Biancani, Giuseppe Aristotelis loca mathematica 1615 Bologna la bianc_locam_01_la_1615 0000000009.xml

ARISTOTELISLOCA MATHEMATICAEx vniuer&longs;is ip&longs;ius Operibus collecta, & explicata.

Aristotelicæ videlicet expo&longs;itionis complementum hactenus de&longs;ideratum.

Acce&longs;&longs;ere de Natura Mathematicarum &longs;cientiarum Tractatio; atque Clarorum Mathematicorum Chronologia.

Authore IOSEPHO BLANCANO Bononien&longs;i è Societate Ie&longs;u, Mathematicarum in Gymna&longs;io Parmen&longs;i Profe&longs;&longs;ore.

Ad Illu&longs;tri&longs;&longs;imum, ac Nobili&longs;&longs;imumPETRVMFRANCISCVM MALASPINAMAedificiorum Marchionem, apud Cæ&longs;. Maie&longs;tatem pro Sereni&longs;s. Parmen&longs;ium Duce Legatum.

BONONIÆ M. D C. X V.

Apud Bartholomæum Cochium. Superiorum permi&longs;&longs;u.

Sumptibus Hieronymi Tamburini.

ILLVSTRISSIMO AC NOBILISSIMOPETROFRANCISCO MALASPINAEÆDIFICIORVM MARCHIONI.

En tandem Illustriß. Marchio opus no­strum de Locis Mathematicis apud Ari­stotelem, vnà cum Tractatione de natura &longs;cientiarum Mathematicarum, necnon Clarorum Mathematicorŭ Chronologia; quod tibi Mecœnati meo munificenti&longs;simo iure meritò dicare, ac &longs;ub clarißimi tui nominis patrocinio in lucem dare con&longs;titui. primùm quidem, vt mei perpetui erga te amoris, & ob&longs;eruantiæ hoc vnum &longs;altem specimen exta­ret: tùm vt idoneum, æquumque propo&longs;itæ rei iudicem nanci&longs;cerer. cùm enim adiu&longs;tum arbitrŭ duo potißimùm requirantur, rerum &longs;cilicet cognitio, atque prudentia, quem te rei, de qua agitur peritiorem, quemuè prudentiorem inuenire potuerim? tu enim cùm Phy&longs;iologiæ, ac Mathe­maticarum omnium Encyclopædiam mirum in modumexcolueris, adintima Mathematicarum penetralia ita per&longs;ua&longs;i&longs;ti, vt Archimedis, & Apollonij admirandis, ac &longs;ubtilißimis Demon&longs;trationibus detinearis. Quanta por­rò in rebus agendis prudentia valeas, toti penè Europæ innotuit, cùm pro no&longs;tris Sereniß. Ducibus, non &longs;olùm ad omnes ferè Italiæ, atque Germaniæ Principes, verùm etiam ad Cæ&longs;aream Maie&longs;tatem rebus fœliciter ge&longs;tis Legatus decimùm extiteris; ac demùm à Sereniß. Duce Ranutio inter primarios de Rep. Con&longs;iliorum Authores ad&longs;citus fueris. Cæterùm in Clarorum Mathematicorum Chro­nologia perlegenda, &longs;æpißimè tibi nobilißimi æquè, ac do­ctißimi Viri, tui omnino per&longs;imiles occurrent, quod tibi nonni&longs;i gratißimum accidere po&longs;&longs;e arbitror. Complectere igitur ea benignitate, atque clementia, qua &longs;oles no&longs;tra stu­dia promouere, mea hæc quantulacumque munu&longs;cula. quæ &longs;i tibi accepta e&longs;&longs;e intellexero, iam tandem ma­ximorum munerum loco habenda e&longs;&longs;e cen&longs;e­bo. incolumem tibi, ac fœlicem D. Opt. Max. longæuitatem tueatur. Vale.

Parmæ Idibus Maij M. DC. XIIII.

Liber de &longs;e ip&longs;o.

Nec di&longs;cet Lector me &longs;olo interprete totum, Nec &longs;ine me totum di&longs;cet Aristotelem.

Ego Iordanus Ca&longs;&longs;ini Præpo&longs;itus Prouincialis Prouinciæ Venetæ Societatis Ie&longs;u, ex auctoritate Adm. Reuer. P. nc&longs;tro Præpo&longs;iti Generalis P. Claudij Aquæuiuæ, facultatem concedo, vt hoc opus P. Io&longs;ephi Blancani eiu&longs;dem Societatis, quod in&longs;cribitur, Ari&longs;t. Loca Mathematica ex vniuer&longs;is ip&longs;ius operibus collecta, & explicata, à deputatis Patribus recognitum, & ap­probatum typis mandari po&longs;&longs;it. Parmæ die 15. Ianuarij 1615.

Iordanus Ca&longs;&longs;ini P.Don Marcellus Balda&longs;&longs;inus pro Illu&longs;tri&longs;s.

& Reuerendi&longs;s. Archiepi&longs;c. Bonon

Imprimatur

Fr. Hieronymus Onuphrius pro Reuerendi&longs;s. P. Inqui&longs;itore Bonon

LECTORI.

Qvod pri&longs;cis olim temporibus (humani&longs;&longs;ime Lector) &longs;um­mi duo Philo&longs;ophi, Philippus Mendeus, ac Theon Smyr­næus in Platonis Dialogis egregiè perfecerunt, vt videli­cet quæ pa&longs;&longs;im &longs;ummus hic Philo&longs;ophus de Mathemati­cis &longs;cripta reliquit, eadem ip&longs;a ab illis &longs;electa, & in vnum qua&longs;i corpus redacta lucubrationibus illu&longs;trarent: idem ego quoque in Ari&longs;totelis operibus efficere &longs;um conatus, vt quæ de Mathematicis re­bus in vniuer&longs;is eiu&longs;dem monumentis &longs;par&longs;a leguntur, eadem in vnum à me collecta, & explicata ijs Philo&longs;ophiæ &longs;tudio&longs;is maxime &longs;eruirent, qui pri&longs;ca illa con&longs;uetudine relicta, Mathematicarum omnium ignari non &longs;ine graui &longs;tudiorum &longs;uorum detrimento Philo&longs;ophiæ curriculum aggrediuntur. Vt autem huius operis nece&longs;&longs;itas, variæque; vtilitates pla­nius cogno&longs;cantur operæpretium erit initio illius cau&longs;as exponere; quæ me poti&longs;&longs;imum ad illud con&longs;cribendum compulerunt, quarum

Prima &longs;it, quod hæc Ari&longs;t. loca Mathematica, quæ quidem ferè 408. numerantur, pe&longs;&longs;imè latinis literis con&longs;ignata &longs;unt v&longs;que adeò, vt Ari­&longs;totelem ip&longs;um, vel inuitum (quod po&longs;tea multis in locis planum fiet) in ab&longs;urdi&longs;&longs;ima errata &longs;æpi&longs;&longs;imè compellant.

Secunda, quòd plurima huiu&longs;modi loca à nemine, quod &longs;ciam, adhuc declarata in tenebris magno no&longs;trorum malo delite&longs;cunt: cuiu&longs;modi &longs;unt ad &longs;exaginta problemata, libellus de lineis in &longs;ecabilibus, libellus de mundo, &longs;i tamen Ari&longs;totelis e&longs;t, & Mechanicæ quæ&longs;tiones, quamuis enim Picolomineus in eas paraphra&longs;im ediderit, loca tamen earum dif­ficiliora non &longs;atis illu&longs;trauit. Vt autem dixi 408. in vniuer&longs;um loca mi­nimùm numerantur, quibus illud Platonis in&longs;criptum e&longs;t ag aiome/trhtos udi/s i/to; & in quibus Mathematicæ di&longs;ciplinæ rudes, & imperiti, quem &longs;equuntur ducem Ari&longs;t. eum &longs;æpe de&longs;erere non &longs;ine turpi dedecoris no­ta coguntur; quo fit vt exempla illa Mathematica lucm rebus aliquan­do allatura, tnbras cimmerijs, vt aiunt vmbris cra&longs;&longs;iores ij&longs;dem obducant.

Tertia, quia Græcieorumdem locorum commentatores breuiter, & ob&longs;curè admodum ea, quæ ad Mathematicum &longs;pectant, attingunt, hoc enim ab ip&longs;is certum ponitur, I ectorem e&longs;&longs;e, vt moris tunc erat, omnium Philo &longs;ophorum, Mathematicis imbutum; at verò no&longs;tra ætate magna cum Philo&longs;ophiæ iactura, quamplurimi earumdem di&longs;ciplinarum de&longs;ti­tuti præ&longs;idijs, ne Græcorum quidem Interpretum explanationes, ne­dum Ari&longs;t. ob&longs;curè dicta intelligunt.

Quarta. Adde, quod etiam &longs;i quis leuiter &longs;it erudito illo Mathemati­corum puluere con&longs;per&longs;us, adeò tamen peruer&longs;a e&longs;t eorumdem Græco­rum in Latinum tran&longs;latio, tantaque; figurarum, quæ nece&longs;&longs;ariæ erant confu&longs;io, & deprauatio, vt nec abeo, qui &longs;it Mathematicarum &longs;cientia excultus, &longs;ine magno labore percipi po&longs;&longs;int. Quin etiam figuræ illæ, quæ omnino nece&longs;&longs;ariæ &longs;unt ob Scriptorum, & Typographorum in&longs;citiam, aut inertiam pluribus in locis de&longs;iderantur. Latini verò multo minus, quàm Græci Mathematicæ periti, qua ratione eadem loca pertractaue­rint, facilius e&longs;t conijcere, quàm vt dici oporteat.

Quinta. Ex his omnibus in aliud incommodum, vel maximum Phi­lo&longs;ophi quidam incidebant; aut enim horum locorum expo&longs;itionem ta­citi declinabant: aut eam minime nece&longs;&longs;ariam ad Ari&longs;t. percipiendam &longs;ententiam a&longs;&longs;erebant; quo quid ab&longs;urdius, quid &longs;tudio&longs;orum progre&longs;­&longs;ibus pernicio&longs;ius excogitari pote&longs;t? Eorum verò nonnulli eorumdem locorum expo&longs;itionem audacter nimis aggrediebantur, atque hinc pueri­les illæ, ac ridiculæ expo&longs;itiones pa&longs;&longs;im auditæ, cuiu&longs;modi e&longs;t illa, quan­do Ari&longs;toteles ait, quod illi frequenti&longs;&longs;imum e&longs;t, omnis triangulus ha­bet tres; nihil aliud &longs;ignificari volunt, quàm omnem triangulum habe­re tres angulos. quod &longs;i dicat, omnis triangulus habet tres æquales duo­busrectis: hic hærent, hinc anguntur: cumque ex his angu&longs;tijs, ac tricis &longs;e minimè expedire valeant, aurea verba illa, quibus ingentes &longs;apientiæ the&longs;auri continentur, alto &longs;ilentij velo contegere Mathematicarum eos cogit in&longs;citia: vnde illud, quod Græcæ linguæ imperitis mutata oratio­ne acclamandum illis foret, Mathematicum e&longs;t, non legitur. Nec mi­nus elegans illa altera expo&longs;itio; Diametrum e&longs;le incommen&longs;urabilem co&longs;tæ; quod &longs;æpe apud Ari&longs;t. legentibus occurrit, nihil aliud &longs;ibi velle, quam Diametrum e&longs;&longs;e longiorem co&longs;ta, quam quidem a&longs;ymetriæ huius ignorantiam Plato de legibus dial. 7. non hominum, &longs;ed &longs;uum, peco­rumque appellare non dubitauit. Quid illa? cum Ari&longs;t. ait duo cubi, cu­bus, ip&longs;um loqui putant de duplatione Geometrici cubi, nondum in­uenta; non intelligentes, eum ibi de numeris cubis &longs;ermonem habere. Auerroes ip&longs;e tantus vir 5. Phy&longs;. commen. 15. quàm &longs;e Mathematicis, reliqui&longs;que Philo&longs;ophis irridendum præbet dum à permutata propor­tione putat &longs;erectè in hunc modum pluribus apud ip&longs;um verbis explica­tum, argumentari,

Vt &longs;e habet voluntas noua ad effectum nouum, It a voluntas antiqua ad effectum antiquum. Ergo permutatim, vt &longs;e habebit voluntas noua ad effectum antiquum, ta voluntas antiqua ad effectum nouum.

Spectatum admi&longs;&longs;i rilum teneatis amici? nego, ait; qui&longs;piam con&longs;equen­tiam, non enim hoc e&longs;t argumentari à permutata ratione, deberet enim inferre, &longs;ic, ergo ita &longs;e habebit voluntas noua ad antiquam, quemad­modum effectus nouus ad antiquum. quæ vitio&longs;a argumentatio quan­tumuis læuis &longs;it, & manife&longs;ta, quo&longs;dam tamen magni nominis philo&longs;o­phantes adeò tor&longs;it, vt adhuc torqueat.

Quanta autem mi&longs;eratione digni, qui publicè aliquando apud &longs;uos auditores totam Per&longs;pectiuam, qua nihil iucundius e&longs;t, de medio tolle­re conati &longs;unt, propterea quod illæ vi&longs;uales lineæ, illi anguli, illæ pyra­mides, aut coni, quibus vi&longs;io perficitur nullibi extarent, &longs;ed e&longs;&longs;ent vana quædam opticorum figmenta. Quì verò fieri potuit, vt non aduerterint i&longs;ti &longs;e Ari&longs;toteli &longs;uo manife&longs;te repugnare, qui &longs;æpius de lineis vi&longs;ualibus per&longs;pectiuum pertractare a&longs;&longs;erit, di&longs;crimenque; inter lineam phy&longs;icam, & opticam a&longs;&longs;ignat, ip&longs;iusque; optices tanquam veræ &longs;cientiæ mentionem &longs;æpius facit.

Alij ex altera parte contra A&longs;tronomos in &longs;urgunt, eccentricos, atque epiciclos omnes de cœlo detrahere cupientes. Verum id i&longs;ti nulla ex­pre&longs;&longs;a nedum probabili ratione faciunt, falsò exi&longs;timantes A&longs;tronomos admirandam illam Cœlorum fabricam a&longs;&longs;erere, non autem &longs;upponere: &longs;ed a&longs;tronomi illam &longs;upponunt, eamque; propterea hypothe&longs;im appellant, non a&longs;&longs;erunt. Quod &longs;i aliqua probabili ratione id facerent, vti nonnulli ex recentioribus, quorum Ticho Coripheus e&longs;t, laudandi potius, quam vituperandi e&longs;&longs;ent. Impugnant itaque a&longs;tronomachi i&longs;ti hypothe&longs;im pro a&longs;&longs;ertione; talesque; &longs;æpè hi &longs;unt, vt non &longs;atis intelligant, quid &longs;it Aequa­tor, aut Zodiacus, ne dum quid Epiciclus, aut Eccentricus. Nec defuit qui viginti duo argumenta excogitarit, atque in medium protulerit, qui­bus contra A&longs;tronomos probare conatus e&longs;t, nullo modo Solem, aut Lunam moueri po&longs;&longs;e motibus contrarijs, ide&longs;t, ab oriente in occidentem motu diurno, & proprio ab occidente in orientem. Sed exi&longs;timandum e&longs;t i&longs;tum Lunam nouam à Sole quotidie magis, ac magis ver&longs;us orientem recedere, nunquam animaduerti&longs;&longs;e; ab ea enim hanc motuum concor­diam didici&longs;&longs;et.

Quid tandem dicendum de quodam magni nominis Philo&longs;opho, om­nium tamen Mathematicarum experte, qui in publica di&longs;putatione axio­ma illud Mathematicum, omne totum e&longs;t maius &longs;ua parte, in &longs;en&longs;u in quo à Mathematicis effertur negare non erubuit, eò, quod in infinito, vt aiebat non concederetur ab omnibus. &longs;cilicet non intelligbat ma­thematicum tantummodo tractare de Quantitate finita, ac terminata, in qua axioma prædictum ab omnibus conceditur. Neque vero hic nonnullorum infen&longs;us in Mathematicas animus quieuit, verum etiam cò progre&longs;&longs;us e&longs;t, vt eas omnes omnino conuellere, atque ex albo &longs;cien­tiarum, quamuis non Ari&longs;totele tantum, &longs;ed ip&longs;a etiam veritate repu­gnante, expungere conati &longs;int; idque ne&longs;cio an vlla alia de cau&longs;a egerint, quàm quod eas non &longs;atis calerent; non &longs;ecus atque Ae&longs;opica illa Vulpes, quæ cum cauda mutilata e&longs;&longs;et, caudarum mutilationem reliquis vulpi­bus vafrè per&longs;uadere conabatur. Verum enim verò optimè &longs;cio, ea, qu&ecedil; hactenus dicta &longs;unt non in omnes no&longs;tri temporis Philo&longs;ophos qua­drare, cum non pauci hodie quoque &longs;int, qui more antiquorum Mathe­maticis &longs;uffulti, optimè &longs;uis &longs;tudijs con&longs;ulentes, reliquam Philo&longs;ophiam non &longs;ine magno compendio aggrediuntur. Quo fit, vt cæteros ageo­metretos ita antecellant, vt eorum Magi&longs;tri appellari po&longs;&longs;int, & debeant; tales fuerunt in primis Vicomercatus, Cardanus, Zabarella, Toletus, Bonamicus, & alij, quibus paulo antiquiores fuerunt D. Tho. & Scotus, Hiomnes Mathematicarum auxilio, quantum inter reliquos philo&longs;o­phantes excelluerint, nemo e&longs;t qui non nouerit. Illud hoc loco minimè tacendum, Iacobum Zabarellam in &longs;uis logicæ commentarijs te&longs;tari &longs;e bis &longs;umma diligentia totum Euclidem perlegi&longs;&longs;e, vt perfectè Ari&longs;t. de demon&longs;tratione &longs;ententiam a&longs;&longs;equi po&longs;&longs;et.

Hi ridiculas illas, ac pueriles expo&longs;itiones &longs;uperius allatas minimè effutierunt, neque reliquis &longs;upra recen&longs;itis incommodis obnoxij fue­runt, quibus magno etiam cum dedecore alij Mathematicarum ope ca­rentes afficiuntur.

In horum igitur gratiam operam diligenter dedi, vt quantum in me e&longs;&longs;et damna à me &longs;upra enarrata aliqua ex parte re&longs;arcirem. Quaprer loca hæc mathematica num rectè e&longs;&longs;ent è græco in latinum tran&longs;lata diligenter prius expendi. Deinde claritate, quàm potui max ma eadem loca interpretatus &longs;um, & in horum, de quibus dixi gratiam, quædam fanè tenuia pro&longs;equutus &longs;um, quæ alioquin libenter omi&longs;i&longs;&longs;em. Tum fi­guras omnes, aut correxi, aut re&longs;titui, aut nouas appo&longs;ui. Hocigitur mo&longs;tro qualicunque labore poterit qui&longs;que omnia illa facile intelligere, atque enumerata incommoda euitare, vnum tantummodo à Lctore ma­thematicarum experte requiram, vt principia &longs;altem illa, &longs;cilicet defini­tiones, po&longs;tulata, & axiomata, quæ primò Euclideis libro præponuntur, diligenter prius perlegat cum illa &longs;ua per&longs;picuitate ommbus &longs;int obuia; cætera ego explicanda recipio. Obiter etiam auctaria nonnulla partim mathematica, partim naturalia in&longs;erui, quæ ob nouitatem, ac pulchri­cudinem grata Lectori, atque iucunda fore exi&longs;timaui.

Sciat præterea Lector no&longs;trum in&longs;titutum e&longs;&longs;e loca hæc mathemati­ca, quatenus mathematica &longs;unt declarare, &longs;iue ea &longs;upplere, quæ ex ma­thematicis petenda e&longs;&longs;ent: reliqua autem me tantum attingere, quan­tum harum rerum cum illis connexio po&longs;tulat.

His omnibus placuit appendices opportune nonnullas addere, qua­rum prima de natura mathematicarum &longs;cientiarum: altera, qua omnes demon&longs;trationes primi libri Euclidis breuiter ad Logicam normam ex­penduntur, vt pateat, quonam demon&longs;trationis genere cen&longs;eri vnaqu&ecedil;que debeat, & ex illis de cæteris iudicium fiat. Tandem in gratiam etiam Mathematicorum tertiam appendicem appendi, qua omnia loca Ari&longs;t. Geometrica ad Euclidis ordinem referuntur; vnde & ip&longs;i ad &longs;uas pr&ecedil;le­ctiones exornandas aliquid &longs;ubinde depromere queant.

Fruere igitur amice Lector hoc no&longs;tro qualiquali labore, quo ad ple­nam totius Ari&longs;t. intelligentiam, cui adhuc mathematicarum ignoratio ob&longs;titit peruenire tandem po&longs;&longs;is: illudque; experiaris, quod optimus qui­dam Philo&longs;ophus, cum totum hunc librum perlegi&longs;&longs;et, effatus e&longs;t, vide­licet, opus hoc Aristot elicæ expo&longs;itionis complementum ad hanc v&longs;que diem de&longs;ideratum iure ac meritò nuncupari po&longs;&longs;e.

Illud demum tanquam parergon addam, quod ego his elucubran­dis experientia didici, ad veram &longs;cilicet, ac perfectam to­tius Ari&longs;totelis intelligentiam linguæ in primis græcæ, necnon mathematicarum om­nium di&longs;ciplinarum haud medio­crem cognitionem ne­ce&longs;&longs;ariam e&longs;&longs;e. Vale.

Pr&ecedil;cipua qu&ecedil;dam, aut noua, autre&longs;taurata, quæ obiter pertractantur.

1De re&longs;olutione. numero marginali.42De figuris vacuum replentibus, vbi Aristotelis, & expo-&longs;itorum erratum aperitur. num.121Inibi, Apum mirabilis quædam in cellis &longs;uis hexagonis constituendis indu&longs;tria detegitur. num.1203De ijs, quæ aquæ in&longs;ident, vnà cum noua demonstratione problema-tis illius Archimedis, quo metallorum mixtionem indi&longs;&longs;oluta Co-rona, explorauit. in additione. ante num.1244De Cometa, recentiorum &longs;ententia. num.1365De altitudine montis Cauca&longs;i.1486De Terræ rotunditate, ac mundi duratione.1517De Iride. in additione.1818Sytala quid.2509Securis antiqua quæ, & qua ratione fieret.25810Statera antiqua quæ,25911De Ae&longs;tu Maris.27212Araneorum indu&longs;tria nuper patefacta: vbi Democritus contra Ari&longs;t. defenditur.29313De Lucis figuratione, & rerum &longs;imulacris in ob&longs;curo loco.34514De Pupilla oculi.40815De Mathematicarum natura. propè finem operis.16Clarorum Mathematicorum Chronologia, in fine operis.

PRIMVS INDEX LOCORVM ARIST.

Quæ in hoc opere explicantur, iuxta ordine librorum ip&longs;ius ex vulgata editione Lugdunen&longs;i.

In Prædicamentis.

Gapite s. de Relatione, vbi de Quadratura circuli.

Cap. de Priori, vbi de Principijs Mathematicarum,

Cap. de Motu, vbi de Gnomone.

In Primo Priorum Re&longs;olutoriorum.

Ad titulum libri de Re&longs;olutione.

Cap. 23. &longs;ect 1. libri 1. de Incommen &longs;ur abilibus.

Cap. 24. &longs;ecti 1. lib. 1. de De&longs;criptionibus.

Cap. 2. &longs;ect 2. lib. 1. de De&longs;criptionibus.

Cap. 3. &longs;ecti 2. lib. 1. de Incommen&longs;urabili.

Cap. 1. &longs;ecti 3. lib. 1. de eo, quod est, omnis triangulus habet tres angulos æquales æquales duobus rectis: Aequalitas Geometrica, quæ.

Cap. eodem, de exemplis, quibus vtuntar Geometræ.

In &longs;ecundo Priorum Re&longs;ol.Cap. 21. de lineis Paralellis, &longs;eu Coalternis.

Cap. eodem. de Paralellis, & de triangulo.

Cap. 26. Quod omnis triangulus habet tres, & c.

Cap. 31. de Abductione.

Cap. codem, de circuli Quadratura, &longs;ecundum Hippocratem Chium.

In primo Po&longs;teriorum.

Textu primo, De Præcognitis Mathematicarum.

T. 2. Omnis triangulus habet tres, & c.

T. 5. De Diametro incommen&longs;urabili. Item De Mathematicarum Principijs.

T. eodem, De Indiui&longs;ibilitate vnitatis.

T. 9. De Puncto, & linea. Item de recto, & circulari. Item de numero pari; impariprimo, & compo&longs;ito; æquilatero, & altera parte longiore.

T. 11. Lineæ punctum inest per &longs;e, & c.

T. 13. De Parallelis. De I&longs;o&longs;cele. De Alterna Proportione, Item quod omnis triangulus habet tres, & c.

T. 14. De ij&longs;aem cum præcedentibus.

T. 20. Magnitudines euadun numeri. Item, quod non duo cubi cubus. Item de Mathematicis &longs;ubalternatis.

T. 23. Quadratura circuli &longs;ecundum Bry&longs;onem. Item per&longs;ectam illam e&longs;&longs;e Demon­&longs;trationem, qua Geometræ o&longs;tendunt, quod Omnis triangulus habet tres, & c. Per&longs;pectinam, & Mechanicam &longs;ubalternari Geometriæ, Mu&longs;icam, Arithmeticæ.

T. 24. De numero pari, impari, quodrangulo, cubo. In Geometria quid irrationale, refrangi, concurrere. Quid Astronomia con&longs;ideret.

T. 25. Geometram non mentiri in &longs;uis exemplis.

T. 28. De Parallelis.

T. 29. Cur in Mathematicis non &longs;it Paralogi&longs;mus. Item quid multiplicata propor­tio. Quid Cæneus dixerit. Cur Affectiones Mathematicorŭ maximè conuertantur.

T. 30. De Lunæ &longs;phæricitate. Quid &longs;tereometria. & De &longs;ubalternatione, &c. & Ma­thematicorum e&longs;t &longs;cire Propter quid: &longs;en&longs;itiuorum verò &longs;cire Quod.

T. 37. I&longs;o&longs;celes, & Scalenum habere tres æquales, &c.

T. 38. Quid Mina, quid Die&longs;is.

T. 39. Habere tres angulos æquales, &c. Item, quod omnis figura habet &longs;uos angu­los externos æquales quatuor tantum rectis.

T. 43. Triangulum tres æquales, &c. De Eclyp&longs;i.

De combu&longs;tione per refractionem ex &longs;phæra vitrea. De principijs &longs;cientiarum.

T. 44. Diameter incommen&longs;urabilis.

In 2. Po&longs;teriorum.

T. 1. Aequalitas, & inæqualitas. Terram e&longs;&longs;e in medio mundi ab A&longs;tronomis per­fectè demon&longs;tratur. Item Quid con&longs;onantia.

T. 2. Omnis triangulus habet tres, &c. Item de Definitionibus Mathematicarum.

T. 7. Geometra, quædam accipit, quædam demon&longs;trat.

T. 11. Angulum in &longs;emicirculo rectum e&longs;&longs;e probari à Geometra per cau&longs;am materia­lem. Zabarella correctus.

T. 24. Echo, Imago è &longs;peculo, Iris.

T. 25. Permutatim proportionale quid; exemplum in triangulis.

In primo lib. Topicorum.

Cap. 13. Diameter est incommen&longs;urabilis. Vox acuta velox, cur. &c. Colores in Mu&longs;ica, qui. tria genera veteris Mu&longs;icæ.

In 4. libro.

Cap. 1. loco 1. lineæ in&longs;ecabiles.

In 6. libro.

Cap. 2. loco 32. Definitio lineæ.

In 8. libro.

Cap. 2. loco 41. V&longs;us Definitionum in Mathematicis.

Cap. 4. loco 86. Elementa geometrica: Numeri capitales.

In Elenchorum lib. 1.

Cap. 10. Quid P&longs;eudographia. Quadraturarur&longs;us Hippocratis, & Bry&longs;enis. Mathe­maticæ non contentio&longs;æ. Quadratio Antiphontis.

Ex 1. Phy&longs;ic.

T. 11. De Quadraturis circuli Hippocratis, & Antiphontis.

Ex 2. Phy&longs;ic.

T. 20. Quatenus Per&longs;pectmus con&longs;ideret lineam.

T. 28. Quid con&longs;onantia Diapa&longs;on.

T. 68. Mathematicas Demon&longs;trationes babere cau&longs;am, quæ reducitur ad defini­tionem.

T. 8. Denece&longs;&longs;ari, quod e&longs;t in Mathematicis. & omnis triangulus habet tres an­gulos, &c.

Ex 3. Phy&longs;ic.

T. 76. Quinam numeri dicantur Gnomones.

T. 31. Quonam infinito vtantur Mathematici.

T. 71. De infinito Mathematica.

Ex 4. Phy&longs;ic.

T. 120. De commen&longs;urab. & incommen&longs;.

Ex 5. Phy&longs;ic.

T. 6. De chordis, graui, acuta; media, & vltima.

Ex 8. Phy&longs;ic.

T. 15. Omnis triangulus habet tres æquales, &c.

Ex 1. de Cœlo.

T. 33. De minimo indiui&longs;ibili.

T. 36. Ratione vtitur lineari; vt probet mundum e&longs;&longs;e finitum.

T. 48. Commen&longs;urab. & incommen&longs;urab. quid.

T. 119. Omnis triangulus habet tres, &c. Item de commen&longs;urabili.

Ex 2. de Cœlo.

T. 24. Plato ex planis &longs;olida componebat, quì.

T. 25. Ordo figurarum planarum.

T. 31. Aquæ &longs;uperficiem e&longs;&longs;e &longs;phæricam.

T. 46. Maiorem circulum velocius moueri. Recentiorum ob&longs;eruationes.

T. 57. De ordine Cœlorum ex &longs;ententia A&longs;tronomorum.

T. 59. De rotunditate Lunæ, bis.

T. 107. Centrum duplex grauit: & molis. Qua ratione grauia ad mundi centrum aptarentur.

T. 109. Terram e&longs;&longs;e rotundam. alio item modo.

T. 110. Terram e&longs;&longs;e paruam re&longs;pectu Cœli.

T. 111. Mare occidentale coniungi indico.

T. 112. De quantitate Terræ.

Ex 3. de Cœlo.

T. 40. Vt componatur &longs;phæra.

T. 66. Omne corpus diui&longs;ibile.

T. 66. Quænam planarum figurarum totum &longs;patium repleant. Hinc de admirabili Apum mgenio.

T. eodem. Num plures Pyramides locum replere valeant, vbi Ari&longs;totiles, & omnes expo&longs;itores erra&longs;&longs;e o&longs;tenduntur.

T. 71. Terram e&longs;&longs;e cubum, cur dictum &longs;it.

Ex 4. de Cœlo.

T. 33. Extare centrum Mundi, quò grauia tendunt, à quo leuia abeant.

T. 44. & &longs;eque Cur quædam grautora quàm aqua, &longs;upernatent.

Ex 2. de Generatione, & Corruptione.

Tex. 56. Cur Planetæ duobus motibus moueri dicantur.

Ex 1. Meteororum.

Summa prima cap. 3. De magnitudine Terræ ad a&longs;tra, & &longs;olem collata.

Cap. eodem. De magnitudine A&longs;trorum.

Cap. 4. De ordine Luminarium Solis, & Lunæ.

Summa 2. cap. 3. de Mercurij stella. Item de Cometa: e&longs;&longs;e in Cœlo.

Cap. 5. De Magnitudine Solis, & de vmbra Terræ.

Cap. 5. De Glaxia.

Cap. 6. Sententia Ari&longs;totelis de Glaxia, partim defenditur: vera, deinde aperitur.

Summa 4. cap 1. De Monte Parna&longs;&longs;o, dubia. Mare extraneum, quod. Errata quæ­dam veterum Geographorum, & Ari&longs;t. corriguntur. Altitudo montis Cauca&longs;i.

Cap. 2. De permutatione Aquarum, & continentis. Noua ob&longs;eruatio de rotundi­tate Terræ, atque Mundi duratione.

Ex 2. Meteororum.

Summa 1. cap. 1. De Marirubro.

Summa 2. cap. 2. De ortu stellarum fixarum: Item de occa&longs;u earumdem.

Cap. eodem, De Canicula. De Zonis temperatis. Corona Ariadnæ. Zonam torridm falsò putabant inho&longs;pitalem. cur habitabilis.

Cap. 3. De Ventorum&longs;itu.

Ex 3. Meteor.

Summa 2. cap. 2. De Halone, &longs;eu Area, &longs;eu Corona, Mathematica demon&longs;iratio.

Cap. 4. De Iridis figura Mathematica demon&longs;tratio, &longs;ed deficiens. Noua de eadem tractatio.

Cap. 5. De Parelio. Rationes Ari&longs;totelis refelluntur.

Ex 1. De Anima.

Tex. 11. Quid rectum, quid obliquum. & omnis triangulus babet tres, &c.

T. 13. Sphæra planum tangit in puncto.

Ex 2. De Anima.

T. 12. D finitioncm formalem, & cau&longs;alem explicat exemplo Quadrationis Geo­metricæ.

T. 86. Acutum, & Graue, vt differant.

T. 159. De Solis magnitudine ad terram.

Ex 3. De Anima.

T. 21. Incommen&longs;urabile.

T. 25. Indiui&longs;ibilia e&longs;&longs;e priuationes.

T. 32. Permutata proportio.

Ex lib. De Sen&longs;u.

Capite 6. Die&longs;is.

Cap. 8. Nete. Diapa&longs;on. Diapen&longs;e.

Ex lib. De Memoria, & Rem.

Cap. 1. Omnis triangulus babet tres, &c.

Cap. 3. Mathemata facile remini&longs;cibilia.

Ex lib. De Somnijs.

Cap. 2. Terra, cur nauigantibus moueri videatur.

Cap. 3. Cur Oculus digito dimotus res geminatas videat.

Ex 1. Methaphy&longs;.

Cap. 1. Initium Mathematicarum ab Aegyptiorum Saterdotibus. Item, Automata, quæ &longs;olstitia. Diameter incommen&longs;.

Summa 2. cap. 3. Pythagorei Mathematicas cæteris præferebant.

T. 47. Geometria habet &longs;uas præcognitiones.

Ex 2. Methaphy&longs;.

T. 14. Leges apud Mu&longs;icos quid.

Ex 3. Methaphy&longs;.

Tex. Mathematicas puras carere cau&longs;is efficiente, & finali. Ariftippus, vt Mathe­maticas &longs;ugillaret. Tetragoni&longs;mus est inuentio mediæ.

Tex. 8. Geodæ&longs;ia quid.

Ex 4. Methaphy&longs;.

T. 4. Quæ &longs;int primæ, & quæ &longs;ecundæ inter Mathematicas.

T. 28. Diameter, commen&longs;urabilis.

Ex 5. Methaphy&longs;.

T. 2. Exemplum cau&longs;æ formalis ex Diapa&longs;on. Quæ &longs;int proportiones Mu&longs;icales.

T. 3. Quæ &longs;it Materia in Mathematicis.

T. 4. Quidnam &longs;int elementa apud Geometras.

T. 12. Die&longs;is.

T. 17. Diameter incommen&longs;urab. Quid potentia vnius lineæ.

T. 34. Diameter incommen&longs;urabilis.

Ex 6. Methaphy&longs;.

T. 1. Principia, elementa, & cau&longs;æ in Mathem.

T. 8. Diameter. commen&longs;urab.

T. 20. De&longs;criptiones. Omnis triangulus habet tres, &c. Cur Angulus in &longs;emicir­culo rectus.

T. 22. Omnis triangulus habet tres, &c.

Ex 10. Methaphy&longs;.

T. 4. Motum diurnum men&longs;uram reliquorum. Die&longs;is.

T. 11. Similes figuræ quæ. Diuer&longs;um in Math. quid.

Ex 11. Methaphy&longs;.

Cap. 2. Ortus punctorum, linearum, &longs;uperficierum.

Ex 12. Methaphy&longs;.

T. 44. Peculiari&longs;&longs;imam Philo&longs;ophiam, Mathematicorum videlicet, A&longs;tronomiam pluralitatem Cœlorum docere.

T. 45. Numerus orbium cœle&longs;t ium &longs;ecundum Eudoxum.

T. 46. Itidem ex Eudoxo.

T. 47. Orbium cœle&longs;tium numerus, & fabrica ex Calippo.

Ex 13. Methaphy&longs;.

Cap. 3. Quaratione Mathematici tractant de Boo.

In Mechanicas Quæ&longs;tiones.

Cap. 1. Quæ &longs;it Mechanica facultas.

Cap. 2. De Admirandis circuli.

Quæ&longs;tio 1. De Libra. cur maior, exactior. inibi Ari&longs;t. lap&longs;us.

Quæ&longs;t. 2. Duplex Libra. Piccolomineus reiectus.

Quæ&longs;t. 3. De Vecte.

Quæ&longs;t. 4. De Remo; Petri Nonÿ in Arist. correctio.

Quæ&longs;t. 5. De Temone Nauis.

Quæ&longs;t. 6. De Antenna.

Quæ&longs;t. 8 De Rota.

Quæ&longs;t. 9. De Trochlea, & Scytali. figura antiquæ &longs;cytalis.

Quæ&longs;t. 10. De Libra vacua.

Qùæ&longs;t. 11. De Curru, & &longs;cytala.

Quæ&longs;t. 13. De lugo. De Succula.

Quæ&longs;t. 15. De Vmbelicis.

Quæ&longs;t. 16. De ligni oblongi, ac breuis flexura.

