs;uppo&longs;ito &longs;egmento CD vacuo, &longs;i verò &longs;upponatur plenum &longs;ubtili materia, contrarium omnino accideret; vbi enim laxatur vitrum, cùm plus &longs;patij re­&longs;tet, dicta materia totum implere non pote&longs;t, vnde Mercurius a&longs;&longs;urgat opor­tet, cùm tamen præ calore &longs;ub&longs;idat; vbi verò vitrum contrahitur, minus &longs;pa­tij &longs;upere&longs;t intra &longs;egmentum CD, quod cùm non &longs;ufficiat, tenui materiæ &longs;uperficiem Mercurij premit, ac proinde hæc &longs;ub&longs;idit, cùm tamen præ figu-re a&longs;&longs;urgat; &longs;ed diutiùs, quàm par &longs;it, hæreo in hac ratione; exprome quæ­&longs;o alias, &longs;i quæ fortè re&longs;tant.

Antim. Non parum, vt video, roboris prædictæ rationi per te acce&longs;&longs;it; &longs;ed ad &longs;eptimam venio; &longs;i po&longs;tquam &longs;ub&longs;idit | Mercurius in CI, vas BAG ita claudatur, vt nulla rima &longs;uper&longs;it, per quam aër &longs;ubeat, non tamen pro­pterea Mercurius CI &longs;ub&longs;idit, &longs;ed tunc non &longs;u&longs;tinetur à cylindro aëris; quia &longs;cilicet non e&longs;t applicatus, hæc ratio non minus per&longs;picua e&longs;&longs;e videtur an­tecedente.

Augu&longs;tin. Nollem, hoc dixi&longs;&longs;es, Antime, in meridiana luce cæcutire vi­deris, quod certè lynceos oculos non decet; quare tibi autor e&longs;&longs;em, vt per­peram dicta revoces, aut &longs;altem procures, vt omnes intelligant, hæc à te di­cta e&longs;&longs;e per jocum animi gratia.

Antim. Me, tibi &longs;ummopere ob&longs;trinxeris, Augu&longs;tine, &longs;i cæcucienti ba­culum &longs;altem ducem porrigas, qui me juxta atque no&longs;tratem Carte&longs;ium, rectiùs philo&longs;ophari doceat; quod de lynceis oculis &longs;ubdidi&longs;ti; &longs;cio, quò &longs;pectet, indignum pror&longs;us me reputo &longs;ummo illo honore, quo me &longs;ereni&longs;­&longs;imus, pro illa &longs;ingulari qua pollet humanitate, cumulare dignatus e&longs;t: &longs;ed quæ&longs;o te, dedoce me; rectè enim meo &longs;altem judicio, mihi videor ratioci­nari, dum ex eo, quod cylindrus aëris exterioris, probè clau&longs;o va&longs;e &longs;uperfi­ciei Mercurij EF applicatus non &longs;it, ab eo nullo modo &longs;u&longs;tineri &longs;egmentum Mercurij extantis IC, deduco.

Augu&longs;tin. Aër inter &longs;uperficiem Mercurij EF, & operculum va&longs;i ap­po&longs;itum contentus re&longs;i&longs;tit; cùm vltra comprimi non po&longs;&longs;it, à Mercurio C I, &longs;icuti neque antequam operculum apponeretur, à cylindro aëris, exte­rioris eju&longs;dem ponderis cum Mercurio IC vltra comprimi poterat, reti­net enim totam compre&longs;&longs;ionem à prædicto aëris cylindro ante impre&longs;&longs;am; cùm igitur Mercurius IC de&longs;cendere non po&longs;&longs;it, ni&longs;i prædictum aëra vl­tra comprimat, hunc porrò comprimere vltra nequeat; quid mirum amabo te, &longs;i de&longs;cendere non valeat, ac proinde &longs;u&longs;pen&longs;us maneat in IC?

Antim. Igitur cylindrus aëris non &longs;u&longs;tinet Mercurium IC ; &longs;ed prædi­ctus aër, operculum inter & &longs;uperficiem Mercurij EF interceptus, impedit, ne cadat; quid quæ&longs;o aliud dico? quid intendo probare, ni&longs;i &longs;egmentum Mer­curij extantis non &longs;u&longs;tentari à cylindro aëris exterioris? Iam verò facilè o&longs;ten­do non &longs;u&longs;tineri, &longs;eu &longs;u&longs;pendi in IC, eo quod aër interceptus inter opercu­lum & &longs;uperficiem EF, vlteriori compre&longs;&longs;ioni re&longs;i&longs;tat; nempe &longs;i admoto dicto operculo, & extante Mercurio in IC, aperiatur foramen in D, Mercurius il­lico infra C de&longs;cendit, idque notabili &longs;egmento; et&longs;i vacuitas EFGA cana­liculo FR conjungatur cum ampli&longs;&longs;imo va&longs;e P vacuo, majore adhuc &longs;e­gmento Mercurius IC de&longs;cendit, vt non &longs;emel probavi.

Augu&longs;tin. In&longs;igni paralogi&longs;mo nos ludis, Antime; retices enim novam vim accedentem, per quam Mercurius IC deprimitur, & dictus aër inter­ceptus vltra comprimitur; cylindri &longs;cilicet aëris, per foramen in D apertum &longs;uperficiei Mercurij C applicati; cùm igitur dupla vis ponderis aëri inter­cepto incumbat, nimirum &longs;egmenti Mercurij IC & ponderis ip&longs;i æqualis, &longs;cilicet cylindri aëris exterioris, quid mirum, &longs;i prævaleat, & aëra interceptum vltra comprimat, atque adeò Mercurius infra C de­&longs;cendat?

Antim. Ad vltimam metam, opinor, hanc difficultatem promovi&longs;ti; ego quoque vltimam manum admoveo, ac dico, non magis comprimi aëra interceptum inter EF & dictum operculum à Mercurio IC, & cylindro aëris gravitantis per foramen D, quàm remoto operculo & clau&longs;o foramine D, ab eodem Mercurio IC, & eodem cylindro aëris exterioris; nam perin­de e&longs;t, &longs;ive tota vis pre&longs;&longs;ionis per lineam vnicam incidat, vel applicetur, five &longs;ubduplum per vnam, & &longs;ubduplum per oppo&longs;itam; &longs;uppone, &longs;i vis, tu­bum; altera parte clau&longs;um, in quem immi&longs;&longs;o embolo contentus aër compri­matur, applicata potentia vt 8.fac &longs;egmentum &longs;eu compre&longs;&longs;ionis men&longs;uram e&longs;&longs;e 4. digitorum; &longs;i idem tubus &longs;it vtrimque pervius, & duo emboli hinc inde immittantur, applicata vtrimque potentia vt 4.idem haud dubiè com­pre&longs;&longs;ionis effectus con&longs;equetur: igitur quantumvis tum Mercurius CI, tum aër gravitans per foramen D, communi quodam ni&longs;u in aëra interceptum, de quo &longs;upra, agant, vt magis illum comprimant, certè vltra comprimere non po&longs;&longs;unt; quia jam compre&longs;&longs;us e&longs;t à viribus æqualibus, id e&longs;t ab ii&longs;dem ponderibus, &longs;ed diver&longs;o modo applicatis; aperto igitur foramine in D, Mercurius CI &longs;ub&longs;idere non po&longs;&longs;et, &longs;ub&longs;idit tamen, cùm priùs nondum aperto foramine, minimè &longs;ub&longs;ideret. Vnde, ni fallor, per&longs;picuè deduco, non ideò, admoto &longs;cilicet operculo in AG, extare Mercurium IC, & minimè &longs;ub&longs;i­dere; quia &longs;cilicet dictus aër interceptus inter &longs;uperficiem Mercurij FE & admotum operculum, comprimi vltra non pote&longs;t; &longs;ed quia materia ten&longs;a C D, cui Mercurius adhæret, tendi vltra nequit, ni&longs;i major vis ponderis ap­plicetur; aperto verò foramine in D, cum vlteriori ten&longs;ione opus non &longs;it, ad de&longs;cen&longs;um Mercurij CI, non parum de&longs;cendit, aérque interceptus tan­tulum comprimitur; accedente quoque va&longs;e vacuo P, vt dictum e&longs;t &longs;upra, profundiùs Mercurius CI de&longs;cendit, quia tantulum compre&longs;&longs;ionis multo aëri faciliùs di&longs;tribuitur, quam modico; cùm &longs;ingulis partibus minùs com­pre&longs;&longs;ionis competat.