Quæ&longs;t. 17. De Cuneo.

Quæ&longs;t. 18. De Trochlea; error Piccolominei.

Quæ&longs;t. 19. De Securi. Securis veteris figura, & con&longs;tructio; vnà cum affectione eius mirabili.

Quæ&longs;t. 20. De Statera. Veteris stateræ figura restaurata.

Quæ&longs;t. 21. De Dentiforcipe.

Quæ&longs;t. 22. De Nucifrago.

Quæ&longs;t. 23. De Motibus in Rhombo.

Quæ&longs;t. 24. De duobus circulis concentricis.

Quæ&longs;t. 25. De funibus lectulorum.

Quæ&longs;t. 26. De ligno humeris gestato.

Quæ&longs;t. 27. De ponderibus humero ge&longs;tatis.

Quæ&longs;t. 28. De Tollenone.

Quæ&longs;t. 29. De onere à duobus phalanga ge&longs;iato.

Quæ&longs;t. 30. De &longs;urgente à &longs;e&longs;&longs;ione.

In libello De Mundo ad Alex.Cap. 2. Ordo Planetarum.

Cap. 3. De Cometis.

Cap. 5. De fluxu maris. noua de maris æ&longs;tu &longs;ententia.

In libro De Admirandis audit.

Num. 8. De nouo orbe.

Nu. 100. De &longs;tro, error Ari&longs;t. & veterum Geographorum.

In libello De lineis in&longs;ecabilibus.

Primus locus. De commen&longs;urabili, & incommen&longs;urabili.

2. locus. De figuris incommen&longs;.

3. locus. Quæ linea rationalis, quæ irrationalis. Binomio, Apotome.

4. locus. De communi men&longs;ura.

5. locus. Lineæ rectæ motus in &longs;emicirculum.

6. locus. Circulorum æqualium ab inuicem motus.

7. locus. Multum Mathematicis demon&longs;trationibus tribuitur ab Ari&longs;totele.

8. locus. Si extarent indiuidua, omnes lineæ e&longs;&longs;ent commen&longs;.

9. locus. Idem probat aliteŕ.

10. locus. Idem ex triangulo.

11. locus. Idem ex quadrato.

12. Ex diui&longs;ione lineæ idem confirmatur.

13. Idem eodem ferè modo cum præcedenti.

14. A quadrato cuiu&longs;uis lineæ.

15. Idem probat ex &longs;uperficie, & ex corpore.

16. Idem ex contactu circuli cum linea recta.

Ex lib. 9. Hi&longs;toriæ Animalium.

Cap. 39. error Ari&longs;t. & noua ob&longs;eruatio de admiranda quadam Aranearum indu&longs;tria.

De Ince&longs;&longs;u Animal.

Cap. 7. qua ratione in gre&longs;&longs;u &longs;iat bypotenu&longs;a. & ea quid &longs;it.

De Motu Animal.

Cap. 1. in flexuris animalium e&longs;&longs;e centrum, & circulum.

Cap. 3. Automata.

De Generatione Animal.

Lib. 2. cap. 1. Automata.

Lib. 2. cap. 4. Omnis triangulus habet tres, &c. Ibidem Diametrum e&longs;&longs;e incommen­&longs;urabilem co&longs;tæ, habet cau&longs;am, & demon&longs;trationem.

In Ethicis ad Nicom.

Lib. 1. cap. 7. Faber, & Geometra diuersè con&longs;iderant angulum rectum.

Lib. 2. cap. 6. De Arithmetica proportione.

cap. 9. Centrum circuli reperire.

Lib. 3. cap. 3. Diameter, & latus incommen&longs;urabilis: Item quid re&longs;olutio Geome­trica: Quid de&longs;ignatio.

Lib. 5. cap. 3. Vnitarius numerus. Quid Proportionalitas. Eam in 4. terminis con­&longs;i&longs;tere. Item quid Permutata proportio. Item quid Geometrica proportio. Propor­tio continuata, & di&longs;iuncta quid.

cap. 6. Proportio Geometrica, & Arithmetica.

Lib. 6. cap. 5. Omnis triangulus, &c.

cap. 8. Principia Mathematica non pendere ab experientia.

Lib. 7. cap. 8. De principijs Mathem.

Ex 1. Magnorum Moralium.

Cap. 1. Numerus pariter par.

Cap. 2. Omnis triangulus habet, &c.

Cap. 10 Omnis triangulus habet, &c.

Cap. 16. Quadratum quatuor rectis æquales habere.

Cap. 30. Proportionale in quatuor terminis con&longs;i&longs;tit.

Ex 1. lib. Moralium Eudemiorum.

Cap. 5. Duplum inter multiplices rationes primum tenet locum.

Ex 1. lib. Mor. Eudemiorum.

Cap. 7 Omnis triangulus habet tres, &c.

Cap. 10. Diametrum commen&longs;. e&longs;&longs;e. Circuli quadratio.

Cap. 12. Triangulus habet tres, &c.

Ex 7. lib. Mor. Eudemiorum.

Cap. 12. Diametralis oppo&longs;itio.

Ex 3. lib. Politicorum.

Cap. 2. Modi Dorius, & Phrygius apud Mu&longs;icos, quì.

Ex 4. lib. Polit.

Cap. 3. Modus Doricus, & Phrygius.

Ex 5. lib. Polit.

Cap. 1. Aequitas Arithmetica, & quæ &longs;ecundum dignitatem.

Ex 8. Polit.

Cap. 5. Mu&longs;ica nuda, & cum melodia. Rithmus quid.

Harmonia lydia. Rithmus quid &longs;it dicetur in Problematibus.

Cap. 7. Harmoniæ, & Rithmi, vt in præcedenti.

Ex Problematibus.

Sectione 1. num. 3. De ortu &longs;yderum innerrantium: Succulæ, Hypades, Atlantides, Virgiliæ, Pleiades. num. 17. De occa&longs;u affixarum &longs;tellarum.

Sectione 15. num. 1. Diametri ethymon.

num. 2. Iterum Diametri ethymologia.

num. 3. Denarius numerus cur perfectus. eius dignitates. Petri Apponen&longs;is deceptio.

4. De inæquali &longs;olis vmbrarum incremento.

5. Cur Solis illuminationes &longs;emper rotundæ, quamuis per angulo&longs;a foramina ingre­diantur.

6. Cur Luna &longs;emiplena videtur linea recta terminari? vbi de illuminatione Lunæ, quæ experientia docetur.

7. Cur Sol, & Luna videantur plana?

8. De vmbris Solis orientis, occidentis, meridiantis.

9. Cur Lunæ, quàm Solis minores vmbræ?

10. Cur in defectu Solis etiam illuminationes ip&longs;ius defectiuæ &longs;unt? modus commodè videndi eclyp&longs;im Solis.

Sect. 16. nu. 1. Cur ba&longs;es bullarum in aquis &longs;unt albæ?

3. Opp lumbati tali.

4. De re&longs;ultu cadentium in terram.

5. Cur conus, & cylindrus diuersè moueantur.

6. De voluminum &longs;ectione.

12. Idem cum præcedenti 3.

13. Idem cum 4 &longs;uperiori. reflexio radiorŭ pulchrè comparatur corporŭ re&longs;ultationi.

Ex &longs;ectione 19. De Mu&longs;ica.

num. 2. Lineæ duplæ quadratum quadruplum. Hoc loco &longs;equentium probl. cau&longs;a, præmittitur totius Mu&longs;icæ ortus breuis tractatio.

3. Vox tam in hypate, quam in nete cantando rumpitur.

4. Cur facilius hypate, quam nete canitur?

5. Cur &longs;uauius notam cantilenam audimus?

7. Cur veteres hypatem omittebant.

8. Cur grauis &longs;onum potest acutæ?

9. Cur cantus ad tibiam vnam, aut lyram &longs;uauior?

10. Teretizare, quid.

11. Vox de&longs;inens acutior fit.

12. Grauior è fidibus contilenam &longs;u&longs;cipit.

13. In Diapa&longs;on graue e&longs;t acuti Antiphonum.

14. Cur Diapa&longs;on vnica vox videtur. Punicum quid.

15. Leges Mu&longs;icæ, quæ. Genera, Diatonicum, Chromaticum, Encharmonium. Tetrachorda quæ.

16. Antiphonum &longs;uauius est &longs;ymphono, cur.

17. Cur &longs;ola Diapa&longs;on canitur. Magadis quid. Magadare.

18. De Antiphonis.

19. Cur Diapente, & Diabe&longs;&longs;acon non canunt in Antiphonis.

20. Me&longs;e &longs;ola di&longs;&longs;onante, totum de&longs;&longs;onat p&longs;alterium.

21. Vocum grauium errores manifestiores, cur?

23. Cur nete duplo acutior, quam hypate?

24. Nete interpellata, hypate re&longs;onare videtur.

25. Cur Me&longs;e &longs;ic appellata e&longs;t.

27. Cur &longs;ola audibilia mores obtinent. Rithmus quid.

28. Cur cantilenæ quædam leges de cebantur?

30. De Harmonijs, &longs;eu Modis, &longs;eu Tonis pri&longs;corum.

31. Vetustiores fui&longs;&longs;e magis Melopæos.

32. De ip&longs;ius Diapa&longs;on ethymo.

33. Cur aptè de acuto in graue, non è contra canitur?

34. Cur bi&longs;diapente, aut bi&longs;diate&longs;&longs;aron con&longs;onantia non e&longs;t.

35. Cur diapa&longs;on omnium pulcherrima e&longs;t con&longs;onantia?

36. Me&longs;e &longs;ola di&longs;&longs;onante, tota perit harmonia.

37. Cur difficilius acutum canere, quam graue?

38. Cur Rythmo, & harmonij omnes gaudent?

39. Cur &longs;uauius e&longs;t &longs;ymphonum vni&longs;ono?

40. Cur &longs;olam Diapa&longs;on magadari &longs;olent?

41. Idem cum 5.

42. Idem cum 34.

43. Idem cum 24. Iugum in lyra veteri quodnam fuerit, vna cum figura vete­ris lyræ.

44. Cur &longs;uauius ad tibiam, quam ad lyram cantatur?

45. Idem cum 25. &longs;uperiori.

46. Idem cum 22.

47. Idem cum 26.

48. Idem cum 7. quid Grauiden&longs;um.

49. Idem cum 30. In choris tragœdiarum, nec &longs;ubdorius, nec &longs;ubphrygius modus erat in v&longs;u.

50. Cur grauior Melodia e&longs;t etiam mollior?

51. Dolia duo æqualia, quorum alterum plenum &longs;it, alterum dimidium, Diapa&longs;on re&longs;onant.

Ex &longs;ectione 23.

De immer&longs;ione Nauigij.

Ex &longs;ectione 30.

6. Omnis triangulus habet tres æquales, &c.

Ex &longs;ectione 31.

7. Cur o culos, ab&longs;que vlla vi, ab inuicem di&longs;&longs;ociari nequimus?

Cur duobus oculis res vna tantum videatur. Cur aliquando rei vi&longs;æ gemina­tio accidat.

11. Cur di&longs;tractis oculis res vna duæ apparent?

17. Oculo in latera contorto, cur non fit geminatio.

21. Cur &longs;olam rectitudinem vnico oculo in&longs;piciamus.

Auctarium De Oculi Pupilla.

Oculi fabrica præmittitur, colores oculi vbi &longs;int: vnde qui noctu vident.

Primo. De pupillæ voce.

2. Cur in oculo appareat.

3. Cur non in tota cornea.

4. Pupillæ definitio.

5. Cur mgra in omnibus hominibus.

6. Cur in Sole euane&longs; cat.

7. Quantitas ip&longs;ius num videatur?

8. Cur modo maior, modo minor videatur, & cui&longs;dam lepida deceptio.

Additamentum de natura Mathematicarum di&longs;ciplinarum.

Primo. De &longs;ubiecto Mathem. &longs;eu de materia intelligibili: vbi o&longs;tenduntur definitio­nes Mathematicæ e&longs;&longs;e perfecti&longs;&longs;imæ.

2. Demon&longs;trationes Mathematicas e&longs;&longs;e perfecti&longs;&longs;imas.

3. Obiectiones: atque etiam calumniæ diluuntur.

4. De præstantia cognitionis, quam Geometria, & Arithmetica gignunt.

5. De 4. Mathematicis medijs: A&longs;tronomia, Per&longs;pectiua, Mu&longs;ica, Mechanica.

6. Appendix de re&longs;olutione omnium demonstrationum primi Euclidis.

7. Clarorum Mathematicorum Chronicon.

Finis Primi Indicis.

ALTER INDEX

Quo loca Aristotelis Geometrica, in hoc Opere explicata, ad Euclidem, &longs;ecundum propo&longs;itionum ordinem refe­runtur; vt Mathematicarum Profe&longs;&longs;ores habeant, vnde &longs;uas prælectiones aliquando valeant locupletare.

In Primo Elem. Euclidis.

Ad verbum ip&longs;um (Elementum Euclidis) vide infra tex. 4. quinti Methaph.

Ad principia primi elementorum, vide infra tex. 5. pri. Po&longs;ter.

Ad definitionem 10. pri. pro angulo recto, vide 30. quæ&longs;t. Mecha­nic. & cap. 7. lib. 1. Eth.

Ad axioma 10. quamuis Ari&longs;toteles nihil hac de re dicat; &longs;cias tamen velim hoc vno axiomate qu&ecedil;&longs;tionem quandam inter Philo&longs;ophos valdè difficilem, facile di&longs;&longs;olui. ea e&longs;t, vtrum marmor, aut adamas, aliudue quidpiam infle­xibile &longs;ucce&longs;&longs;iuè findi, & aperiri po&longs;&longs;it. qui enim aiunt, &longs;ic refelluntur, quia nimirum &longs;equeretur, duas rectas lineas habere &longs;egmentum commune: in­telligantur enim duæ lineæ, vna in vna &longs;uperficie, altera vero in altera, quæ antequam incipiat apertio, congruant; Quoniam igitur tota illa apertio non fit in in&longs;tanti, &longs;ed &longs;ucce&longs;&longs;iuè, facta iam aliqua apertionis parte con&longs;i­derentur prædictæ lineæ, erit igitur earum pars aliqua ab inuicem &longs;epara­ta, altera verò adhuc alteri congruens, ergo &longs;equetur, duas lineas habere &longs;egmentum commune, quod e&longs;t impo&longs;&longs;ibile, quia contra 10. axioma.

Ad Calcem axiomatum primi accommodetur tex. 1. primi Po&longs;ter.

Ad primam primi, po&longs;t ip&longs;ius explicationem, commodè declarari pote&longs;t, cur Ari&longs;t. Demon&longs;trationes Geometricas appellet De&longs;criptiones, & De&longs;igna­tiones, vide cap. de Priori, & cap. 24. &longs;ecti primi, libri primi Priorum, & tex. 4. quinti Methaph. & tex. 20. &longs;exti Methaph. & cap. 3. lib. 3. Ethic. Item ad primam primi, vide tex. 7. &longs;ecundi Po&longs;ter. loco 2.

Ad 5. primi, vide cap. 24. &longs;ecti 1 lib. 1. Priorum.

Ad 21. primi, vide tex. 20. primi Po&longs;ter. loco 2.

Ad 22. primi, vide locum 10. de lineis in&longs;ecabilibus.

Ad 28. primi, vide cap. 21. & cap. 22. &longs;ecundi Priorum, & tex. 13. primi Po&longs;ter.

Ad 32. primi, vide cap. 1. &longs;ecti 3. lib. 1. Prior. & cap. 26. &longs;ecundi Priorum, & tex. 2. primi Po&longs;ter. loco 4. & tex. 23. primi Po&longs;ter. vbi ait hanc e&longs;&longs;e poti&longs;&longs;imam demon&longs;trationem. & tex. 37. primi Po&longs;ter. & tex. 39. primi Po&longs;ter. Ibidem loco 4. & tex. 43. primi Po&longs;ter. & tex. 2. &longs;ecundi Po&longs;ter. bis. & tex. 89. &longs;e­cundi Phy&longs;. & tex. 15. octaui Phy&longs;. & tex. 119. primi de Cœlo. & tex. 25. &longs;ecundi de Cœlo. tex 11. primi de Anima. & cap. 1. de mem. & remini&longs;c. & tex. 35. quinti Methaphy&longs;. & tex. 20. &longs;exti Methaphy&longs;. & tex. 22. &longs;exti Methaphy&longs;. & cap. 4. lib. 2. de Generat. animal. & cap. 5. lib. 6. Ethic. & cap. 2. Magnorum Moral. & cap. 10. Mag. Moral. & cap. 16. Mag. Moral. & cap. 7. &longs;ecundi Eudem. & cap. 12. &longs;ecundi Eudem. & problema 6. &longs;ectio­nis 30. tot Ari&longs;totelis loca illu&longs;trat vnica hæc Euclidis Demon&longs;tratio.

Ad &longs;cholion præcedentis 32. primi, vide tex. 39. primi Po&longs;ter. loco 3. Item tex. 25. &longs;ecundi Po&longs;ter. loco vlt.

Ad 45. primi, vide locum 9. de lineis in&longs;ecabilibus.

Ad 46. primi, vide locum 11. de lineis in&longs;ecabilibus.

Ad 47. primi, vide locum 11. de lineis in&longs;ecab. Item locum 14. de ij&longs;dem.

In &longs;ecundo Elem.

Ad 2. definitionem 2. Gnomonis, vide cap. de Motu in Po&longs;tprædicam. Qua­dratum augetur Gnomone circumpo&longs;ito.

Ad 14. propo&longs;. 2. opportunum e&longs;t Auditores de Quadratura circuli erudire, vide igitur cap. de relatione in prædicam. & cap. 31. &longs;ecundi Priorum, & tex. 23. primi Po&longs;ter. & finem 1. cap. primi Elenchorum. lege primam Ar­chimedis de dimen&longs;ione circuli.

In tertio Elem.

Ad primam 3. vide cap. 9. lib. 2. Ethycorum.

Ad 2. tertij, vide tex. 13. lib. 1. de Anima. & locum 16. de lineis in&longs;ecab.

Ad 31. tertij, vide tex. 11. &longs;ecundi Po&longs;ter. & tex. 20. &longs;exti Methaph. loco 2.

In quarto.

Ad commentarium P. Clauij extremum lib. 4. elementorum. lege tex. 66. tertij de Cœlo.

In quinto.

Ad 4. definitionem 5. vide cap. 3. lib. 2. Ethyc.

Ad 9. definitionem 5. vide cap. 3. lib. 5. Ethyc. loco 4. & cap. 31. primi Ma­gnorum Moralium.

Ad 10. definitionem 5. vide tex. 29. primi Po&longs;ter. loco 2.

Ad 12. definitionem 5. vide tex. 13. primi Po&longs;ter. loco 3. & tex. 25. &longs;ecundi Po&longs;ter. & tex. 32. tertij de Anima. & cap. 3. lib. 5. Ethyc. loco 4.

Ad 16. propo&longs;. 5. vide tex. 25. &longs;ecundi Po&longs;ter. loco 2. ex hac Euclidis demon­&longs;tratione patet, vitio&longs;am e&longs;&longs;e illam Auerrois argumentationem, 8. Phy&longs;. comm. 15. &longs;cilicet.

Vt &longs;e habet voluntas antiqua ad antiquum effectum, Ita &longs;e habet etiam voluntas noua ad effectum nouum: Ergo permutando, ita &longs;e habebit voluntas antiqua ad effectum nouum. Quemadmodum voluntas noua ad effectum antiquum.

Non enim in permutando confert antecedentem ad antecedentem, & con­&longs;equentem ad con&longs;equentem, vt par erat, &longs;ed confert antecedentem ad con&longs;equentem, quod non licet.

In &longs;exto.

Ad 2. propo&longs;it. 6. vide cap. 2. lib. 8. Topicorum loco 41.

Ad 13. &longs;exti, vide tex. 12. &longs;ecundi de Anima, & tex. 3. tertij Methaphy&longs;.In &longs;eptimo.

Ad primam definitionem 7. vide tex. 5. primi Po&longs;ter.

Ad 8. definitionem 7. vide cap. 1. lib. 1. Magnorum Moral.

In octauo.

Ad 4. propo&longs;. 9. vide tex. 20. primi Po&longs;ter. loco 2.

Ad 8. propo&longs;. 9. vide problem. 3. &longs;ectionis 15. loco 4.

In decimo.

Ad primam definitionem 10. vide cap. 23. &longs;ecti 1. primi Priorum. & tex. 48. primi de Cœlo.

Ad 118. decimi, vide cap. 23. &longs;ecti 1. libri 1. Priorum. & &longs;ecto 2. cap. 23. li­bri 1. Priorum. & cap. 22. lib. 2. Priorum. & tex. 5. primi Po&longs;ter. & tex. 44. primi Po&longs;ter. & cap. 15. primi Po&longs;ter. & tex. 119. primi de Cœlo. & tex. 120. quarti Phy&longs;. & tex. 21. tertij de Anima. & cap. 1. primi Methaphy&longs;. & tex. 28. quarti Met. & tex. 34. quinti Met. & tex. 8. &longs;exti Met. & cap. 4. lib. 2. de Generat. animal. & lib. 3. cap. 3. Ethyc. & cap. 10. &longs;ecundi Eu­dem. tot Ari&longs;t. loca ab hac vna Euclidis Demon&longs;tratione illu&longs;trantur.

In decimotertio.

Ad primam propo&longs;. 13. &longs;ecundum editionem Commandini, aut Zamberti. vide initio Priorum, in verbum (Re&longs;olutio)

Atqne hæc &longs;unt, quæ ex Elementorum opere Ari&longs;toteles pa&longs;&longs;im v&longs;urpauit, quæque nos infra explicabimus.

Finis Secundi Indicis.

Quæ verò ad alias Mathematicas, Mu&longs;icam &longs;cilicet, Per&longs;pe­ctiuam, Mechanicam, & A&longs;tronomiam pertinens, facilè poterunt ex primo Indice ad vnamquamque earum &longs;eor­&longs;um cum libuerit, &longs;ecerni.

TERTIVS INDEX ALPHABETICVS,

cuius numeri re&longs;pondent numeris marginalibus Operis.

AAbductio quid. eius inuentor. numero 16. marginali.Acuti den&longs;um quid.399Aequalitas mathematica, quæ.10Ae&longs;tus maris natura.272Aequitas arithmetica, & æquitas &longs;ecundum dignitatem.330Agathir&longs;i populi.382Angulus quid. vt nominari debeat 10. angulum in &longs;emicirculo e&longs;&longs;e rectum o&longs;tendi per cau&longs;am materialem.71Angulus rectus variè con&longs;ideratur à Geometra, & à Fabro.301Antiphontis quadratura circuli.13Antennæ nauis problema.248Antipbonæ voces. 358. 363. 370. 371.373Apum mirabilis indu&longs;tria.120Apotome linea, quæ.279Aquæ &longs;uperficiem e&longs;&longs;e &longs;phæricam ratione mathematica.107Arithmetica proportio.302Aranei industria patefacta, qua ad res inaca&longs;&longs; as tran&longs;eat.293filum emittit ex &longs;ece&longs;&longs;u contra Ari&longs;totelem pro Democrito.ibidem.Astronomiæ principia duo, Apparentia, & Ob&longs;eruatio.8Automata, quæ. 199. 298.a. b.BBa&longs;is ballarum in aqua, cur &longs;it alba, & cur non faciat vmbram.351Binomium linea, quæ.279Bra&longs;ilien&longs;es, qua ratione numer are &longs;oliti.340Bry&longs;onis quadratura circuli.35CCalippi opinio de numero Cœlorum.236Cantilenam notam &longs;uauius, quam ignotam audimus.362Centrum circuli reperire. 303. Centrum mundi mathematicè o&longs;tenditur. 123. Cen-trum grauitatis, & molis. 38.112Chordarum veterum nomina.359Circuli quadratura quid. an po&longs;&longs;ibilis. num. 1. Circulorum concentricorum maiores velocius moueri. 108. Circuli admiranda. 239. De circulorum concentricorum volutatione.263Coalternæ lineæ, quæ. 12. 14.44Cœlorum ordinem petendum ex A&longs;tronomis 109. item numerum233Colores in mu&longs;ica 78. Colores oculorum vnde.408Cometarum tractatiuncula ex recentioribus, qui eas in Cœlo collocant. 136. e&longs;&longs;e &longs;u-pra aerem longi&longs;&longs;imo &longs;altem interuallo o&longs;tenditur mathematicè. 129. in additione.Con&longs;onantia, quid. 64. quibus numeris con&longs;onantiæ con&longs;tent.210Conus, & cylindrus, cur variè mouentur.355Cubus numerus. duo cubi cubus, quid &longs;ignificet.33Curru problema.252Cunei problema.256Cylindri, & coni motus comparatio problematica.335DDefinitiones mathematicæ e&longs;&longs;e e&longs;&longs;entiales, & perfe&longs;&longs;imas. cap. 1. de nat. Math. definitionum v&longs;us in Mathematicis.81De&longs;criptio, & de&longs;cribere, quid. 2. 6. 7.205De&longs;ignatio pro demon&longs;tratione mathematica.305Demon&longs;trationis perfectæ exemplum. 36. demon&longs;trationum mathematicarum præ-&longs;tantia. cap. 4. de nat. Mathem.Dentiforcipis problema.260Denarij numeri perfectio. 339. cur v&longs;que ad denariŭ omnes gentes numerent.339. 8. &c.Diameter incommen&longs;urabilis costæ. 5. diametri etymon.337Diapa&longs;on quid. 90. 350. omnium con&longs;onantiarum pulcberrima.388Diapa&longs;on diapente.359Diapente con&longs;onantia, quæ.359Diate&longs;&longs;aron con&longs;onantia, quæ.359Di&longs;d apa&longs;on con&longs;onantia, quæ.359Die&longs;is, quid. 53.226Dolia duo, quomodo aliquando Diapa&longs;on re&longs;onent.402Duplum inter multiplicia primum e&longs;t.322EElementa mundi non componi ex figuris geometricis.120Elementa geometrica, quæ. 82.213Eudoxi opinio de numero Cœlorum.234Exempla mathematicorum, qualia. 11. non e&longs;&longs;e fal&longs;a.43Exemplorum veritas, & conformitas, quatenus requirantur.36FFiguram omnem planam habere &longs;uos angulos externos quotcŭque æquales quatuor rectis angulis, quæ e&longs;t mira proprietas.59Figuræ &longs;imiles, quæ.70Figurarum planarum ordo 88. quæ nam totum locum repleant.96Figurarum &longs;olidarum, quænam totum locum repleant: vbi Ari&longs;t. & omnium expo&longs;i-torum rratum aperitur.121Figuratio lucis.345Figurationes pro demonftrationibus Mathem.194Filum Araneorum, ex qua parte corporis exeat, & ex qua materia.293Fluxus, ac refluxus maris.272Fuium lctorum problema.264GGalaxia quid. 131. Ari&longs;toteles defen&longs;us. 132.140Galibei recens ob&longs;eruatio.141Generatria Mu&longs;icæ veteris. 78. Fusè explicantur.371Geodæ&longs;ia.207Geographiæ veteris plura errata, 145. 146. 147. 148.149Gnomon, quid. 3. &331Gnomones numeri.93Graue qua ratione ad centrum mundi de&longs;cenderet, eiqué aptaretur.112Grauiden&longs;um, quid.399HHalonis demonfiratio.161Hippocratis chij quadratura circuli. 17. eiu&longs;dem quadratura lunulæ optima.17Hyades, Atlantides, & Succulæ.335Hypate, quid.360Hypotenu&longs;a in ince&longs;&longs;u animalium.294IIlluminationes Solis deficientis per foramina tran&longs;euntes, eur &longs;int defectiuæ.350modus videndi eclyp&longs;im facilis, ac iucundus.ibidem.Ince&longs;&longs;us animalium lineis explicatur.294. & &longs;eqqueIncommen&longs;urabilia, quæ, & eorum inuentores.5Indiui&longs;ibilia mathematica e&longs;&longs;e priuationes. 189. oriri ex diui&longs;ione. 231. eorum duo genera.276Infinito, qua ratione vtantur Mathematici. 94.96Iridis demon&longs;tratio &longs;ecundum Ari&longs;t. 163. & &longs;equentibus. Item noua de Iride tra-ctatio. ibidem in additione.Iugum in lyra quid, & eius figura.396LLeges mu&longs;icales.204Libra maior, cur exactior. initio Mechanicarum quæ&longs;t.Liea, quæ terminus est illuminationis in Luna, cur modo recta, modo curua vi-deatur.346Lineæ rationales, & irrationales, &c.279Lumen oculorum noctu videntium, in qua oculi parte manet. in addit. de Pupilla.Lumen Solis, cur &longs;it circulare, quamuis per foramina angulo&longs;a ingrediatur.345Luna plana, cur appareat, cum &longs;it &longs;phærica. 347. cur in eadem altitudine cum Sole &longs;upra horizontem, maiorem vmbram efficiat.349Lunam e&longs;&longs;e &longs;phæricam. 48. illuminari &longs;phæricè quid: ibidem & de illuminatione Lu-næ. iterum e&longs;&longs;e &longs;phæricam ab eclyp&longs;ibus.111Luminarium Solis, & Lunæ ordo.133Lychanos, quid.360Lyræ veteris figura.396MMagalis, &longs;eu magas, & magadi&longs;&longs;are. 373.393Matera intelligibilis. fusè verò. explicatur in tract. de nat. Mathem.Mathemaicæ mediæ, &longs;eu &longs;ubalternatæ habent propter quid &longs;uarum demon&longs;iratio-nem.50Mathematici negant reperiri quantitatem indiui&longs;ibilem, &longs;eu minimam.100Mathematicæ non &longs;unt contentio&longs;æ. 83. ostendunt per cau&longs;am formalcm.91Mathematics inuenerunt Aegyptij Sacerdotes.198Mathematicæ o&longs;tendunt per cau&longs;am materialem, & formalem. 205. earum vtilitas. ibidem. De earum natura. in proprio tractatu. Mathematicæ maximè tractant de Bono, & Pulcro, qua ratione.237Mechanica facultas, quæ.238Melodia.331Melopeia quid.384Medium Demonstrationum Mathem. in earum tractatu.Me&longs;e quid.360Mina in men&longs;uris quid.53Monochordiux.359Motus nauigij, & remi comparatio. 247. Pulchra P. Nonij in id annotatio con-tra Ari&longs;t.Modi mu&longs;ici.383Modorum antiquorum ordo, numerus, &c.383Motus primi mobilis, &longs;eu diurnus e&longs;t men&longs;ura cœlestium motuum.225Mu&longs;ici recentiores reprehen&longs;i. 331. & in fine Chronologiæ.Mu&longs;icæ totius elementa.359Mu&longs;ica nuda, & cum melodia.331NNete quid.360Nucifragi in&longs;trumenti problema.261Numerus, par, impar, primus, & compo&longs;itus, quadratus, &longs;eu æquilaterus, altera parte longior. 24. Cubus num.33Numeri capitales, qui.82Numerum parem e&longs;&longs;e cau&longs;am infiniti: imparem verò finiti.93Numerorum parium alij &longs;unt primi, alij non.224Numerus vnitarius.307OOculi cur moueantur con&longs;imiliter.405Oculi anathome.408. &c.Omophonæ voces. 372.392Oppo&longs;itio diametralis e&longs;t omnium maxima.327Ortus, & occa&longs;us &longs;yderum, quid, & quotuplex: vbide Orione, & Canicula.153PParanete quæ voces, aut chordæ.360Parame&longs;eParhypateParelia, cur appareant nondum &longs;atis explicari.182Parna&longs;&longs;us mons, vbinam &longs;it. Item paropame&longs;&longs;us.145Partes quantitatis &longs;unt materia illius.211Per&longs;pectiuus, quatenus con&longs;ideret lineam.89Pa&longs;&longs;iones Mathematicorum cum &longs;ubiecto conuertuntur.47Pila chri&longs;tallina, vel vitrea, qua ratione comburat.60Planetæ, qua ratione moueantur duplici motu.130Plato &longs;olida ex planis componebat. 105. cur Elementis figuras Geometricas attri-bueret.122Planetarum ordo.271Principia Mathematicorum. 2.118Principia &longs;cientiarum duplicia. Ex quibus, & circa quod.61Principia Mathematica non pendere ab experientia.315Proportio alterna. 28. multiplicata, &longs;eu multiplex &longs;ecundum Cæneum.46P&longs;eudographia quid.83Proportionalitas quid.308Proportio continuata, & di&longs;iuncta quid. 310. alterna, &longs;eu permutata quid.inibi.Proportio Geometrica. 311. Arithmetica.302Proportio &longs;ecundum dignitaem, e&longs;t Geometrica.330Problemata mu&longs;icalia varia à 360. v&longs;que ad finem &longs;ectionis 19. problematum.Punicum, mu&longs;icum in&longs;trumentum.370Pupillæ oculi etymon., & natura. 408. cur in oculo no&longs;tro imago pupillæ appareat. problem. 2.ibidem.Cur nigra in omnibus bominibus. probl. 5.Cur in Sole euane&longs;at. probl. 6.Cur modo maior, modo minor appareat.Pythagorici primi Mathematicis operam dedere, eas&queacute; ceteris &longs;cientijs præponebăt.202QQv adraura circuli. vide circulus. de quadratura figurarum rectangularum, & quadraturæ duplex definitio cau&longs;alis, & formalis.185Quantitas an conctet ex indiui&longs;ibili. toto libello de lineis in&longs;ecabilibus argumentis mathematicis.RRemi problema.245Re&longs;olutio logica, & mathematica, vt conueniant. 4. &305Re&longs;ultus cadentium in terram, quibus angulis fiat.354Rythmus fusè explicatur.381Rubrum mare duplex.152SScythala quid, & eius figura 250. &252Securis problema, vbi deantiquæ &longs;uris figura, & angulo pulchra demon&longs;tran-tur.258Semitonium, quid.360Solem e&longs;&longs;e terra multo maiorem: probatur.131Sphæram planum tangit in puncto. demon&longs;tratur.184Statera antiqua, quæ: eius figura, & problema.259Stereomatria, vt differat à Geometria.49Succula.253Symphonæ voces. 372.392Symphonia.391TTemonis nauis problema.246Terram e&longs;&longs;e rotundam ex eclyp&longs;i. 114. Item aliter. 115. e&longs;&longs;e re&longs;pectu Cœli paruam valde. 115. e&longs;&longs;e cubum cur Plato voluerit.122Terræ quantitas.115Terram paulatim reduci ad pefféctam rotunditatem.151Tetragoni&longs;mus. vide Quadratura.Teretizare, quid.366Tetrachordon, quid.386Tollenonis problema.267Tonus mu&longs;icus, qui; vnde oriatur.360Trochleæ problemata. 249. 250.251Tunic oculi. 408. in tractatu de Pupila.VVentorum nomina, & &longs;itus.160. a.Vectis quotuplex, & c.244Veteres canere &longs;olitos non &longs;olum in choris, &longs;ed etiam in &longs;cenis. 371. 384.400Virgiliæ, Pleiades.335Vi&longs;æ res gemmantur di&longs;tractis oculis.406Vi&longs;æ rei geminatio non fit altero oculo in latera torto, cur.407Vi&longs;us res vi&longs;as, cur non duplicet, etiam &longs;i duos oculos habeamus.405Vmbelici litoralis problema.254Vmbram terræ parum &longs;upra Lunam tran&longs;cendere.137Vmbrarum incrementa, & decrementa, cur inæqualia. 344.348Vi&longs;us res geminat, &longs;i alter oculorum digito pellatur, cur.197Vocum mu&longs;icalium antiquæ appellationes.360Vox acuta velocior, grauis verò tarda, cur.77Voluminum &longs;ectio modo rectam lineam, modo curuam refert, cur.356Vnitas, cur indiui&longs;ibilis.22ZZonas terræ, vt Arist. de&longs;ignet: & quæ &longs;ecundum ip&longs;um &longs;int habitabiles.156Zonam torridam quatuor reddunt habitabilem.159

Finis Tertij Indicis.

Vi&longs;um e&longs;t etiam opportunum Lectori fore, ea &longs;imul in vnum loca colligere, in quibus Ari&longs;toteles mihi vi&longs;us e&longs;t in Ma­thematicis &longs;copum non attigi&longs;&longs;e, vt alij pr&ecedil;&longs;ertim Peripa­tetici facilius ea inuenire, atque de ij&longs;dem iudicium ferre po&longs;&longs;int.

121Nvmero marginali: vbi ait plura Octaedra, &longs;eu Pyramides re-plere locum: in quo omnes pariter expo&longs;itores lap&longs;i &longs;unt.124Latitudinem figura, ait, cau&longs;am e&longs;&longs;e &longs;upernatationis. & aquam re&longs;i&longs;tere &longs;impliciter diui&longs;ioni.136Cometas in &longs;uprema aeris regione collocat; cuius contrarium ibi line ari demonctratione ostenditur.147Ait Tanaim, & Indum oriri ex monte Paropami&longs;&longs;o. & c.148Ait, tertia parte noctis Cauca&longs;i verticem illuminari à Sole.149Ait Danubium ex Pyreneo monte defluere.150Ait fluuium quendam non minorem Rhodano in Liguria ab&longs;orberi, & iterum egredi.152Ait Rubrum mare parum Atlantico Oceano commi&longs;ceri.159Zonam torridam inhabit abilem exi&longs;timat.164Putat Iridis angulos non po&longs;&longs;e vnum &longs;upra alterum collocari, &longs;ed tantummodo in orbem.182Rationes, quas in Parelij dubitationibus affert, videntur inanes.236In &longs;ubducendo cœle&longs;tium orbium numero, memoria labitur.243Ait lineam O L, &longs;uperare lineam L R, quantitate P L, vt in figura.245Remum ad vectem primi generis reducit.246Temonem nauis reducit ad vectem primi generis.247In motu Remi collato cum motu Nauigij, à Nonio erroris manifestè arguitur. eodem modo in motu Temonis.250Ait maioribus trochleis, aut rotulis facilius onera &longs;ubleuari.256Reducit cuneum ad vectem primi generis.270Cur res in vorticibus ad medium ferantur, veram cau&longs;am a&longs;signa-re non videtur.275Ait Danubium altero ramo in Mediterraneum, altero in Pontum effluere.293Negat Araneum filum ab intrin&longs;eco emittere, Democritum iniuria refellens. quamuis hoc vltimum ad Phy&longs;icum pertineat.403Problem. 2. &longs;ect. 2 3. non benè videtur a&longs;signare cau&longs;am variæ im-mer&longs;ionis nauigij.