Augu&longs;tin. Iam multa lux ex iis, quæ hactenus à te dicta &longs;unt, a&longs;&longs;equendi veritatem, mihi afful&longs;it: jam enim clari&longs;&longs;imè con&longs;tat, &longs;egmentum CD va­cuum non e&longs;&longs;e, in quo, ni fallor, omnes ferè conveniunt.

Antim. Omi&longs;eram pulcherrimum argumentum cuilibet obvium, in quo vel ip&longs;is oculis, &longs;patium illud non e&longs;&longs;e vacuum comprobatur, po&longs;tquam enim &longs;ub&longs;idit Mercurius in CI, &longs;i fene&longs;tras conclavis in quo degis claudi jubeas, excepto modico foramine per quod radius &longs;olaris traiciatur, & &longs;egmentum CD intra radium trajectum immergas, videbis illico intra ca­vitatem CD radio & luce perfu&longs;am atomos fluitantes: vnde nece&longs;&longs;e dictu &longs;it, fluitare in materia no&longs;tro aëri non ab&longs;imili, vt jam &longs;upra indica­veram.

Augu&longs;tin. Iucundum &longs;anè, juxta atque facilè experimentum, quod vacuum omnino profligat: con&longs;tat etiam non &longs;u&longs;tineri extantem Mercu­rium CI ab exterioris aëris cylindro, &longs;altem &longs;olo, vt jam obiter monui&longs;ti: nec etiam ab aëre compre&longs;&longs;o, &longs;ive libero, &longs;ive intercepto: alioquin plus aëris compre&longs;&longs;i plus Mercurij attolleret: plus autem e&longs;&longs;et aëris compre&longs;&longs;i adjun­cto va&longs;e P: tunc igitur plus Mercurij attolleretur: cùm tamen minùs attol­latur, & profundiùs &longs;ub&longs;idat extans Mercurius CI. Iam re&longs;tat, vt quid &longs;en­tias, exponas.

Antim. Antequam illud exequar, alia quædam hypothe&longs;is rejicienda e&longs;t: Nempe aliqui volunt, e&longs;&longs;e quoddam corpus tenui&longs;&longs;imum, aere no­&longs;tro longè &longs;ubtilius (&longs;unt qui æthera vocent) quod per poros omnium corporum facilè penetret, &longs;eu permeet: hoc autem adduci volunt à Mer­curio de&longs;cendente per poros vitri, donec re&longs;i&longs;tentia partium aëris, quæ vltra con&longs;tipari non po&longs;&longs;unt, vt &longs;ic loquar, ni&longs;i à majore pondere, quàm &longs;it pondus extantis Mercurij CI pondus adæquet &longs;egmenti Mercurij ex­tantis.

Chry&longs;oc. Hæc &longs;ententia valde ingenio&longs;a mihi &longs;emper vi&longs;a e&longs;t, cùm totam remi&longs;tam ad circulationem Platonicam reducat: qua fiat &longs;cilicet, vt dum vnum corpus pello, hoc etiam aliud pellat, & hoc aliud, & &longs;ic deinceps, do­nec vltimò pul&longs;um, facto qua&longs;i circuitu, in locum primi pul&longs;i &longs;uccedat: &longs;ic adduci volunt, aquam, per &longs;yringam, educto embolo: nempe &longs;egmentum emboli eductum pellit aëra, & illius locum occupat: hic porro aër pellit alium, & hic alium: donec tandem vltimò pul&longs;us, &longs;uperficiem aquæ pellat, & hæc aquam in &longs;yringam intrudat, in locum &longs;egmenti emboli educti: atque ita nullus e&longs;t vacui metus, nulla corporum adhæ&longs;io, & omnia per communia principia explicantur.

Antim. Hæc mera e&longs;t circulatio Platonica, contra quam tamen in&longs;upe­rabiles difficultates militare videntur: & primò quidem contra id, quod vl­timo loco dicebas, Chry&longs;ocome luculentum facit experimentum: &longs;i enim &longs;egmentum emboli, quod ex &longs;yringa educitur, in alium tubum, cujus cavi­tati probè congruat, & alterum extremum clau&longs;um &longs;it, compre&longs;&longs;o &longs;cilicet aëre immittas, aqua pariter per &longs;yringam citra prædictam aëris circulatio­nem attollitur.

Augu&longs;tin. Dicerem attolli ab aëris cylindro incubantis in &longs;uperficiem aquæ: nec enim, opinor, negabis, dato quod &longs;egmentum &longs;yringæ, educto embolo, vacuum maneret, futurum, vt aër in aquam gravitans, eam per &longs;y­ringam ad occupandum vacuum impelleret.

Antim. Nihil probas, contra me, hoc enim non facit, quin citra prædi­ctam circulationem aëris, educto embolo, aqua attollatur, cùm nulla peni­tus circulatio in hoc ca&longs;u intercedat: deinde admoto va&longs;i, in quo aqua con­tinetur, operculo, vt &longs;upra dictum e&longs;t, modò mediocris aëris portio inter &longs;uperficiem aquæ & admotum operculum intercepta remaneat, adducto embolo, attollitur aqua: igitur nec cylindro aëris incubantis, nec per circu­lationem attollitur: nec e&longs;t, quod ad prodigio&longs;am illam aëris compre&longs;&longs;io­nem confugias, quam &longs;upra jam rejecimus, neque hic repetere vacat.

Chry&longs;ocom. Dicent æthera per appo&longs;iti operculi poros intro &longs;u­bire, ac premere &longs;uperficiem aquæ, vnde non mirum, &longs;i hæc attol­litur.

Antim. Sed æquè facilè, immo faciliùs intra ip&longs;am &longs;yringam æther ille &longs;ubiret per poros: dico faciliùs: quia id fieret citra elevationem aquæ, cui pondus eju&longs;dem &longs;e&longs;e opponit, deinde æther ille per poros aquæ facilè &longs;ubiret in locum ab embolo relictum, intra &longs;yringam. Deni­que, quo plus e&longs;t aëris intercepti, operculum inter & &longs;uperfi­ciem aquæ, eò faciliùs adducto embolo, aqua per &longs;yringam attolli­tur: ídque multò magis, &longs;i &longs;patium illud ab aëre intercepto occupa­tum, canaliculo cum majore va&longs;e vacuo conjungatur, eo modo, quo &longs;upra dictum e&longs;t.

Augu&longs;tin. Sed dic mihi, &longs;odes, Antime, numquid putas, aquam educto embolo, ideò attolli, quia ab aëris cylindro in &longs;uperficiem aquæ gravitante attollitur?

Antim. Dum adduco embolum, totum aquæ pondus &longs;entio, illius &longs;cilicet, quæ attollitur: quomodo igitur à dicto aëris cylindro attollitur, aut &longs;u&longs;tinetur? prætereà &longs;egmentum emboli, quod educitur attollit æqua­lem cylindrum aëris: aqua igitur quæ extremæ emboli ba&longs;i adhæret, cum embolo adducitur eo modo, quo &longs;upra dictum: equidem &longs;i quis per fi­&longs;tulam, &longs;eu cannam catapultæ longioris, cujus cavitas accuratè ac dili­genter tornata &longs;it, & immi&longs;&longs;æ glandi pror&longs;us æqualis, admoto ore addu­cat, vt fieri &longs;olet, anhelitum, glans ip&longs;a tanto cum impetu adducitur, vt hæc in dentem maximo cum impetu, non tamen &longs;ine periculo impingatur, quia &longs;cilicet adducto aëre pilam inter & buccam intercepto, totus cylin­drus aëris adver&longs;us glandem à tergo gravitationis &longs;uæ vim exerit: quid mirum ergo, &longs;i prædictam glandem magna vi impellat? hujus rei pericu­lum fecit vir jam &longs;upra, &longs;ed nunquam &longs;atis laudatus Eu&longs;tachius, cum fracti dentis jactura, vt mihi deinde narravit.

Chry&longs;ocom. Sed quæ&longs;o te, quid in hac hypothe&longs;i adducti æthe­ris in &longs;egmentum CD tibi di&longs;plicet? Mercurius enim in vas de&longs;­cendens extrudit è &longs;ummo va&longs;e illam aëris portionem, vt ejus locum oc­cupet: hæc vt locum inveniat alias pellit, & cùm nihil vacui &longs;it præ­ter &longs;egmentum CD, & cum eo aër intrudi non po&longs;&longs;it, &longs;ubtilior æther intru­ditur.

Antimus. Multa ob&longs;unt huic hypothe&longs;i: Primo ve&longs;icæ cyprinæ adeò intume&longs;centis, po&longs;tquam Mercurius de&longs;cendit in CI, phænomenon in dicta hypothe&longs;i explicari nequit, cùm tumere non po&longs;&longs;it ni&longs;i ab aëre intus compre&longs;&longs;o, vel ambiente dilatato: æther neutrum præ&longs;tat. Secundo pul­pa digiti intus adducta, vis impacti Mercurij, & alia quamplurima, quæ vim illam exuctivam, vt &longs;ic loquar, manife&longs;tè demon&longs;trant atque adeò materiam dilatatam in &longs;egmento CD, præfatæ hypothe&longs;i repugnant: nempe illa materia prædictos effectus impediret potiùs, quàm produce­ret. Tertio, cùm maxima &longs;it ætheris copia, Mercurius de&longs;cendens ex C in I, æquè facilè portionem hujus ætheris in fi&longs;tulam intruderet ad occu­pandum &longs;patium CI, ac cylindrus aëris, vel alia quælibet cau&longs;a in fi&longs;tu­lam inclinatam regerit Mercurium, & extrudit æthera ex &longs;egmento CD, & verò cum totus ni&longs;us in eo po&longs;itus &longs;it, vt &longs;cilicet intrudatur æther in fi&longs;tulam ab aëre &longs;ecretus, ideò Mercurius extat in IC juxta i&longs;tam hypo­the&longs;im; quia illius ponderis vis non &longs;ufficit, vt intrudat plus ætheris per poros fi&longs;tulæ; quid ergo amabo in fi&longs;tulam inclinatam retrudit Mercu­rium, & ex CD æthera extrudit? non certè cylindrus aëris, in quem hæc hypothe&longs;is hoc phænomenon non refert; deinde æqualia &longs;unt momen­ta Mercurij extantis CI, & præfati cylindri; cùm igitur vis ponderis CI minor &longs;it, quàm par &longs;it, ad intrudendum æthera in &longs;egmentum CI, vis etiam cylindri aëris minor erit, quàm par &longs;it ad extrudendum æthere ex CD, eadem enim vi extruditur, qua intruditur.

Chry&longs;ocom. Dicent, aëra compre&longs;&longs;um manere po&longs;t de&longs;cen&longs;um Mercurij, immo inde fortè compre&longs;&longs;um e&longs;&longs;e, quòd partes ætheris ante interceptæ, expre&longs;&longs;æ fuerint, & in fi&longs;tulam per poros intru&longs;æ; vltra autem comprimi non pote&longs;t, ni&longs;i vis major &longs;it pondere extantis Mercurij CI; vbi verò in­clinatur fi&longs;tula, vis aëris compre&longs;&longs;i, cùm decre&longs;cat momentum ponderis Mercurij CI, illud facilè &longs;uperat, novumque Mercurium in fi&longs;tulam re­trudit.

Antim. Nihil horum cum recta ratione con&longs;entit; Primò, quia aër ex­ternus po&longs;t de&longs;cen&longs;um Mercurij nullo &longs;en&longs;u compre&longs;&longs;ior percipi pote&longs;t. Secundò; Illius partes non &longs;unt magis con&longs;tipatæ quàm ante, cùm æthe­ris copia affatim &longs;uppetat. Tertiò, flante vento novus aër identidem fi&longs;tu­lam ambit. Quartò, illa vis aëris compre&longs;&longs;i, quam ponis, &longs;i potis e&longs;t, non modò per fi&longs;tulam inclinatam Mercurium attollere, novumque intrude­re, verùm etiam æthera per poros fi&longs;tulæ ex &longs;egmento CD extrudere, potiori iure intruderet in &longs;egmentum CI fi&longs;tulæ perpendiculariter ere­ctæ, externum æthera, præ&longs;ertim cùm nihil extantis Mercurij deor­&longs;um ad prædictam intru&longs;ionem concurrat: adde &longs;is omnes alias ratio­nes, quæ contra &longs;upra rejectam hypothe&longs;im à me adductæ &longs;unt; cùm æquè ferè militent contra i&longs;tam, tu vide &longs;is, nam repetere non vacat.

Augu&longs;tin. Sed quid tandem tu &longs;i enim ad hoc phænomenon expli­candum cylindrus aëris non &longs;ufficit, nec vacuum, nec aëris compre&longs;&longs;io, nec æther, quid tibi quæ&longs;o re&longs;tabit.