LOCAMATHEMATICAEX LIBROPRÆDICAMENTORVMPer ordinem declarata.

1

Ex c. 3. De his, quæ ad aliquid. Porrò quemadmodum vnus angulus vni angulo æqualis e&longs;t, ita aliquando duo anguli &longs;unt vni angulo æquales, vt patet, &longs;i vnus angulus, v.g. angulus B A C, vbi ait (Scientia verò &longs;i non &longs;it, nihil probibet e&longs;&longs;e &longs;cibile, vt circuli quadratura, &longs;i e&longs;t &longs;cibilis, &longs;cientia quidem eius nondum e&longs;t) Cum velit Ari&longs;t. o&longs;tendere, nó omnia correlatiua &longs;imul e&longs;&longs;e natura, id de &longs;cibili, & &longs;cien­tia variè probat, præ&longs;ertim verò, quia multa &longs;int &longs;cibilia, quæ tamen nondum &longs;ciantur, vt patet, inquit, in Quadratu­ra circuli, & &longs;cientia ip&longs;ius, quia quamuis ip&longs;a circuli quadratura &longs;it &longs;cibi­lis, nondum tamen &longs;imul cum ip&longs;a, &longs;cientia illius extat. Quæ vt perfectè intelligantur, &longs;ciendum e&longs;t, quadraturam circuli, quæ à Græcis tetrago­ni&longs;mus dicitur, nihil aliud e&longs;&longs;e, quàm propo&longs;ito cuilibet circulo exhibere quadratum æquale. Quæ æqualitas debet intelligi de areis, &longs;eu &longs;patijs, ita vt area circuli, &longs;eu &longs;patium illud, &longs;iue &longs;uperficies illa circularis, &longs;it æqualis areæ, &longs;eu &longs;uperficiei quadratæ. Qua in re plurimi decipiuntur exi&longs;timantes per quadraturam cir culi inquiri æqualitatem linearum, ita vt circumferen­tia circuli debeat e&longs;&longs;e æqualis ambitui, &longs;eu quatuor lateribus quadrati: quod omnino fal&longs;um e&longs;t.

Quadratio porrò circuli dupliciter proponi pote&longs;t, vel tanquam Theo­rema, vel tanquam Problema (theorema autem e&longs;t propo&longs;itio, in qua nihil fa­ciendum proponitur; problema verò aliquid fseri expo&longs;cit) neutrum a tm tem­pore Ari&longs;t. erat adinuentum nam theorema inuentum e&longs;t po&longs;t ip m ducen­tis circiter annis ab Archimede: problema verò nondum à quoquam per­fectè potuit reperiri. qua di&longs;tinctione &longs;aluari po&longs;&longs;unt nonnulli, vt Boetius hocloco, qui aiunt, &longs;e vidi&longs;&longs;e Demon&longs;trationem quadraturæ huius, &longs;i nimi­rum intelligant theorema. & alij etiam verum a&longs;&longs;erunt, dum negant hacte­nus repertam e&longs;&longs;e, &longs;i nimirum de problemate loquantur, theorema Archi­medis e&longs;t propo&longs;itio prima acuti&longs;&longs;imi libelli de Dimen&longs;ione circuli; e&longs;t au­tem huiu&longs;modi. Quilibet circulus æqualis e&longs;t triangulo rectangulo, cuius quidem &longs;emidiameter vni laterum, quæ circa rectum angulum &longs;unt, ambi­tus verò ba&longs;i eius e&longs;t æqualis.

Sit, v.g. datus circulus, cuius &longs;emidiameter A B; & fit trian gulum rectangu­lum A B C, cuius angulus B, &longs;it rectus, & latus B A, con&longs;tituens angulum re­ctum B, cum ba&longs;i B C, &longs;it æquale &longs;emidiametro A B; ba&longs;is verò B C, &longs;it æqua­lis peripheriæ eiu&longs;dem circuli dati. demon&longs;trat iam ibi Archimedes acuta æquè, ac euidenti demon&longs;tratione triangulum i&longs;tud æquale e&longs;&longs;e circulo illi. quod perinde e&longs;t, ac &longs;i o&longs;tendi&longs;&longs;et cuinam quadrato &longs;it æqualis, cum per vl­timam 2. Eucl. po&longs;&longs;imus triangulo huic quadratum æquale con&longs;truere, quod con&longs;equenter dato circulo æquale erit. Quod &longs;i in modum Problematis ita proponatur: Dato circulo æquale quadratum con&longs;truere, nondum inuenta e&longs;t ratio, quæ demon&longs;tratione confirmetur, qua id geometricè penitus, hoc e&longs;t ad æqualitatem mathematicam, &longs;eu exacti&longs;&longs;imam effici po&longs;&longs;it, totaque; dif­ficultas po&longs;ita e&longs;&longs;e videtur in inue&longs;tigando, quonam modo exhibeamus li­neam rectam B C, æqualem peripheriæ circuli dati. quam nullus hactenus geometricè illi æqualem potuit exhibere, atque exhibita euidenti demon&longs;tra­tione comprobare; Quamuis Archimedes acumine &longs;anè mirabili in lib. de lineis &longs;piralibus, eam quoque theorematicè, non tamen problematicè inue­&longs;tigauit. nam propo&longs;itione 18. illius admirandi operis inuenit lineam rectam æqualem circumferentiæ primi circuli &longs;piralis lineæ; propo&longs; verò 19. repe­rit aliam rectam æqualem circumferentiæ &longs;ecundi circuli. tu ip&longs;um con&longs;ule, &longs;i admirandarum rerum contemplatione delectaris. Multa hac de re Pap­pus Alexandrinus lib. 4. Math. coll. & Ioannes Buteo vnico volumine om­nes quadraturas tain pri&longs;corum, quam recentiorum comprehen&longs;us e&longs;t. Qua­re qui plura cupit, eos adeat; nos tamen infra &longs;uis locis explicabimus tres illas celebres antiquorum Antiphontis, Bri&longs;&longs;onis, & Hippocratis quadra­turas, quamuis fal&longs;as, quarum &longs;æpe meminit Ari&longs;t. & alij. &longs;olet autem à non­nullis di&longs;putari, vtrum quadratura i&longs;ta problematica &longs;it po&longs;&longs;ibilis, nec ne, cum videant eam à nemine, quamuis diu magno labore perqui&longs;itam, hacte­nus adinuentam e&longs;&longs;e. ego quidem e&longs;&longs;e po&longs;&longs;ibilem exi&longs;timo, quis enim dubi­tare pote&longs;t, po&longs;&longs;e exi&longs;tere quadratum æquale circulo propo&longs;ito? Quod &longs;i po­te&longs;t fieri, quare non etiam demon&longs;trari? pr&ecedil;fertim cum videamus ab Archi­mede iam inuentam e&longs;&longs;e, quatenus Theorema e&longs;t. & præterea con&longs;tet Hip­pocratem quadra&longs;&longs;e lunulam, vt &longs;uo loco dicemus, & Archimedem in libel­lo de quadratura Paraboles, quadra&longs;&longs;e ip&longs;am Parabolem, quæ tamen duæ fi­guræ, lunula &longs;cilicet, & parabola &longs;unt curuilineæ.

2

Ex cap. de Priori (in &longs;cientijs demon&longs;tratiuis e&longs;t prius, & po&longs;terius ordine, elementa enim priora &longs;unt ijs, quæ de&longs;cribuntur, nam principia prior a &longs;unt theore­matibus ordine) verba illa, nam principia, &c. quæ non &longs;unt in antiqua tran­&longs;latione de&longs;ump&longs;imus ex ca&longs;tigati&longs;&longs;imo græco codice editionis Francfor­dien&longs;is, propterea quod totum hunc locum declarant; &longs;unt autem i&longs;ta, ai/gar arxai/ pro/terai tw_n qewrhma/twn th ta/xei. per &longs;cientias autem demon&longs;tra­tiuas intelligendas e&longs;&longs;e hoc loco ip&longs;as Mathematicas ex eo patet, quod illis a&longs;&longs;ignet Ari&longs;t. De&longs;criptiones; nam hoc verbo, De&longs;criptiones, &longs;eu figuratio­nes, &longs;olet ip&longs;e Mathematicas Demon&longs;trationes innuere, quod in ip&longs;is figu­rationes, & De&longs;criptiones adhibeantur, vt alijs locis patebit: idcirco ver­ba illa à nobis addita ex græco, optim è præcedentia exponunt, cum per ele­menta intelligantur principia, qualia &longs;unt initio Euclidis, & per de&longs;criptio­nes exponant theoremata. quod autem principia illa ordine priora &longs;int de­mon&longs;trationibus, &longs;iue ip&longs;as præcedant, ex ip&longs;a primi Euclidis in&longs;pectione patere pote&longs;t.

3

Ex cap. de motu (Quadratum augetur Gnomone circumpo&longs;ito) Gnomon vox græca inter alia &longs;ignificat in&longs;trumentum illud, quod Latini tum amu&longs;&longs;im,

tum normam appellant, Itali verò, Squadra, ad cuius &longs;imilitudinem Geometræ denominarunt fi­guram quandam, &longs;eu portionem cuiu&longs;uis paralle­logrammi, vt videre e&longs;t in definitione &longs;ecunda 2. elem. & in præ&longs;enti figura, in qua quadratum A B C D, circumpo&longs;ito gnomone E F G, augetur, & fit maius quadratum H B I L.

Idem etiam verum e&longs;t in quadrato arithmeti­co, &longs;iue in numero quadrato: is enim pariter ad­dito Gnomone augetur. i. addito numero impari. quemadmodum infra 3. Phy&longs;. tex. 26. fusè explicabimus.

Ex Primo Priorum re&longs;olutoriorum.

4

Aliquorum opinio e&longs;t, Ari&longs;totelem ho&longs;ce libros appella&longs;&longs;e re&longs;olu­torios, quod per illos doceat &longs;yllogi&longs;mum, ac demon&longs;trationem iam factam in &longs;ua immediata principia re&longs;oluere, quam opinio­nem meum non e&longs;t, nunc refellere. per&longs;ua&longs;um tamen mihi e&longs;t, rem multo aliter &longs;e habere, veram rationem huius tituli petendam e&longs;&longs;e ex peni­tiori Mathematicorum eruditione. Sciendum itaque id, quod tradit Pappus Alex. initio &longs;eptimi Mathem. collect. antiqui&longs;&longs;imos videlicet Geometras, Euclidem, Apollonium Pergæum, & Ari&longs;t&ecedil;um &longs;crip&longs;i&longs;&longs;e libros de re&longs;olutio­ne, in quibus ars tradebatur, qua propo&longs;ito quouis theoremate, aut proble­mate po&longs;&longs;ent facile ex eo, tanquam vero accepto inue&longs;tigare aliquam veri­tatem, per quam deinde componerent illius, quod quærebatur, Demon&longs;tra­tionem; inue&longs;tigationem illam appellabant re&longs;olutionem: compo&longs;itionem verò nominabant di&longs;cur&longs;um illum, quo ex vero illo per re&longs;olutionem inuento, o&longs;tendebant conclu&longs;ionem. Porrò Diogenes Laert. huius re&longs;olutionis in­uentorem facit Platonem: à quo eam Leodamas Tha&longs;ius didicit, cuius be­neficio, pluries deinde Geometricas demon&longs;trationes adinuenit. definitio vtriu&longs;que e&longs;t a pud Euclidem ad primam propo&longs;. 13. Elem. iuxta tran&longs;latio­nem Zambrti, & Commandini; vbi etiam quinque priora theoremata, pri­mò per re&longs;olutionem, deinde per compo&longs;itionem demon&longs;trantur, quæ tan­quam per&longs;picua exempla rei propo&longs;itæ in&longs;eruire po&longs;&longs;unt. &longs;unt præterea fre­quentes huiu&longs;modi re&longs;olutiones in operibus Archimedis, Apollonij, & Pap­pi. extat adhuc liber Datorum Euclidis, qui geometricis re&longs;olutionibus in­&longs;eruiebat. vtinam extarent etiam alij de re&longs;olutione, quorum auxilio non tantopere recentiores Mathematici in inueniendis Demo&longs;trationibus la­borarent; hanc re&longs;olutionem, &longs;ic Pappus fu&longs;ius, quam Euclides explicat; re&longs;olutio e&longs;t via à quæ&longs;ito tanquam conce&longs;&longs;o per ea, quæ exip&longs;o con&longs;equun­tur ad aliquod certum, & conce&longs;&longs;um: in re&longs;olutione enim id, quod quæritur tanquam factum, & verum &longs;upponentes, quid ex hoc &longs;equatur, con&longs;idera­mus, quou&longs;que incidamus in aliquod iam cognitum, vel quod &longs;it è numero principiorum. Quod quidem erat fignum euidens, quæ&longs;itum quoque verum e&longs;&longs;e. eadem omnino habet Proclus in comm. ad &longs;extam primi elem. Quod porrò Ari&longs;t. ip&longs;e hanc re&longs;olutionem Mathematicam cognouerit e&longs;&longs;e medij inqui&longs;itionem manife&longs;tum e&longs;t ex cap. 3. lib. 3. Ethyc. vbi &longs;ic ait (Qui enim con&longs;ultat, quærere videtur, & re&longs;oluere prædicto modo, quemadmodum de&longs;igna­tiones) vbi per de&longs;ignationes intelligit Geometricas demon&longs;trationes, vt &longs;upra innuimus, & infra probabimus; cum ergo con&longs;ultatio nihil aliud &longs;it, quam medij idonei ad finem in rebus agendis inqui&longs;itio, eamque dicat e&longs;&longs;e &longs;imilem re&longs;olutioni Geometricæ, manife&longs;tum e&longs;t, ip&longs;am quoque re&longs;olutionem e&longs;&longs;e medij in rebus &longs;peculatiuis idonei perue&longs;tigationem. Exi&longs;timo igitur cum docti&longs;&longs;imis Zabarella, Burana, Toleto, & alijs, Ari&longs;totilem non &longs;olum hanc &longs;uam logicam ad mathematicarum &longs;cientiarum typum compegi&longs;&longs;e, verum potius imitatum e&longs;&longs;e opus illud Euclidis de re&longs;olutione, atque ex eo non &longs;olum plurima exempla Geometrica, verum etiam titulum de&longs;ump&longs;i&longs;&longs;e, præ&longs;ertim cum argumentum e&longs;&longs;et ferè idem vtrobique, &longs;ed Ari&longs;t. intentio fuerit accommodare re&longs;olutionem omnibus &longs;cientijs; Euclidis verò, & alio­rum Geometriæ &longs;oli. hinc patere pote&longs;t, cur hi libri re&longs;olutorij in&longs;cribantur, quod &longs;cilicet tradunt methodum, qua valeamus quæ&longs;itum quoduis re&longs;olue­re, ide&longs;t, ex quæ&longs;ito tanquam vero inue&longs;tare aliquam veritatem, per quam deinde propo&longs;itæ quæ&longs;tionis rationem methodo compo&longs;itiua reddamus. Et verò cum reliquas appellationes Problematis, Theorematis, Propo&longs;itionis, definitionum, po&longs;tulatorum, axiomatum, & alia huiu&longs;modi ex Geometri­cis ad omnes &longs;cientias tran&longs;tulerit, quid ni etiam re&longs;olutionem? maximè verò, quia &longs;i horum lib. intentio e&longs;&longs;et docere iam factum &longs;yllogi&longs;mum in &longs;ua principia re&longs;oluere, parum e&longs;&longs;et vtilis; imò nec vtilis, &longs;ed &longs;uperfluum quid. at verò vbinam docuit hanc re&longs;olutionem? profecto nullibi. quid opus e&longs;t iam factum &longs;yllogi&longs;mum re&longs;oluere? at verò propo&longs;itam quæ&longs;tionem re&longs;ol­uere veterum mathematicorum more, hoc opus, hic labor e&longs;t.

Hanc porrò re&longs;olutionem attendendam e&longs;&longs;e primò penes formam, quam docet primis duobus analyticis; &longs;ecundò penes materiam, quam tradit duo­bus vltimis, non prætereundum. reliquas duas logicæ partes, Topicam &longs;ci­licet, & Elenchos, quæ &longs;yllogi&longs;mos probabilem, & apparentem docent, no­luit appellare re&longs;olutorios, quamuis inuentionem mediorum doceant, quia iam mos i&longs;te inoleuerat apud Philo&longs;ophos, & Mathematicos, vt illa &longs;ola pars, quæ ex materia nece&longs;&longs;aria doceret &longs;yllogi&longs;mum demon&longs;tratiuum con­&longs;truere, diceretur re&longs;olutio: cum Mathematici, qui primi de re&longs;olutione &longs;crip&longs;erunt, talem materiam &longs;olum con&longs;iderent.

5

Ex cap. 23. &longs;ecti primi lib. 1. (Vt quod diameter incommen&longs;urabilis eo, quod imparia æqualia paribus fiant, &longs;i fuerit po&longs;ita commen&longs;ur abilis. æqualia igitur fieri imparia paribus ratiocinantur, diametrum vtrò incommen&longs;urabilem e&longs;&longs;e ex &longs;uppo­&longs;itione mon&longs;trant, quoniam fal&longs;um accidit propter contradictionem) Euclides pri­mis duabus definitionibus 10. elem. definit, quæ nam &longs;int magnitudines commen&longs;. & quæ incommen&longs;. &longs;ic; commen&longs;. magnitudines dicuntur, quas

eadem men&longs;ura metitur, vt &longs;i fuerint duæ magnitu­dines, A, & B, quas eadem men&longs;ura C, ide&longs;t quan­titas C, metiatur, ide&longs;t quantitas C, applicata quan­titati A, & per ip&longs;am aliquoties replicata ip&longs;am ad­æquatè ab&longs;umat, vt &longs;i linea C, quinquies &longs;uper li­neam A, replicata eam præcisè, & perfectè omninò adæquaret: & eadem linea C, applicata lineæ B, & &longs;uper illam ter, v.g. re­petita ip&longs;am con&longs;umeret, diceretur vtranque metiri, & proinde duas lineas A, & B, e&longs;&longs;e comm. definit po&longs;tea incommen&longs; hoc modo, incomm, autem, qua­rum nullam contingit communem men&longs;uram reperiri; vt &longs;i duarum linea­
rum, A, B, nunquam po&longs;&longs;et reperiri aliqua men&longs;u­ra, quæ vtranque adæquatè metiretur, v. g. &longs;i linea C, men&longs;uraret A, quater &longs;umpta, ter autem &longs;umpta non adæquaret omnino lineam B, &longs;ed deficeret, vel ex­cederet aliquantulum, atque hoc fieret in quauis alia men&longs;ura, loco ip&longs;ius C, a&longs;&longs;umpta, &longs;iue maior, &longs;iue minor ip&longs;a C, vt vtranque nunquam perfectè metiretur, e&longs;&longs;ent duæ illæ lineæ incommen&longs;. Extare porrò tales lineas, & &longs;uperficies, & corpora, eaque; quam­plurima, ac penè infinita ex 10. Elem. manife&longs;tum e&longs;t. inuentum autem hu­ius a&longs;ymmetriæ, quod Pythagoricis veteres attribuunt, mihi &longs;emper vi&longs;um e&longs;t omni maius admiratione, cum nulla experientia, nullusque; effectus in ip­&longs;ius cognitionem potuerit pri&longs;cos illos Geometras inducere. Quapropter non immeritò diuinus ille Plato lib. 7. de legib. huius a&longs;ymmetriæ ignora­tionem, adeo dete&longs;tatus e&longs;t, vt eam non hominum, &longs;ed &longs;uum, pecorumque ignorantiam cen&longs;uerit. inter lineas incommen&longs;. &longs;unt diameter, & latus eiu&longs;­dem quadrati, quia nulla pote&longs;t reperiri men&longs;ura quantumuis exigua, vti
e&longs;t lineola E, in præ&longs;enti quadrato, etiam&longs;i illam in infinitum &longs;ubdiuidas, quæ vtranque lineam, diame­trum &longs;cilicet A C, & latus quoduis ex quatuor, v. g. latus B C, præcisè omnino metiatur. theorema i&longs;tud demon&longs;tratur in vltima 10. Elem. eodem me­dio, quod ab Ari&longs;totele hic innuitur; Euclides ex &longs;uppo&longs;itione alterius partis contradictionis ip&longs;ius propo&longs;itionis, quæfal&longs;a e&longs;t, nimirum &longs;uppo&longs;ito prædictas lineas e&longs;&longs;e comm. deducit ad impo&longs;&longs;ibile, &longs;iue, vt ait hic Ari&longs;t. fal&longs;um ratiocinatur, quod &longs;ci­licet idem numerus e&longs;&longs;et par, & impar, quod Ari&longs;t. &longs;ignificat, quando ait, imparia æqualia paribus fiunt. ex quo ab&longs;urdo deducitur fal&longs;am e&longs;&longs;e prædi­ctam &longs;uppo&longs;itionem, quæ a&longs;truebat e&longs;&longs;e comm. & proinde altera pars con­tradictionis, quæ e&longs;t, e&longs;&longs;e incomm. vera a&longs;truitur. ex quibus &longs;atis videtur ex­plicari hic locus. videas igitur, quàm leuiter nonnulli no&longs;træ tempe&longs;tatis ageometreti i&longs;tud exponant, dicentes diametrum e&longs;&longs;e incomm. co&longs;tæ, nihil aliud &longs;igni&longs;icare, quam diametrum e&longs;&longs;e longiorem co&longs;ta, qua expo&longs;itione nihil ineptius. Aduerte tandem figuram vulgatæ editionis e&longs;&longs;e ineptam, cum habeat duo quadrata alterum &longs;uper diametro alterius, quorum maius &longs;uperuacaneum e&longs;t.

6

Et cap. 24. &longs;ecti primi libri primi (Sed magis efficitur manife&longs;tum in de&longs;cri­ptionibus, vt quod æquicruris, qui ad ba&longs;im æquales &longs;int, ad centrum ductæ A B, A C, &longs;i igitur æqualem accipiat A G, angulum ip&longs;i A B D, non omnino ex. &longs;timans æquales, qui &longs;emicirculorum, & rur&longs;us G, ip&longs;i D, non omnem a&longs;&longs;umens eum, qui &longs;e­cti. amplius ab æqualibus existentibus totis angulis, & ablatorum æquales e&longs;&longs;e re­tiquos E, F, quod ex principio petet, ni&longs;i acceperit ab æqualibus demptis æqualia derelinqui.) Primum &longs;cias characteres vulgatæ editionis, vna cum figura ip­&longs;is re&longs;pondente, e&longs;&longs;e mendo&longs;os; propterea ex textu græco vtrunque corri­gendum putaui in hunc, quem vidi&longs;ti modum. Secundo, per de&longs;criptiones Ari&longs;t. intelligere demon&longs;trationes Geometricas &longs;upra diximus, quod ex hoc loco euidenter confirmatur, vbi manife&longs;tè loco de&longs;criptionis &longs;upponit li­nearem demon&longs;trationem. In hoc itaque exemplo vult Ari&longs;t. illud demon­&longs;trare, quod Euclides in 5. primi o&longs;tendit, alio tamen modo, &longs;cilicet I&longs;o&longs;ce­lium triangulorum, qui ad ba&longs;im &longs;unt anguli, inter &longs;e &longs;unt æquales. e&longs;t au­tem figura in omnibus textibus deprauata, quam &longs;ic puto rè&longs;tintuendam e&longs;&longs;e ex quodam græco codice, qui characteres hoc modo appo&longs;uerat. &longs;it I&longs;o&longs;ce­

les C A B, cuius ba&longs;is C B, Dico angulos &longs;upra ba&longs;im, in quibus literæ E F, e&longs;&longs;e inuicem æquales. facto centro in A, de&longs;cribatur circulus A B C, tran&longs;iens per puncta C B, iam &longs;ic. omnes anguli &longs;emicirculi &longs;unt æquales in­ter &longs;e, ergo anguli A C G, A B D, &longs;unt æquales. Præte­rea cùm anguli ciu&longs;dem &longs;ectionis &longs;int æquales ad inui­cem, erunt anguli &longs;ectionis C B D G, nimirum anguli, in quibus &longs;unt G, & D, inter &longs;e æquales: cumque; hi duo anguli &longs;ectionis &longs;int partes angulorum &longs;emicirculi A C G, A B D, &longs;i illi ab his auferantur, auferuntur æquales anguli ab æqualibus an­gulis, ergo anguli, qui remanent, &longs;cilicet E, & F, erunt æquales, quod erat demon&longs;trandum. hinc Ari&longs;t. infert manife&longs;tum e&longs;&longs;e oportere in omni &longs;yllo­gi&longs;mo, reperiri vniuer&longs;ales, & affirmatiuas propo&longs;itiones, vt Factum e&longs;t in præcedenti aliter e&longs;&longs;et petitio principij. Quænam vero &longs;it æqualitas, quam Geometræ con&longs;iderant, infra cap. 1. &longs;ecti 3. explicabicur.

7

Ex cap. 2. &longs;ecti 2. lib. 1. (Secundum veritatem quidem ex ijs, quæ &longs;ecundum veritatem de&longs;cribuntur ine&longs;&longs;e, ad dialecticos autem &longs;yllogi&longs;mos ex propo&longs;itionibus &longs;ecundum opinionem) verba illa; ex ijs, quæ &longs;ecundum veritatem de&longs;cribuntur ine&longs;&longs;e; &longs;ic græcè, e/a tw_n xata\ aleiq/ei/an diagegramme/non, vbi manife&longs;tè vtitur verbo, De&longs;cribere, per quod &longs;uperius annotauimus apud Ari&longs;t. &longs;ignificari Geometricas demon&longs;trationes, nam eas opponit dialecticis &longs;yllogi&longs;mis, &longs;e­quentibus verbis, cum dixit (ad diale cticos autem &longs;yllogi&longs;mos ex propo&longs;i­tionibus &longs;ecundum opinionem) hac adhibita con&longs;ideratione, quam inter­pres non videtur adhibui&longs;&longs;e, &longs;en&longs;us huius loci non erit ob&longs;curus.

8

Ex eodem loco paulo po&longs;t (Quare principia quidem, quæ &longs;ecundum vnum­quodque &longs;unt experimenti est tradere: dico autem, vt a&longs;trologicam experientiam a&longs;trologicæ &longs;cientiæ: acceptis enim apparentibus &longs;ufficienter, ita inuentæ &longs;unt a&longs;tro­logicæ demonstrationes) Cum rationem tradat inueniendorum mediorum ad quodlibet problema demon&longs;trandum; nunc docet, non omnia in &longs;eientijs po&longs;&longs;e probari, aut demou&longs;trari: principia enim &longs;cientiarum non demon&longs;tran­tur, &longs;ed &longs;ola experientia manife&longs;ta &longs;unt; vt patet in A&longs;tronomia, quæ ab ex­perientia &longs;ua &longs;olet &longs;tabilire principia: principijs autem experimento con&longs;ti­tutis ex ip&longs;is reliqua problemata demon&longs;trantur. duo autem &longs;unt apud a&longs;tro­nomos genera experimenti, primum dicitur Phænomena, ide&longs;t, apparentiæ; & &longs;unt ea, quæ vulgo omnibus patent, vt Solem oriri, & occidere; a&longs;tra fer­ri circulariter, diem augeri modo, modo minui: & his &longs;imilia. alterum ge­nus dicitur ob&longs;eruationes, quæ tantummodo a&longs;tronomiæ peritis per ob&longs;er­uationem innote&longs;cunt, vt Solem inæqualiter ferri proprio motu per Zodia­cum; aliquando maiorem, aliquando minorem videri; plures dies immo­rari citra æquatiorem in parte Zodiaci boreali, quam in altera vltra æqua­torem au&longs;trali. dies naturales e&longs;&longs;e inuicem inæquales, &c. ex quibus deinde ponunt eccentricos, & augem, ad &longs;aluandas tum apparentias, tum ob&longs;erua­tiones; & hac ratione a&longs;trologica &longs;cientia paulatim reperta e&longs;t, ac in dies reperitur.

9

Ex cap. 3. &longs;ecti 2. lib. 1. (Vt an ne diameter incomm.) loquitur de a&longs;ymme­tria diametri, & co&longs;tæ eiu&longs;dem quadrati, de qua fusè egimus &longs;uperius in cap. 23. &longs;ecti 1. huius libri; quæ &longs;i repetantur, optimè hunc locum declarant.

10

Ex cap. 1. &longs;ecti 3. lib. 1. (Sit A, duo recti, in quo B, triangulus, in quo C, æquicrus, ip&longs;i itaque C, ine&longs;t A. per B; ip&longs;i vero B, non amplius per aliud, per &longs;e namque triangulus habet duos rectos) nullum aliud exemplum tam frequenter v&longs;urpat Philo&longs;ophus, quam i&longs;tud ex Mathematicis de&longs;umptum de triangu­lo, &longs;cilicet, omnis triangulus habet tres angulos æquales duobus rectis an­gulis, cuius Demon&longs;tratio e&longs;t in 32. primi Elem. quod, vt probè intelliga­tur, explicandum e&longs;t penes quid attendenda &longs;it æqualitas inter angulum, & angulum, quod facile a&longs;&longs;equemur, &longs;i meminerimus angulum e&longs;&longs;e in clinatio­nem illam, quam duæ lineæ non in directum po&longs;itæ faciunt: &longs;iue etiam (vt melius percipiamus) angulum e&longs;&longs;e acumen illud, &longs;iue mucronem illum, quem duæ lineæ non in directum con&longs;titutæ faciunt, vt duarum linearum A B, A C,

inclinatio in puncto A, &longs;iue acumen illud, &longs;iue mucro, e&longs;t ratio anguli. &longs;olum igitur duo anguli erunt æqua­les, quando vnius acumen æquale erit acumini alterius; etiam &longs;i lineæ con&longs;tituentes vnum angulum &longs;int lon­giores lineis alterum angulum con&longs;tituentibus, quia quantitas anguli non attenditur penes longitudinem linearum, &longs;ed penes inclinationem, & mucronem, quem faciunt: vnde etiam&longs;i duæ lineæ prædictæ A B, A C, productæ, &longs;iue etiam decurtatæ fuerint, dum­modo &longs;itus, &longs;iue po&longs;itio ip&longs;arum, quam ad inuicem habent, non varietur, erit &longs;emper eadem quantitas anguli A. Aduertendum præterea rationem anguli non po&longs;&longs;e &longs;aluari in &longs;olo puncto A, in quo lineæ concurrunt, &longs;ed ne­ce&longs;&longs;ariam e&longs;&longs;e aliquam quantitatem, quamuis exiguam, linearum A B, A C. Notandum etiam, quod in nominatione angulorum, quæ fit per tres lite­ras, &longs;emper literam illam e&longs;&longs;e medio loco proferendam, quæ ad acumen ip­&longs;um po&longs;ita e&longs;t, vt in &longs;uperiori, litera A, debet &longs;emper media proferri, dicen­do angulum B A C, &longs;iue C A B, nunquam tamen licet dicere angulum A C B, vel C B A. Porrò quemadmodum vnus angulus vni angulo æqualis e&longs;t, ita aliquando duo anguli &longs;unt vni angulo æquales, vt patet, &longs;i vnus angulus, v.g. angulus B A C, diuidatur in duos angulos à linea A D. tunc enim duo angu­
li partiales B A D, D A C, erunt æquales totali angulo B A C, cum partes omnes &longs;imul &longs;umptæ &longs;int &longs;uo toti æqua­les. pariter tres anguli po&longs;&longs;unt æquari & vni, & duobus alijs angulis, quando nimirum a cumina, &longs;iue mucrones il­li &longs;imul ad vnum punctum con&longs;tituti adæquarentur mucro­niilli, quem con&longs;tituerent alij duo anguli, quibus illi tres &longs;unt pares, v.g. &longs;int tres anguli trianguli A B C, &longs;intque; alij duo anguli recti,
quos linea perpendicularis D E, facit cum li­nea F G; &longs;it inquam anguli recti D E F, D E G, tunc tres anguli illius trianguli dicentur æqua­les duobus hi&longs;ce rectis, &longs;i tres illi mucrones trianguli fimul &longs;umpti, & vniti ad punctum E, ad quod duo quoque mucrones angulorum
rectorum coeunt, congruent omnino duobus prædictis angulis rectis, &longs;iue duobus illis mu­cronibus angulorum rectorum, &longs;iue con&longs;ti­tuent lineam rectam F E G, &longs;icuti faciunt etiam duo illi anguli recti; &longs;iue etiam dica­mus, occupabunt idem &longs;patium omninò, & præcisè, quod occupant duo recti: v.g. &longs;i mucro B, ibi poneretur, faceret angulum F E H, & &longs;i ibi iuxta ip&longs;um apponeretur mucro A, faceret angulum H E I. quem &longs;i deinceps &longs;ub&longs;equetur reliquus angulus C, con&longs;titueret reli­quum angulum I E G. iam, vt vides, illi tres anguli ad E, tran&longs;lati, &longs;unt æqua­les duobus rectis ad E, pariter con&longs;titutis, cum illi tres fiant partes duorum rectorú, vel quia occupant idem &longs;patium, vel eandem lineam rectam F E G, con&longs;tituant. habet igitur omne triangulum &longs;iue &ecedil;quilaterum, &longs;iue &longs;calenum, &longs;iue I&longs;o&longs;celes mirabilem hanc proprietatem, vt tres anguli, cuiu&longs;uis trian­guli &longs;int æquales duobus rectis angulis. Quam demon&longs;trationem primi om­nium Pythagorici perfecerunt, vt refert Proclus ad 32. primi Elem. Eucli­des deinde ibidem aliter, quam Pythagorici idem demon&longs;trauit. Quod &longs;i quis huius rei experientiam aliquam velit; etiam&longs;i non exactam (cum æqua­litas mathematica non cadat &longs;ub &longs;en&longs;um, &longs;ed &longs;ola intelligentia percipiatur, quippe quæ in materia intelligibili, non autem &longs;en&longs;ibili ver&longs;atur, & cuius æqualitas nullum di&longs;crimen, quantumuis minimum admittat, quod &longs;en&longs;ui vitare ob &longs;ui imperfectioneon licet: vnde inter eæ, quæ mathematicè &longs;unt æqualia, nullus intellectus aliquam valeat reperre differentiam) &longs;umat inquam triangulum quodpiam materiale, vt ex charta, quantum fieri po­ce&longs;t perfectum, deinde ducat lineam vnam perpendicularem &longs;uper aliam, quæ &longs;cilicet faciat, cum illa duos angulos rectos. po&longs;tea ab&longs;cindat tres an­gulos trianguli materialis, eosque; ita &longs;imul componat, vt mucrones illorum &longs;int vniti, & contigui ad punctum lineæ perpendicularis cum altera, vti e&longs;t in &longs;uperiori figura punctnm E; & illicò apparebit tres illos angulos mate­riales obtegere adæquatè totum illud &longs;patium duorum rectorum, quos per­pendicularis con&longs;tituit. Hoc autem experiri poteris in diuer&longs;is admodum triangulis Scalenis, Rectangulis, I&longs;o&longs;celibus, Aequilateris, &c. non &longs;ine de­lectatione, atque hic e&longs;t &longs;en&longs;us illorum verborum, omnis triangulus habet tres &ecedil;quales duobus rectis. Ab&longs;tineo à demon&longs;trationibus geometricis, quo­niam ij, qui Mathematicis &longs;unt imbuti, no&longs;tra hac opera parum indigent. &longs;i quis tamen volet, con&longs;ulat 32. primi Elem. Ex hac igitur declaratione licet cogno&longs;cere nonnullos ageometretos locum hunc, & &longs;imiles &longs;ub&longs;equen­tes non &longs;atis intelligere, dicentes, nihil aliud verba illa Ari&longs;t. velle &longs;ignifi­care, quàm omnem triangulum habere tres angulos, quod inquiunt, noti&longs;­&longs;imum e&longs;t. Sed &longs;i incidant in &longs;equentia; æquales duobus rectis, tunc, cum hæc non intelligant, ab&longs;tinent etiam à priorum declaratione, quibus præ­mi&longs;&longs;is facile e&longs;t Ari&longs;t. textum percipere. &longs;it A, duo recti, ide&longs;t, duo anguli recti &longs;int pa&longs;&longs;io demon&longs;tranda, in quo B, triangulus, in quo C, æquicrus. ip&longs;i itaque C, ide&longs;t triangulo æquicru&longs;i, ine&longs;t A, &longs;cilicet duo recti, hoc e&longs;t, ine&longs;t æquicru&longs;i hæc, pa&longs;&longs;io habere tres angulos æquales duobus rectis per B, ide&longs;t per triangulum vniuer&longs;ale, quia hæc proprietas e&longs;t trianguli propria, & compe­tit æquicru&longs;i, non vt æquicrus e&longs;t, &longs;ed, vt triangulum e&longs;t; quare B, non crit medium ip&longs;ius A, quia prædicta pa&longs;&longs;io. A, non competit triangulo B, per aliud, &longs;ed per &longs;e, de eo enim primo, & per &longs;e demon&longs;tratur in 32. primi Elem. optimè Aegydius, & Niphus in hunc locum.