Antim. Sen&longs;u duce, in hanc hypothe&longs;im veni, vt dicerem in &longs;egmento CD tenuem quandam materiam ten&longs;am contineri, quæ cùm à pon­dere Mercurij extantis CI tendi vltra non po&longs;&longs;it, & alioquin adhæreat fi&longs;tulæ, ip&longs;ique Mercurius; non mirum e&longs;t, &longs;i Mercurius maneat &longs;u&longs;­pen&longs;us: dixi &longs;en&longs;u duce; dum enim video præfatam ve&longs;icam intume&longs;­cere, in de&longs;cen&longs;u Mercurij, in a&longs;cen&longs;u verò, inclinata fi&longs;tula, detume&longs;ce­re, antequam Mercurius ve&longs;icam tangat, illud dumtaxat occurrit, vt dicam, ab ambiente materia ve&longs;icam illam dilatari ac tendi, quod quo­modo fiat fingi non pote&longs;t, ni&longs;i materia illa ten&longs;a &longs;it. Secundò, dum &longs;en­tio carnem digiti attolli, & in vber tume&longs;cere, eo modo, quo &longs;upra ex­po&longs;itum fuit, immo & &longs;anguinem exugi, licèt oppo&longs;ita digiti pars nihil prorsus &longs;entiat, nihil aliud in mentem venit, ni&longs;i trahi ab intrin&longs;eco, ac proinde ab aliqua ten&longs;a materia. Tertiò, Dum video Mercurium incli-nata fi&longs;tula tanta vi in ba&longs;im D impingi, itemque elevato &longs;upra &longs;uper­ficiem EF extremo aperto B; item &longs;i admoto pre&longs;&longs;è digito extremo B fi&longs;tula educatur, inclineturque; cuncta hæc attentè con&longs;ideranti, & in­tuenti nulla tanti impetus cau&longs;a extrin&longs;eca e&longs;&longs;e videtur, vt patet ex iis quæ fusè à me &longs;upra di&longs;putata &longs;unt; immo admoto pre&longs;&longs;è digito, nulla cau&longs;a exterior applicata e&longs;t; igitur interna e&longs;t, vel intrin&longs;eca; igitur vel à corpore compre&longs;&longs;o vel ten&longs;o: Non primum, nam non loci, &longs;ed locati &longs;unt angu&longs;tiæ; igitur alterum. Quartò, dum admoto pre&longs;&longs;è digito, eductam fi&longs;tulam &longs;ic libro, vt modo in D, modò in B Mercurius magna vi impingatur, hoc ferè in in&longs;tanti fieri videtur, ad in&longs;tar qua&longs;i fulguris coru&longs;cantis; &longs;ed tanta vis motus tribui non pote&longs;t motui gravium in plano inclinato, cùm vix fi&longs;tula à plano horizontali tantulum deflectat, ac proinde planum hoc adeò celerem motum non patitur; alia igitur cau&longs;a e&longs;t tam velocis motus; non compre&longs;&longs;io, vt dixi; igitur ten&longs;io. Quintò, Illa materia quæ priùs occupabat &longs;egmentum CD, inclinata fi&longs;tu­la & labente Mercurio in CD, temporis ferè momento tran&longs;it in CI, nec vlla via apparet, qua tran&longs;eat; ten&longs;am igitur e&longs;&longs;e nece&longs;&longs;e e&longs;t; ten&longs;a enim illico adducuntur.

Augu&longs;tin. Hanc hypothe&longs;im apprimè intelligo, videoque, multa &longs;anè in ea explicari po&longs;&longs;e. Primò, cur extet Mercurius CI, quia &longs;cilicet re&longs;i­&longs;tentia ad vlteriorem materiæ ten&longs;ionem, adæquat vim ponderis Mer­curij CI. Secundò, Cur &longs;emper eadem &longs;it extantis Mercurij CI nimi­rum pedum 2. & ferè &longs;ive angu&longs;tior &longs;it fi&longs;tula, &longs;ive laxior; quia in eadem proportione cre&longs;cit re&longs;i&longs;tentia materiæ ad vlteriorem ten&longs;ionem, in qua cre&longs;cit pondus Mercurij extantis. Tertiò, Cur inclinata fi&longs;tula adduca­tur Mercurius in CD ; quia tunc minus e&longs;t ponderis Mercurij momen­tum in plano inclinato; quid mirum ergo; &longs;i à ten&longs;ionis momento &longs;u­peretur, quod &longs;upponitur æquale momento ponderis in perpendiculo. Quartò, cur ve&longs;ica cyprina infletur, pulpa digiti ad in&longs;tar vberis attolla­tur, &longs;anguis exugatur; ten&longs;a enim materia alia corpora, quibus e&longs;t con­tigua, ad &longs;e adducit & trahit. Quintò, Cur Mercurius educta fi&longs;tula ex Mercurio, tanta vi in oppo&longs;itam fi&longs;tulæ ba&longs;im impingatur; tribus illis modis, de quibus &longs;upra; vis enim ten&longs;ionis, quæ tunc prævalet; initio maxima e&longs;t; in hoc di&longs;&longs;imilis potentiæ motrici gravium, quæ initio mi­nima e&longs;t. Sextò, Cur applicato ferro candente &longs;egmento fi&longs;tulæ CD &longs;ub­&longs;idat Mercurius infra C; quia tunc rare&longs;cit illa materia, vnde magis ex­tenditur; hinc deor&longs;um Mercurium CI nece&longs;&longs;ariò deprimit; &longs;ecus verò applicato gelu den&longs;atur, atque adeò contrahitur, & Mercurium &longs;ur&longs;um attollit. Septimò, Cur appen&longs;a fi&longs;tula DB totum extantis Mercurij CI pondus &longs;entiatur; quia Mercurius adhæret materiæ ten&longs;æ, & hæc fi&longs;tu­læ. Octavò, Cur &longs;tatim po&longs;t de&longs;cen&longs;um, libretur aliquamdiu Mercurius, ita vt modò &longs;upra C a&longs;cendat, modò infra deprimatur; quia cùm de­&longs;cendat motu accelerato vires acquirit eundo, ac proinde re&longs;i&longs;tentiæ momentum &longs;uperat; at decre&longs;cente pondere, prævalet tandem ten&longs;io­nis re&longs;i&longs;tentia; vnde &longs;ur&longs;um denuò Mercurius adducitur; atque ita ali-quamdiu &longs;ur&longs;um deor&longs;umque libratur: Cogita pondus funependulum ex chorda ten&longs;a vel arcu. Nonò, Cur &longs;i tantulum aëris in fi&longs;tula relinqua­tur, Mercurius po&longs;t de&longs;cen&longs;um &longs;ub&longs;idat infra C: quia illud tantulum aëris tum à Mercurio, tum à materia ten&longs;a dilatatur, vnde majus &longs;pa­tium occupet nece&longs;&longs;e e&longs;t; ac proinde, vt &longs;patium CD explicatur, ita CI contrahitur; &longs;ecus accidit intru&longs;a aqua, loco aëris; quia aqua, vt ad compre&longs;&longs;ionem, ita ad ten&longs;ionem inepta e&longs;t. Decimò, Cur admoto pre&longs;&longs;è digito ori B, & librata huc illuc fi&longs;tula, illa materia tam cito tran­&longs;eat ab extremo ad extremum: nam propter ten&longs;ionem, non modò ci­ti&longs;&longs;imè adducitur, verùm etiam facilè contrahitur, inter fi&longs;tulam & Mercurium. Cuncta hæc & alia quamplurima, quæ facilè &longs;uggeres, in hac tua hypothe&longs;i explicare po&longs;&longs;em; &longs;ed vnde quæ&longs;o i&longs;ta materia? & quo tandem illa, cùm inclinata fi&longs;tula a&longs;&longs;urgit Mercurius, & totam implet?

Antim. Vel inde tibi maximoperè ob&longs;trictus &longs;um, quod ab onere illa explicandi me liberum e&longs;&longs;e volueris; quæ obiter quidem, clari&longs;&longs;imè ta­men &longs;ub vnum eundemque ad&longs;pectum adduxi&longs;ti; reliqua &longs;i quæ &longs;uper­&longs;unt, per&longs;tringam; &longs;ed ante omnia, declarandum mihi e&longs;t, vnde or­tum ducat, & quò tandem abeat illa materia ten&longs;a. Et verò quemad­modum alij, vt naturales effectus explicent, eorumque indagent cau­&longs;as, multa fingunt, quæ &longs;en&longs;ibus minimè &longs;ubjiciuntur, vt &longs;piras aëris, arcus, ramos, æthera, &longs;ubtilem materiam, cochleas magneticas, bul­las, &longs;phærulas, ramenta, & motus diver&longs;i generis; licèt nihil horum videant, aut &longs;entiant, &longs;ed gratis fortè &longs;tatuant, ad effectus &longs;en&longs;ibiles explicandos, quos ex communibus principiis explicari non po&longs;&longs;e &longs;ibi per&longs;ua&longs;erunt; quidni & mihi aliquid &longs;imile fingere liceat, vel vt ve­riùs dicam &longs;tatuere & ex communibus principiis deducere? Lico igi­tur, vt rem paulò altiùs repetam, elementa no&longs;tra pura non e&longs;&longs;e, &longs;ed omnino mixta, vt omnes mihi facilè concedent; etiam ip&longs;am aquam, quam bibimus, ip&longs;um aëra quem haurimus; & cùm omne mixtum ex mi&longs;cibilibus con&longs;tet, haud dubiè quælibet mixti pars longè major e&longs;t parte mi&longs;cibilis, totum &longs;cilicet &longs;ua parte majus; hinc aër per poros corporum etiam laxiores non &longs;ubit, multò minùs aqua; immo aliqua corpu&longs;cula aquis &longs;tygiis in&longs;unt, quæ &longs;ubtilis humoris vehicula in du­ri&longs;&longs;imorum etiam corporum poros &longs;ubeunt, eorumque &longs;olvunt plexum; hæc porrò mixta e&longs;&longs;e, nemo inficias eat; igitur longè minores &longs;unt par­tes mi&longs;cibilium, ex quibus illa con&longs;tant. Cùm autem ad multum natu­ræ v&longs;um, tenuis quædam materia, quæ ad purum aëris elementum lon­gè propiùs accedit, quàm aër, qui nos ambit, nece&longs;&longs;aria e&longs;&longs;et, illam haud dubiè omi&longs;&longs;am fui&longs;&longs;e, ac de&longs;iderari nemo dixerit; & vt &longs;unt præ­cipui tres corporum &longs;tatus, duri &longs;cilicet, &longs;eu concreti, liquidi & &longs;pira­bilis, nec non innumeræ &longs;ub quolibet genere &longs;pecies; nihil ob&longs;tat, quin aliquæ &longs;int corporis &longs;pirabilis &longs;pecies, quæ longè majorem tenuitatem præ &longs;e ferant.

Chry&longs;ocom. Non video, quem v&longs;um nece&longs;&longs;arium huic &longs;ubtili ma-teriæ a&longs;&longs;ignare po&longs;&longs;is, ni&longs;i &longs;altem aliqua fingas, & gratis ad&longs;truas.

Antim. Nihil fingo, nihil ad&longs;truo, quod ex communibus principiis non deducatur; & primò quidem, certum e&longs;t, corpori etiam gravi&longs;&longs;i­mo & den&longs;i&longs;&longs;imo poros ine&longs;&longs;e; nullum enim e&longs;t corpus durum &longs;ine poris; pori autem illi vacui non &longs;unt, iuxta naturæ in&longs;titutum; de quo &longs;upra; aliqua igitur materia pleni, quæ certè aëre longè &longs;ubtilior &longs;it, immo &longs;it ip&longs;e aër purior, id e&longs;t, mixtum aëreum, &longs;eu &longs;pirabile, ad pu­rum elementum aëris propiùs accedens, quàm no&longs;ter aër, addere po&longs;&longs;em &longs;onorum rem, quæ vix &longs;ine illa materia &longs;ubtili explicari pote&longs;t.

Chry&longs;oc. Multi &longs;anè non admittunt quintam illam e&longs;&longs;entiam, quæ vix ab æthere di&longs;tinguitur; & verò vt atomos illas democriticas nun­quam probavi, ita nec &longs;ententia quorumdam Peripateticorum; &longs;eu po­tiùs Platonicorum, qui ne&longs;cio quam e&longs;&longs;entiam ætheream ab iis quin­tam appellatam, eamque, vt nonnullis vi&longs;um e&longs;t, animatam po&longs;uerunt, mihi vnquam arri&longs;it.

Antim. Mentem meam reverà non capis, Chry&longs;ocome, nullam enim quintam e&longs;&longs;entiam approbo, nullum corpus &longs;tatuo, quod vel &longs;implex elementum non &longs;it, vel ex elementis compo&longs;itum; nempe hæc &longs;ubtilis materia, cujus multiplici v&longs;u natura indiget, ex aëre humore, igne, ac terra compo&longs;ita e&longs;t, quanquam ad aëra purum propiùs accedit; alius autem illius v&longs;us e&longs;t, præter illos quos &longs;upra indicavi, vt ad ten&longs;ionem & compre&longs;&longs;ionem corporum multum conferat, vnde fortè aër compre&longs;­&longs;ionis ac ten&longs;ionis præ cæteris corporibus patiens e&longs;t, quia multa ine&longs;t aëri, immo aëris cra&longs;&longs;iores & majores partes in dicta materia qua&longs;i in medio natant, eiu&longs;dem ferè cum eo gravitatis: Itaque &longs;uppo&longs;ita illa materia, cujus maxima pars aëri commixta e&longs;t, vnde hic tam facilè com­primi & dilatari, &longs;eu tendi po&longs;&longs;it, ratione &longs;cilicet hujus materiæ, alia verò intra poros omnium corporum latet, ex quibus citra ten&longs;ionem educi non pote&longs;t; tendi porrò non pote&longs;t ab&longs;que vi, &longs;eu ponderis, &longs;eu alterius potentiæ motricis applicatæ; vtrumque experimento proba­tur, primum quidem in fi&longs;tula BD, nempe Mercurius &longs;ubducto digito de&longs;cendens educit ex vitro; immo & ex &longs;e ip&longs;o qua&longs;i ex propriis vi&longs;ceri­bus, materiam illam, quæ cum poros vitri non de&longs;tituat, alioquin vacui manerent, eam tendi ac dilatari nece&longs;&longs;e e&longs;t, vt totam vacuitatem CD im­pleat, alterum verò in embolo, qui magna vi ex va&longs;e clau&longs;o, cui congruit, educitur.

Augu&longs;tin. Quot & quantæ difficultates qua&longs;i turmatim &longs;e&longs;e mihi ob­jiciant, vix ac ne vix quidem dicere valeo.