11

Ex eodem cap. (Non oportet autem exi&longs;timare penes id, quod exponimus, ali­quid accidere ab&longs;urdum, nihil enim vtimur eo, quod e&longs;t hoc aliquid e&longs;&longs;e. &longs;ed &longs;icut Geometra pedalem, & rectam hanc, & &longs;ine latitudine dicit, quæ non &longs;unt. verum non &longs;ic vtitur, tanquam ex his ratiocinans) Quoniam Ari&longs;t. in exemplis affert pro rebus characteres, A, B, C, po&longs;&longs;et qui&longs;piam &longs;u&longs;picari aliquod propterea ab&longs;urdum accidere: cui &longs;u&longs;picioni Ari&longs;t. re&longs;pondet, dicens, nihil inde ab&longs;ur­di accidere po&longs;&longs;e, quoniam ip&longs;e vtitur hi&longs;ce literis, non quatenus literæ &longs;unt, &longs;ed quatenus rerum vicem, pro quibus exponuntur, gerunt: quemadmodum etiam Geometræ faciunt, qui lineam, quæ pedalis non e&longs;t, pedalem, & quæ non e&longs;t recta, rectam; & quæ lata e&longs;t, non latam, &longs;upponunt, & tamen nihil inde ab&longs;urdi contingit. Ex quibus intelligimus per lineas illas &longs;en&longs;ibiles, & phy&longs;icas, quas Geometræ in &longs;uis figuris ducunt, intelligendas e&longs;&longs;e lineas ve­rè Mathematicas omni latitudine carentes; vtitur enim inquit Ari&longs;t. Geo­metra lineis phy&longs;icis, non tanquam phy&longs;icis, nec de eis tanquam de phy&longs;icis lineis ratiocinatur, &longs;ed ijs vtitur tanquam verè mathematicis. idem dicen­dum e&longs;t de &longs;uperficiebus, necnon de corporibus, quæ ijdem Goometræ de­&longs;cribunt, vt per ea, de verè mathematicis di&longs;currant.

Ex Libro &longs;ecundo Priorum.

12

Ex cap. 21. (Quod faciunt, qui coalternas putant &longs;cribere, latent enim ip&longs;&longs;e ip&longs;os talia accip entes, quæ non est po&longs;&longs;ibile monstrare uon exiftentibus o lternis) Vult Ari&longs;t. exemplo mathematico explicare, quid &longs;it pe­titio principij. vbi per coalternas intelligit parallelas lineas, vox enim græca parallhlos, idem &longs;ignificat, ac mutuus, & coalternus. quoad exempli explicationem vtor figura textibus apponi &longs;olita, quæ e&longs;t præ&longs;ens.

probat Euclides in 28. primi Elem. quod &longs;i linea recta quædam, vti E F, cadens &longs;uper duas rectas, vti &longs;unt A B, C D, fe cerit angu­los alternos &ecedil;quales, angulos nimirum A G H, G H D, ij enim dicuntur alterni; &longs;iue alios dnos, nimirum B G H, G H C, hi enim &longs;unt quoque alterni; probat inquam has duas li­neas A B, C D, e&longs;&longs;e inuicem parallelas. Iam &longs;i quis vellet probare, &longs;e duas parallelas duxi&longs;&longs;e, hac ratione, quia &longs;cilicet fa ciunt prædictos angulos al­ternos æquales; & probaret facere angulos alternos æquales, quia &longs;unt pa­rallelæ, hic peteret principium, ide&longs;t, illud, quod principio probandum erat, afferret pro ratione, & cau&longs;a, quod dicitur peti principium, quia tunc pe­timus, vt concedatur nobis, id, quod principio, & primo omnium demon­&longs;trare propo&longs;ueramus. aduerte, quod characteres, qui &longs;unt in &longs;equentibus verbis huius loci, non appellant characteres figuræ appo&longs;itæ; in quo quidam decepti, nullo pacto poterant locum hunc intelligere.

13

Ex cap. 22. lib. 2. Priorum (Vt &longs;i volens mon&longs;trare, quod diameter e&longs;t incom­men&longs;. argueret Zenonis rationem, quod non e&longs;t moueri) &longs;uperius &longs;ecto 3. lib. 1. fusè explicauimus hanc a&longs;ymmetriam, quam &longs;i quis vellet demon&longs;trare ea­dem illa ratione, qua Zeno motum impugnabat, quia &longs;cilicet men&longs;ura com­munis, quæ debet vtramq, quantitatem men&longs;urare, debet in men&longs;urando infinitas partes pertran&longs;ire, uimirum medietates medietatum in in&longs;initum, e&longs;t autem impo&longs;&longs;ibile pertran&longs;ire infinitas huiu&longs;modi partes, & propterea non poterit metiri, neque vnam, neque alteram ex quantitatibus, quæ putaban­tur commen&longs;urabiles, afferret hic, inquit Ari&longs;t. non cau&longs;am pro cau&longs;a.

14

Ex eodem cap. (Quoniam idem vtique fal&longs;um per plures petitiones accidere nihil forta&longs;&longs;e inconueniens, veluti coalternas coincidere; & &longs;i maior e&longs;t extrin&longs;ecus angulus intrin&longs;eco; & &longs;i triangulus habet plures rectos duobus) per plures po&longs;i­tiones &longs;ubaudi fal&longs;as. per coalternas intellige lineas æquidi&longs;tantes, &longs;eu pa­rallelas, vt in &longs;uperiori cap. monuimus. Cæterum Euclides propo&longs;. 28. pri­mi Elem. o&longs;tendit, quod &longs;i fuerint duæ parallelæ veluti in præcedenti figura, A B, C D, &longs;uper quas alia recta E F, incidat, nece&longs;&longs;ario faciet angulum ex­trin&longs;ecum E G B, v. g. æqualem interno, & oppo&longs;ito, & ad ea&longs;dem partes, angulo videlicet G H D. &longs;i ergo inquit Ari&longs;t &longs;upponamus i&longs;tud fal&longs;um, an­gulum &longs;cilicet E G B, externum e&longs;&longs;e maiorem angulo interno G H D, &longs;equi­tur etiam fal&longs;um, videlicet lineas æquidi&longs;tantes A B, C D, concurrere. & pro­batur con&longs;equentia hoc modo, quia &longs;i angulus E G B, maior e&longs;t angulo G H D, appo&longs;ito vtiq communi angulo B G H, erant primum, duo anguli E G B, B G H, maiores, quam &longs;int duo B G H, G H D, quia &longs;i inæqualibus æqualia addantur, tota erunt inæqualia, vt prius per 4, axioma: hoc loco communis angulus additur &longs;emel maiori angulo, & &longs;emel minori; & ideo totum illud, in quo e&longs;t maior angulus, adhuc maius e&longs;t altero toto, in quo minor angulus continetur. at illi duo E G B, B G H, per 13. primi, &longs;unt æquales duobus rectis angulis, ergo duo quoque recti erunt maiores duobus internis B G H, D H G, &longs;iue hi duo interni erunt minores duobus rectis. At quando hi duo interni &longs;unt minores duobus rectis, tunc lineæ A B, C D, &longs;unt concurrentes, &longs;i protrahantur ad partes prædictorum angulorum. quod P. Clauius luculenti, & hactenus de&longs;iderata demon&longs;tratione ad 28. primi demon&longs;trauit. Atque hoc pacto ex prima fal&longs;a &longs;uppo&longs;itione, nimirum angu­lum illum externum e&longs;&longs;e maiorem interno, & oppo&longs;ito; &longs;equitur fal&longs;um, ni­mirum lineas parallelas concurrere.

Præterea &longs;i &longs;upponamus aliam fal&longs;itatem, &longs;cilicet triangulum habere tres angulos maiores duobus rectis, &longs;equetur eadem iterum fal&longs;itas, &longs;cilicet pa­

rallelas coincidere, & probatur &longs;ic; &longs;int enim trianguli A B C, tres anguli maiores, quam duo recti anguli, & per punctum C, ducta &longs;it recta C D, parallela lateri B A. quia ergo angulus A, æqualis e&longs;t angulo &longs;ibi alterno A C D, per 29. primi, & quia totalis angulus B C D, æqua­lis e&longs;t duobus angulis B C A, A C D, quos tanquam &longs;uas partes adæquatas continet, quorum alter, &longs;cilicet A C D, e&longs;t æqualis angulo A. erit idem to­talis angulus B C D, æqualis duobus angulis A, & A C B, trianguli propo&longs;i­ti. ergo totus i&longs;te angulus B C D, &longs;imul cum reliquo trianguli angulo B. con­flabit compo&longs;itionem ex tribus angulis trianguli dati: & con&longs;equenter ta­lis compo&longs;itio trium angulorum erit maior, quam &longs;int duo anguli recti. ex quo &longs;equitur duas rectas B A, C D, &longs;uper quas cadit linea B C, faciens duos angulos internos, & ad ea&longs;dem partes, &longs;cilicet A B D, maiores duobus re­ctis non e&longs;&longs;e parallelas, &longs;ed concurrentes (vt patet ex nuper citata demon­&longs;tratione P. Clauij) quod fal&longs;um e&longs;t. & &longs;equitur ex &longs;ecunda fal&longs;a &longs;uppo&longs;itio­ne. ex quibus textus Ari&longs;t. videtur &longs;atis clarus.

15

Ex cap. 26. (Vt &longs;i A, duo recti, in quo autem P., triangulus, in quo vero C, &longs;en&longs;ibuis triangulus, &longs;u&longs;picari namque po&longs;&longs;et aliquis non e&longs;&longs;e C, &longs;ciens, quod omnis triangulus habet duos rectos: quare &longs;imul no&longs;cet, & ignorabit idem. no&longs;ce enim omnem triangulum, quod duobus rectis, non &longs;implex e&longs;t: &longs;ed hoc quidem eo, quod vniuer&longs;alem habet &longs;cientiam: illud autem eo, quod &longs;ingularem. &longs;ic igitur, vt vni­uer&longs;ale nouit C, quod duo recti; vt autem &longs;ingulare non nouit, quare non habebit contrarias) vide, quæ diximus lib. 1. &longs;ecto 3. cap. 1. ex quibus quidquid Ma­thematicum e&longs;t hic, clarum redditur. reliqua verò, quæ ad Logicum &longs;pe­ctant, huius loci commentatores pro&longs;equuntur.

In cap. 31. de Abductione.

16

Notandum hic cum eruditi&longs;&longs;imo Burana, Abductionem hanc, de qua in hoc cap. agitur e&longs;&longs;e vocem mathematicam, camque; Ari&longs;t. quemadmodum multa alia à Mathematicis mutuatum ad omnes alias &longs;cientias tran&longs;tuli&longs;&longs;e. e&longs;&longs;e autem terminum mathematicum colligitur manife&longs;tè ex Proelo, qui lib. 3. in comm. Elem. Euclidis ad primam propo&longs;itionem primi Elementi, pag. 121. &longs;ic ait, Abductio verò e&longs;t tran&longs;itus à propo&longs;ito problemate, vel theo­remate ad aliud, quo cognito, aut comparato Propo&longs;itum quoque per&longs;pi­cuum e&longs;t. Exempli cau&longs;a, cum cubi duplicatio propo&longs;ita e&longs;&longs;et ad inue&longs;ti­gandam quæ&longs;tionem in aliud tran&longs;tulere, quod illud propo&longs;itum con&longs;equi­tur, ad duarum nempe mediarum linearum inuentionem tran&longs;lata e&longs;t quæ­&longs;tio, & &longs;ic quærebant deinceps, quonam modo datis duabus rectis lineis, duæ mediæ proportionales reperirentur. Primum autem dicunt Hippocra­tem Chium pr&ecedil;dictorum titulorum, Abductionem feci&longs;&longs;e, qui & lunulæ qua­dratum fecit æquale, & alia multa in Geometria inuenit. hæc Proclus. vbi non di&longs;&longs;imulandum nos re&longs;titui&longs;&longs;e verbum, Abductionem, cuius loco inter­pres Procli vtitur inductionis voce, &longs;equuti & rationem, & græcum textum, qui no&longs;tram hanc expo&longs;itionem euidenter po&longs;tulat, apagwgh\ enim valet & inductionem, & abductionem, &longs;ed abductio omnino rei propo&longs;itæ quadrat.

Notandum præterea Hippoetatem Chium fui&longs;&longs;e auctorem huius Abdu­ctionis, eumque; feci&longs;&longs;e Abductionem à propo&longs;ito Problemate quadrandi cir­culi, vnde manife&longs;tè apparet, Ari&longs;totelem ex Mathematicis hunc terminum mutuò accepi&longs;&longs;e, quandoquidem ex ij&longs;dem accepit etiam exemplum Abdu­ctionis Mathematicæ, imò etiam exemplum ip&longs;ius authoris AbductioniMathematicæ. &longs;yllogi&longs;mus autem Hippocratis, quo o&longs;tendebat circuli qua­draturam reducebatur ad has propo&longs;itiones, omnis rectilinea figura qua­dratur, &longs;ed circulus reducitur ad figuram rectilineam, ergo circulus qua­dratur. in probatione minoris facta e&longs;t Abductio, cum enim ip&longs;e vellet re­ctificare circumferentiam circuli per lunulas, nec valeret, alij per lineam, quandam quadratricem, vt e&longs;t apud Pappum Alexandrinum, & apud P. Cla­uium in fine &longs;exti Elem. & alij aliter fru&longs;tra conarentur, facta e&longs;t Abductio circa probationem minoris, in qua adhuc Mathematici verfantur; quæ pro­batio, &longs;i tandem inueniri po&longs;&longs;et, mox &longs;equeretur principale propo&longs;itum pro­blema, nimirum circulus quadraretur; vide quæ &longs;crip&longs;mus in cap. 3. Præ­dicam. de hac re, quia plurimum hunc conferunt. &longs;ed iam ad textus expli­cationem veniamus.

17

Ex eodem cap. (Veluti &longs;i K, e&longs;&longs;et quadrari, in quo autem E, rectilineum, in quo verò F, circulus, &longs;i ip&longs;ius E F, vnum &longs;olum e&longs;&longs;et medium, hoc, quod e&longs;t, cum lunulis æqualem fieri circulum rectilineo, e&longs;&longs;e po&longs;&longs;et propè ip&longs;um cogno&longs;cere, cum vero B C, neque credibilius &longs;it, quam A C, neque pauca media, non dico Abductio­nem: neque quando B C, &longs;it immediatum, tale enim &longs;cientia est) Aduerte figuram vulgatæ editionis e&longs;&longs;e mendo&longs;am, & propterea re&longs;tituendam e&longs;&longs;e, qualis pri­ma &longs;equens ex Simplicio ad tex. 11. primi Phy&longs;ic. hoc modo Hippocrates Chius conabatur circulum ad quadrum redigere; fit circulus A B G C, qua­drandus; con&longs;tituatur itaque &longs;uper diametro cius B C, quadratum B C D F, cuius diameter B D, &longs;ecatur bifariam in G, à circumferentia circuli dati, quod patet ducta &longs;emidiametro H G, perpendiculari ex B C, quæ &longs;uo extre­mo puncto G, &longs;ecat bifariam, & diametrum B D, & circumferentiam B G C. facto ergo centro G, de&longs;cribatur alter circulus per puncta B C D F, conne­ctaturque; recta G C. in triangulo orthogonio B C D, latus B D, &longs;ubtenditur

angulo recto C, ergo quadratum eius ex eorol­lario 47. primi, duplum erit quadrati B C, quare etiam circulus B C D F, duplus erit circuli A B­G C, per 2. duodecimi, & &longs;emicirculus B C D, duplus erit &longs;emicirculi B A C: & quadrans B E­C G, æqualis erit &longs;emicirculo B A C: ablato igi­tur communi &longs;egmento B E C H, remanet lunu­la B A C E, æqualis triangulo B C G, quod trian­gulum &longs;i per vltimam &longs;ecundi quadretur, erit lu­nula B A C, con&longs;equenter quadrata. hucu&longs;que be­nè procedit Hippocrates. &longs;ed vt reliquum circu­li quadret, &longs;ic pergit, ponatur recta L M, dupla ip&longs;ius B C, &longs;upra quam &longs;emicirculus de&longs;cribatur
L O M, cui in&longs;cribatur hexagoni æquilateri dimidium L Q S M, & &longs;u­per tribus hexagoni lateribus, &longs;int tres &longs;emicirculi, vt in figura. & quo­niam diameter L M, dupla e&longs;t vniu&longs;­cuiu&longs;que diametrorum B C, L Q, Q S, S M, erit &longs;emicirculus L O M, &ecedil;qua­lis quatuor &longs;emicirculis prædictis per 2. duodecimi, & per 4. &longs;ecundi ablatis igitur tribus &longs;egmentis com­munibus L N Q, Q O S, S P M, relinquetur trapezium L Q S M, æquale &longs;e­micirculo B A C, & tribus lunulis L H Q N, Q R S O, S X M P, ab&longs;cindan­tur itaque detrapezio tria triangula æqualia tribus lunulis, eo modo, quo &longs;u­pra in prima figura factum e&longs;t, & quod relinquetur æquale erit &longs;emicirculo B A C. quod deinde quadretur per vlt. &longs;ecundi, &longs;ed aduerte, quod quando ait, ab&longs;cindantur de trapezio tria triangula æqualia lunulis, eo modo, quo &longs;upra, committit deceptionem, quia eodem modo, quo &longs;upra minimè id fa­cere po&longs;&longs;umus, quia in &longs;uperiori figura triangula erant con&longs;tituta &longs;uper la­tus B C, quadrati B C D F, intra circulum de&longs;cripti, qui circulus facit cum B C, maius &longs;egmentum, quam faciat &longs;emicirculus L O M, cum lateribus L Q, Q S, S M. & propterea &longs;emicirculus i&longs;te non habet eandem proportionem ad vnamquamque lunularum &longs;uarum, quam habet &longs;emicirculus &longs;uperior B C D, ad lunulam B A C E. atque hæc e&longs;t fallacia, quam authorem &longs;uum mi­nimè latui&longs;&longs;e putandum, cuius Ari&longs;t. &longs;æpius mentionem in &longs;equentibus fa­ciet : quì enim fieri pote&longs;t, vt tam acutus inuentor, adeo manife&longs;tum erro­rem non vidi&longs;&longs;et, verum propter adinuenti excellentiam, authori &longs;uo pla­cuit paralogy&longs;mus. mirabilis tamen &longs;emper habita e&longs;t illa &longs;uperior lunulæ quadratio. Ex quibus &longs;atis clara e&longs;&longs;e po&longs;&longs;unt ea, quæ ad Mathematicum per­tinent, ad locum hunc de Abductione declarandum. facta e&longs;t igitur abdu­ctio ab Hippocrate in quadratione trium po&longs;teriorum lunularum, in qua­rum quadratione diu immoratus, nunquam ni&longs;i cum paralogy&longs;mo quadra­re valuit. Hæc pluribus, vt &longs;equentibus etiam textibus, in quibus huius te­tragoni&longs;mi fit mentio &longs;atisfacere po&longs;&longs;imus. Hippocrates i&longs;te Chius e&longs;t alter ab illo Hippocrate Coo medicorum Magi&longs;tro, vt colligitur ex Alexandre Aphrod. in Primum Meteororum de Cometis.

Ex Primo Posteriorum re&longs;olutoriorum.

18

Textu primo (Omnis doctrina, & omnis di&longs;ciplina di&longs;cur&longs;iua ex præexi­&longs;tenti fit cognitione. manife&longs;tum autem hoc &longs;peculantibus in omnibus, Mathematicæ namque &longs;cientiarum per hunc modum accedunt) quo mo­do Mathematicæ fiant ex præcedenti cognitione, &longs;cilicet Princi­piorum per&longs;picuè quilibet videbit, qui &longs;altem primum Elementorum Eucli­dis, vel è ianuis in&longs;pexerit; pr&ecedil;cedunt enim primo principiorum tria gene­ra, quorum primum continet definitiones &longs;ubiecti Geometriæ, vt definitio­nes lineæ, &longs;uperficiei, trianguli, &c: Secundum continet Po&longs;tulata. Tertium Axiomata, &longs;eu communes omnium conceptiones, & &longs;ententias, ex quibus tanquam ex vberrimis, & chri&longs;taltinis fontibus Demon&longs;trationes Geome­tricæ deriuantur. Idem vìdere licet in operibus aliorum Geometrarum, Archimedis, Apollonij, Pappi, & cæterorum. Aliæ &longs;iniliter mathematicæ, vt Arithmetica, Per&longs;pectiua, Mu&longs;ica, Mechanica, A&longs;tronomia, non ni&longs;t ex præmi&longs;&longs;is, ac manife&longs;ti&longs;simis principijs &longs;uas demon&longs;trationes deducunt. Nulla porrò alia &longs;cientia tam di&longs;tinctè &longs;ua præmittit principia, tamque; per­&longs;picua, &longs;icuti Mathematicæ, vt non immeritò Philo&longs;ophus eas, tamquam veræ &longs;cientiæ typum, eumque; omnibus numeris ab&longs;olutum &longs;ibi ob oculos pro­po&longs;uerit, ex quo veræ &longs;cientiæ de&longs;criptionem hi&longs;ce libris complecteretur.

19

Tex. 2. (Quod enim omne triangulum habet duobus rectis æquales, præ&longs;ciuit: quod autem hoc, quod e&longs;t in &longs;emicirculo triangulum e&longs;t, &longs;imul inducens cognouit)vide primo, quæ &longs;upra libro 1. Prior. &longs;ecto 3. cap. 1. explicaui de angulis trianguli. deinde &longs;cias, quod quando Ari&longs;t. ait, hoc, quod e&longs;t in &longs;emicir cu­lo triangulum, &c. alludit ad demon&longs;trationem quandam, quam ip&longs;e infe­rius in exemplum adducet, & quæ e&longs;t in 3. Elem. Euclidis 31. in qua talis fi­gura proponitur qualis e&longs;t præ&longs;ens, in qua vides triangulum A B C. in &longs;e­

micirculo. tunc autem dicitur triangulum in &longs;emicirculo, quando ba&longs;is ip&longs;ius e&longs;t diameter &longs;emicirculi, & reliqua duo latera ita concur­runt &longs;imul in angulum B, vt ip&longs;um paricer in circumferentia con&longs;tituant, quibus pr&ecedil;mi&longs;sis &longs;ic textum explicaueris: quod enim omne triangulum habet tres angulos æquales duo­bus rectis angulis præ&longs;ciuit vniuer&longs;aliter per 32. primi; quod autem hoc particulare triangulum A B C, quod e&longs;t in &longs;e­micirculo habeat eandem proprietatem, &longs;imul, ac qui&longs;piam animaduertit illud e&longs;&longs;e triangulum cogno&longs;cit, ab&longs;que vlla demon&longs;tratione, &longs;ed &longs;olum virtu­te illius maioris propo&longs;itionis; omne triangulum habet tres, &c.

20

Tex. 5. (Vera quidem igitur oporter e&longs;&longs;e, quoniam non e&longs;t non ens &longs;cire, vt quod diameter &longs;it commen&longs;urabi is) con&longs;ule ea, quæ &longs;crip&longs;imus ad cap. 23. primi Priorum, &longs;ecto 1. &longs;ine quibus locus hic &longs;atis intelligi nequit; ijs autem per­ceptis &longs;ic locum hunc explicare po&longs;&longs;umus, cum diameter quadrati &longs;it incom­men&longs;urabilis lateri &longs;ui quadrati, fal&longs;um erit dicere diametrum e&longs;&longs;e com­men&longs;urabilem prædicto lateri, quod autem fal&longs;um e&longs;t, illud non e&longs;t; igitur impo&longs;sibile e&longs;t &longs;cire diametrum e&longs;&longs;e commen&longs;urabile.

21

Hoc eodem cap. plura dicuntur de Principijs Demon&longs;trationis, &longs;iue &longs;cien­tiæ, vt &longs;unt Dignitates, Po&longs;itiones, Definitiones, & &longs;imilia, quæ quo modo &longs;e habeant, & quo modo illis Demon&longs;trationes innitantur, optimè ex con­templatione primi libri Elem. Euclidis percipi pote&longs;t. vt propterea benè ij &longs;entiant, inter quos præcipui &longs;unt Toletus, & Zabarella, qui a&longs;&longs;erunt, Ari&longs;t. Mathematicas &longs;cientias tamquam typum perfecti&longs;simarum &longs;cientiarum &longs;ibi ob oculos propo&longs;ui&longs;&longs;e; ex quo typo veræ &longs;cientiæ de&longs;criptionem his li­bris complectaretur.

22

Eodem tex. 5. (Ponit enim Arithmeticus vnitatem indiui&longs;ibilem e&longs;&longs;e &longs;ecun­dum quantum) hoc quamquam non ponatur ab Arithmeticis expre&longs;sè, præ­&longs;upponitur tamen ab eis: nu&longs;quam enim Euclides in totis tribus Arithme­ticis libris, infra vnitatem de&longs;cendit, vt propterea appareat, ip&longs;am in quan­titate di&longs;creta e&longs;&longs;e minimum, & indiui&longs;ibile. Verum dubitabit forrè qui&longs;­piam hoc modo, &longs;i vnitas minimum, atque indiui&longs;ibile e&longs;t in quanto di&longs;creto, qua igitur ratione Arithmetici practici eam diuidunt in dimidium, in trien­tem, in quadrantem, & alijs &longs;imiliter modis, vnde numeri illi, qui fractio­nes appellantur, exurgunt? Re&longs;pondemus, quotie&longs;eunque vnitas diuiditur ab Arithmeticis, tunc ip&longs;i eam accipiunt tanquam totum quoddam continuum in plures partes diui&longs;ibile: &longs;iue tanquam aggregatum quoddam vnitatum, quæ vnitates &longs;unt partes illius, vt quando dicunt, vnum horæ quadrantem, vel duos horæ quadrantes, vel tres horæ quadrantes, accipiunt horam tan­quam aggregatum quatuor quadrantum, & propterea numeri illi 1/4. 2/4. 3/4. & &longs;imiles fractiones, nihil aliud &longs;unt, quam numeri partium vnius horæ: ex quo patet huiu&longs;modi fractiones omnes reduci ad numeros integros, qui enim dicit tres quadrantes /4. dicit tres partes alicuius totius, quod intel­ligitur diui&longs;um e&longs;&longs;e in 4. æquales partes, ex quibus illæ tres tantummodo numerat.

23

Tex. 9. (Per &longs;e autem, quæcunque & in&longs;unt in eo, quod quid e&longs;t, vt triangulo li­nea, & lineæ punctum; &longs;ub&longs;tantia namque ip&longs;orum ex his e&longs;t, & in oratione dicen­te, quid e&longs;t, in&longs;unt) aggreditur explicare quænam &longs;int ea, quæ per &longs;e dicun­tur: quotque; modis dicatur aliquid per &longs;e. quorum primus e&longs;t, ea &longs;cilicet, per &longs;e de aliquo &longs;ubiecto dici, quæcunque in definitione illius ponuntur, cu­iu&longs;modi &longs;unt linea, & punctum, quæ per &longs;e prædicantur, illa de triangulo, i&longs;tud de linea; in de&longs;initione enim trianguli ponitur linea recta, quia linea recta dum terminat illam &longs;uperficiem, quæ dicitur triangulus illi trianguli naturam impertitur, & ideo triangulus definitur &longs;ic, triangulus e&longs;t figura tribus lineis rectis terminata. &longs;imiliter in definitione lineæ, non in&longs;initæ, &longs;ed finitæ, & terminatæ ponitur punctum, quia duo puncta, quæ &longs;unt extre­ma illius, faciunt, vt ea &longs;it line a finita, & definitur &longs;ic, linea finita e&longs;t lon­gitudo, caius extrema &longs;unt puncta. quamuis autem hæc definitio apud Eu­clidem expre&longs;&longs;a non habeatur, tamen ex definitionibus ip&longs;ius præ&longs;ertim &longs;e­cunda, tertia, & quarta elici pote&longs;t.

24

Eodem tex. 9. (Et quibu&longs;cunque iuexi&longs;tentium ip&longs;is, ip&longs;æ &longs;unt in oratione, quidest declarante, quemadmodum rectum ine&longs;t lineæ, & circulare: & impar, & pnumero, & primum, & compo&longs;itum, & æquilaterum, & altera parte longius. & oimbus bis in&longs;unt in oratione, quid e&longs;t declarante, ibi quidem linea, hic vero numerus)quia locus hic benè exponitur à Toleto, & melius etiam à Conymbr. addam tantummodo quædam, quæ ad perfectam eius intelligentiam de&longs;iderantur. Sciendum igitur primò, nu&longs;quam ab Euclide definiri rectum, circulare, impar, par, primum, compo&longs;itum, æquilaterum, nec altera parte longius: verum ab ip&longs;o in definitionibus primi definiri lineam rectam, non tamen cir­cularem expre&longs;sè. in definitionibus deinde &longs;eptimi definiri numerum parem, & imparem, item numerum primum, & compofitum, & æquilaterum, & al­tera parte longiorem. ex quibus definitionibus po&longs;&longs;unt erui definitiones re­cti, circularis, imparis, & cæterorum, quorum hic Ari&longs;toteles meminit. Cæterum Euclides definitione 11. &longs;eptimi, &longs;ic definit numerum primum: primus numerus e&longs;t, quem vnitas &longs;ola metitur. numerus autem, vel vnitas metiri dicitur alium numerum, quando &longs;æpius repetita ip&longs;um omnino ad­æquat, vt ternarius metitur nouenarium, quia ter repetitus ip&longs;um ad vn­guem explet. illi igitur numeri dicuntur ab Arithmeticis primi, qui à nullo alio, præterquam ab vnitate men&longs;urantur, quales &longs;unt, 2. 3. 5. 7. &c. Defi­nitione verò 13. definit numerum compo&longs;itum &longs;ic; compo&longs;itus numerus e&longs;t, quem numerus qui&longs;piam metitur, vt &longs;enarius erit compo&longs;itus, quia ip&longs;um binarius metitur, nam ter repetitus, ip&longs;i perfectè adæquatur.

Per æquilaterum, intelligit quadratum, quadratus autem numerus defi­nitione 18. &longs;eptimi &longs;ic explicatur: Quadratus numerus e&longs;t, qui &longs;ub duobus æqualibus numeris continetur, ide&longs;t, qui fit ex ductu vnius numeri in &longs;e ip­

&longs;um, vt &longs;i ducantur 3. in 3. fient 9. qui continetur &longs;ub duobus ternarijs; omnes autem ternarij &longs;unt æquales. is autem nu­merus dicetur quadratus, quia, vt apparet in figura, nouem ip&longs;ius vnitates po&longs;&longs;unt in plano ita ad inuicem collocari, vt referant quadratum; & &longs;icuti quadratum geometricum ha­bet latera æqualia, ita etiam quadratum arithmeticum: &longs;i­ue numerus quadratus, habet &longs;ua latera æqualia, quot enim vnitates &longs;unt in vno, tot etiam &longs;unt in reliquis, vt in præ&longs;enti &longs;unt tres vnitates in &longs;ingulis lateribus. pr&ecedil;terea quemadmodum quadratum geometricum re&longs;olni pote&longs;t in plura quadrata, ita etiam arithmeticum, vt præ&longs;ens, qui re&longs;oluitur in quatuor quadrata arithmetica. Neque enim pote&longs;t quilibet numerus, vt opi­nantur ageometreti, in hunc modum di&longs;poni, &longs;ed &longs;olum ij, qui producuntur ex multiplicatione numeri alicuius in &longs;e ip&longs;um.

Per altera parte longius, intelligit numerum, qui producitur à duobus

numeris inæqualibus inuicem multiplicatis, qualis e&longs;t duodenarius, qui ex ductu trium in quatuor produci­tur, & refert figuram altera parte longiorem, &longs;iue, vt ait Boetius longilateram, cuius vnum latus e&longs;t maius altero, vt in appo&longs;ita figura videre licet. atque hæc &longs;unt, quæ ex Mathematicis petenda erant, ad huius loci intelligentiam.

25

Tex. 11. (Per &longs;e autem, & &longs;ecundum quod ip&longs;um, idem, vt per &longs;e lineæ inestpunctum, & rectum; etenim &longs;ecundum quod linea, & triangulo, &longs;ecundum quod triangulum duo recti: etenim per &longs;e triangulum duobus rectis æquale. Vniuer&longs;ale autem e&longs;t tunc, quando in quolibet, & primo mon&longs;tratur, vt duos rectos habere, neque figuræ e&longs;t vniuer&longs;ale, quamuis e&longs;t mon&longs;irare de figura, quod duos rectos habet, &longs;ed non de qualibet figura, neque vtitur qualibet figura monstrans, quadrangulum enim figura a quidem est, non habet autem duobus rectis æquales. Aequicrus verò babet quidem quodcunque duobus rectis æquales, &longs;ed non primò, &longs;ed triangulum prius. quod igitur quoduis primum mon&longs;tratur duos rectos habens, aut quodcunque aliud, huic primo ine&longs;t vniuer&longs;ale, & demonstratio de hoc vniuer&longs;aliter e&longs;t, de alijs verò quodammodo, non per &longs;e, neque de æquicrure e&longs;t vniuer&longs;aliter, &longs;ed in plus) pro quorum intelligentia nece&longs;&longs;aria &longs;unt ea, quæ primo Priorum &longs;ecto 3. cap. 1. &longs;crip&longs;imus. deinde memineris figuram vniuer&longs;aliorem e&longs;&longs;e triangulo, & tri­angulum vniuer&longs;alius æquicrure. quando ait (vt duos rectos habere) vult dicere, habere duos angulos rectos non actu, &longs;ed potentia; quæ affectio e&longs;t trianguli, quia, vt &longs;uperius diximus, habet tres angulos æquales duobus rectis angulis: quæ proprietas vniuer&longs;aliter, & primò competit triangulo. non autem figuræ, quia figura e&longs;t vniuer&longs;alior. neque i&longs;o&longs;celi, quia i&longs;o&longs;celes e&longs;t re&longs;trictius triangulo. omittimus reliqua &longs;ingillatim exponere, tum quia &longs;a­tis clara &longs;unt, tum quia ab interpretibus benè explicantur.

26

Tex. 13. (Si quis igitur mon&longs;trauerit, quod rectæ non coincidunt, videbitur vtique buius e&longs;&longs;e demonstratio, eo quod in omnibus e&longs;t rectis; non e&longs;t autem: &longs;i quidem non quoniam &longs;ic æquales, fit hoc, &longs;ed &longs;ecundum quod quomodocunque æquales) pro­ponit tres errores, qui circa demon&longs;trationem de vniuer&longs;ali contingunt, quos omnes Geometricis exemplis illu&longs;trat; affert autem primo pro tertio errore duo exempla, quorum primum in præmi&longs;&longs;is verbis continetur, atque ex 28. primi Elem. de&longs;umitur, quam propterea primo loco exponendam

cen&longs;ui. Quando igitur duæ rectæ con&longs;titu­tæ fuerint, vt A B, C D, in quas alia recta, vt G F, incidens, faciat duos angulos in­ternos, re&longs;pectu rectarum A B, C D, & ad ea&longs;dem partes rectæ E F, vt &longs;unt ex parte &longs;ini&longs;tra anguli A G H, C H G; exparte ve­rò dextra B G H, D H G; &longs;i inquam linea E F, fecerit duos illos angulos ex parte &longs;ini&longs;tra &longs;imul &longs;umptos, æquales duobus rectis angulis, vel duos ex parte dextra pariter æquales duobus rectis, pro­bat Euclides rectas A B, C D, non concurrere, &longs;iue parallelas e&longs;&longs;e. Verum, quia linea E F, pote&longs;t facere aliquando prædictos angulos non tantum æqua­les duobus rectis, verum etiam rectos, quo etiam modo probarentur cædem lineæ e&longs;&longs;e parallelæ, vt in &longs;equenti figura, cum &longs;int anguli A G I, C I G, re­
cti, probabitur de rectis A B, C D, æquidi&longs;tan­tia. Ex his facile textum in hunc modum expo­nemus; &longs;i quis igitur mon&longs;trauerit, quod rectæ A B, C D, nunquam coincidunt, etiam&longs;i in in&longs;i­nitum producantur, &longs;eu quod &longs;unt æquidi&longs;tantes, quando anguli prædicti interni &longs;unt duo recti, videbitur vtique huius e&longs;&longs;e demon&longs;tratio de vniuer&longs;ali per &longs;e, & de primo &longs;u­biecto, vel &longs;ecundum quod ip&longs;um, eò quod probatur vniuer&longs;aliter de lineis omnibus habentibus prædictos angulos rectos. non autem de omni, &longs;ecun­dum quod ip&longs;um, &longs;i quidem non competit affectio hæc, e&longs;&longs;e parallelas, li­neis habentibus illos angulos rectos actu; &longs;ed primò, & vniuer&longs;aliter, & &longs;e­cundum quod ip&longs;um competit lineis habentibus illos angulos æquales duo­bus rectis, quomodocunque æquales &longs;int duobus rectis, &longs;iue ambo &longs;int recti, &longs;iue vnus acutus, alter obtu&longs;us, &longs;ed tamen ambo &longs;imul æquentur duobus re­ctis, quales &longs;unt lineæ primæ figuræ. In tertio igitur errore, vniuer&longs;ale exi­&longs;tit quidem, & habet nomen, &longs;ed tamen prætermittetur, &longs;eu &longs;trictius &longs;ume­tur, quam oportet. alij latini, quos quidem viderim, præter Zabarellana perperam omnino ob mathematicarum ignorantiam, exemplum i&longs;tud in­terpretantur.