Antim. Libenter eas excipiam; &longs;i enim &longs;olvendo non &longs;im, facilè &longs;en­tentiam mutabo; expone igitur illas, Augu&longs;tine, rem enim grati&longs;&longs;imam mihi feceris.

Augu&longs;tin. Primo loco illam expono, quæ longè difficillima mihi vi­detur; &longs;i enim Mercurius ideò de&longs;cendit ex CD in CI, quia &longs;uperat re­&longs;i&longs;tentiam prædictæ materiæ, ne dilatetur, &longs;eu tendatur; cur igitur vt magnum pondus prædictam materiam valdè tendit; ita minus pondus parum tendit? quod tamen repugnat experimentis; &longs;i enim fi&longs;tula &longs;it tantum vel vnum vel duos pedes alta, etiam &longs;ubducto digito non de&longs;cen­dit Mercurius, vt patet, de&longs;cendere tamen deberet, licèt minus.

Antim. Fateor gravem e&longs;&longs;e difficultatem; ad quam tamen re&longs;pondeo, duo e&longs;&longs;e capita, ex quibus dicta re&longs;i&longs;tentia petitur; primum e&longs;t, vt educatur ex poris, alterum vt tendatur; &longs;i tantùm &longs;ecundum caput con&longs;ideretur, ma­gna vis ponderis, multum; parva verò, parum illam materiam tendit; quo­ad verò primum, ea e&longs;t re&longs;i&longs;tentia, quæ determinatam vim exigit, vt &longs;u­peretur; Cogita quæ&longs;o fixum in ligno clavum, qui tanta vi dumtaxat re­figitur, non verò minore; ita pror&longs;us ex poris corporum illa materia edu­ci nequit, ni&longs;i tanta vis applicetur; vbi verò &longs;emel educta e&longs;t, pro majo­re vel minore pondere magis vel minùs tenditur; hinc &longs;i aëris tantulum immittatur in fi&longs;tulam BD, non tantùm infra C de&longs;cendit Mercurius, verùm etiam materia illa, quæ jam educta e&longs;t, & aëri admixta, maximè dilatatur.

Chry&longs;ocom. Non video, quæ vis de&longs;ideretur, vt educatur ex Mer­curio, corpore &longs;cilicet liquido, quod parum re&longs;i&longs;tit: idem de aqua di­cendum e&longs;t,

Antim. Immò videtur, quod minore vi opus &longs;it ad educendam illam materiam ex Mercurio, quàm ex vitro, cùm multæ partes movendæ, & qua&longs;i amovendæ &longs;int; cùm tamen in corpore &longs;icco paulò liberiores &longs;int pori; non e&longs;t igitur dubium, quin aliqua re&longs;i&longs;tentia &longs;it; cogita rete quod­dam perexiguis annulis di&longs;tinctum, quod &longs;ine aliqua re&longs;i&longs;tentia ex aqua non educitur, non e&longs;t igitur mirum, &longs;i cum illa materia ex tot meandris & pororum labyrinthis eruenda &longs;it, tanta &longs;it in hoc difficultas, vt majore vi ad eam &longs;uperanda, opus &longs;it, quàm reverà &longs;it pondus Mercurij extantis CI. analogia clavi refigendi, præ&longs;ertim &longs;i per diver&longs;os anfractus eat, rem i&longs;tam ob oculos ponit.

Augu&longs;tin. Illa igitur materia per poros vitri abundè ab extrin&longs;eco aëre intra fi&longs;tulam adduci pote&longs;t; nulla ergo ten&longs;io intercedit; immò hæc &longs;en­tentia eadem e&longs;&longs;e videtur cum illa, quam vltimo loco impugnabas.

Antim. Licèt ex poris vitri educatur, non tamen ex hoc &longs;equitur, illam ab aëre extrin&longs;eco elici; nec enim pori illi ita &longs;unt pervij, vt liber tran&longs;i­tus pateat; alioquin, nullum corpus vnquam comprimi po&longs;&longs;et, nullum tendi, aut dilatari; equidem in corpore liquido &longs;ecus accidit; cùm enim non &longs;ine aliquo partium motu hæc fiat, ex iis eductio, inde fit, vt materia illa dilatabilis meliùs colligatur, ad aliquam &longs;cilicet altitudinem. Acce­dit quòd in illo de&longs;cen&longs;u agitantur corporis liquidi partes, & hæc agita­tio collectionem materiæ dilatabilis non parum juvat; hinc fortè procedit, vt laudatus &longs;upra Autor etiam ob&longs;ervat, longè majore vi opus e&longs;&longs;e ad edu­cendum ex Cylindro cavo embolum, cujus extrema ba&longs;is ita adhæret fun­do Cylindri, vt nihil aëris interceptum maneat.

Chry&longs;ocom. Putabam fieri non po&longs;&longs;e, vt embolus abeo fundo vlla vi hu­mana avelleretur; immò putabam te e&longs;&longs;e in eadem &longs;ententia.

Antim. In ea fui aliquando, ne quid di&longs;&longs;imulem, novis tamen experi-mentis edoctus in meliorem &longs;ententiam de&longs;cendi; & verò longè diffici­liùs educitur ex corpore &longs;icco illa materiæ copia, quæ ad occupandum to­tum illud vacuum nece&longs;&longs;aria e&longs;t; &longs;ed hæc nihil ad præ&longs;entem quæ&longs;tionem; accedit, quod embolus &longs;ino corio, Cylindro cavo rectè non congruit; co­rium autem poro&longs;um e&longs;t & &longs;pongio&longs;um, at que adeò multum aëra, multum­que prædictæ materiæ continet.

Augu&longs;tin. Sed quæ&longs;o te, quando alti&longs;&longs;ima e&longs;t fi&longs;tula, vnde tanta copia il­lius materiæ, qua &longs;cilicet &longs;egmentum CD repleatur, quando longi&longs;&longs;i­mum e&longs;t?

Antim. Demus hoc, nec enim vnquam probatum e&longs;t, in longi&longs;&longs;imis illis fi&longs;tulis; Demus, inquam; cavæ &longs;uperficies vitri &longs;unt vt altitudines; item labentis Mercurij quantitates, &longs;eu Cylindri ; quid mirum ergo, &longs;i in eadem proportione materia dilatabilis &longs;uppeditetur?

Chry&longs;oc. Nunquid fortè meliùs diceres, &longs;i partibus dumtaxat aëris inter Mercurium & cavam &longs;uperficiem fi&longs;tulæ interceptis hoc tribueres?

Antim. Non &longs;unt haud dubiè aëris partes inter partes Mercurij, nec etiam inter Mercurium & dictam &longs;uperficiem cavam, &longs;ed tantùm partes illius materiæ dilatabilis, quæ cadente Mercurio inde facilè educitur: & verò cùm aër, &longs;i quis intru&longs;us &longs;it, ita &longs;uum locum occupet, vt inclinata fi­&longs;tula Mercurius totam cavitatem CD non occupet, &longs;ed &longs;patium nece&longs;&longs;a­rium aëri relinquat; vbi Mercurius a&longs;&longs;urgens nullum &longs;patium vacuum re­linquit, vt aliquando accidit, nullus profectò aër ine&longs;t.