27

Ibidem (Et &longs;i triangulum non e&longs;&longs;et aliud, quam I&longs;o&longs;celes, &longs;ecundum quod I&longs;o­&longs;celes videretur vtique ine&longs;&longs;e) i&longs;tud e&longs;t &longs;ecundum exemplum tertij erroris. Por­rò cum tres &longs;int &longs;pecies triangulorum, æquilaterum, I&longs;o&longs;celes, Scalenum, &longs;i accideret, vt ex illis tribus vna tantum &longs;pecies, v. g. I&longs;o&longs;celes in mundo re­periretur; tuncque; qui&longs;piam de I&longs;o&longs;cele o&longs;tenderet affectionem quampiam, putans &longs;e o&longs;tendi&longs;&longs;e pa&longs;&longs;ionem de proprio &longs;ubiecto, & primo, falleretur, quia aifectio illa competeret I&longs;o&longs;celi, non vt huic &longs;peciei I&longs;o&longs;celis, &longs;ed quatenus e&longs;t triangulum, cui primo, & per &longs;e, & &longs;ecundum quod ip&longs;um conuenit. hoc loco di&longs;ce&longs;&longs;imus à Zabarella, qui putat i&longs;tud e&longs;&longs;e exemplum primi erroris, cum verba textus adeo clara &longs;int, vt expo&longs;itionem illius nullo modo admit­tant. &longs;unt autem hæc textus verba (Et &longs;i triangulum non e&longs;&longs;et aliud, quam I&longs;o­&longs;celes, &longs;ecundum quod I&longs;o&longs;celes videretur vtique ine&longs;&longs;e) quibus verbis manife&longs;tè apparet Ari&longs;t. accipere pro &longs;ubiecto vniuer&longs;ali non indiuiduum vnum, vt in primo errore contingit, &longs;ed &longs;peciem loco generis, &longs;cilicet I&longs;o&longs;celes, quod e&longs;t &longs;pecies trianguli pro genere ip&longs;o, nimirum pro Triangulo. ait enim, &longs;i non e&longs;&longs;et aliud, quam I&longs;o&longs;celes, &longs;ecundum quod I&longs;o&longs;celes: quibus verbis cla­rè &longs;peciem, non indiuiduum, &longs;igni&longs;icat, ex his duobus exemplis manife&longs;tus e&longs;t tertius error, qui erat, quando erat (vt in parte totum) quodque; illis verbis expo&longs;uerat (vei contingit etiam, vt in parte totum, in quo mon&longs;tratur: ijs emm, quæ &longs;unt in parte inerit quidem demon&longs;tratio, & erit de omni, &longs;ed tamen non erit buius primi vniuer&longs;aliter demon&longs;tratio. dico auttm huius primi, &longs;ecundum quod buius demonstrationem, quando &longs;it primi vniuer&longs;aliter) ide&longs;t, quando vniuer&longs;ale &longs;ubiectum exi&longs;tit quidem, &longs;ed tamen non de ip&longs;o &longs;it demon&longs;tratio, &longs;ed de ali­qua parte ip&longs;ius, v. g. de &longs;pecie aliqua demon&longs;tratur aliquid, quod deberet o&longs;tendi primò de ip&longs;o vniuer&longs;ali, cum illi primò competat.

28

Ibidem (Et proportionale, quod alternatim, &longs;ecundum quod numeri, & &longs;ecun­dum quod lineæ, & &longs;ecundum quod &longs;olida, & &longs;ecundum quod tempora: quemad­modum & mon&longs;trabatur aliquando &longs;eor&longs;um, contingens vtique de omnibus vnica demon&longs;tratione mon&longs;irari; &longs;ed quia non &longs;unt nominatum quidam omnia hæc vnum, numeri, longitudines, tempora &longs;olida, & &longs;pecie differunt à &longs;einuicem &longs;cor&longs;um ac­cipiebantur. nunc autem vniuer &longs;aliter mon&longs;tratur, neque enim &longs;ecundum quod lineæ, aut &longs;ecundum quod numeri, inerat; &longs;ed &longs;ecundum quod boc, quod vniuer &longs;ale &longs;up­ponunt e&longs;&longs;e) affert exemplum &longs;ecundi erroris, quiaccidit, quando vniuer&longs;a­le exi&longs;tit quidem, &longs;ed tamen e&longs;t innominatum, pro cuius explicatione &longs;cien­dum quid &longs;it alterna proportio. Alternam igitur proportionem definit Eu­clides definitione 12. quinti, &longs;ic, e&longs;t &longs;umptio antecedentis ad antecedentem,

& con&longs;equentis ad con&longs;equentem. Explico, exponantur qua­tuor quantitates proportionales, v.g. vt 6. ad 3. ita &longs;int 4. ad 2. &longs;i igitur argumentemur &longs;ic, vt 6. ad 3. ita 4. ad 2. ergo al­ternatim erit, vt 6. ad 4. ita 3. ad 2. &longs;iue dixerimus, vt pri­mum ad &longs;ecundum, ita tertium ad quartum, igitur alterna­tim erit, vt primum ad tertium, ita &longs;ecundum ad quartum: valebit con&longs;e­quentia; quæ quidem probatur deinde propo&longs;itione 16. quinti de magnitu­dinibus, hoc e&longs;t in vniuer&longs;um de lineis, &longs;uperficiebus, & &longs;olidis. quando igi­tur Ari&longs;t. ait, mon&longs;tramus proportionale, ide&longs;t, qua&longs;uis quatuor quantita­tes proportionales, habere hanc proprietatem, vt &longs;int etiam alternatim proportionales, & non mon&longs;tramus vnica demon&longs;tratione de omni quouis proportionali, &longs;ed &longs;eparatim de magnitudinibus in 16. quinti, de numeris in 13. &longs;eptimi, & &longs;eor&longs;um de temporibus in a&longs;tronomia, vel phy&longs;ica; hoc modo non o&longs;tendimus vniuer&longs;aliter de primo &longs;ubiecto, quia talis affectio conuenit &longs;ingulis, non vt numeri, aut ma gnitudines, aut tempora &longs;unt, &longs;ed &longs;ecundum quandam naturam illis omnibus communem, cui primò illa pa&longs;­&longs;io debetur; quæ quidem natura communis nomine caret, & propterea e&longs;t cau&longs;a erroris.

29

Nunc autem vniuer&longs;aliter demon&longs;tratur) nu&longs;quam apud Mathematicos in­uenio hanc demon&longs;trationem vniuer&longs;alem de illo communi omnibus præ­dictis, quare dicendum cum Zabarella, illud, nunc, e&longs;&longs;e intelligendum &longs;ic, nunc autem, ide&longs;t, in præ&longs;entia autem deberet vniuer&longs;aliter demon&longs;trari, quod tamen cum non &longs;iat, contingit nos decipi putantes vniuer&longs;aliter de­mon&longs;tra&longs;&longs;e. vel dicendum i&longs;tud verificari tantum de lineis, &longs;uperficiebus, & &longs;olidis, de quibus &longs;imul in vnica natura communi, quæ e&longs;t magnitudo, de­mon&longs;tratur in 16. quinti vniuer&longs;aliter. atque hoc modo explicatum e&longs;t exem­plum &longs;ecundi erroris, qui verbis illis (Vel &longs;it quidem, &longs;ed innominatum &longs;it in rebus &longs;pecie differentibus) continebatur.

30

Ibidem (Propter hoc &longs;i quis mon&longs;trauerit &longs;ingulum triangulum. demon&longs;tratio­ne aut vna, aut altera, quod duos rectos habet vnumquodque, æquilateium &longs;eor&longs;um, & &longs;calenum, & æquicrus: nondum nouit triangulum, quod duobus rectis, &longs;i &longs;o­phi&longs;tico modo, neque vniuer&longs; aliter triangulum, neque &longs;i vllum e&longs;t præter prædicta triangulum alterum. non enim &longs;ecundum quod triangulum, neque omnetriangulum, ni&longs;i &longs;ecundum numerum, &longs;ecundum &longs;peciem autem non omne; & &longs;i nullum e&longs;t, quod non nouit) vltimo loco ponit exemplum primi erroris, quem &longs;upra verbis il­lis (Quando vel nibil &longs;it accipere &longs;uperius, præter &longs;ingulare) expre&longs;&longs;erat, quod, vt benè intelligamus, opus e&longs;t ea, legere, quæ libro primo Priorum &longs;ecto 3. cap. 1. &longs;crip&longs;imus de propriette illa trianguli, quod &longs;cilicet habet tres an­gulos æquales duobus rectis angulis, quibus præmi&longs;&longs;is, &longs;ic deinde locum hunc interpretaberis; Propter hoc, quod præcedenti textu dictum e&longs;t; no­tandum in primo errore vniuer&longs;ale, tanquam &longs;i non e&longs;&longs;et vniuer&longs;ale o&longs;ten­ditur de &longs;ingulari, &longs;i quis igitur mon&longs;trauerit &longs;ingillatim de vnoquoque trian­gulo in &longs;ingulari, &longs;cilicet de vno æquilatero, tantum, & de vno Scaleno, & de vno I&longs;o&longs;cele, &longs;eparatim, vtens auteadem demon&longs;trationc dum de vnoque; &longs;epatatim o&longs;tendit, aut vtens diuerfis demon&longs;trationibus, vna pro æquila­tero, altera pro I&longs;o&longs;cele, tertia pro Scaleno, o&longs;tendens, quod vnumquodque illorum habet tres angules æquales duobus rectis angulis; i&longs;te nondum no­uit triangulum omne habere talem affectionem, ni&longs;i modo &longs;ophi&longs;tico, quia non cogno&longs;cit hanc affectionem illis competere propter naturam illam com­munem trianguli, cui primo, & per &longs;e competit; & neque vniuer&longs;aliter co­gno&longs;cit triangulum omne e&longs;&longs;e tale, etiam &longs;i nullum aliud reperiatur trian­gulum, præter illud æquilaterum, vel illud I&longs;o&longs;celes, vel illud Scalenum, de quibus &longs;eparatim demon&longs;trauit, & &longs;ecundum numernm, ide&longs;t de vnoquoque, quatenus e&longs;t vnum numero. non nouit autem &longs;ecundum &longs;peciem, ideft fecun­dum naturam, & formam communem illis tribus indiuiduis, quæ e&longs;t natu­ra trianguli. hoc autem e&longs;&longs;e exemplum primi erroris manife&longs;tè conuincitnr, tum ex verbis illis, quando nihil &longs;it &longs;uperius, præter &longs;ingulare, tum ex hu­ius textus verbis illis (Singulum triangulum) & ex illis (Ni&longs;i &longs;ecundum nume­rum) ide&longs;t, ni&longs;i de vno, quod &longs;it vnum numero. propterea nos de &longs;in gulari triangulo omi&longs;&longs;a Zabarellæ &longs;ententia explicauimus tandem in confirma­tionem no&longs;træ expo&longs;itionis in hæc tria errata illud non omittendum, &longs;atiue&longs;&longs;e dicere, Ari&longs;t. attuli&longs;&longs;e pro tribus erratis tria exempla ordine retrogra­do, quàm, quod facit Zabarella, primum e&longs;&longs;e pro tertio, &longs;ecundum pro pri­mo, tertium verò pro &longs;ecundo; eo enim modo, Ari&longs;t. confu&longs;ionem nulla ra­tione, imò contra omnem rationem imponimus.

31

Textu 14. continet quidem quædam mathematica, &longs;ed ferè eadem cum &longs;uperioribus, quæ quia tum ex prædictis facile intelligi po&longs;&longs;unt, tum quia benè ab expo&longs;itoribus explicantur, ne actum agamus, prætermittimus.

32

Tex. 20. (Ni&longs;i magnitudines numeri &longs;int) hoc e&longs;t, ni&longs;i magnitudines &longs;int di­fcretæ, ita vt cadant &longs;ub numernm, vt &longs;i linea quæpiam diuidatur in partes decem, vel duodecim, tunc euadit quantitas di&longs;creta, &longs;iue numerus. & tunc linca numerus e&longs;t. idem de &longs;uperficie, ac &longs;olido intelligendum.

33

Ibidem (Propter hoc Geometriæ non licet mon&longs;trare, quod contrariorum vna e&longs;e &longs;cientia, &longs;ed neque quod duo cubi cubus) quo ad verba illa, duo cubi cubusquæ ad nos pertinent, vult Ari&longs;t. docere, quod non debet Geometra o&longs;ten­dere numerorum affectiones (per enbos enim intelligit numeros quo&longs;dam &longs;ic dictos, vt paulo po&longs;t o&longs;tendam) vt &longs;i quis vellet geometricè o&longs;tendere id, quod o&longs;tenditur in 4. noni Elem. &longs;cilicet, &longs;i cubus numerus cubum numerum multiplicauerit, productus numerus erit pariter cubus. nonnulli latinorum perperam textum hunc expo&longs;uerunt putantes reperiri &longs;olummodo cubos geometricos, at Euclides definit. 19. &longs;eptimi, &longs;ic arithmeticum cubum de­finit, cubus numerus e&longs;t, qui &longs;ub tribus numeris æqualibus continetur, qua­lis e&longs;t. 8. qui e&longs;t ad in&longs;tar cubi geometrici, & continetur&longs;ub tribus binarijs multiplicatis inuicem, quæ multiplicatio &longs;ic in&longs;tituitur, exponuntur tres bi­

narij, 2, 2, 2, primus ducitur in &longs;ecundum, & producitur. 4. qui e&longs;t numerus quadratus huius figuræ,
, deinde tertius binarius ducitur in prædictum quadratum 4. & pro­ducitur 8. qui dicitur cubus, quia &longs;i intelligantur duo qua­zernaij, vnus &longs;upra alterum, vt in præ&longs;enti figura refe­runt cubicam figuram, cuius tam longitudo, quam latitudo, & altitudo, e&longs;t 2. Similiter cubus numerus e&longs;t 27. quia &longs;it ex tribus terna­rijs inuicem modo prædicto multiplicatis, 3. 3. 3. nam 3. in 3. ductis &longs;it 9.
qui e&longs;t quadratus. quo deinde ducto in tertium ter­narium, producitur 27. qui e&longs;t cubus, & refert &longs;igu­ram cubicam hanc. Iam verò &longs;i cubus 8. multipli­cet cubum 27. procreabitur 216. qui pariter cubus e&longs;t. atque hoc &longs;ibi volunt verba illa, &longs;i duo cubi cubus, ide&longs;t, &longs;i duo numeri cubi multiplicentur mutuò, cu­bus alter producetur; ex quibus videas, quam in­eptè illi interpretentur hunc locum, qui dicunt, Ari­&longs;totilem velle dicere non pertinere ad Geometram probare duos cubos geometricos &longs;ibi additos face­re alium cubum, quod erat problema Delphicum de duplatione cubi, nondum inuentum; bis enim i&longs;ti peccant, primo in Logi­cam, quia &longs;ic non tran&longs;iret Geometra de genere in genus, ip&longs;ius enim e&longs;t agere de duplatione cubi; &longs;ecundò in Mathematicas, cum nondum noue­rint arithmeticos cubos; & præterca ignorent duos cubos &longs;ibi additos, non facere alium cubum. Quod præterea hoc loco intelligendi &longs;int cubi arith­metici certò certius con&longs;tat, ex &longs;equenti 24. textu, vbi &longs;ic dicitur (Veluti Arithmetica quidem, quid impar, aut par, aut quadrangulum, aut cubus.)

34

Ibidem (Neque alij &longs;cientiæ quod alterius, ni&longs;i quæcunque ita &longs;e habent inter &longs;e, vt &longs;it alterum &longs;ub altero, vt per&longs;pectiua ad Geometriam, & harmonica ad Arith­meticam) excipit ab illa regula (qua prohibetur, quamuis &longs;cientiam in alie­nam falcem immittere) &longs;cientias &longs;ubalternatas, quæ propriè in Mathemati­cis reperiuntur, Per&longs;pectiua enim propriè &longs;ubalternatur Geometriæ, quia vtitur Demon&longs;trationibus linearibus, quas applicat lineis vi&longs;ualibus, & Mu­&longs;ica &longs;ubalternatur Arithmeticæ, quia ab ip&longs;a mutuatur demon&longs;trationes nu­merorum, quas applicat numeris &longs;onoris. v.g. Per&longs;pectiua dicit, ea, quæ vi­dentur eminus videri minora, quam quæ videntur cominus, quia illa viden­tur &longs;ub angulo minori, hæc verò &longs;ub angulo maiori, quod verò remotiora videantur &longs;ub angulo minori, quam propinquiora cæteris paribus probat

per 21. primi Elem. &longs;it enim ma­gnitudo vi&longs;a A B, remotior ab o­culo in C, po&longs;ito, & vi&longs;a propin­quior ab oculo in D. ductis lineis vi&longs;ualibus C A, C B: D A, D B; ab oculis C, & D, ad extremitates &longs;pectatæ magnitudinis, erit remo­tioris vi&longs;ionis angulus C, minor angulo D, propinquioris, vt ex præallegata Demon&longs;tratione pater. Hine per&longs;picuè vides, qua ratione Per&longs;pectiua Geometriæ &longs;ubalternetur, &longs;iue quid &longs;it ip&longs;a &longs;ubalternatio, vbi medium e&longs;t Geometricum, conclu&longs;io autem optica. Exemplum &longs;ubalternationis Muficæ &longs;it, con&longs;onantia Diapa&longs;on, quam vulgò octauam appellant in data chorda collocare, hoc e&longs;t, vocem grauio­rem facere duplam vocis acutioris &longs;umatur chorda A B, & diuidatur bifa­riam, &longs;ine in æqualia in C; tota igitur chorda A B, ad dimidium A C, haber
proportionem, quam 2. ad 1. &longs;iue duplam, ergo etiam &longs;o­nus totius chordæ A B, ad &longs;o­num chordæ dimidiæ A C, ha­bebit eandem rationem, nimirum quam 2. ad 1. &longs;iue duplam. &longs;ed &longs;onus chor­dæ A B, ad &longs;onum chordæ A C, con&longs;onat diapa&longs;on, &longs;eu octauam, ergo in data chorda collocata e&longs;t con&longs;onantia diapa&longs;on, quod oportebat. vides me­dium e&longs;&longs;e arithmeticam, conclu&longs;ionem verò harmonicam. Aliud exemplum Tonus, quod e&longs;t interuallum primæ vocis, Vt, ad &longs;ecundam, Rè, in duo æqua­lia &longs;emitonia diuidi nequit, ratio e&longs;t Arithmetica, quia proportio &longs;uper­particularis in duo æqualia arithmeticè &longs;ecari nequit; at Tonus con&longs;i&longs;tit in ratione &longs;uperparticulari, nempè in &longs;e&longs;quioctaua, ergo Tonus bifariam diui­di nequit. de&longs;umptum e&longs;t ex Boetio.

35

Tex. 23. (Est autem &longs;ic mon&longs;trare, quemadmodum Bry&longs;o quadraturam, &longs;ecun­dum enim commune mon&longs;trant tales rationes) cum velit e&longs;tendere veram de­mon&longs;trationem con&longs;tare debere ex proprijs, non autem ex communibus; primum affert exemplum demon&longs;trationis cuiu&longs;dam Bry&longs;onis, quæ ex com­munibus procedat, vt autem benè intelligamus, quale&longs;nam &longs;int huin&longs;modi demon&longs;trationes, quæ per communia o&longs;tendunt, legenda prius ea &longs;unt, quæ &longs;crip&longs;imus de quadratura circuli in pr&ecedil;dicamento relationis. Bry&longs;o itaque, vt tradit Alexander, in hunc modum conabatur quadrare circulum. &longs;it qua­drandus circulus A B C D, cui circum&longs;eribatur quadratum E F G H. per 7 quarti, & alterum quadratum I L M N, eidem in&longs;cribatur per 6. quarti, quid autem &longs;it circum&longs;cribere, & in&longs;cribere figuram circulo, ex definitione

3. & 4. eiu&longs;dem libri petatur, quamuis ex in&longs;pectione figuræ pr&ecedil;sentis &longs;atis per­cipi po&longs;&longs;it; deinde aliud quadratum me­dium inter prædicta duo con&longs;tituatur, &longs;itque; O P Q R. Iam &longs;ic o&longs;tendebat i&longs;tud medium quadratum e&longs;&longs;e æquale circu­lo propo&longs;ito. Quæcunque &longs;unt, &longs;imul ma­iora eodem, & minora eodem, &longs;unt in­uicem æqualia, &longs;ed circulus, & quadra­tum medium, &longs;unt ambo maiora qua­drato in&longs;cripto, & ambo minora qua­drato circum&longs;cripto, ergo circulus, & quadratum medium, &longs;unt æqualia. vte­batur, inquit Ari&longs;t pr&ecedil;dicto principio, etiam numeris, lineis, temporibus, & qualitatibus communi, neque deducto ex natura circuli, aut quadrati, de qui­bus erat demon&longs;tratio. præterea aduertendum e&longs;t, illud e&longs;&longs;e fal&longs;um, nam &longs;ex, & quinque, ambo &longs;unt maiores, quam quatuor, & minores, quam &longs;eptem, & tamen non &longs;unt æquales.

36

In codem textu (Vnumquodque autem &longs;cimus, non &longs;ecundum accidens, quando &longs;ecundum illud cogno&longs;camus, &longs;ecundum quod ine&longs;t ex principijs illius, &longs;ecundam quod illud; vt duobus rectis æquales, habere, cui ine&longs;t per &longs;e, quod dictum e&longs;t exprincipijs huius) affert nunc exemplum alterius demon&longs;trationis, quæ non ex communibus, vt præcedens Bry&longs;onis, &longs;ed ex proprijs principijs o&longs;tendit affectionem de &longs;ubiecto proprio. E&longs;t autem illud exemplum toties decan­tatum de triangulo habente tres angulos æquales duobus rectis angulis; id­circo operæpretium e&longs;&longs;e puto explicare demon&longs;trationem, 32. primi Eucli­dis, quæ i&longs;tud ex proprijs principijs demon&longs;trat, & quam hoc loco Ari&longs;to­teles innuit, hoc enim modo ip&longs;ius Ari&longs;t. mentem probè penetrare poteri­

mus. &longs;it ergo triangulum A B C. Dico ag­gregatum trium ip&longs;ius angulorum A, B, C, e&longs;&longs;e æquale aggregato ex duobus angu­lis rectis (vt autem melius intelligas, quæ &longs;equuntur, lege prius ea, quæ dicta &longs;unt in lib. 1. Priorum &longs;ecto 3. cap. 1.) produ­catur latus B C, v&longs;que in D, vt fiat angulus externus A C D; Iam &longs;ic, quoniam pro­batum e&longs;t in 13. primi, duos angulos, quos facit linea A C, cum linea B D, &longs;cilicet angulos A C B, A C D, e&longs;&longs;e pares duobus rectis: & quia pariter in prima parte huins propo&longs;. 32. probatum e&longs;t ab Euclide duos angulos A B, e&longs;&longs;e æquales externo angulo A C D: &longs;i ter­tius angulus reliquus A C B, &longs;umatur bis, &longs;emel cum duobus angulis A, B, & &longs;emel cum externo A C D, addentur æqualia æqualibus, & propterea tres anguli A, B, A C B, &longs;imul &longs;umpti, erunt æquales duobus A C D, A C B, &longs;imul &longs;umptis; &longs;ed his duobus &longs;unt æquales duo recti, ergo cum quæ &longs;unt æqualia vni tertio, &longs;int etiam æqualia inuicem, erit aggregatum trium angulorum A, B, A C B, æquale aggregato duorum rectorum; quod erat demon&longs;tran­dum. Medium itaque huius demon&longs;trationis, &longs;i res ad trutinam Logicam ex­pendatur, e&longs;t, quod partes aggregati trium angulorum A, B, A C B, &longs;unt æqua­les partibus aggregati duorum, & ideo aggregatum, aggrega to æqua­le e&longs;t. quod medium e&longs;t in genere cau&longs;æ materialis. quod verò partes illius &longs;int æquales partibus huius, probatur, per dignitatem illam, quæ &longs;unt æqualia vni tertio, &longs;unt etiam inter &longs;e. partes porrò aggregati trium angulorum erant hæ, anguli A, B, vna; altera verò angulus A C B; partes verò aggre­gati duorum rectorum erant A C B, A C D, quibus partibus, illæ &longs;unt æqua­les, & ideo totum toti æquale. quod medium e&longs;t omnino intrin&longs;ecum, & ex proprijs ip&longs;ius trianguli, &longs;iue ex proprijs angulorum ip&longs;ius, cum &longs;int ip&longs;ius partes. quod pariter medium ex parte pa&longs;&longs;ionis, quæ demon&longs;tratur, e&longs;t ex proprijs, cum &longs;int partes illius materiales. per materiam autem oportet hoc loco intelligere materiam intelligibilem, ide&longs;t quantitatem à qualita­tibas ab&longs;tractam, & terminatam, de qua pluribus agemus infra in tractatu de natura mathematicarum. Hinc videas eos magnopere decipi, qui pu­tant, hanc demon&longs;trationem e&longs;&longs;e per extrin&longs;eca, eò quod ad demon&longs;tran­dum producatur linea B C, in D, putantes lineam illam productam C D, e&longs;&longs;e demon&longs;trationis medium; lineæ namque huiu&longs;modi, quæ in demon&longs;tra­tionibus geometricis con&longs;truuntur, nunquam &longs;unt media propria demon­&longs;trationum, &longs;ed tantummodo a&longs;&longs;umuntur ad probandum medium iam ex­cogitatum e&longs;&longs;e veram cau&longs;am conclu&longs;ionis. Hinc etiam manife&longs;tè colligas Mathematicas facultates habere demon&longs;trationes perfecti&longs;&longs;imas, quod ageometreti negare &longs;olent, &longs;ed audacter aiunt exempla Ari&longs;t. non e&longs;&longs;e vera: neque requiri veritatem exemplorum; in quorum vtroque peccant, nam dictum illud v&longs;urpari &longs;olet, & debet de exemplis moralibus. at vero requiri confor­mitatem exemplorum cum regulis traditis, nemo &longs;anæ mentis dubitabit. Vernm i&longs;ti confundunt conformitatem cum veritate. Veritas exemplo tunc ine&longs;t, quando illud, quod in exemplo narratur, verè extitit, vt &longs;i quis in exemplum pudicitiæ afferret hi&longs;toriam Io&longs;ephi, verum i&longs;tuà e&longs;&longs;et exemplum. quæ veritas in exemplis moralibus non &longs;emper e&longs;t nece&longs;&longs;aria, talia exempla &longs;unt &longs;æpè parabolæ, & fabulæ, quæ nunquam extiterunt, v. g. narratur ab Ari&longs;t. de quodam filio, qui patrem crudeliter traxerat, qui po&longs;tea grandior factus, cum filium procrea&longs;&longs;et, ab eodem pariter raptatus e&longs;t ip&longs;e, v&longs;que ad eundem locum, quo ip&longs;e patrem &longs;uum impiè raptauerat. non e&longs;t nece&longs;&longs;e, ta­lem extiti&longs;&longs;e filium, neque patrem. Verumtamen &longs;emper conformitas exem­pli cum regulis, & præceptis, quæ traduntur nece&longs;&longs;aria e&longs;t, alioquin exem­pla de&longs;truerent id, quod præceptio con&longs;truit, illique contraria e&longs;&longs;et, quod om­nino ab&longs;urdum foret. non &longs;ecus, ac &longs;i quis vellet alium docere characteres latinos, illique; barbaros, quos Gothicos vocant in exemplum proponeret. re­quiritur igitur &longs;emper in omni exemplo conformitas cum eo, quod doce­tur; in moralibus tamen non &longs;emper requiritur veritas, vti diximus; Alij verò dicunt non requiri in exemplis determinatam veritatem, &longs;ed &longs;atis e&longs;&longs;e, &longs;i exemplum verum &longs;it &longs;ecundum opinionem aliquorum: quorum &longs;ententiam non improbamus. Exempla igitur ab Ari&longs;t. pa&longs;&longs;im ex mathem aticis allata, congrua, conformiaque; omninò &longs;unt ip&longs;ius doctrinæ, aliter ip&longs;um perpetuò mentientem facimus. Po&longs;tremò illud etiam e&longs;t aduertendum, fortè Ari&longs;t. in præ&longs;enti textu &longs;pecta&longs;&longs;e non ad hanc Euclidianam demon&longs;trationem, &longs;ed po­tius ad Pithagoricam. Pithagorei enim eam aliter, quamuis per idem me­dium, &longs;cilicet à cau&longs;a materiali, demon&longs;trabant; con&longs;truebant enim aliter, neque vlla vtebantur diui&longs;ione. quod dictum velim propter nonnullos, qui ab huiu&longs;modi diui&longs;ionibus abhorrent, timentque; ne demon&longs;trationis perfectio­ni per eas plurimum derogetur. Pithagoreorum demon&longs;trationem vide apud Clauium in &longs;cholio 32. primi Euclidis, quam ex Eudemo etiam Pro­clus in comm. eiu&longs;dem recitat.

37

Ibidem (Sed quemadmodŭ harmonica per Arithmeticam) vide &longs;upra tex. 20.

38

Ibidem (Demon&longs;tratio autem non computatur in aliud genus; m&longs;i, vt dictum e&longs;t geometricæ demon&longs;trationes in Per&longs;pectiuas, aut Mcchamcas, & arithmeticæ in harmonicas) exempla &longs;ubalternationis Per&longs;pectiuæ, & Mu&longs;icæ in tex. 20. at­tulimus; nunc Mechanicæ &longs;ubalternationis, quam hic Ari&longs;t. in&longs;inuat, exem­plum &longs;it illud, quod Archimedes prop. 14. primi Aequep. demon&longs;trat, ni­mirum centrum grauitatis omnis trianguli e&longs;&longs;e punctum illud, in quo rectæ lineæ ab angulis trianguli ad dimidia latera oppo&longs;ita ductæ concurrunt. &longs;it triangulum A B C, à cuius angulis A, & B, ducantur duæ rectæ A D, B E, ita vt bifariam &longs;ecent latera A C, B C, in punctis D, & E, & concurrant in F. Dico F, e&longs;&longs;e centrum grauitatis propo&longs;iti trianguli. Quoniam enim in 13. Aequep. probauit centrum grauitatis e&longs;&longs;e in ea linea, quæ ducta ab angulo quouis &longs;ecat oppo&longs;itum latus bifariam, crit in linea A D, centrum grauitatis.

&longs;ed eadem ratione erit etiam in linea B E, er­go non ni&longs;i in puncto F, quod &longs;olum e&longs;t in vtra­que, quod erat demon&longs;trandum. ex quibus ap­paret, qua ratione mechanica conclu&longs;io Geo­metriæ &longs;ubiaceat, dum lineari di&longs;cur&longs;u ip&longs;a demon&longs;tratio perficitur. Scias præterea cen­trum grauitatis e&longs;&longs;e tale punctum, ex quo &longs;i &longs;u­&longs;pendatur corpus triangulare vniformis cra&longs;­&longs;itici, manet &longs;emper horizonti parallelum, &longs;i tamen antequam &longs;u&longs;penderetur, iacebat plano horizontis, æquidi&longs;tans; neque &longs;i &longs;u&longs;pen&longs;um feratur huc illud nutat, &longs;ed &longs;emper in codem &longs;itu per&longs;euerat.

39

Tex. 24. (Veluti Arithmetica quidem quid impar, aut par; aut quadrangu­lum, aut cubus) cogno&longs;cas hinc certò certius quadrangulum, & cubum e&longs;&longs;e &longs;pecies numerorum, &longs;icuti &longs;upra tex. 9. & 20. explicauimus, quò nunc te vi­ci&longs;&longs;im, vt præ&longs;entem locum intelligas, remittimus.

40

Ibidem (Geometrica verò quid irrationale, aut refrangi, aut concurrere) per verbum, irrationale, non videtur Ari&longs;t. intellexi&longs;&longs;e proprietatem illam duo­rum linearum incommen&longs;urabilium longitudine, & potentia, quia v&longs;us fui&longs;­&longs;et verbo, a/rrpton. quod apud Geometras v&longs;urpari &longs;olet in illa &longs;ignificatio­ne, &longs;ed v&longs;us e&longs;t verbo, a\logon, quod latinè redditur improportionale.

41

Per verbum (Refrangi) &longs;eu frangi, intelligit lineam aliquam rectam, non in directum rendere, &longs;ed in aliquo puncto frangi, &longs;eu declinari à rectitudine, ita vt con&longs;tituat angulum.

Per verbum (Concurrere) intelligit, non e&longs;&longs;e parallelas, &longs;ed ad idem ali­quod punctum coire, &longs;i protrahantur.

42

Ibidem (Et Astrologia &longs;imiliter) per A&longs;trologiam intelligit Ari&longs;t. non iu­diciariam, quamuis à recentioribus hoc nomine vocetur, &longs;ed quam hodie dicunt A&longs;tronomiam, aitque; ip&longs;am con&longs;iderare quantitatem, figuram, mo­tum, & locum totius Mundi, ac partium ip&longs;ius integrantium, vt &longs;unt Cœli, & Elementa.

43

Tex. 25. (Neque Geometra fal&longs;a &longs;upponit, quemadmodum quidam a&longs;&longs;eruere di­centes, quod non oportet fal&longs;o vti: Geometram verò mentiri dicentem pedalem, non pedalem, aut rectam de&longs;criptam, non rectam existentem: Geometra verò nihil con­cludit eò, quod bæc e&longs;t linea, &longs;ed quæ per hæc e&longs;tenduntur) innuit his verbis eam materiam intelligibilem, quæ e&longs;t &longs;ubiectum Geometriæ: eam &longs;cilicet, quæ &longs;ub figuris Geometricis &longs;en&longs;ibilibus, & plerunque fal&longs;is latet; nam &longs;æpè Geo­metra vtitur linea quadam &longs;en&longs;ibili pro recta, quæ verè nec e&longs;t linea mathe­matica, nec recta; &longs;upponit aliquando talem lineam e&longs;&longs;e pedalem, quæ ve­rè non e&longs;t pedalis: Verumtamen non mentitur, quia re&longs;picit ad veram li­neam mathematicam, quæ &longs;ub illa intelligitur, & quæ recta concipitur; & quidem hæc omnia verè concipiuntur, quoniam ita e&longs;&longs;e re vera po&longs;&longs;unt.

44

Tex. 28. (Coaltern as verò coincidere) per coalternas intelligendas e&longs;&longs;e pa­rallelas lineas, alias, & nunc quoque monemus.

45

Tex. 29. (In Matbematicis verò non est &longs;imiliter paralogi&longs;mus, quoniam me­diŭ e&longs;t &longs;emper, quod duplex, de hoc enim omni, & hoc rur&longs;us de alio dicitur omni)aduerte, quod quamuis nonnulli codices habeant pro, in mathematicis, in di&longs;cipliis, idem tamen apud græcos maqhmata &longs;unt, ac apud latinos di&longs;ci­plmæ; verbum autem maqhmata v&longs;urpat hoc loco Ari&longs;toteles. Porrò non e&longs;t in mathematicis, &longs;icut in alijs paralogi&longs;mus, quia in omni demon&longs;tra­tione maius extremum dicitur de omni medio, & rur&longs;us medium dicitur de omni minori extremo, ac &longs;i diceret mathematicæ demon&longs;trationes &longs;unt in primo modo, qui barbarè à latinis recentioribus Barbara appellatur. Hæc e&longs;t autem pulcherrima mathematicarum commendatio, quippe præclarum e&longs;t à laudato laudari. In mathematicis, inquit, non accidit &longs;imiliter para­logi&longs;mus, ide&longs;t, tam frequenter, quemadmodum in &longs;yllogi&longs;mis dialecticis, quia modus argumentandi mathematicarum e&longs;t perfecti&longs;&longs;imus, quippe in primo modo primæ figuræ.

46

Eodem tex. (Contingit autem quo&longs;dam non &longs;yllogi&longs;ticè dicere, & quod ex vtri&longs;­que con&longs;equentia accipiunt, quemadmodum & Cæneus facit, quod ignis in multi­plici proportione: etenim ignis celeriter gignitur, vt ait: & hæc est proportio. &longs;ic autem non e&longs;t &longs;yllog &longs;mus, ni&longs;i celerrimam proportio &longs;equatur multiplex: & ignem celerrima in motu proportio) verba illa (in multiplici proportione) græcè &longs;ic &longs;e habent, en th pollaplasioni analogia, quod melius redditur latinè in mul­tiplici proportione, quemadmodum fecimus, quam in multiplicata, quem­admodum in vulgata editione. porrò quid inter multiplicem, & multipli­catam rationem inter&longs;it, optimè declarat no&longs;ter Clauius ad 4. definit. lib. 5. Elem. ex quo etiam loco pauca decerpam, quæ huic loco declarando con­ducunt. Proportio igitur multiplex e&longs;t habitudo inter duas quantitates in­æquales, quarum maior continet minorem, bis, vel ter, vel quater, &c. vn­de proportio multiplex habet &longs;ub &longs;e genera infinita, quando enim maior continet minorem bis, dicitur Dupla: quando ter, Tripla: quando quater, Quadrupla: & &longs;ic in infinitum: v. g. 2. ad 1. e&longs;t proportio dupla; 3. ad 1. tri­pla; 4. ad 1. quadrupla, &c. omnes tamen continentur &longs;ub genere multipli­cis rationis. porrò &longs;i qu&ecedil;piam proportio ex genere multiplici progrediatur per plures terminos, v. g. proportio quadrupla progrediatur hoc modo, 1. 4. 16. 64. 256. &c. fit, vt &longs;ub&longs;equentes termini mirum in modum augean­tur. hic vides primum ip&longs;am quadruplam rationem in di&longs;po&longs;itis terminis progredi, quia quilibet &longs;equens terminus ad præcedentem e&longs;t quadruplus. cernis etiam in paucis terminis, quinque &longs;cilicet magnum factum e&longs;&longs;e incre­mentum, cum v&longs;que ad 256. excreuerint. Cæneus igitur dicens ignem augeri &longs;ecundum multiplicem rationem, vnam ex prædictis intelligebat aliquam, quia quælibet illarum magnopere cre&longs;cit, &longs;i propagetur, vt ad 10. quinti definit. traditur: & vt paulo ante exemplo licuit per&longs;picere. argumentaba­tur igitur Cæneus in hunc modum; quod in multiplici ratione augetur, ce­lerrimè augetur: ignis celerrimè augetur, ergognis in multiplici ratione augetur, quæ argumentatio vitio&longs;a e&longs;t, ex duabus quippe affirmatiuis in &longs;e­cunda figura procedens, vt colligitur ex verbis illis tex. (Ex viri&longs;que con&longs;e­quentia accipiunt) ex his mathematica huius locis patere &longs;atis po&longs;&longs;unt.