Augu&longs;tin. Legi apud Autorem &longs;upra laudatum, &longs;i fi&longs;tula multiplici &longs;uc­cu&longs;&longs;u fatigetur, dum in eam Mercurius infunditur, &longs;egmentum Mercurij extantis inde altius fore; immò &longs;i ferrum candens admoveatur lateri fi­&longs;tulæ CI, a&longs;cendunt quædam aëris bullulæ; aër igitur Mercurio inerat: idem in aqua fieret.

Antim. Illæ bullæ non &longs;unt aëre plenæ, &longs;ed vel humore rarefacto, qui multus ine&longs;t Mercurio, vel illa materia tenui, quæ facilè rare&longs;cit; quan­quam dicerem potiùs, humorem rarefactum; vt enim materiam illam te­nuem ad elementum aëris propiùs accedentem, vtpote nece&longs;&longs;ariam ad multos naturæ v&longs;us agno&longs;co, ita & admitto humorem quendam &longs;ubtilem, ad elementum aquæ proximè accedentem, &longs;ine quo fortè frigoris, effe­ctus explicari non po&longs;&longs;unt: &longs;ed veni quæ&longs;o ad alias, quæ tibi &longs;ubortæ &longs;unt difficultates.

Augu&longs;tin. Illa materia, quæ po&longs;t de&longs;cen&longs;um Mercurij &longs;egmentum CD obtinet, e&longs;t rarior & levior aëre; igitur aër extrin&longs;ecus per medium Mercurium in illam gravitat; &longs;i ergo hæc vis gravitationis Cylindri aëris extrin&longs;eci major e&longs;t vi gravitationis Mercurij extantis CI, illam haud dubiè &longs;uperabit, attollet que Mercurium; idem faciet, &longs;i æqualis &longs;it; acce­dente &longs;cilicet vi ten&longs;æ materiæ; &longs;i denique minor e&longs;t, cur non vincitur de&longs;­cenditque Mercurius infra C?

Antim. Licèt hæc omnia darem, nihil tamen inde contra meam hy­pothe&longs;im; &longs;upponamus enim exempli gratia, vim Cylindri aëris extrin­&longs;eci plu&longs;quam centuplo majorem vi gravitationis Mercurij CI; non po-terit propterea &longs;u&longs;tinere &longs;egmentum Mercurij centuplum &longs;egmenti CI; quia &longs;upponamus &longs;u&longs;tineri; cùm hic Mercurius gravitet, & hæc vis gra­vitationis &longs;uperet re&longs;i&longs;tentiam prædictæ materiæ educendæ & dilatandæ, non e&longs;t dubium, quin prævalere debeat, atque adeò Mercurius de&longs;cendere; illa materia educi & tendi, donec ad punctum C perveniat, in quo æqua­lis e&longs;t vis gravitationis Mercurij CI prædictæ re&longs;i&longs;tentiæ; licèt autem &longs;u­perficies Mercurij EF tantulum attollatur, non tamen propterea totus Cy­lindrus, cujus ba&longs;is incumbit in &longs;uperficiem EF attollendus e&longs;t, &longs;ed tantu­lum comprimitur aër per appul&longs;um & exceptionem illius, qui Mercurio in vas ABG illap&longs;o in locum cedit; &longs;ic pror&longs;us per appul&longs;um fumi, va­poris cuju&longs;libet halitus, immò alicujus aëris rare&longs;centis tractus, reliquus aër comprimitur; nempe dictu, immò & cogitatu ridiculum e&longs;t, totum aëris Cylindrum inde attolli; ex hac &longs;olutione manife&longs;tum argumentum ducitur, contra primam illam hypothe&longs;im, quam &longs;upra refutavi.

Augu&longs;t. Sæpè miratus &longs;um, hæc ab iis non videri, qui con&longs;tanti&longs;&longs;imè a&longs;&longs;erunt, præfatum vtriu&longs;que Cylindri, aëris &longs;cilicet, & Mercurij æquili­brium, ducta à duobus aliis Cylindris, aquæ &longs;cilicet & Mercurij analogia; licèt enim in his præfatum æquilibrium locum habeat, &longs;ecus tamen in il­lis, & manife&longs;tum di&longs;crimen e&longs;t, quia Mercurius de&longs;cendere nequit, ni&longs;i vel aquæ Cylindrus attollatur, vel aqua, aut ip&longs;e Mercurius, vi ponderis &longs;eu pre&longs;&longs;ionis comprimatur; &longs;ed aqua comprimi nequit, nedum Mercu­rius; vt jam &longs;uprà dictum e&longs;t; &longs;ervatur igitur æquilibrium; at verò aër facilè comprimi pote&longs;t, vt patet; vnde Mercurij Cylindrus ID facilè de&longs;­cendit; nempe aër tantulùm comprimitur; nec ideò infra C non de&longs;cen­dit, quod &longs;it æquilibrium inter Cylindrum aeris, & Cylindrum Mercu­rij IC, &longs;ed quia de&longs;cendere nequit, ni&longs;i &longs;uperet re&longs;i&longs;tentiam materiæ di­latabilis, eamque geminam, vt &longs;upra rectè di&longs;tinguere mihi vi&longs;us es; &longs;ed ad alias objectiones venio; dicunt enim oppo&longs;itæ &longs;ententiæ a&longs;&longs;ertores, &longs;e­gmentum Mercurij extantis IC in ima Valle e&longs;&longs;e longius, in vertice mon­tis brevius; ita probatum fui&longs;&longs;e ferunt, in montibus Alverniæ, & Majo­ris Britanniæ; hoc autem, quia in ima Valle Cylindrus aëris altior e&longs;t; igitur majus illius pondus; igitur longius Mercurij &longs;egmentum &longs;u&longs;tinet; &longs;ecus in vertice montium.

Antim. Si laudatus &longs;upra Autor, qui hæc refert, te&longs;tis oculatus fui&longs;&longs;et, non detrectarem fidem Autori ac curati&longs;&longs;imo; &longs;ed quia hæc à &longs;e tan­tum auribus accepi&longs;&longs;e vltro fatetur, plenam fidem adhibendam e&longs;&longs;e non crediderim, præ&longs;ertim cum aliquando contigerit, vt hoc experimentum in alti&longs;&longs;imis regionibus probatum, &longs;ecus quàm illi ferunt, &longs;ucce&longs;&longs;erit; præ­terquam quod cuipiam homini, qui primus hoc proba&longs;&longs;e dicitur in mon­tibus Alverniæ, nullam fidem habendam e&longs;&longs;e duco; cujus enim fidei homo &longs;it, omnes catholici probè norunt. Sed demus, ita e&longs;&longs;e, non tamen inde concluditur, præfatum Cylindrorum æquilibrium, cùm alia cau&longs;a & ra­tio e&longs;&longs;e po&longs;&longs;it; nempe in alti&longs;&longs;imis montibus, præ&longs;ertim &longs;i in acumina­tum verticem attollantur, non verò &longs;i in va&longs;tas planities explicentur, vel &longs;en&longs;im a&longs;&longs;urgant, leniore ac molliore clivo, in alti&longs;&longs;imis; inquam, mon-tibus aër purior e&longs;t, id e&longs;t, à vaporibus liberior. Igitur plus ine&longs;t materiæ dilatabilis corporibus liquidis prædicto aëri expositis; quid mirum ergo, &longs;i ten&longs;io facilior e&longs;t, multa enim faciliùs tenditur, quàm modica; præterea fieri potuit, vt aliquid aëris in tubum irrep&longs;erit; fatetur enim præfatus Au­tor, quamvis alioquin hoc experimentum &longs;æpiùs probaverit, vna dumtaxat vice à fi&longs;tula aëra exula&longs;&longs;e: ille autem aër purior faciliùs comprimi & di­latari pote&longs;t: Hinc ij, qui de rebus Americæ &longs;crip&longs;erunt, te&longs;tantur, in vertice cuju&longs;dam montis, auram ita tenuem e&longs;&longs;e, vt re&longs;pirationi vix &longs;erviat; in his, vt vides, nulla e&longs;t difficultas.