47

Ibidem (Conuertuntur autem magis, quæ&longs;unt in mathematicis, quoniam nul­lum accidens accipiunt (m quo quidem ijs præ&longs;tăt, quæ di&longs;putationibus traduntur) &longs;ed definitiones) Hæc e&longs;t altera mathematicarum laus, vnde earum quoque præ&longs;tantia elucet, quia &longs;cilicet mathematicæ pro medijs vtuntur definitio­nibus &longs;ubiecti, aut pa&longs;&longs;ionis, quæ nuilo modo &longs;unt accidentalia conclu&longs;ioni, v. g. in prima Euclidis demon&longs;tratione per definitionem &longs;ubiecti probantur tres lineæ e&longs;&longs;e æquales, quia nimirum &longs;int &longs;emidiametri circulorum æqua­lium, quæ e&longs;t ip&longs;arum definitio. & in 4. primi probantur ba&longs;is, & anguli vnius trianguli æquales e&longs;&longs;e ba&longs;i, & angulis alterius trianguli per formalem definitionem pa&longs;&longs;ionis, videlicet æqualitatis, quæ traditur in octauo axio­mate &longs;ic, quæ &longs;ibi mutuo congruunt, ea inter &longs;e &longs;unt æqualia. probat igitur Euclides in quarta ba&longs;im, & angulos vnius trianguli e&longs;&longs;e æqualia ba&longs;i, & an­gulis alterius trianguli, quia o&longs;tendit, quod, &longs;i ba&longs;is illa huic ba&longs;i, & illi an­guli hi&longs;ce angulis &longs;uperponantur, congruunt; ex qua congruentia mutua, quæ e&longs;t æqualitatis definitio, infert æqualitatem ip&longs;arum ba&longs;ium, necnon angulorum. eadem deinde æqualitatis definitione totam demon&longs;trationem concludit, &longs;cilicet totum triangulum toti triangulo æquale e&longs;&longs;e, quia vnum alteri congruat. A&longs;tronomi quoque demon&longs;trant eclyp&longs;im de Luna, per in­rerpo&longs;itionem terræ inter Lunam, & Solem, quæ interpo&longs;itio e&longs;t definitio cau&longs;alis ip&longs;ius eclyp&longs;is, &longs;cilicet pa&longs;&longs;ionis. huiu&longs;modi &longs;excentas reperies apud Geometras, Arithmeticos, A&longs;tronomos, cæterosque; Mathematicas demon­&longs;trationes: ita vt meritò dixerit Ari&longs;t. Mathematicas alias omnes natura­les &longs;cientias, quæ di&longs;putabilibus rationibus traduntur ex hac parte antecel­lere. a&longs;&longs;umunt igitur terminos conuertibiles, quia adhibent &longs;æpè definitio­nes ad demon&longs;trandum. Reliqua logici expo&longs;itores declarant.

48

Tex. 30. (Rur&longs;us quemadmodum mon&longs;trant Lunam, quod &longs;phærica &longs;it per aug­menta: &longs;i enim quod ita augetur, e&longs;t &longs;phæricum; augetur autem Luna; planŭ quod &longs;phærica) Illius demon&longs;trationis, quæ ab effectu procedit, affert exemplum ex a&longs;tronomia; A&longs;tronomi enim demon&longs;trant Lunam e&longs;&longs;e &longs;phæricam ab ef­fectu ip&longs;ius &longs;phæricitatis, qui e&longs;t illuminatio &longs;phærica: &longs;ic enim ratiocinan­tur: ea, quæ &longs;phæricè illuminantur &longs;unt &longs;phærica, Luna &longs;phæricè illumina­tur, ergo &longs;phærica e&longs;t: quæ argumentatio fu&longs;ius explicanda e&longs;t; quod ait, quod ita augetur, ide&longs;t, &longs;phæricè, e&longs;t &longs;phæricum, ide&longs;t, quia lumen nouæ Lu­næ augetur &longs;phæricè, hoc e&longs;t, ad eum modum, quo quæuis &longs;phæra obiecta corpori lumino&longs;o &longs;olet illuminari. illuminatio porrò Lunæ in &longs;e &longs;emper e&longs;t eadem, quia &longs;emper dimidium Lunæ quod Solem a&longs;picit, illuminatur; dici­tur tamen augeri re&longs;pectu oculi no&longs;tri, quia &longs;cilicet initio facto à nouilunio pars illuminata incipit quotidie magis vergere ad oculum no&longs;trum, ita vt in dies maiorem, ac maiorem illuminationem videamus, donec opponatur Soli, in qua oppo&longs;itione totum ferè Lunæ illuminatum con&longs;picitur. Vt autem huius illuminationis non iniucundam f cias experientiam; cape &longs;phæram quampiam &longs;olidam manu, cum qua recede ad medium cubiculi, & pone lu­men &longs;eor&longs;um ad partem aliquam: deinde brachio exten&longs;o oppone &longs;phæram lumini, quo &longs;itu nihil de illuminatione videbis, quamuis dimidium ferè il­lius illuminetur. po&longs;tea conuerte te ip&longs;um ibidem paulatim, ita vt aliquid illuminationis oculo tuo appareat; & videbis partem illam illuminationis, falcatæ, &longs;eu nouæ Lunæ &longs;imilem. Deinde adhuc magis te conuerte, & cer­nes illuminationem dimidiatæ Lunæ &longs;imilem: verte adhuc te ip&longs;um donec &longs;it &longs;phæra ita lumini oppo&longs;ita, vt inter ip&longs;am, & lumen oculus tuus &longs;it me­dius; apparebit tunc tota illuminatio, quæ erit in&longs;tar plenilunij. perge ad­huc te ip&longs;um conuertere, & videbis paulatim lumen oculo tuo decre&longs;cere non aliter ac in Luna &longs;ene&longs;cente. atque hoe e&longs;t &longs;phæricè illuminari, fierique &longs;phærica illuminationis augmenta. cum ergo videamus Lunam eo modo lu­mine augeri, quo &longs;phæra, hinc ip&longs;am quoque &longs;phæricam-e&longs;&longs;e argumentamur.

49

Po&longs;t nonnulla (Vt Per&longs;pectiua ad Geometriam, & Mechanica ad Stereome­tricam, & Harmonica ad Arithmeticam, vt Apparentia ad A&longs;trologicam) &longs;upra tex. 20. exempla &longs;ubalternationum Per&longs;pectiuæ, & Mechanicæ cum Geo­metria &longs;unt allata. hic primo notandum Stereometriam non ef&longs;e &longs;cientiam di&longs;tinctam à Geometria, ni&longs;i &longs;icuti partem à toto: nam cum Geometria con&longs;ideret quantitatem, &longs;ecundum tres dimen&longs;iones, longitudinem, latitu­dinem, & profunditatem, oritur triplex illius diui&longs;ro, de lineis, de &longs;uperfi­ciebus, de &longs;olidis. pars igitur, quæ de &longs;olidis tractat, pattimque; continetur 11. 12. 13. 14. & 15. Euclidis, partim aliorum Geometrarum libris, vt li­bro Archim. de Sphæra, & Cyl. & &longs;imilibus, dicitur Stereometria à græco steoeov, ide&longs;t &longs;olidum. Porrò cur malit Ari&longs;t. Mechanicam &longs;ubalternari Ste­reometriæ, quam toti Geometriæ, qua tamen, vt videre e&longs;t apud Archime­dem, innititur, fortè ea ratio e&longs;t, quia Mechanica præcipuè con&longs;iderat ma­chinas, quæ corpora &longs;unt, & propterea præcipuè, & primò debet Stereome­triæ, quæ corpora pariter contemplatur, &longs;ubalternari. Quod ait Apparen­tia ad A&longs;irol. inteiligit per Apparentia vulgarem quandam Nautarum, & Agricolarum a&longs;tronomiam, quæ quodammodo &longs;ubaiternatur, & pendet ex &longs;cientia A&longs;trologiæ; indiget enim cognitione ortus, & motus a&longs;trorum, præ&longs;ertim Lunæ, Hyadum, Pleiadum, & Canis. Reliqua v&longs;que ad &longs;inem ca­pitis optimè à Zabarella explicantur, neque ad nos pertinet, cum de Mathe­maticis agant, quatenus ad Logicum &longs;pectant.

50

Po&longs;t nonnulla (Hic enim ip&longs;um quidem quod &longs;en&longs;itiuorum e&longs;t &longs;cire, ip&longs;um ve­rò Propter quid Mathematicorum; hi namque habent cau&longs;arum demon&longs;trationes, &c.) &longs;en&longs;us e&longs;t in &longs;ubalternatis, & dependentibus di&longs;ciplinis, quas &longs;en&longs;itiuas appellat, quia de rebus &longs;en&longs;ibilibus &longs;unt, vt in Per&longs;pectiua de obiectis vifibi­libus, & in Mu&longs;ica de &longs;onis cogno&longs;citur Quod, ide&longs;t effectus: cuius effectus cau&longs;a, &longs;eu Propter quid &longs;citur auxilio Mathematicarum, ide&longs;t, traditur à &longs;cientijs &longs;ubalternantibus. v. g. alicuius effectus in Per&longs;pectiua cau&longs;a inqui­ritur, & inuenitur ope Geometriæ, cuiilla &longs;ubiacet. Hic obiter notandum, Ari&longs;t. fateri manife&longs;tè Mathematicas &longs;ubalternatas, &longs;eu medias o&longs;tendere per cau&longs;as, quas &longs;ubalternantium ope perue&longs;tigant.

51

Et po&longs;tea (Se habet autem & ad Per&longs;pectiuam, vt hæc ad Geometriam, alia ad hanc, vt quoæ e&longs;t de Iride ip&longs;um enim quod Naturalis e&longs;t &longs;cire, ip&longs;um vcrò Prop­ter quid Per&longs;pectiui) &longs;icut &longs;e habet, inquit, &longs;cientià Naturalis de Iride ad Per­&longs;pectiuam, ita Per&longs;pectiua ad Geomettiam. qua verò ratione cau&longs;a Iridis pertineat ad opticam, atque hine tandem ad Geometriam, optimè patebit in Meteoris, cum ip&longs;ius demon&longs;trationem afferemus.

52

Tex. 37. (Vt æquicruri, & Scaleno hoc, quod e&longs;t duobus rectis æquales habere &longs;ecandum commune aliquod ine&longs;t) quid &longs;it habcre tres æquales duobus rect&longs;atis explicatum e&longs;t lib. r. Priorum &longs;ecto 3. cap. r. nunc igitur paraphra&longs;olum huius loci dabo. Triangnlo I&longs;o&longs;celi, & Scaleno connenit pa&longs;&longs;io ihabere tres angulos æquales duobus rectis angulis &longs;ecundum aliquodmune, quia illis competit, quatenus ambo &longs;unt figura quædam, ide&longs;t, qua­tenus vtrumque illorum triangulum e&longs;t; triangulo namque omni primo com­petit habere tres angulos æquales duobus rectis.

53

Tex. 38. (Et quemadmodum in alijs principium &longs;implex, boc autem non idem vbique, &longs;ed in pondere quidem mina, in cătu verò die&longs;is) Die&longs;is apud Muficos e&longs;t pars Toni. Tonus autem e&longs;t interuallum duarum vocum, quale e&longs;t inter pri­mam vocem, Vt, & &longs;ecundam Rè, vt modo loquuntur. i&longs;tud interuallum diuidunt Mu&longs;ici primum in &longs;emitonia, non tamen æqualia, &longs;ed vnum maius altero. minus iterum in duas partes æquales &longs;ubdiuidunt, quarum vtramque veteres harmonici die&longs;im dixerunt. & h&ecedil;c die&longs;is e&longs;t minima vox ab eis con­&longs;iderata; & quæ prima cadit &longs;ub &longs;en&longs;um; & propterea veluti &longs;implex prin­cipium, & clementum, ex quo alia maiora interualla conftent; & in quod re&longs;oluuntur. die/ois porrò græcè valet inter alia, diui&longs;ionem. igitur interual­lum i&longs;tud minimum dictum e&longs;t die&longs;is, quod &longs;it quædam diui&longs;io, &longs;eu &longs;egmen­turn Toni (Quemadmodum in pondere mina) qui de ponderibus antiquis tra­ctant, a&longs;&longs;erunt, Minam fui&longs;&longs;e maiorem libra per &longs;emunciam, æquipondera­bat enim centum drachmis: quæ refragantur huic loco. &longs;ed fortè dicendum, Ari&longs;t. con&longs;idera&longs;&longs;e, Minam re&longs;pectu Talenti, re&longs;pectu enim illius dici pote&longs;t principium, cum &longs;ex millia minarum in Attico talento continerentur.

54

Tex. 39. (Si enim quod duobus rectis ine&longs;t, non in quantum æquicrus, &longs;ed in quantum triangulus, no­&longs;cens, &c.) ide&longs;t, &longs;i enim qui cogno&longs;cit, quod ha­bere tres angulos æquales duobus rectis conuenit æquicruri, non quatenus æquicrus e&longs;t, &longs;ed quate­nus triangulus e&longs;t, &c. quid &longs;it habere tres æqua­les duobus rectis, &c. fusè explicatum e&longs;t in lib. 1. Priorum &longs;ecto 3. cap. 1. quò te nunc mitto.

55

Po&longs;t pauca (Ine&longs;t omni triangulo hoc quod est duos, &c.) ide&longs;t, hæc proprietas, quæ e&longs;t habere duos angulos rectos non actu, &longs;ed per æquiualen­tiam trium angulorum trianguli. Vide quæ im­mediatè &longs;upra de hac re dixi, & quò te remi&longs;r.

56

Eodem tex (Quando igitur cognofcimes, quod­quatuor exteriores &longs;unt æquales, quoniam I&longs;o&longs;celes, adhuc defseit, propier quid I&longs;o&longs;celes? quoniain trian­gulus: & hoc quoniam figura rectilinea, &c.) exem­plo geometrico vult o&longs;tendere demon&longs;trationem vniuer&longs;alem e&longs;&longs;e particulari præ&longs;tantiorem: e&longs;t autem exemplum de pulcherrima, atque admira­bili proprietate, quæ omnibus figuris rectilineis conuenit, e&longs;t que; huiu&longs;modi: Omnis figuræ rectili­neæ anguli externi omnes &longs;imul &longs;umpti, &longs;unt æqua les quatuor rectis angulis, quæ affectio demon­&longs;tratur in &longs;cholio 32. primi Elem. dicuntur autern anguli externi, qui productis lateribus fiunt, vt in triangulo pra&longs;enti anguli externi &longs;unt, B D C, D F E, F B A, ita vt quælibet figura tot angulos externos &longs;ortiatur, quot habet latera; cum exproductis lateribus oriantur. Vt autem propo&longs;itio ve­rificetur, &longs;ingula latera ordinatim &longs;unt producenda, hoc e&longs;t, ver&longs;us eandem partem, vt in figuris appo&longs;itis vides. Quæuis igitur figura rectilinea, &longs;iue trilatera &longs;it, &longs;iue quadrilatera, vel etiam millelatera, & proinde mille quo­que angulos externos habeat, hanc tamen mirabilem proprietatem (quod vix credi pote&longs;t) po&longs;&longs;idet, vt omnes illi anguli externi &longs;imul &longs;int æquales quatuor rectis angulis. vnde tres externi anguli trianguli, & quatuor exter­ni quadranguli, & quinque externi pentagoni, &c. &longs;unt æquales quatuor tan­tum rectis, nec aliter res &longs;e habet in figura millelatera. Ex quo fit, vt an­guli externi cuiu &longs;uis figuræ &longs;int æquales angulis omnibus externis alterius cuiu&longs;libet figuræ. Ari&longs;t. igitur inquit, quando cogno&longs;cimus, quod quatuor angulis rectis &longs;unt æquales exteriores omnes anguli alicuius figuræ, quo­niam figura illa e&longs;t triangulum &longs;calenum, adhuc talis cognitio e&longs;t defecti­ua, quia non illi competit illa pa&longs;&longs;io, quia &longs;it triangulum &longs;calenum, neque competit &longs;caleno, quia &longs;it triangulum; &longs;ed his omnibus competit, quia &longs;unt figuræ rectilineæ, cui hæc proprietas ine&longs;t primo, & vniuer&longs;aliter: qui igi­tur &longs;cit, &longs;calenum habere prædictam affectionem, ex eo, quod &longs;it figura re­ctilinea, perfectius &longs;cit, quia nihil amplius quæri pote&longs;t, quia illa figura re­ctilinea illud vniuer&longs;ale e&longs;t, cui primo competit; reliquis autem per illam. qui igitur vniuer&longs;ale &longs;cit, perfectius &longs;cit; quod volebat Ari&longs;t. demon&longs;trare.

57

Eodem tex. (Vt &longs;i quis nouit, quod omnis triangulus habet tres duobus rectis æquales) nihil &longs;requentius. vide &longs;upra lib. 1. Priorum &longs;ecto 3. cap. 1.

58

Tex. 43. (Sed planum, quod et&longs;i e&longs;&longs;et &longs;entire triangulum, quod duobus rectis æquales habet angulos) vide &longs;upra lib. 1. Priorum &longs;ecto 3. cap. 1.

59

Po&longs;t pauca (Quare & &longs;i &longs;upra Lunam e&longs;&longs;emus, & videremus obiectam terram, non vtique &longs;ciremus cau&longs;am eclyp&longs;is) loquitur de defectu Lunæ, qui fit, quando terra inter Lunam, & Solem po&longs;ita, impedit, ne lumen Solis feratur in Lu­nam, &longs;ed efficit, vt vmbra ip&longs;ius terræ eam contegat.

60

Et paulo po&longs;t (Qutmadmodŭ &longs;t vi­trum perforatum videremus, & lumen permeans, planum vtique e&longs;&longs;et propter quid comburit) Ioquitur de ea com­bu&longs;tione, cuæ fit per refractionem media &longs;phæra vitrea. de qua Vitel­io propo&longs;. 48. decimi libri; non au­tem de ea, quæ fit per reflexionem ex &longs;peculo concauo quando combu­&longs;tio fit per refractionem, cau&longs;atur à radijs Solis vitrum permeantibus, in quo ita franguntur, vt egredien­tes è vitro &longs;imul vniantur, ex qua vnione ita calor intenditur, vt ibi comburat. vt in appo&longs;ita figura cer­nere facile e&longs;t; in qua radij à Sole manentes, &longs;phæram vitream perua­dunt, atque in exitu ita refraguntur, vt ad A, punctum coaceruati, ibi po&longs;­&longs;int, &longs;i quid combu&longs;tibile occurrat, comburere. Si igitur, inquit Ari&longs;t. vide­remus illos radios &longs;ic permeare, & refrangi, planum vtique nobis e&longs;&longs;et pro­pter quid incendant.

61

Ad finem tex. 43. (Principia enim duplicia &longs;unt, ex quibus, & circa quod: quæ quidem igitur, ex quibus, communia &longs;unt: quæ autem circa quod propria, vt numerus, magnitudo) nonnulli codices corruptè legunt (vt numerus magni­tudine) &longs;ed ex græco tex. corrigendi &longs;unt, vti fecimus. Cæterum per prin­cipia, ex quibus intelligit Dignitates, quia ex illis di&longs;currimus. per princi­pia verò circa quod, intelligit Definitiones, quibus, vt apparet apud Eucli­dem, explicatur &longs;ubiectum, circa quod &longs;cientia ver&longs;atur; vt in definitioni­bus primi Elem. docemur, quid &longs;it linea, quid triangulum, quid circulus, quid magnitudines reliquæ, quæ &longs;unt materia, circa quam Geometria &longs;pe­culatur. In &longs;eptimo verò traduntur definitiones numerorum, quid &longs;it nu­merus, quid impar, quid compo&longs;itus, quadratus, cubus, & reliquæ nume­rorum &longs;pecies, quæ &longs;unt materia &longs;eptimi, octaui, & noni, in quibus de Arith­metica tractatur.

62

Tex. 44. (Commen&longs;urabilem namq e&longs;&longs;e diametrum verè opinari, ab&longs;urdum e&longs;t)vide, quæ de commen&longs;urabilitate diametri quadrati cum latere expo&longs;uimus lib. 1. Priorum &longs;ecto 1. cap. 23. ait igitur Ari&longs;t. ab&longs;urdum e&longs;&longs;e opinari dia­metrum e&longs;&longs;e commen&longs;urabilem co&longs;tæ, &longs;eu lateri eiu&longs;dem quadrati, reli­qua &longs;unt Logica.

Ex Secundo Posteriorum.

63

Tex. 1. (Dico autem &longs;impliciter quidem &longs;ubiectum, vt Lunam, aut ter­ram, aut Solem, aut triangulum; aliqud verò defectum, æqualitatem, inæqualitatem. &longs;i in medio, aut non) Zabarella locum hunc, etiam quatenus ad Mathematicum attinet, optimè declarat. In quæ­&longs;tionibus, & demon&longs;trationibus duo &longs;unt, &longs;ubiectum, & prædicatum, vtriu&longs;que cau&longs;æ exi&longs;tunt, & quæruntur: v. g. Luna, terra, Sol, & triangulum &longs;unt &longs;u­biectum in demon&longs;tratione, quorum prædicata &longs;unt, Lunæ quidem, & So­lis, eclyp&longs;is. terræ autem e&longs;&longs;e in medio mundi, quod ab A&longs;tronomis ratione ab eclyp&longs;ibus de&longs;umpta, euidentius, quam ab alio quoquam demon&longs;tratur, vt patet ex tractatu de &longs;phœra. in quo Zabarella non probatur, qui &longs;olum ait, terram e&longs;&longs;e in medio mundi, à Phy&longs;icis demon&longs;trari. triangulum autem, &longs;eu angulorum ip&longs;ius prædicatum e&longs;t æqualitas, & inæqualitas: vt cum in 32. primi Elem. demon&longs;trat Euclides, omne triangulum habcre tres angulos æquales duobus rectis.

64

Ibidem (Quid e&longs;t con&longs;onantia? ratio numerorum in acuto, & graui, &c) tan­git breuiter Ari&longs;t. cau&longs;am formalem con&longs;onantiæ, & con&longs;equenter defini­tionem ip&longs;ius. definiunt igitur Mu&longs;ici con&longs;onantiam hoc modo; Con&longs;onan­tia e&longs;t compo&longs;itio &longs;oni grauis, & acuti, quæ &longs;uauiter auribus accidit; & quo­rum &longs;onorum proportio ad inuicem &longs;it &longs;icuti proportio numerorum, qui quaternario includuntur: vt e&longs;t proportio 2. ad 1. vel 3. ad 1. vel 4. ad 1. vel 3. ad 2. vel 4. ad 3. Quotie&longs;eunque igitur duo &longs;oni habuerin quampiam ex quinque prædictis proportionibus, &longs;i &longs;imul coaluerint, ita vt ex eis vnue tantum &longs;onus efficiatur; &longs;onus ille erit concordans, & auribus gratus. atque hæc e&longs;t &longs;ententia pri&longs;corum præ&longs;ertim Pythagoreorum, qui propterea di­cebantnon licere Mu&longs;ico vltra quaternarium pertran&longs;ire, eò quod &longs;olæ pro­portiones, vt diximus, numerorum quaternario contentorum, concordem, ac con&longs;onantem concentum efficere poterant: quod vt adhuc melius per­

cipiamus, accipe exemplum. Sint duæ chordæ A, & B, æqualis cra&longs;&longs;itici, & æquè ten&longs;æ. qua­rum A, dupla &longs;it ip&longs;ius B, quia igitur corpora &longs;onantia &longs;unt in dupla proportione, erunt pa­riter corum &longs;oni in ratione dupla (vt patet ex principijs harmonicæ) hoc e&longs;t, eorum &longs;oni erunt, vt 2. ad 1. quia &longs;cilicet &longs;onus maioris chordæ A, erit duplus ad &longs;onum mi­noris chordæ B. hoc e&longs;t, erit, vt 2. ad 1. & propterea, &longs;i &longs;imul ambæ chordæ pul&longs;entur, &longs;onus, quem ex duobus mixtum edent, con&longs;onans, atque grati&longs;&longs;i­mus auribus no&longs;tris perueniet. huiu&longs;modi porrò con&longs;onantia, quæ e&longs;t in proportione dupla, quæque omnium &longs;uaui&longs;&longs;ima e&longs;t, à græcis dicebatur Dia­pafon. atque hæc in præ&longs;entia &longs;ufficiant, cum plura de his ad &longs;ectionem pro­blematum 19. quæ tota e&longs;t de Mu&longs;ica, dicenda &longs;int.

65

Tex. 2. (Vt quod omnis triangulus duobus rectis æquales babet) vide anno­tata lib. 1. Priorum &longs;ecto 3. cap. 1.

66

Eodem tex. (Definitiones verò apparent omnes &longs;upponentes, & accipientes ip&longs;um quid e&longs;t, vt Mathematicæ, quid vnitas, quid par, & impar) alludit ad de­finitiones 7. Elem. vbi agitur de numeris. Quæ verò hoc loco de principijs dicuntur, luculenti&longs;&longs;imè patent con&longs;ideranti definitiones, & axiomata, quæ Mathematicis demon&longs;trationibus in omnibus ferè libris præmittuntur; ex quibus &longs;tatim demon&longs;trationes deriuantur.

67

Et paulo po&longs;t (Neque vtique de plano figura, non enim e&longs;t planum figura, neque fi­gura planum) alludit ad definitiones planarum figurarum, qualis e&longs;t circu­lus, cuius definitio e&longs;t inter definitiones primi Elem. 15. & e&longs;t huiu&longs;modi: circulus e&longs;t figura plana, &longs;ub vnica linea comprehen&longs;a, quæ periphæria ap­pellatur, ad quam ab vno puncto eorum, quæ intra figuram &longs;unt po&longs;ita, ca­dentes omnes rectæ lineæ inter &longs;e &longs;unt æquales: in qua quidem definitione non prædicatur planum de figura, nec figura de plano: neque enim planum, &longs;au plana &longs;uperficies e&longs;t figura &longs;ecundum &longs;e, ni&longs;i terminetur; neque figura e&longs;t plana &longs;uperficies, cum plurimæ &longs;int figuræ curuæ, & præterea &longs;olidæ quam­plurimæ.

68

Ibidem (Quoniam mon&longs;tratum e&longs;t I&longs;o&longs;celes habere tres angulos æquales duo­bus rectis, &longs;i id de omni triangulo mon&longs;tratum &longs;it) ex dictis lib. 1. Priorum &longs;ecto 3. cap. 1. petatur huius loci declaratio.

69

Tex. 7. (Quid enim &longs;ignificat triangulum, accipit Geometra) vt manife&longs;tum e&longs;t in 20. dednitione primi Elem.

70

Ibidem (Quod autem &longs;it, monstrat) vt per&longs;picuum e&longs;t in prima demon&longs;tra­tione primi Elem. vbi triangulum æquilaterum con&longs;truit, & po&longs;tea probat illud e&longs;&longs;e triangulum æquilaterum. Certum tamen e&longs;t, Geometram luppo­nere triangulum in communi, cum inter definitiones ip&longs;ius contineatur, quod tamen non ob&longs;tat, quominus probare po&longs;&longs;it, aliquando po&longs;&longs;e con&longs;trni, & e&longs;&longs;e aliquod particulare triangulum, vt fit in prædicta demon&longs;tratione, Euclidis.

71

Tex. 11. (Manifetum autem, & &longs;ic, propter quid e&longs;t rectus in &longs;emicirculo)affert exemplum demon&longs;trationis per cau&longs;am materialem, idque; vti &longs;olet ex Mathematicis petitum, e&longs;t enim apud Euclidem 31. demon&longs;tratio 3. Elem. vbi ip&longs;e o&longs;tendit angulum in &longs;emicirculo e&longs;&longs;e rectum. Vbi aduertendum e&longs;t propo&longs;itionem hanc 31. ab Euclide demon&longs;trari duobus modis; ex quibus &longs;ecundum innuit hoc loco Ari&longs;t. cui a&longs;cripta e&longs;t figura &longs;imilis huic no&longs;træ; in editione Clauiana. quod fortè non benè aduertens Iacobus Zabarella, alioquin in his &longs;atis oculatus incidit in errorem, dicens, &longs;e nullo pacto vi­dere medium Euclidianæ demon&longs;trationis e&longs;&longs;e cau&longs;am materialem; quod tamen nos mox aperiemus. per angulum in &longs;emicirculo intelligas eum, qui fit à lineis ductis ab extremitatibus diametri, & &longs;imul in quoduis punctum

circumferentiæ coeuntibus, vt in figura præ&longs;enti vides lineas A C, B C, ad C, pun­ctum conuenire, ibique; facere angulum, A C B, qui dicitur angulus in &longs;emicircu­lo, quia de&longs;criptus e&longs;t in &longs;emicirculo A­C B. e&longs;tque; &longs;anè mirabilis hæc &longs;emicirculi proprietas, cum vbicunque punctum C, in periphæria &longs;umptum fuerit, &longs;emper ta­men angulus A C B, fiat rectus. quod Euclides eodem pror&longs;us medio, quod Ari&longs;t. hic innuit, hoc modo demon&longs;trat. ducta enim recta D C, à centro D, ad punctum C, exurgunt duo l&longs;o&longs;celia triangula A D C, C D B, ergo per 5. primi, anguli D C A, D A C, &longs;unt æquales: pariter anguli D C B, D B C, æquales &longs;unt. & quia per 32. primi, anguli D A C, D C A, &longs;imul &longs;unt æqua­les angulo externo C D B, & inter &longs;e æquales, erit angulus A C D, dimidium anguli C D B. eadem ratione probatur angulus D C B, e&longs;&longs;e dimidium an­guli C D A. ergo totus angulus A C B, dimidium erit duorum angulorum A D C, C D B, qui per 13. primi, &longs;unt vel recti, vel duobus rectis æquiualent. Sequitur igitur, angulum A C B, in &longs;emicirculo e&longs;&longs;e dimidium duorum re­ctorum; & quia omnes recti &longs;unt æquales, &longs;equitur dimidium duorum re­ctorum, nihil aliud e&longs;&longs;e, quam vnum rectum angulum, ergo angulus in &longs;e­micirculo, cum &longs;it &longs;emi&longs;&longs;is duorum rectorum, erit vnus rectus angules; quod erat probandum. ex quibus vides medium illud, quod Ari&longs;t. a&longs;&longs;ump&longs;it, e&longs;&longs;e omnino idem cum eo, quo Euclides vtitur, &longs;cilicet, e&longs;&longs;e dimidium duorum rectorum, & propterea e&longs;&longs;e rectum: quod etiam medium in toto demon­&longs;trationis decur&longs;u e&longs;t vltimum, & principale, quod proximè conclu&longs;ionem attingit, & propterea dici meretur e&longs;&longs;e medium huius demon&longs;trationis. Cæterum, quod medium i&longs;tud &longs;it in genere cau&longs;æ materialis, patet ex co, quod e&longs;t, e&longs;&longs;e dimidium; nam e&longs;&longs;e dimidium, vel e&longs;&longs;e tertiam partem, & &longs;i­milia, nihil aliud e&longs;t, quam e&longs;&longs;e partem; e&longs;&longs;e autem partem e&longs;t e&longs;&longs;e materiam totius, etiam ex &longs;ententia ip&longs;ius Ari&longs;t. ex hac præterea materia conflatur definitio minoris extremi, vel &longs;ubiecti; dm dicitur, angulus in &longs;emicircu­lo e&longs;t dimidium duorum rectorum. &longs;yllogi&longs;mus enim reducitur tandem ad hanc formam, dimidium duorum rectorum e&longs;t rectus, angulus in &longs;emicir­culo e&longs;t dimidium duorum rectorum, ergo angulus in &longs;emicirculo e&longs;t rectus. vides in minori propo&longs;itione contineri definitionem &longs;ubiecti materialem? adeò vt hæc &longs;it demon&longs;tratio omnibus numeris ab&longs;oluta per cau&longs;am mate­rialem, vt benè &longs;entit Ari&longs;t. Reliqua ad logicum pertinent, etiam&longs;i per cha­racteres more mathematicorum exponantur.

72

Tex. 24. (Vt propter quid re&longs;onat? aut propter quid apparet? aut propter quid Iris? omnia enim hær idem problemata &longs;unt genere, omnia enim &longs;unt refractio, &longs;ed &longs;pecie altera) propter quid re&longs;onat? &longs;cilicet echo; propter quid apparet? &longs;cilicet imago in &longs;peculo. dicit cau&longs;am echo, imaginis in &longs;peculo, & iridis in nubibus e&longs;&longs;e eandem; nimirum refractionem; quamuis tres illæ refractio­nes, &longs;eu; vt melius loquamur, reflexiones differant &longs;pecie ab inuicem, illa enim e&longs;t repercu&longs;&longs;io vocis; hæc reflexio &longs;peciei vi&longs;ibilis ex corpore ter&longs;o; i&longs;ta denique radiorum Solis ex nube rorida in &longs;tato angulo repercu&longs;&longs;us. qua ratione autem i&longs;ta omnia fiant, longum e&longs;&longs;et exponere, & ab intelligentia huius loci fortè alienum. Illud tamen non prætereundum, quod &longs;i propriè cum Per&longs;pectiuis loqui velimus, dicendum e&longs;&longs;e, omnia illa e&longs;&longs;e reflexionem, non refractionem. nam reflexio e&longs;t, quando linea vi&longs;ualis, per quam fertur &longs;péecies in aliquod corpus ter&longs;um, impingit, ex quo deinde ad oculos refle­ctitur. refractio tunc e&longs;t, quando &longs;pecies obiectivi&longs;ibilis tran&longs;it per media diuer&longs;æ cra&longs;&longs;itiei., vt quando &longs;pecies lapilli per aquam primùm, deinde per æerem means ad oculum peruenit; tunc enim linea, per quam &longs;pecies pro­greditur, frangitur in confinio aquæ, & aeris, ita vt &longs;pecies non per vnicam lineam rectam, &longs;ed per fractam, &longs;eu refractam in confinio illo, oculis tan­dem accidat.

In fine textus (Quoniam Luna deficit) non intelligit defectum illum, qui eclyp&longs;is appellatur, &longs;ed ilium, quo paulatim lumen Lunæ minus oculis no­&longs;tris apparet: decre&longs;cente enim Luna &longs;olent humida augeri.

73

Tex. 25. (Vt propter quid, & permutatim proportionale? & c.) quod quan­titates, quæ &longs;unt proportionales, &longs;int etiam alternatim, &longs;eu permutatim proportionales explicatum e&longs;t ad tex. 13. primi Po&longs;ter. quæ etiam nece&longs;&longs;a­ria &longs;unt ad hunc locum benè intelligendum. Illud autem commune propter quod ea, quæ &longs;unt proportionalia, &longs;int etiam permutatim proportionalia, e&longs;t quoddam innominatum, de quo ibi dictum e&longs;t, quod cum conueniat li­neis, & numeris, & tamen &longs;eparatim de vtri&longs;que illa pa&longs;&longs;io demon&longs;tretur, quærit cuinam primò, & per &longs;e conueniat hæc pa&longs;&longs;io, e&longs;&longs;e permutatim pro­portionale; &longs;cilicet quidnam &longs;it illud innominatum; in quo deinde commu­nicent lineæ, & numeri, vt inde habeant e&longs;&longs;e etiam permutatim propor­tionalia.

74

Ibidem (Hic quidem forta&longs;&longs;e proportionaliter habere latera, & angulos) vult indicare, in quonam con&longs;i&longs;tat &longs;imilitudo inter duas-figuras rectilineas geo­metricas, quam &longs;imilitudinem Euclides definit. 1. &longs;exti, &longs;ic explicat: &longs;imi­les figuræ rectilíneæ &longs;unt; quæ & angulos &longs;ingulos, &longs;ingulis angulis æquales habent, atque etiam latera, quæ circa angulos æquales &longs;unt proportionalia. vt &longs;i duo triangula appo&longs;ita habeant angulos æquales, angulum A, angulo D: angulum B, angulo E. angulum C, angulo F. & præterea latera, quæ &longs;une

circa angulos æquales, v. g. cirea an­gulos A, & D, habeant proportiona­lia, hoc e&longs;t, vt latus A B, ad latus A C; ita &longs;it latus D E, ad latus D F; & &longs;ic de lateribus alijs circa reliquos angulos æquales; erunt tunc prædicta duo tri­angula fimilia.

75

Ibidem (Vt extrin&longs;ecos æquales e&longs;&longs;e) ide&longs;t extrin&longs;ecos angulos cuiu&longs;uis fi­guræ rectilineæ æquales e&longs;&longs;e quatuor rectis angulis: vide quæ &longs;crip&longs;imus de hac re ad tex. 39. &longs;ecundi Po&longs;ter. quæ huic pariter loco &longs;atisfaciunt.

EX TOPICIS.

Ex Primo Libro.

76

Cap. 13. (Con&longs;iderare, quod diameter est co&longs;tæ incommen&longs;urabilis) vide quæ de hac re &longs;crip&longs;i lib. 1. Priorum &longs;ecto 1. cap. 23.

77

Eodem cap. (Similiter autem & acutum; non enim idem &longs;impliciter in omnibus dicitur: nam vox acuta quidem velox (&longs;icut dicunt, qui &longs;e­cundum numeros harmonici &longs;unt) angulus autem acutus, qui minor e&longs;trecto; gla­dius verò, qui e&longs;t anguli acuti) affert tres &longs;pecies acuti, aliud dicens e&longs;&longs;e acu­tum, quod e&longs;t in voce acuta; aliud, quod e&longs;t in angulo acuto: aliud denique, quod e&longs;t in gladio acuto horum enim trium acumen diuer&longs;o modo &longs;e habet. nam acumen vocis, & &longs;oni ex celeritate motus, qua aer percu&longs;&longs;us impelli­tur; grauitatem autem ex tarditate oriri tradiderunt antiqui Mu&longs;ici om­nes: quamuis non ex &longs;ola celeritate, & tarditate, &longs;ed ex alijs etiam cau&longs;is oriri po&longs;&longs;e voluerint. Primus omnium Architas Tarentinus, vt e&longs;t apud Por­phirium in harmonicis Ptolæmei, & Zarlinum pag. 58. complem. mu&longs;ica­lium, ait, &longs;i virga celerius feriat aerem, gigni motum celeriorem in aere, atque hinc &longs;onum acutiorem reddi, experientia con&longs;tat: &longs;i autem eadem vir­ga tardius aerem feriat, gigni motum in aere tardiorem, ex quo etiam &longs;o­num grauem, vt experientia docet. Ptolæmeus deinde lib. 1. cap. 3. Harm. cum ex alijs, tum ex celeritate oriri &longs;onum acutum, grauem verò ex tardi­tate a&longs;&longs;erit; vt &longs;i chorda eadem parum inten&longs;a pul&longs;etur, tardius aerem ver­berat, & ideo grauiorem &longs;onum efficit: &longs;i autem magis intendatur, validius aerem pul&longs;abit, & proinde citiorem motum illi imprimet, & propterea acutiorem &longs;onum reddet. hæc ille. videmus etiam, quod cannæ organo­rum maiores cum plus aeris moucant, & idcirco tardius, &longs;onum grauiorem emittunt, quàm cannæ graciliores, quæ quia parum aeris cient, & ideo ce­lerius, &longs;onum acutum edunt. ab hac &longs;ententia po&longs;teriores Mu&longs;ici non recel­&longs;erunt, vt videre e&longs;t apud Zarlinum.

In quo po&longs;tea con&longs;i&longs;tat ratio acnti anguli, explicat inducens definitionem ip&longs;ius, quæ e&longs;t inter de&longs;initiones primi Elem. huiu&longs;modi, Angulus acutus e&longs;t, qui minor recto e&longs;t. Demum explicat, cur nam gladius dicatur acutus, quia nimirum habet angulum acutum &longs;uperficialem, ide&longs;t, quem duæ &longs;uper­ficies &longs;imul in acie gladij concurrentes efficiunt.

78

Eodem cap. (Rur&longs;um &longs;i eorundem; quæ &longs;unt &longs;ub eodem nomine diuer&longs;æ d ffe­rentiæ &longs;unt; vt coloris, qui e&longs;t in corporibus, & in melodijs) veteres Mu&longs;ici can­tilenas omnes ad tria genera reuocarunt, videlicet Enharmonicum, Chro­maticum, & Diatonicum; quæ diftinguebantur inuicem ex varia diui&longs;ione interuallorum, ex quibus ip&longs;orum Monochordia conftabant: &longs;iue ex varijs vocum interuallis, v. g. quia in vno continebantur plures toni, vt in Diato­nico; in alio plures die&longs;es, vt in Enharmonico; in tertio verò plura &longs;emito­nia, vt in Chromatico: quæ vox deducitur à chroma, græco, quod latinis e&longs;t color; quare Chromaticum latinè redditur coloratum. Hic e&longs;t igitur color ille, quem hic Ari&longs;t. innuit. quod genus for&longs;itan à calore denomina­batur, quòd ip&longs;ius notæ mu&longs;icales e&longs;&longs;ent coloratæ, vt hoc modo ab alijs ge­neribus digno&longs;eeretur quam con&longs;uetudinem exi&longs;timat Zarlinus cap. 46. &longs;e­cundæ partis, etiam no&longs;tra tempe&longs;tate aliquo modo per&longs;euerare, cum vi­deamus in organis, & alijs huiu&longs;modi in&longs;trumentis, quæ pinnas, vulgò ta­&longs;tos, habent; illas inquam pinnas, quæ chromaticis interuallis deputatæ &longs;unt, colore nigro tinctas e&longs;&longs;e.

Libro Quarto.

79

Cap. 1. loco 10. (Si quis in&longs;ecabiles ponens lineas) nonnulli antiquorum Philo&longs;ophorum putarunt omnia ex indiui&longs;ibilibus componi, vt Demo­critus, & Leucippus, & propterea dixerunt, etiam lineas con&longs;tare ex lineis quibu&longs;dam ade ò paruis, quæ omnino e&longs;ient in&longs;ecabiles, &longs;eu indiui&longs;ibiles: de quibus plura in libello de line is in&longs;ecabilibus.

Libro Sexio.

80

Cap. 2. loco 32. (Vt qui lineam definiunt longitudinem &longs;ine latitudine e&longs;&longs;e) &longs;uppenimus lectorem inteil exi&longs;&longs;e definitiones &longs;altem primi Elem. in­ter quas dfnitio lineæ e&longs;t &longs;ecunda, cademque; cum hac Ari&longs;totelis.

Libro Octauo.

81

Cap. 2. loco 41. (Videntur dutem in di&longs;ciplinis, &longs;eu Mathematicis quædam ob de&longs;initionis defectum non facile de&longs;cribi; vt & quoniam, quæ ad latus &longs;e­cat planum linea, &longs;imiliter diuidit & lineam, & locum: definitione autem dicta, fi m man fe&longs;tut&longs;t, quod dicitur, nam eandem ablationem habent lota, & inea, se latus planæ figuræ, est autem definitio eiu&longs;dem proportionis hæc) mendosè lugitur à nonnullis (E&longs;t distem de&longs;initio eiu&longs;dem orationis hæc) quos puto de­ceptos ab æquiuoco lsgous quod & orationem, & rationem, &longs;iue proportio­nem &longs;ignificat: hic autem &longs;ignificare proportionem res &longs;ubrecta &longs;atis mani­fe&longs;tat. Notandum po&longs;tea cum Alexandro (quod & &longs;uperius alias commo­nui in cap. de Priori, & alibi) per verbum (De&longs;cribi) fignificari hoc loco geometricè demon&longs;trare, quoniam Geometræ non ni&longs;i adhibit is de&longs;criptio­nibus, &longs;u figutis demon&longs;trant. Vult autem Ari&longs;t. exemplo mathematico o&longs;tendere, difficile e&longs;&longs;e di&longs;putare, aut rgumentari, ni&longs;i prius rectè a&longs;&longs;ignetur definitio illius rei, de qua di&longs;&longs;eritur. Porrò exemplum mathematicum hic allatum &longs;ic videtur explicandum: Conetur aliquis demon&longs;trare hanc pro­po&longs;itionem; &longs;i linea ducta fuerit æquidi&longs;tans lateri vnius plani trianguli, &longs;e­cabit & latera, & locum, ideft &longs;uperficiem illam triangularem &longs;imiliter, ide &longs;t

in eadem proportione, vt in triangulo A B C, linea D E, parallela ba&longs;i B C, &longs;ecat latera A B, & A C, in punctis D, & E, in eadem ratione, in qua etiam fecat totum triangulum, ita vt eadem &longs;it proportio lineæ A D, ad D B, & lineæ A E, ad E C, quæ e&longs;t partium totalis trianguli A B C, &longs;eilicet quæ e&longs;t partis A D E, ad partem E D C, fiue ad partem D E B. quod con&longs;tat ex &longs;ecunda 6. Elem. Inquit ergo Ari&longs;t. Si quis vellet hoc demon&longs;trare nondum præmi&longs;&longs;a defi­nitione eorum, quæ habent eandem rationem, &longs;iue nondum definitione al­lata quantitatum proportionalium, hic difficile id valeret o&longs;tendere: at ve­rò allata prins definitione quantitatum proportionalium facile demon&longs;tra­bit. Subdit verò Ari&longs;t. dictam definitionem, dicens, tunc quantitates e&longs;&longs;e proportionales, quando habent eandem ablationem, ide&longs;t, eandem diui&longs;io­nem, ide&longs;t, eadem diui&longs;io ne tantum proportionaliter de vna, quantum de altera magnitudine re&longs;ecatur: Quemadmodum etiam Euclides loco cita­to probat, latera illius trianguli, & &longs;uperficiem e&longs;&longs;e &longs;imiliter diui&longs;a, ex quo &longs;equitur e&longs;&longs;e proportionalia. Porrò Euclides definit. &longs;eptima 5. paulo ali­ter definit quantitates proportionales e&longs;&longs;e illas, quæ eandem habent ratio­nem, v. g. &longs;i &longs;it, vt prima ad &longs;ecundam, ita tertia ad quartam. ex quibus quoad Mathematicas &longs;pectat, huic loco &longs;atisfactum &longs;it.

82

Cap. 4. loco 86. (Tentandum autem, & ea, in quæ &longs;æpi&longs;&longs;imè incidunt di&longs;puta­tiones, tenere, nam quemadmodum in Geometria ante opus e&longs;t circa elementa exer­citatum e&longs;&longs;e, & in numeris circa capitales promptè &longs;e habere, & multum refert ad boc, & alium numerum cogno&longs;cere multiplicatum) Elementa vocabant antiqui demon&longs;trationes faciliores, & &longs;impliciores, quales propriè &longs;unt omnes, quæ &longs;ex prioribus libris Euclidianis continentur: ex illis enim tanquam ex ele­mentis ab&longs;tru&longs;iores, & difficiliores demon&longs;trationes deducebant. atque hæc e&longs;t ratio, cur Euclides &longs;uos librs elementa nuncupauerit. ait igitur curan­dum e&longs;&longs;e horum elementorum cognitionem in promptu habere, quia fre­quens de ip&longs;is incidit di&longs;putatio. Per capitales numeros intelligo &longs;implices ab vitate, v&longs;que ad nouem inclu&longs;iuè. & quando ait, alium numerum cogno­&longs;cere multiplicatum, &longs;ignificat vtile valdè e&longs;&longs;e ad quotidianum v&longs;um cogno&longs;cere, quemnam numerum producant numeri capitales, &longs;i ad inuicem multiplicentur, quamuis huiu&longs;modi co­gnitio facilis, ac leuis &longs;it: qua de cau&longs;a vide­mus v&longs;que in hanc diem pueros diu in Abaco memoriter perdi&longs;cen­do detineri.

Ex Primo Elenchorum.

83

Cap. 10. (Nam p&longs;eudograpbiæ non contentio&longs;æ (&longs;ecundum enim ea, quæ &longs;ub arte &longs;unt, captio&longs;æ &longs;unt ratiocinationes) neque &longs;i aliqua e&longs;t p&longs;eudogra­phia circa verum, vt Hippocratis quadratura, quæ per lunulas, &longs;ed, vt Bry&longs;&longs;o quadrauit circulum; & tamet&longs;i quadretur circulus, quia tamen non &longs;ecundum rem, ideo &longs;ophi&longs;ticus) qua ratione Hippocrates orbi quadrum exhibere æquale tentauerit, explicatum e&longs;t abundè in 2. Priorum cap. 31. & quo itidem modo Bry&longs;&longs;o lib. 1. Po&longs;ter. tex. 23. &longs;olummodo id hoc loco no­tandum per p&longs;eudographiam intelligere, vt apertè etiam inferius explicat, Geometricam demon&longs;trationem fallacem, eò quod demon&longs;trationes geo­metricæ fiant adhibitis de&longs;criptionibus, &longs;eu figurationibus: p&longs;endographia autem latinè idem e&longs;t, ac fal&longs;a de&longs;criptio; quemadmodum è contrariò, &longs;i­cuti &longs;upra in Topicis, & alibi ob&longs;eruaui, per de&longs;cribere intelligit geometri­cè demon&longs;trare, & per de&longs;criptiones intelligit demon&longs;trationes geometri­cas. Qua ratione item Hippocrates ex ijs, quæ &longs;ub arte Geometriæ &longs;unt, procederet ibi dictum e&longs;t, propter quod non e&longs;t contentio&longs;a, quamuis fallax ip&longs;ius demon&longs;tratio: appellat enim Ari&longs;t illas demon&longs;trationes contentio­&longs;as, quæ non procedunt ex proprijs illius &longs;cientiæ, in qua fiunt, &longs;ed ex com­munibus alijs &longs;cientijs: captio&longs;as verò, & &longs;ophi&longs;ticas, quæ ex proprijs &longs;cien­tiæ, in qua fiunt, decipiunt. At verò demon&longs;tratio, &longs;eu p&longs;eudographia Bry&longs;­&longs;onis erat contentio&longs;a, quia ex communibus, & extra Geometriam petitis argumentabatur: quemadmodum ibi explicatum e&longs;t.

84

Eodem cap. (Quadratura per lunulas non contentio&longs;a) inquit Hippocratis tetragoni&longs;mum, de quo in 2. Priorum, quæ non contentio&longs;a dicitur, quia ex proprijs Geometriæ deducebatur.

85

Ibidem (Bry&longs;&longs;onis autem contentio&longs;a: & illam quidem non e&longs;t transferre, ni&longs;i ad Geometriam &longs;olum; eo quod ex proprijs &longs;it principijs) quando ait (& illam qui­dem) intelligit quadrationem Hippocratis. vide 2. Prior cap. 31. & quæ pau­lo ante in præcedentibus locis diximus.

86

Ibidem (Hanc autem ad plures) intelligit tetragoni&longs;mum Bry&longs;&longs;onis, qui per communia deducebatur. lege &longs;uperius dicta in præcedentibus locis hu­ius capituli.

87

Ad &longs;inem cap. (Aut vt Antiphon quadra­uit) &longs;imile peccatum pecca&longs;&longs;e Antiphon­tem in orbe quadrando, ac Hippocratem, Ari&longs;t. his verbis videtur &longs;ignificare, ide&longs;t, ip&longs;um, quamuis ex proprijs Geometriæ, fal&longs;is tamen ratiocinatum e&longs;&longs;e. Cæterum Antiphontem in hunc modum orbem ad quadrum redigere tenta&longs;&longs;e, tradit Simpli­cius. circulo quadrando in&longs;cribebat pri­mò quadratum A B C D. deinde in &longs;ingu­lis quatuor &longs;egmentis in&longs;cribebat totidem trigona æquilatera, vt patet in ad&longs;cripta figura. po&longs;tea &longs;uper &longs;ingula latera horum triangulorum in reliquis &longs;egmen­tis in&longs;cribebat adhuc triangula &longs;imilia triangulo A I E. alia in&longs;uper trigona &longs;uper latera i&longs;torum con&longs;tituebat, donec ambitus figuræ illius multilateræ in circulo delinearæ, circumferentiæ circuli aptaretur. quod fieri po&longs;&longs;e ille falsò contra Geometriæ principia a&longs;&longs;umebat; e&longs;t enim principium Geome­tricum continuum e&longs;&longs;e diui&longs;ibile in infinitum, neque per diui&longs;ionem ab&longs;umi po&longs;&longs;e; cui principio aduer&longs;atur, dum putat &longs;e con&longs;umpturum rotum circu­lum, diuidendo illud in triangula &longs;emper minora; vel quia putat, lineam curuam con&longs;tare ex minimis lineis rectis. Similiter igitur atque Hippocra­res errauit, qúi pariter in Geometria fallebatur: Antiphon quidem contra principia illius: Hippocrates verò a&longs;&longs;umens fal&longs;i quidpiam in Geometria. At Bry&longs;&longs;o, eo quod per communia alijs &longs;cientijs deduceret ratiocinatio­nem propterea p&longs;eudographia Antiphontis non litigio&longs;a quidem, &longs;ed tamen fallax extitit, non enim per communia alijs &longs;cientijs procedat; vnde nec transferri poterat ip&longs;ius fal&longs;a de­&longs;criptio, &longs;eu demon&longs;tratio extra Geometriæ li­mites, quod cau&longs;a e&longs;t contentionis.

Logcorum locorum finis.

EX PRIMO LIBROPHYSICORVM.

88

Tex. 11. (Simul autem neque conuenit omnia &longs;oluere', &longs;ed quæcunque ex principijs aliquis demon&longs;trans mentitur; quæcunque verò non, minimè: vt tetragoni&longs;mum, eum quidem, qui per &longs;ectiones Geometrici est di&longs;­&longs;oluere: illum autem, qui Antiphontis non Geometrici e&longs;t) Tetrago­ni&longs;mum, &longs;eu circuli quadraturam per &longs;ectiones, e&longs;&longs;e illam Hip­pocratis Chij exi&longs;timant græci expo&longs;itores, qui per lunulas, quas Ari&longs;t. &longs;e­ctiones appellat, orbem quadrare tentabat. Eius den on&longs;trationem expli­caui ad cap. 31. de Abductione in 2. Priorum, quam inibi videas. hoc &longs;olum hic notandum pertinere ad Geometram, ip&longs;am refellere, quia ex fal&longs;a qua­dam præmi&longs;&longs;a ex Geometria de&longs;umpta, ratiocinabatur, idcirco debet (in­quit Ari&longs;t.) Geometra illius deceptionem inuenire. Tetragoni&longs;mum autem Antiphontis non e&longs;t Geometræ confutare, quia aduer&longs;abatur principijs Geo­metriæ, &longs;upponebat enim circuli circumferentiam ex indius, minimisque; lineis rectis componi: cuius fal&longs;am demon&longs;trationem expram iuenies ad cap. 10. primi Elench. po&longs;&longs;umus addere tertiam rat cet Hippocrates non procedebat per communia alijs &longs;ciad tex. 23. primi Po&longs;ter. cap. 8. vbi ip&longs;ius p&longs;endographimodum igitur Geometra di&longs;&longs;oluit fal&longs;as tantumuatis Geometricis principijs procedunt; non au riæ principia conuellunt: ita Phy&longs;ico non incumbit contra P Me­li&longs;&longs;um naturæ principia de&longs;truentes di&longs;ceptare, aut falla rationes coarguere. Hoc volebat Ari&longs;toteles inferre.

Ex Secundo Phy&longs;icorum.

89

Tex. 20. (Geometria enim de phy&longs;ica linea con&longs;iderat, &longs;ed non quatenus e&longs;t phy&longs;ici: Per&longs;pectiua autem ma hematicam quidem imcam, &longs;ed non quatenus phy&longs;ica e&longs;t) quamuis textus hic non pertineat ad Mathe­maticum, libuit tamen illum in ordinm no&longs;trum recen&longs;ere, ope­ræpretium etenim e&longs;t ea, quæ in ip&longs;o continentur à nonnullis recentioribus rectè intelligi, vt ab his moniti, ab inani quadam optices impugnatione ab­&longs;tineant, ac tandem ex Ari&longs;t. lineas illas vi&longs;uales quas ip&longs;i de medio tollunt, per&longs;picuè videant. cætera, quæ in præcedentibus locis Ari&longs;t. de Natura Ma­thematicarum habet, &longs;unt præter no&longs;trum in&longs;titutum.

90

Tex. 28. (Alio autem modo, &longs;orma, & exemplum: bæc autem e&longs;t ratio ip&longs;ius, quod quid erat e&longs;&longs;e, & huius genera, vt ip&longs;ius diapa&longs;on duo ad vnum, & omnino numerus, & partes, quæ in ratione &longs;unt) vt benè intelligas, quod in præ&longs;enti textu mathematicum e&longs;t, con&longs;ule prius, quæ &longs;crip&longs;i ad tex. 1. cap. primi 2. Po­&longs;ter. &longs;uper verba illa (Quid e&longs;t con&longs;onania?) vbi per&longs;picuè videbis, cur con­&longs;onantiæ, quæ dicitur Diapa&longs;on, e&longs;&longs;entia, & definitio &longs;it ip&longs;a proportio dupla, quæ &longs;ub his num. 2.1. continetur: quibus per&longs;pectis facilis erit phy&longs;ico totius loci intelligentia.

91

Tex. 68. (Aut enim ad ip&longs;um quid e&longs;t, reducitur ip&longs;um propter quid in immo­bihbus, vt in Mathematicis, ad definitionem enim recti, aut commen&longs;urabilis, aut alius cuiu&longs;piam reducitur vltimum) ex his manife&longs;tè videas Mathematicas de­mon&longs;trare per cau&longs;am formalem, cum cau&longs;am ip&longs;am ad ip&longs;um quid e&longs;t, ide&longs;t, ad definitionem reducant. quorum exempla in logicis ex Mathematicis at­tuli: &longs;ed etiam &longs;equentis loci exemplum de triangulo idem apertè manife­&longs;tat; in quo probat duos angulos A C B, A C D, e&longs;&longs;e rectos, ex definitione ip&longs;orum, &longs;iue ex definitione lineæ perpendicularis A C, quod idem e&longs;t.

92

Tex 89. (E&longs;t autem nece&longs;&longs;arium in Mathematicis, & in his, quæ &longs;ecundum natur am fiunt qua&longs;i eodem modo; quoniam enim hocrectum e&longs;t, nece&longs;&longs;e e&longs;t, trian­gulum trcs angulos habere æquales duobus rectis; &longs;ed non, &longs;i hoc, illud; &longs;ed &longs;i hoc non e&longs;t, neque rectum e&longs;t.) cum animaduerterim non parum e&longs;&longs;e di&longs;&longs;en&longs;ionis, & difficultatis in exemplo hoc mathematico explicando, ita vt recentiores quidam textum hunc pro arbitratu &longs;uo perperam latinè verterint: ideò pri­mum ex græcis codicibus interpretationem hanc veram attuli. deinde, quia etiam græci in exemplo mathematico enodando, vel malè, vt Simplicius; vel ob&longs;curè nimis, vt reliqui; Latini verò vel nihil, vel peius multò loquun­tur, ideò &longs;ic ego exponendum cen&longs;ui. cum velit Ari&longs;t. o&longs;tendere nece&longs;&longs;ita­tem, quæ in &longs;cientijs inter præmi&longs;&longs;as, &longs;cu medium, & conclu&longs;ionem reperi­tur, affert exemplum illud mathematicum &longs;ibi familiare, demon&longs;trationem &longs;cilicet illam, qua o&longs;tenditur, omne triangulum habere tres angulos æqua­les duobus rectis angulis, cuius fu&longs;i&longs;&longs;imam explicationem inuenies &longs;upra in primo Priorum, &longs;ecto 3. cap. 1. quam nece&longs;&longs;e e&longs;t, con&longs;ulas. pro medio autem huius pa&longs;&longs;ionis accipit lineam perpendicularem, quam innuit verbis illis (quoniam enim hoc rectum e&longs;t) vt in figura &longs;it triangulum A B C, &longs;itque; vt latus

A C, &longs;it perpendiculare cum latere B C, & pro­ducatur B C, in D; tunc triangulum A B C, habere tres angulos, A, B, & A C B, æquales duobus rectis planum erit: nam cum latus A C, &longs;it perpendiculare (quod Ari&longs;t. dicit, cum re­ctum hoc &longs;it) erunt duo anguli deinceps A C B, A C D, recti, ex definitione lineæ perpendicu­laris, cum ergo duo anguli A, & B, externo, rectoque; A C D, &longs;int æquales per 32. primi, & reliquus angulus A C B, communis, ide&longs;t, &longs;it angulus triangu­li, & angulus vnus lineæ perpendicularis, & ideò rectus; manife&longs;tè apparet, tres angulos A, B, A C B, e&longs;&longs;e æquales nece&longs;&longs;ariò duobus rectis, ex po&longs;itio­ne illius recti, &longs;iue lateris perpendicularis, quia ex verò, verum nece&longs;&longs;ariò &longs;equitur; non tamen po&longs;ita hac pa&longs;&longs;ione, &longs;iue conclu&longs;ione, habere &longs;cilicet tres angulos æquales duobus rectis, nece&longs;&longs;ariò &longs;equitur illud e&longs;&longs;e rectum, idelt latus illud A C, e&longs;&longs;e perpendiculare ad latus B C, quia verum &longs;equi pote&longs;t ex verò, & falsò. valebit tamen hæc con&longs;e quen­tia, &longs;i triangulum non habet hanc proprietatem, ne­que illud rectum e&longs;t, ide&longs;t, neque latus prædi­ctum crit perpendiculare, quia fal&longs;um non, ni&longs;i exfal&longs;o &longs;equitur.

Ex Tertio Phy&longs;icorum.

93

Tex. 26. (Et hi quidem infinitum e&longs;&longs;e par; hoc enim compræhen&longs;um, & ab impari terminatum tribuit ijs, quæ &longs;unt, infinitatem. &longs;ignum autem huius id e&longs;&longs;e, quod contingit in numcris, circumpo&longs;it is enim Gnomoni­bus circa vnum, & &longs;eor&longs;um, aliquando quidcm &longs;emper aliam fieri &longs;pe­ciem, aliquando autem vnam) vt melius percipiantur ea, quæ &longs;equuntur, lege prius, quæ in cap. de Motu in po&longs;t prædicamentis &longs;crip&longs;i de Gnomone, ad &longs;imilitudinem enim Gnomonis illius Geometrici, inueniuntur etiam in nu­meris Gnomones Arithmetici. Pythagorici enim (à quibus i&longs;ta mutuatus e&longs;t Ari&longs;t. numeros impares &longs;olos appellabant Gnomones, eò quod in for­mam normæ æquilateræ, &longs;iue Gnomonis con&longs;titui po&longs;&longs;int, vt patet in his

nimirum in ternario, quinario, &longs;eptenario, & &longs;ic de reliquis imparibus. pares autem numeri, quia ne­queunt in figuram normæ æquilateræ di&longs;poni, cum non habeant vnitatem pro angulo, & paria po&longs;tea la­tera, vt oportet, non merentur appellari Gnomones, vt quaternarius, &longs;i di­&longs;ponatur &longs;ic
non refert Gnomonem, quia lateribus in&ecedil;qualibus con­&longs;tat; neque &longs;i hoc modo
quia dee&longs;t huic figuræ angularis vnitas, quæ illi nece&longs;iaria e&longs;t. Pythagorici igitur dicebant, numerum parem ideò e&longs;&longs;e infinitum ip&longs;um, quia videbant ip&longs;um e&longs;&longs;e cau&longs;am perpetuæ diui&longs;ionis, cum quælibet res quanta &longs;it diui&longs;ibilis bifariam, ide&longs;t in duo &longs;ecundum numerum parem, & &longs;ubdiui&longs;ibilis po&longs;tea bifariam, & &longs;ic in infinitum, vt de linea pro­blematicè probatur in 10. primi Elem. quamuis theorematicè &longs;it axioma. hunc porrò numerum parem dicebant terminatum e&longs;&longs;e ab impari, quia ori­tur ex diui&longs;ione cuiu&longs;uis rei, quæ vna &longs;it, &longs;umentes vnitatem pro impari. &longs;ignum præterea huius finitatis ab impari, & infinitatis à pari numero pro­cedentis, aiunt e&longs;&longs;e Gnomones, numeros &longs;cilicet impares: Gnomones enim, ide&longs;t impares numeri vnitati additi, producunt eandem perpetuò numero­rum formam, videlicet quadratum: at verò è contrariò numeri pares vni­tati additi, conflant perpetuò varias numerorum formas: quapropter vi­dentur numeri impares e&longs;&longs;e finitatis cau&longs;a; &longs;icut pares exaduersò infinitatis principium. quæ vt melius intelligas, declaranda e&longs;t 26. propo&longs;. 7. Arith­metices lordani, vbi i&longs;tud idem demon&longs;trat, quæ e&longs;t hæc. &longs;it vnitas, & &longs;uo or­dine &longs;equantur impares, vt in &longs;equenti hac &longs;erie apparet 1. 3. 5. 7. 9. & c.
&longs;i igitur vnitati addatur ternarius in Gnomo­nis modum, vt vides in prima figura, produ­cetur quaternarius numerus, qui e&longs;t numerus quadratus (quid &longs;it quadratus numerus expli­caui in Logicis tex. 9. primi Po&longs;ter.) etfi huic quaternario addatur &longs;equens impar, qui e&longs;t quinarius in modum Gnomonis, vt in &longs;ecundfigura, &longs;it numerus nouenarius, qui pariter e&longs;t quadratus. et&longs;i huic &longs;imiliter addatur &longs;e quens impar, nimirum &longs;eptenarius, conflabitur &longs;edenarius, qui numerus pariter quadratus e&longs;t, vt in tertia figura, & hoc modo, &longs;i in infini­tum procedatur, numeri &longs;emper quadrati progignentur. Vides igitur, qui ratione Gnomonum, &longs;iue imparium additione fiat &longs;emper eadem &longs;pecies, &longs;cilicet quadratus numerus, quod &longs;ignum e&longs;t, inquiunt, imparem numerum non infinitatis, &longs;ed finitatis e&longs;&longs;e auctorem. Po&longs;t prædictam 26. propo&longs;itio­nem Iotdani, &longs;unt aliquot propo&longs;itiones, quarum &longs;umma hæc e&longs;t: &longs;i pares numeri ab vnitate coaceruentur; coaceruati erut &longs;emper variæ formæ nu­merorum. quæ &longs;ic explicantur: &longs;int ab vnitate pares di&longs;po&longs;iti ordinatim hoc modo, 1. 2. 4. 6. &c. &longs;i igitur vnitati binarius coaceruetur, fit numerus
triangularis, vt in prima figura. &longs;i huic ternario coaceruetur &longs;equens par, fiet altera &longs;pecies, ni­mirum exagonus numerus, vt in &longs;ecunda figu­ra. cui &longs;i &longs;equens addatur par, &longs;cilicet &longs;enarius, fiet iterum noua numeri forma, v. g. dodecago­nus, vt in tertia figura. & &longs;ic &longs;emper in infinitum nouæ ac variæ numerorum formæ ex hac additione parium prouenient, quod argumento e&longs;t numerum parem infiniti naturam &longs;apere. Porrò reperiri numeros triangulares, pen­tagonos, & &longs;imiles, con&longs;tat ex Arithmetica Nicomachi, Boetij, & Iordani, citati in definitionibus 7. &longs;uæ Arithmeticæ, atque ex tractatu Diophantis Alex. de numeris rectangulis. atque ex his locus hic &longs;atis clarus redditur.

94

Tex. 31. (Vtuntur etiam Mathematici infinito) aliquando Mathematici du­cunt lineas quantumuis longas, &longs;eu indefinitæ longitudinis, quas etiam in­finitas appellant: & hoc modo vtuntur infinito, vt infra tex. 71. ip&longs;e Ari&longs;t. exponit. alio præterea modo vtuntur infinito, vt quando &longs;upponunt data quauis quantitate po&longs;&longs;e &longs;umi maiorem, vel etiam minorem in infinitum, vt patet ex 6. po&longs;tulato primi Elem. editionis Clauianæ. numerum quoque au­geri po&longs;&longs;e in infinitum, e&longs;t &longs;ecundum po&longs;tulatum libri 7. Elem. vel demum quando probant quamlibet lineam po&longs;&longs;e diuidi bifariam, quia hinc &longs;equitur po&longs;&longs;e &longs;ub diuidi in infinitum; his igitur modis Mathematicis infinitum in v&longs;u e&longs;t.

95

Tex. 68. & 69. plura de magnitudine, & numero continent; &longs;ed quæ non indigeant opera no&longs;tra.

96

Tex. 71. (Non remouet autem ratio Mathematicos à contemplatione auferens &longs;ic e&longs;&longs;e infinitum, vt actu &longs;it ver&longs;us augmentum, vt intran&longs;ibile, ncque enim nunc in­digent infinito, neque vtuntur, &longs;ed &longs;olum e&longs;&longs;e quantumunque velint fiaitam) ratio phy&longs;ica tollens infinitum actu, non e&longs;t Mathematicis impedimento, quia ip&longs;i non vtuntur infinito actu; quam enim ip&longs;i ducunt lineam infinitam, non e&longs;t verè infinita, &longs;ed indefinit, eam enim quantumlibet magnam producunt, vt po&longs;&longs;it ad demon&longs;trandum &longs;ufficere.

Ex Quarto Phy&longs;icorum.

97

Tex. 120. ter in hoc textu meminit commen&longs;urabilitatis, & incommen­&longs;urabilitatis, quæ e&longs;t diametri ad co&longs;tam: cuius explicationem vide primo Priorum, &longs;ecto primo, cap. 23.

Ex Quinto Phy&longs;icorum.

98

Tex. 6. (Vt media grauis ad vltimam, & acuta ad primam) alludit ad or­dinem chordarum in mu&longs;icis in&longs;trumentis, vbi media chorda edit &longs;o­num, re&longs;pectu quidem vltimæ, & &longs;upremæ chordæ grauem: re&longs;pectu verò primæ, & infimæ acutum.

Ex Octauo Phy&longs;icorum.

99

Tex. 15. (Etenim triangulus habet tres angulos æquales duobus rectis angulis)lib. 1. Priorum, &longs;ecto 3. cap. 1. huius rei explicationem reperies.

EX PRIMO DE COELO.

0

Tex. 33. (Vt &longs;i quis minimam quădam e&longs;&longs;e dicat magnitudinem, hic enim minimum introducens, maxima vbique amoueret mathematicorŭ) ide&longs;t, &longs;i quis, vt Democritus po&longs;uerit in magnitudinibus e&longs;&longs;e minima, &longs;eu indiui&longs;ibilia, ex quibus entia mathematica componerentur, hic euerteret maxima mathematicorum, ide&longs;t maxime ip&longs;orum demon&longs;tra­tiones, atque etiam effata euerterentur: v. g. 10. primi Elem. quæ docet quamlibet lineam po&longs;&longs;e diuidi bifariam nulla e&longs;&longs;et, quia linea illa, quæ con­&longs;taret ex tribus Democriti atomis, nulla ratione bifariam &longs;ecari po&longs;&longs;et. pa­riter totus ferè decimus liber Elem. deceptiuus, & nullus e&longs;&longs;et, &longs;i enim da­rentur illæ atomi, ex quibus quantitas conflaretur, nullæ e&longs;&longs;ent lineæ incom­men&longs;urabiles, quandoquidem omnes communi illa, ac indiuidua, commen­&longs;urarentur. po&longs;tulatum quoque illud, qualibet data magnitudine &longs;umi po&longs;&longs;e minorem pror&longs;us irritum redderetur, quia data atomo, illa minor accipi non po&longs;&longs;et.

101

Tex. 36. (Sit itaque linea, in qua A G E, infinita ad partes E; & alia vtrinque infinita, in qua b B; &longs;i itaque de&longs;cribat circulum linea A G E, cir ca centrum G, fe-

retur circulariter linea A G E, &longs;ecans ali­quando lineam b B, tempore finito; totum enim tempus, in quo circulariter latum e&longs;t Cœlum finitum e&longs;t, & ablatum igitur, quo &longs;ecans ferebatur; erit igitur aliqued prmcipium, quo primum linea A G E, li­neam b B, &longs;ecuit. &longs;ed impo&longs;&longs;ibile est; non est igitur circulariter verti infinit&, quare neque mundum, &longs;i e&longs;&longs;et infinitus) quamuis textus hic parum &longs;it mathematicus, quia tamen &longs;upponit figuram mathe­maticam, quæ in codicibus pariter, ac commentarijs de&longs;ideratur, illam pla­cuit apponere. in qua quidem, quamuis duæ lineæ infinitæ &longs;upponantur, vna ad alteram tantum partem in qua E: altera verò ad vtramque partem b, & B, non potuerunt tamen de&longs;cribi, ni&longs;i finitæ; appo&longs;itæ idcircò &longs;unt ad partes illas, ad quas deberent e&longs;&longs;e infinitæ lineolæ quædam infinitatem indicantes. debemus po&longs;tea, vt mentem Ari&longs;t. percipiamus concipere lineam A G E, moueri circulariter facto centro in G. quæ quia infinita &longs;upponitur ad par­tem E, &longs;ecabit nece&longs;&longs;ariò alteram vtrinque infinitam b B, illamque; nece&longs;&longs;ariò finito tempore percurret, finito enim tempore tota mundi circulatio per­agitur, &longs;patio videlicet viginti quatuor horarum. ex quo Ari&longs;t. infert mun­dum non po&longs;&longs;e e&longs;&longs;e infinitæ magnitudinis; quia &longs;i mundus e&longs;&longs;et infinitus; &. duæ lineæ infinitæ, quales &longs;unt prædictæ in ip&longs;o, atque cum ip&longs;o moueri alte­ra earum A E, intelligatur, alteram b B, manentem in tempore finito, ide&longs;t, in diurna conuer&longs;ione pertran&longs;ibit: fieri autem nequit, vt infinita magni­tudo finito tempore percurratur; quare dicendum e&longs;t, mundum e&longs;&longs;e finita magnitudine præditum.