Augu&longs;tin. Nulla &longs;anè; &longs;ed cur quæ&longs;o &longs;egmentum IC toties alitudinem mutat, nulla temporum habita ratione? aliquando enim cum Thermome­tro convenit, ita vt fervente æ&longs;tu &longs;ub&longs;idat, & &longs;æviente bruma a&longs;&longs;urgat, aliàs omnino &longs;ecus accidit; vnde hoc quæ&longs;o, Antime?

Antim. In alia hypothe&longs;i hoc nullo modo explicari pote&longs;t, in no&longs;tra facilè explicatur; nempe pro diver&longs;a ratione auræ purioris, &longs;eu defæcatio­nis, cui &longs;cilicet materiæ dilatabilis plus ine&longs;t, varia e&longs;t &longs;egmenti extantis al­titudo; quò enim plùs ine&longs;t prædictæ materiæ, minor e&longs;t, quo minùs, major, vt patet ex dictis; plùs autem, vel minùs ine&longs;t, pro diver&longs;o ventorum, ha­lituum & effluviorum appul&longs;u: porrò diver&longs;æ &longs;unt combinationes, vt vo­cant majoris &longs;cilicet, & minoris quantitatis hujus materiæ; itemque caloris & frigoris ambientis; vnde fieri pote&longs;t, vt vnum ab alio minuatur vel au­geatur. V.g.major quantitas illius materiæ, cum majore caloris vi acceden­te conjuncta, brevius &longs;egmentum extantis Mercurij facit; reliquæ combina­tiones facilè fieri po&longs;&longs;unt, quare vltro illas omitto, ne &longs;im fortè prolixior.

Chry&longs;ocom. Quid autem cen&longs;es de illa ob&longs;ervatione, quam præfatus Au­tor indicat, & de qua Venetiis &longs;criptum e&longs;t, &longs;cilicet æ&longs;tu cre&longs;cente, &longs;egmen­tum extantis Mercurij decre&longs;cere, cre&longs;cere verò æ&longs;tu decre&longs;cente, an fortè aliquid de illa proba&longs;ti?

Antim. Si Mercurij extantis &longs;egmentum à Cylindro aëris &longs;u&longs;tineretur, hoc reverà accidere deberet, iuxta illam no&longs;tram hypothe&longs;im, quam in &longs;u­periore congre&longs;&longs;u fusè &longs;atis tradidimus, vt patet; &longs;ed cùm prædictum &longs;e­gmentum ab aëris Cylindro non &longs;u&longs;tineatur, vt &longs;upra o&longs;ten&longs;um e&longs;t, æ&longs;tus maris ad rem hanc nihil facit: vbi autem hæc inaudij, probavi rem accura­ti&longs;&longs;imè, &longs;ervata fi&longs;tula in &longs;itu perpendiculari BD eum &longs;egmento extantis Mercurij CI, per totos ferè 30. dies, ob&longs;ervavi multam mutationem altitu­dinis; nam Mercurius aliquando &longs;upra C a&longs;&longs;urgere, aliquando infra &longs;ub&longs;idere mihi, alii&longs;que, quibus o&longs;tendi, &longs;æpè ac &longs;æpiùs vi&longs;us e&longs;t, nunquam tamen æ&longs;tus maris leges &longs;ervavit, &longs;ive diurnas, ita vt momento &longs;ummi æ&longs;tus, quo Luna e&longs;t in Meridiano, &longs;ub&longs;ideret, & momento &longs;ummi rece&longs;&longs;us, &longs;eu reflu­xus, Luna &longs;cilicet Meridianum &longs;extæ horæ occupante, a&longs;&longs;urgeret; &longs;ive leges men&longs;truas, ita vt in Plenilunio & Novilunio &longs;ub&longs;ideret, in Quadraturis a&longs;­&longs;urgeret: Idem Florentiæ & Liburni ob&longs;ervatum fuit, vt à viro &longs;umma fi­de digno accepi; quare non e&longs;t, quod multùm curemus de prædicta illa ob­&longs;ervatione, quæ cum certis experimentis minimè con&longs;entit; quare, ne tem­pus teramus, profer quæ&longs;o, &longs;i quid fortè re&longs;tat.

Augu&longs;tin. Ve&longs;tri Pari&longs;ien&longs;es aliquid jactant, quod tibi fortè nonnihil

negotij face&longs;&longs;at; Sit enim vas ABD, in quod in­fundatur Mercurius, &longs;it fi&longs;tula CP, cum ampulla IP, aperta in P, latiore foramine, & aliud vas HKNL ampullæ in&longs;it, recto &longs;itu, vt vides; in&longs;eratur fi&longs;tula OI, admotoque pre&longs;sè digito in C, infundatur per O Mercurius, donec tum vas HN, tum fi&longs;tu­la CP, tum ampulla, tum fi&longs;tula IO impleantur; tum &longs;uilla ve&longs;ica probè ob&longs;truantur, debito &longs;ci­licet tempore, foramina P & O, itemque perexi­guus canaliculus R ; his demum omnibus peractis, &longs;ubducatur digitus ex C, Mercurius ruit deor&longs;um ex vtraque fi&longs;tula, ita vt totum extans &longs;egmen tum NO vacuum Mercurio maneat, extetque &longs;e­gmentum FT Mercurio plenum, altum ferè pe­des duos & Si autem vel minima acicula in ve­&longs;ica R foramen aperias, & tantulum aëris &longs;ub­eat, &longs;ub&longs;idit illico Mercurius infra T, in fi&longs;tula CP, a&longs;&longs;urgitque &longs;upra in fi&longs;tula IO, quia &longs;cilicet, inquiunt, aër qui &longs;ubiit, premit &longs;uperficiem Mer­curij TV, & LN, vnde vtramque deprimi ne­ce&longs;&longs;e e&longs;t, &longs;ed LN deprimi non pote&longs;t, ni&longs;i Mercurius &longs;upra LN, in fi&longs;tula IO a&longs;cendat.

Antim. Hæc dicunt, &longs;at &longs;cio; &longs;ed quis amabo &longs;ibi per&longs;uadeat, tantulum aëris qui &longs;ubit, adeò compre&longs;&longs;um manere, vt vtramque illam Mercurij &longs;u­perficiem deprimat; in no&longs;tra hypothe&longs;i longè faciliùs res i&longs;ta explicatur; nempe cùm po&longs;t Mercurij de&longs;cen&longs;um, tum in PV, tum in NO,