102

Tex. 48. (Nihil autem refert grauitates, commen&longs;urabiles &longs;int, an incommen­&longs;ur abiles) quidnam &longs;it commen&longs;urabilitas, & incommen&longs;urabilitas, expli­catum e&longs;t lib. 1. Priorum, &longs;ecto 1. cap. 23.

103

Tex. 119. (Est autem impo&longs;&longs;ibile, & po&longs;&longs;ibile; fal&longs;um, & verum, ex &longs;uppo&longs;itio­ne quidem, dico autem, vt triangulum impo&longs;&longs;ibile e&longs;t duos rectos habere, &longs;i hæc)ide&longs;t, &longs;i &longs;upponantur fal&longs;a quædam, quæ &longs;upponi po&longs;&longs;unt, &longs;equetur impo&longs;&longs;i­bile e&longs;&longs;e triangulum habere tres angulos æquales duobus rectis angulis, vi­de, quæ &longs;crip&longs;i lib. 1. Priorum, &longs;ecto 3. cap. 1. de hoc, quod e&longs;t, habere tres angulos æquales duobus rectis. v. g. &longs;i in triangulo pag. 73. producto late­re A C, in D. &longs;i &longs;upponatur externus angulus B C D, non e&longs;&longs;e æqualis duobus internis, & oppofitis A, & B, nunquam poterimus eo modo, quo Euclides, demon&longs;trare pa&longs;&longs;ionem prædictam de triangulo A B C. huiu&longs;modi impo&longs;&longs;i­bile, cuius oppo&longs;itum non &longs;olum po&longs;&longs;ibile, &longs;ed etiam nece&longs;&longs;arium e&longs;t, vocat Ari&longs;t. impo&longs;&longs;ibile ex &longs;uppo&longs;itione, quia &longs;cilicet impo&longs;&longs;ibile euadit ex quo­dam fal&longs;o &longs;uo &longs;uppo&longs;ito, vt in allato exemplo, triangulum habere tres an­gulos æquales duobus rectis, quamuis nece&longs;&longs;arium &longs;it, tamen ex fal&longs;a &longs;up­po&longs;itione, impo&longs;&longs;ibile oua&longs;it.

104

Ibidem (Et diameter commen&longs;urabilis est co&longs;tæ, &longs;i bæc) vide primo Priorum, &longs;ecto 3. cap. 23. hoc &longs;olum nunc addendum (Si hæc) v. g. &longs;i &longs;upponamus li­neas e&longs;&longs;e compo&longs;itas ex indiui&longs;ibilibus, con&longs;ectarium erit diametrum e&longs;&longs;e commen&longs;urabilem co&longs;tæ, quia indiui&longs;ibile illud, ex quo vtraque linea con­&longs;tat, erit vtriu&longs;que men&longs;ura communis.

Ex Secundo de Cælo.

105

Tex. 24. (Amplius qui &longs;olida diuidunt in plana, atque ex planis corpora generant, his te&longs;tes fui&longs;&longs;e videntur: &longs;olam enim figurarum &longs;olidarum &longs;phæram non diuidunt, vt non plures &longs;uperficies. quam vnam habenum. diui&longs;io enim in plana non perinde e&longs;&longs;icitur, vt qui&longs;piam diuidens in par­tes diuidat totum, &longs;ed vt in &longs;pecie diuer&longs;a: patct igitur &longs;phæram e&longs;&longs;e &longs;olidarum primam) qui &longs;olida diuidunt in plana, ca diuidunt &longs;ecundum numerum &longs;uper­&longs;icierum, quibus ambiuntur, v. g. diuidunt cubum in &longs;ex &longs;uperficies, quia cubus &longs;ex quadratis planis &longs;uperficiebus continetur: qua ratione nequcunt &longs;ohæram in plana vlla re&longs;oluere, neque in alias plures &longs;uperficies, quia &longs;phæ­ra ambitur vnica tantum &longs;uperficie &longs;phærica. quando verò ex planis corpo­ra generant, vt facit Plato in Timæo, accipíunt primò triangulum æquila­terum, & ex quatuor triangulis æquilateris &longs;imul compactis conficiunt py­ramidem; & hoc modo alia &longs;olida à pluribus &longs;uperficiebus ambita con&longs;ti­tuunt: verum hac ratione nullo modo po&longs;&longs;unt &longs;phæram componere, quia vnica tantum, eaque; &longs;phærica &longs;uperficie compræhenditur: atque hoc pacto i&longs;ti diuidentes, & componentes corpora fidem faciunt, &longs;phæram, cum ex nullis componatur, &longs;olidorum e&longs;&longs;e primam.

106

Tex. 25. (Est autem, & &longs;ecundum numerorum ordinem a&longs;&longs;ignantibus, &longs;ic po­nentibus rationabili&longs;&longs;imam, circulum quidem &longs;ecundum vnum; triangulum autem &longs;ecundum dualitatem, quoniam duo recti. &longs;i autem &longs;ecundum triangulum, vnum. circulus non erit figura) In ordine figurarum conueniens e&longs;t, inquit, primam facere circulum propter &longs;implici&longs;simam ip&longs;ius naturam, cum vnica, ac per­fecta circulari linea comprehendatur: Triangulum verò &longs;ecundam, quoniam duo anguli recti, ide&longs;t, quia triangulum habet tres angulos æquales duobus rectis angulis; quod fusè explicatnm e&longs;t lib. 1. Priorum, &longs;ecto 3. cap. 1. De­mum &longs;i primum locum dederimus triangulo, nullus alius remanet pro cir­culo, quod e&longs;t inconueniens, ergo circulus prima figura erit.

107

Tex. 31. (At verò, quod aquæ &longs;uperficies talis &longs;it, manife&longs;tum e&longs;t hac &longs;uppo&longs;i­tione &longs;umpta, quod apta natura e&longs;t &longs;emper conluere aqua ad magis concauum: ma­gis autem concauum e&longs;t, quod centro propinquius est. ducantur ergo ex centro A,

linea A B, & linea A C, & producatur, in qua B C, duct igitur ad ba&longs;im linea, in qua A D, minor e&longs;t eis, quæ ex centro. magis igitur concauus locus e&longs;t, quare influet aqua, donec vtique æquetur. æqualis e&longs;t autem eis, quæ ex centro linea A E, quare nece&longs;&longs;e e&longs;t apud eas, quæ ex centro, e&longs;&longs;e aquam, tunc enim quie&longs;cet. linea autem, quæ eas, quæ ex centro tangit, circularis e&longs;t, &longs;phærica igitur aquæ &longs;uperficies e&longs;t, in qua B E C.) toto hoc textu lineari demon&longs;tratione probat aquæ manen­tis &longs;uperficiem e&longs;&longs;e &longs;phæricam: quæ demon&longs;tratio per&longs;picua euadit, &longs;i &longs;igura, quæ in codicibus tam græcis, quam latinis, atque etiam in commentarijs de&longs;ideratur, quemadmo­dum fecimus, re&longs;tituatur. &longs;it igitur in præcedenti figura A, centrum mundi, ex quo educantur duæ rectæ lineæ æquales A B, A C, quæ deinde alia recta B C, coniungantur. educatur quoque recta alia ex centro A, quæ pertingat ad B C, quæ ba&longs;is e&longs;t trianguli B A C, & producatur vlterius quantumlibet in E. intelligatur demum circumferentia tran&longs;ire per puncta B, & C, quia illæ duæ lineæ A B, A C, &longs;unt æquales, quæ circumferentia alteram A D, quæ fuit protracta, &longs;ecet in E. Iam &longs;ic argumentatur: aqua natura &longs;ua &longs;emper de&longs;luit ad locum magis concauum, ide&longs;t, ad loca centro A, terræ propin­quiora, quale e&longs;&longs;et in figura locus D, re&longs;pectu locorum B, & C, quia A D, linea minor e&longs;t ijs, quæ ex centro eductæ &longs;unt A B, A C. quapropter aqua debet de&longs;luere ex B, ad D, vel ex C, ad idem D, donec pertingat ad E. qui locus non e&longs;t decliuior punctis B, & C. quare cum loca B, E, C, quæ &longs;unt ex­trema linearum, &longs;int æquè decliuia, nece&longs;&longs;e e&longs;t aquæ &longs;uperficiem apud ip&longs;a con&longs;i&longs;tere, tunc enim debet quie&longs;cere, aliter nunquam quie&longs;ceret; &longs;ed vide­mus aquam manentem, & quietam, ergo quie&longs;cit circa puncta B, E, C, à centro terræ æquidi&longs;tantia, per quæ tran&longs;it linea circularis coniungens illa; et&longs;i &longs;uperficies per eiu&longs;modi loca pertran&longs;iret, e&longs;&longs;et &longs;phærica: &longs;ed &longs;uper&longs;i­cies aquæ tran&longs;it per talia loca, ergo &longs;phærica e&longs;t. Huius etiam habes acu­ti&longs;&longs;imam Archimedis demon&longs;trationem initio libelli de ijs, quæ vehuntur in aqua, quam in &longs;uam &longs;phæram retulit Clauius.

108

Tex. 46. (Reliquum e&longs;t orbes quidem moueri, stellas verò quie&longs;cere, & infixas ip&longs;is orbibus ferri; &longs;olum enim &longs;ic nullum ab&longs;urdum accidit. celeriorem enim e&longs;&longs;e maioris circuli velocitatem, rationabile e&longs;t circa idem centrum infixis: vt enim in alijs maius corpus velocius fertur propria latione, &longs;ic, & in circularibus: maius enim e&longs;t eorum, quæ auferuntur b eis, quæ ex centro, maioris circuli &longs;egmentum)ex intellectione vltimæ periodi textus totius intelligentia pendet: &longs;it igitur

figura præ&longs;ens, in qua cum &longs;int duo circuli concen­trici, vnus altero maior, eductæque; &longs;int ex centro duæ &longs;emidiametri A D, A E, quæ vtrunque circulum &longs;e­cant, apparet maius e&longs;&longs;e &longs;egmentum D E, quod è ma­iori circulo &longs;emidiametri ex centro eductæ auferunt, quam &longs;egmentum B C, minoris circuli, quod ei&longs;dem &longs;emidia metris intercipitur. Verumtamen &longs;i circuli ambo &longs;imul moueantur, maior circulus æquali tem­pore maius illud &longs;patium D E, & minor minus B C, pertran&longs;ibit: idem igitur de cœle&longs;tibus orbibus di­cendum, qui quamuis omnes diurnum &longs;imul motum ab&longs;oluunt, maiores tamen celerius conuertuntur: quo fit, vt &longs;tellæ maiori­bus circulis infixæ, atque delatæ, maiori celeritate &longs;uos cur&longs;us peragant, ne­que oportet eas, dum mouentur cœlum di&longs;&longs;ecare, quod accideret, &longs;i pro­prio motu veluti pri&longs;ces per aquam progrederentur.

Hæc quidem Ari&longs;t. con&longs;entanea ob&longs;eruationibus veterum A&longs;tronomo­rum; at verò illis no&longs;træ ætatis ob&longs;eruationes repugnant; præ&longs;ertim illæ, quæ fiunt circa &longs;tellas errantes: ex quibus fatendum e&longs;&longs;e videtur, Cœlum, qua parte Planetas continet, liquidum e&longs;&longs;e, ac per illud Planetas proprio motu, ceu pi&longs;ces in aqua progredi. Tycho namque Brahe, alijque; plures exactè demon&longs;trant Cometas in regione Planetarum e&longs;&longs;e, eosque; motu quodam in tran&longs;uer&longs;um moueri, quo nece&longs;&longs;ario C&ecedil;lú deberent perforare; ijdem o&longs;ten­dunt nonnullos Planetas, Martem præ&longs;ertim, ac Venerem modo &longs;upra So­lem, modo infra a&longs;cendere, & de&longs;cendere. Idem patet ex ob&longs;eruatione no­ua per nouum Tele&longs;copij i &longs;trumentum in Venere facta, quæ lunulata vtrinque à Sole apparet: quando nimirum e&longs;t in imo epicyclo. iterumque; rotunda ve­luti Luna plena, cum in &longs;ummo epicyclo ver&longs;atur: quæ minimè apparerent, ni&longs;i &longs;upra, ac infra Solem circumiret. His rationibus conantur ip&longs;i proba­re Cœlum e&longs;&longs;e liquidum; atque in eo Planetas, veluti aues in aere, permearc: quarum &longs;olutio mihi nulla occurrit, alijs forta&longs;&longs;is occurrct.

109

Tex. 57. (De ordine autem ip&longs;orum, quo quidem modo &longs;ingula di&longs;penantur, vt quædam &longs;int priora, quædam posteriora, & quomodo &longs;patijs &longs;e hbeă ad inuicem,ex ijs circa A&longs;trologiam, con&longs;ideretur: dicitur enim &longs;ufficienter) &longs;umit hoc loco A&longs;trologiam, pro A&longs;tronomia, &longs;i iuxta recentiores loqui velimus. Dicit igi­tur ordinem cœlorum, ac &longs;yderum, item &longs;itum, & proportiones magnitu­dinum corundem, cum per naturalis &longs;cientiæ princip ia &longs;ciri nequeant, ex rationibus A&longs;tronomorum petenda e&longs;&longs;e, apud quos i&longs;ta &longs;ufficienter demon­&longs;trentur. & meritò quidem hæc dicuntur; po&longs;teriores enim ab Ari&longs;t. ordines, &longs;itus, ac magnitudines tam cœlorum, quam &longs;yderum firmis rationibus, atque inuentu peracutis demon&longs;trarunt. quorum princeps fuit ptolæmeus; no&longs;tra tamen ætate Tycho Brahe, qui certis ob&longs;eruationibus, quas maximo labo­re, ac &longs;umptu exantlauit, in nonnullis à Ptolæmeo, ac reliquis di&longs;&longs;entjt: &longs;tan­dum autem e&longs;&longs;e recentioribus ob&longs;eruationibus apud A&longs;tronomiæ peritos in confe&longs;&longs;o e&longs;t.

110

Tex. (Luna autem o&longs;tenditur per ea, quæ circa vi&longs;um, quod &longs;phærica &longs;it: non enim vtique fieret accre&longs;cens, & decre&longs;cens, plurimŭ quidem alter a ex parte curua, altera concaua, aut vtrmque curua, &longs;emel autem bipartita) ait per ea, quæ circa vi&longs;um, ide&longs;t per opticem probari Lunam e&longs;&longs;e &longs;phæricam: &longs;ed con&longs;ule, quæ primo Po&longs;ter. tex. 3. de hac re &longs;crip&longs;i, & plenam etiam huius loci intelligen­tiam a&longs;&longs;equeris, præ&longs;ertim &longs;i experimentum ibi traditum inieris.

111

Ibidem (Et rur&longs;us per Astrologica, quia vtique non e&longs;&longs;ent &longs;olis eclyp&longs;es lunulæ &longs;peciem præ&longs;eferentes. Quare &longs;i vnum est tale, palam e&longs;t, quod & alia vtique erunt talia) &longs;icuti præcedens &longs;phæricitatis Lunæ ratio ex Per&longs;pectiua de&longs;umpta e&longs;t, ita præ&longs;ens ex A&longs;tronomia, ex eò enim, quod eclyp&longs;is Solis habeat figuram lunulæ, ide&longs;t, &longs;i in&longs;tar Lunæ falcatæ, probant A&longs;tronomi Lunam e&longs;&longs;e &longs;phæri­cam. intellige tamen partem illam Solis, quæ non eclyp&longs;atur, habere figu­ram lunulæ, pars enim à Luna obumbrata non videtur, et&longs;i videretur oua­lem quandam &longs;peciem, præ&longs;eferret: pars igitur, illa e&longs;t corniculata, quia

cum Solis defectio ex interpo&longs;itione Lunæ inter nos, & Solem contingat, & Luna &longs;it &longs;phærica, nece&longs;&longs;ariò &longs;phæ­ricè, & circulariter Solem obumbrabit; quare pars illa non obumbrata remanet falcata, & corniculata, vt in præ&longs;enti figura vidcre e&longs;t; vbi cernis, Lunam Solem or­biculariter offu&longs;care in linea A D C, partem Solis de­tectam contentam lineis curuis A B C D, e&longs;&longs;e lunularem, & falcatam; cum ergo in hunc modum fiat Solis deli­quium, &longs;ignum certum e&longs;t, Lunam e&longs;&longs;e &longs;phæricam.

112

Tex. 107. (Quod autem dubitatur, hoc e&longs;t; videre autem non e&longs;t difficile, &longs;i pa­rum con&longs;iderauerimus, & di&longs;tinxerimus, quonam modo cen&longs;eamus quantamuis ma­gnitudinem grauem ad medium ferri. manife&longs;tum enim e&longs;t, quod non quou&longs;que ex­tremum tangat ip&longs;um centrum; &longs;ed maior pars vincat, oportet, quou&longs;que &longs;uo medio ip&longs;um medium compræhendat; hucn&longs;que enim habet propen&longs;ioncm) &longs;en&longs;us Ari&longs;to­telis e&longs;t, debere nos exi&longs;timare, quod &longs;i quæpiam grauis magnitudo de&longs;cen­dat ad centrum mundi, eam non perman&longs;uram, &longs;latim ac ip&longs;ius extremum centrum mundi attigent; &longs;ed cò v&longs;que de&longs;cen&longs;uram, quou&longs;que ip&longs;ius medium, mundi medium, &longs;iue centrum a&longs;&longs;equutum &longs;it; maior enim ip&longs;ius pars, in qua &longs;cilicet medium e&longs;t, minorem partem propellit, donec vtrinque à centro mundi æquè emineat; omne enim graue hucu&longs;que habet propen&longs;ionem, &longs;iue hucu&longs;que grauitat, v. g. &longs;i lapis illuc de&longs;cenderet, non quie&longs;ceret &longs;tatim ac prima ip&longs;ius pars ad mundi centrum pertingeret, &longs;ed reliquæ ip&longs;ius partes adhuc grauitarent, &longs;icque; vlterius primam partem impellerent, donec lapi­áis medium, mundi medio congrueret: quo facto lapis quie&longs;ceret. quæ num vera &longs;int, vt intelligamus, oportet prius præmittere, iuxta Mathematicos duplex e&longs;&longs;e medium, &longs;iue centrum cuiu&longs;uis magnitudinis: aliud enim e&longs;t centrum molis, aliud e&longs;t centrum grauitatis. centrum molis e&longs;t illud pun­ctum, à quo extrema æquidi&longs;tant: centrum grauitatis e&longs;t punctum illud, à quo extrema æque ponderant, &longs;iue à quo graue &longs;u&longs;pen&longs;um æquè ponderat, &longs;iue in æquilibrio manet. Porrò in corporibus regularibus, &longs;i vnifo mia &longs;int idem, & vnum &longs;unt centrum molis, ac centrum grauitatis: vt in &longs;phæra plumbea, idem crit vtrumque centrum: &longs;i verò difformia &longs;int in grauitate, vt in &longs;phæra partim plumbea, partim lignea, diuer&longs;um erit centrum molis, à centro grauitatis; illud enim erit in medio &longs;phæræ; centrum verò graui­tatis in parte plumbea exi&longs;tet. In corporibus deinde irregularibus, etiam&longs;i &longs;int vniformis ponderis, aliud tamen e&longs;&longs;e pote&longs;t centrum molis à centro gra­uitatis, vt in corpore oblongo, cuius alterum extremum &longs;it reliquis parti­bus multò maius, vti e&longs;t claua: vbi centrum molis erit in medio longitudi­nis clauæ; centrum verò grauitatis, erit propinquius capiti clauæ. quando igitur Ari&longs;t. ait, graue de&longs;cen&longs;urum, donec ip&longs;ius medium, &longs;iue centrum, mundi centrum attingat; benè dicit, &longs;i de medio grauitatis intelligat; ma­lè autem &longs;i de medio molis. quia grauia omnia ratione centri grauitatis ponderant, neque manent; ni&longs;i ip&longs;um maneat: quare ni&longs;i ip&longs;um attingant cen­trum mundi &longs;emper grauitabunt, & mouebuntur. Verum enim verò ex an­tiquorum monumentis manife&longs;tum e&longs;t, Archimedem, qui multò po&longs;t Ari­&longs;totelem floruit, primum omnium de centro grauitatis e&longs;&longs;e philo&longs;ophatum, qua ratione dicendum e&longs;&longs;et, Ari&longs;totelem de centro, molis loquutum e&longs;&longs;e, & perinde non v&longs;quequaque verè.

113

Tex. 109. (Præterea quoque & per ta, quæ apparent &longs;ecundum &longs;en&longs;um, neque enim Lunæ eclyp&longs;es tales haberent deci&longs;iones; nunc enim in ijs, quæ &longs;ecundum men­&longs;em fiunt, figurationibus, omnes accipit diui&longs;iones: etenim recta fit, & vtrinque curua, & concaua) probat terram e&longs;&longs;e &longs;phæricam ratione a&longs;tronomica, ex Lunæ eclyp&longs;ibus de&longs;umpta: nam ni&longs;i terra e&longs;&longs;et rotunda, nunquam Luna in eclyp&longs;i haberet tales deci&longs;iones, ide&longs;t non haberet falcatas, aut lunulatas partes illas, quæ in eclyp&longs;i ob&longs;curantur, & quafi à Luna re&longs;ecantur. quam­uis enim &longs;ingulis men&longs;ibus Luna terminetur modo linea concaua, vt quan­do noua e&longs;t; modo recta, vt quando diuidua e&longs;t: modo vtrinque curua, vt cum à diuiduæad plenilunium tendit. quod fu&longs;ius primo Po&longs;ter. tex. 30. ex­po&longs;ui. in eclyp&longs;ibus tamen &longs;emper curuam habet lineam illam, quæ partem ec'yp&longs;atam de&longs;init; vt paulo po&longs;t explicabo. Vide precedentem textum 59. & ca, quæ ibi annotaui, quæque tibi propo&longs;ui, & plenam huius loci intelligen­tiam a&longs;&longs;equeris. vide etiam, quæ mox &longs;ubdam circa huius loci reliquum.

114

Ibidem (Circa autem eclyp&longs;es, &longs;emper curuam habet terminătem lmeam: qua­re qaon'am eclyp&longs;im palitur propter terræ obiectionem, terræ circumferentia &longs;phæ­rica exi&longs;tens, figuræ cau&longs;a erit) probat rotunditatem terræ ab eclyp&longs;i lunari, ex eo, quod Luna &longs;phæricè eclyp&longs;etur, quod innuitur illis verbis, &longs;emper curuam hzbet terminantem lineam, linea &longs;cilicet, quæ terminat partem eclyp&longs;atam à non eclyp&longs;ata, &longs;emper apparet circularis; cum autem hæc li­nea &longs;it terminus vmbræ terræ, quæ lumen obumbrat, &longs;ignum manife&longs;tum e&longs;t vmbram ip&longs;am e&longs;&longs;e rotundam; nam cum Luna deficiat propter terræ obie­ctionem inter ip&longs;am, & Solem, ita, vt vmbra terræ protendatur v&longs;que ad Lu­nam, eamque; in omni eclyp&longs;atione, &longs;iue eclyp&longs;is &longs;it &longs;upra terram, &longs;iue infra, ad quamlibet denique partem terræ fiat, orbiculariter eam contegit, &longs;ignum per&longs;picuum e&longs;t terram proijcere quoquouer&longs;us vmbram rotundam, quæ vt in &longs;phæra o&longs;tenditur, e&longs;t rotunda ad modum coni; cum ergo vmbra terræ ex quauis parte proijciatur, &longs;it rotunda, certò certius colligitur, terramque; quoque ip&longs;am rotunda &longs;igura præditam e&longs;&longs;e. hanc eandem rationem, &longs;i libue­rit, fu&longs;ius pertractatam videre poteris apud P. Clauium in &longs;phæra.

115

Tex. (Præterea per astrorum apparentiam, non &longs;olum manife&longs;ium e&longs;t, quod re­tunda, &longs;ed & quod magnitudine non magna &longs;it; paruo enim facto ncbis tran&longs;itu ad meridiem, & Vr&longs;am, manifa&longs;tè fit alter horizon circulus, ita vt a&longs;tra, quæ &longs;uper caput, magnam habcant mutationem, & non eadem appareant, & ad Vr&longs;am, & ad meridiem tran&longs;euntibus, quædam enim in Acgypto quidem stellæ videntur, & cir­ca Cyprum, in ijs autem, quæ ad Vr&longs;am vergunt regionibus, non viaentur. & a&longs;tro­rum ea, quæ &longs;emper in ijs, quæ ad Vr&longs;am vergunt, apparent, in illis locis occidunt. Quare non &longs;olum ex his manife&longs;tum e&longs;t rotundam e&longs;&longs;e figuram terræ, &longs;ed & &longs;phæræ non magnæ: non enim tam celeriter in&longs;igne quippiam faceret, tran&longs;latis nobis adeò parum) hic textus ei, qui &longs;phæram mundi audiuerit perfacilis e&longs;t: propte­rea eum breuiter &longs;ic paraphra&longs;ticè exponam. Terram e&longs;&longs;e rotundam, atque re&longs;pectu cœle&longs;tium corporum non magnam, &longs;ignum e&longs;t, quod facto à nobis paruo itinere &longs;iue ad meridionalem plagam, &longs;iue ad &longs;eptentrionalem (quam Vr&longs;am dicit) magnopere mutatur horizon: quod apparet primo ex varia­tionc a&longs;trorum, nam quæ in primo loco &longs;upra no&longs;trum verticem tran&longs;ibant, in &longs;ecundo loco non amplius, &longs;ed alia, atque alia valde ab inuicem &longs;eiuncta

exfacto quamuis paruo itinere tran&longs;eunt. &longs;it in præ&longs;enti figura terra, vbi A, in qua facta parua mutatione ex loco F, in locum G, fieret magna mutatio a&longs;trorum ver&longs;icalium B, in C, quæ mul­tum ab inuicem di&longs;tant. &longs;i autem terra e&longs;&longs;et maior, v. g. circulus medius, tunc facta maio­ri mutatione ex D, in E, fieret eadem a&longs;trorum variatio ex B, in C; &longs;ed cum nos experiamur &longs;ieri magnam a&longs;trorum mutationem, ex parua locorum intercapedine, &longs;ignum e&longs;t magnope­re mutari horizontem, ac proinde terram e&longs;&longs;e rotundam, ac re&longs;pectu cœle&longs;tium corporum paruam. aliud præterea &longs;ignum hums horizontis permutationis e&longs;t, quod &longs;tellæ, quæ in priori loco &longs;upra horizontem apparebant, mutato paululum loco ad alterutram plagam, &longs;tatim ab&longs;conduntur; aliæ verò nouæ apparent vt in Acgypto, & Cypro, &longs;tella, quæ dicitur Canobus &longs;upra horizontem a&longs;cendit; quæ &longs;i paululum Vr&longs;am, &longs;eu &longs;eptentrionem ambulaueris, &longs;tatim latitabit. Demum ciu&longs;dem citæ mutationis &longs;initoris indicium etiam &longs;it, quod regiones &longs;eptentrionales incolentibus plurima &longs;unt a&longs;tra, quæ nun­quam occidunt, quamuis horizontem leuiter per&longs;iringant, quæ tamen Cy­prijs, atque Aegyptijs oriuntur, atque occidunt. ex quibus & rotunditas, & paruitas terræ colligi pote&longs;t. has ea&longs;dem rationes fu&longs;ius explicatas repe­ries apud P. Clauium in &longs;phæra.

116

Tex. 111. (Quapropter existimantes eum, qui circa Herculcas columnas e&longs;t lo­cum coniungi ei, qui circa Indiam, & boc modo mare vnum e&longs;&longs;e, nen admcdum incredibilia exi&longs;timare videntur &c.) exi&longs;timatores ho&longs;ce non perperam exi­&longs;tima&longs;&longs;e apertè conuincunt Chri&longs;tophori Columbi, Argonautarum principis nauigationes; quibus nouus orbis repertus e&longs;t, qui inter columnas Hercu­lis, atque orientalem Indiam totus vna cum mari Oceano Atlantico interiacet.

117

Tex. 112. (Matbematicorum etiam, qui circum ferentiæ magnitudinemratio­cinari tentant, ad 400. dicunt ftadiorum millia, &c.) quam &longs;ubtilibus rationi­bus inue&longs;tigauerint A&longs;tronomi quantitatem terræ, optimè, ac dilucidè ex­ponitur à P. Clauio in &longs;phæra: quem &longs;i libet, con&longs;ule, ne inani labore opu­&longs;culum i&longs;tud exere&longs;cat.

Ex Tertio de Cœlo.

118

Tex. 40. (Figuræ autem omnes componuntur ex pyramidibus: rectilinea quidem ex rectilmeis: fphæra verò ex octo partibus componitur) Ale­xander exiftimat, Ari&longs;totelem dicere &longs;phæram con&longs;tare ex octo partibus illis, quæ de&longs;ignantur per tres circulos, quorum duo &longs;e­cant &longs;e mucuò ad angulos rectos, vt in &longs;phæra mundi faciunt duo coluri; tertius verò medios illos diuidit æquidi&longs;tanter à &longs;ectionibus illorum mutuis, quemadmodum æquator in &longs;phæra mundi &longs;ecat duos coluros. ex quibus &longs;e­ctionibus tota &longs;phæra in octo partes diuiditur, quibus &longs;phæram componi vult Ari&longs;toteles. aduerte tamen hanc &longs;phæræ compo&longs;itionem nullo modo habere partes actu, cum &longs;phæra &longs;it vnica &longs;implici &longs;uperficie terminata; &longs;ed quæ tantum &longs;int à prædictis imaginatis circulis de&longs;ignatæ: at verò aliæ fi­guræ, quæ pluribus planis terminantur, vt cubus, octaedrum, & &longs;imilia, quæ Ari&longs;t. vocat rectiliheas, quia terminantur &longs;uperficiebus rectilineis actu di­&longs;tinctis ab inuicem ex natura &longs;ua, non per no&longs;tram de&longs;ignationem, ideò re­ctè dicuntur componi ex pyramidibus, v. g. dicimus cubum componi ex &longs;ex pyramidibus, quia cum habeat &longs;ex ba&longs;es, cogitamus &longs;upra vnamquamque il­larum &longs;ingulas pyramides erigi, quarum omnium vertices ad idem punctum medium intra cubum imaginatum coeant. & &longs;ic de reliquis &longs;olidis. quæ qua ratione re&longs;oluantur in plures pyramides, con&longs;tat ex 10. 11. 12. & 13. Ele­mentorum Euclidis, at verò in &longs;phæra nullum reale compo&longs;itionis, aut di­ui&longs;ionis fundamentum reperitur.

119

Tex. (Ad hæc nece&longs;&longs;e e&longs;t non omne corpus e&longs;&longs;e diui&longs;ibile dicere, &longs;ed repugnare certi&longs;&longs;i nis &longs;cientijs; nam Mathematicæ ip&longs;um quideæ intelligibile, accipiunt diui­&longs;ibile) ip&longs;um intelligibile, ide&longs;t, quantitatem ab&longs;tractam tam continuam, quam di&longs;eretam, quam &longs;tatuunt Philo&longs;ophi e&longs;&longs;e &longs;ubiectam materiam ma­thematicarum. quam ideo appellant intelligibilem, quia cum &longs;it ab&longs;tracta per intellectum à &longs;en&longs;ibilibus affectionibus, re&longs;tat vt &longs;it tantummodo intel­lectu perceptibilis. Hanc eandem &longs;upponunt e&longs;&longs;e diui&longs;ibilem in infinitum, vt &longs;upra 3. Phy&longs;. textu 31. dictum e&longs;t.

120

Tex. 66. (Ommnò autem eniti &longs;implicibus corporibus figur as tribuere irratio­nabile e&longs;t. primò quidem, quia accidit non repleri totum; nam in planis tres figuræ videntur implere locum, Triangulus, Quadratum, & Sexangulus) per &longs;implicia corpora intelligit quatuor elementa. Vult enim probare quatuor elemen­ta non habere figuras illas mathematicas, quas illis Plato tribuebat, vt au­tem Ari&longs;t. rationem probè percipiamus, &longs;ciendum, quod implere totum, &longs;iue locum, illæ figuræ dicuntur, quæ &longs;imul &longs;uis angulis in plano quopiam ad vnum, atque idem punctum vnitæ locum illum totum, qui cirea punctum il­lud con&longs;i&longs;tit, contegunt, ita vt nihil vacui inter ip&longs;as relinquatur. tales &longs;unt, quibus fieri po&longs;&longs;unt pauimenta, oportet enim, vt &longs;imul vnitæ nihil vacui in pauimento relinquant. huiu&longs;modi &longs;unt triangula æquilatera (de his enim intelligendus e&longs;t textus) quadrata, & hexagona, &longs;iue &longs;exilatera regularia;

nam &longs;ex triangula æquilatera &longs;imul iuncta in plano paui­re po&longs;&longs;unt, vt patet in figura præ&longs;enti; ratio huius e&longs;t, quia omnes anguli circa idem punctum (y. g. A, in hac figura) in plano, quotquot fuerint con&longs;tituti, &longs;unt æqua­les quatuor rectis, ex coroll. &longs;ecundo 15. primi Elemen­ti: cum igitur &longs;ex anguli, trianguli æquilateri æquiualeant quatuor rectis angulis, con&longs;tituti omnes circa punctum A, totum locum circa illud implere po&longs;&longs;unt. Quadratum etiam replere lo­
cum manife&longs;tum e&longs;t, cum enim ip&longs;ius anguli &longs;intrecti, &longs;i quatuor quadrata ad idem punctum A, copulentur, vt in figura apparet, replebunt eadem de cau&longs;a vacuum.

Hexagonum quoque regulare, ide&longs;t æquilaterum, & æquiangulum idem præ&longs;tare pote&longs;t; cum enim tres angu­li ip&longs;ius æquiualeant quatuor rectis, &longs;i tria hexagona ad idem punctum A, vt in &longs;igura adaptentur, nece&longs;&longs;ariò ni­hil vacui inter ip&longs;a relinquetur, vt in figura hac o&longs;tenditur. præter has tres

figuras, nulla alia reperitur, quæ i&longs;tud efficere pol­&longs;it. cuius demon&longs;trationem perfectam videre pote­ris in fine commentarij P. Clauij &longs;uper 4. Elem. nos ea tantum attingimus, quæ percipi po&longs;&longs;int ab homi­ne vix mathematicis tincto: &longs;ed tamen, quæ &longs;en&longs;um Ari&longs;totelis patefaciunt. Aliæ porrò figuræ replen­tes locum planum, quibus aliquando Architectores vtuntur, vel &longs;unt irregulares, vel ad prædictas redu­ci po&longs;&longs;unt. cum igitur tres tantum ex figuris planis totum repleant, hæ &longs;olæ poterunt elementis attri­bui, ac propterea non &longs;ufficient, ni&longs;i pro tribus elementis. quare quartum ab&longs;que figura relinquetur; quod e&longs;t ab&longs;urdum.

Admirabilis quædam A&pgrave;um industria.

Cæterum occa&longs;ione harum figurarum illud hoc loco apponere vi­&longs;um e&longs;t, quod Pappus Alexandrinus initio quinti libri collectionum mathematicarum &longs;cribit, De admirabili Apum indu&longs;tria, atque prudentia in con&longs;truendo &longs;uas cellulas figura hexagona regulari. cum enim vellent omne vacuum excludere, & præterea capaci&longs;&longs;imam om­nium figuram habere, hexagonam accepere, quæ inter prædictas tres vtrum­que præ&longs;tat, nam & inane omne excludit, & illarum trium capaci&longs;&longs;ima e&longs;t, cum magis ad circularem figuram accedat: vt patet ex tractatu de figuris I&longs;operimetris, qui e&longs;t apud Clauium in &longs;phæra, necnonin Geometria pra­ctica. hoc ideò libentius recen&longs;ui, quia animaduerti naturales hi&longs;toriogra­phos omnes latere, vel ip&longs;um Aldobrandum no&longs;trum, qui quamuis indu­&longs;trio&longs;æ Apis in&longs;tar omnia delibauerit, i&longs;tud tamen de Apibus artificium tan­ta &longs;apientia plenum, ne&longs;cio quo modo prætermi&longs;it.

121

Ibidem (In folidis verò duæ &longs;oum pyramis, & cubus) ide&longs;t replent locum &longs;olidum. nullum reperi, qui in hoc loco explicando non errauerit; nam Græ­ci, qui alioqui &longs;olent mathematica probè intelligere, hic omnes lap&longs;i &longs;unt, &longs;ecumque; & Arabes, & Latinos in eandem foueam &longs;upra &longs;e mi&longs;erè traxerunt. communis ferè error omnium fuit, pyramides plures &longs;imul compactas po&longs;­&longs;e replere &longs;olidum locum. quod vt melius intelligamus, &longs;ciendum e&longs;t, reple­re locum &longs;olidum nihil aliud e&longs;&longs;e, quam &longs;i plura corpora &longs;olida &longs;imul ad idem punctum coaptata, ita con&longs;tipentur, vt totum &longs;patium, quod e&longs;t circa pun­ctum illud omninò occupent, hoc e&longs;t, nihil vacui inter ip&longs;a relinquatur: &longs;i­cut enim prædictæ tres &longs;iguræ planæ, de quibus paulò ante, replent locum planum, ide&longs;t &longs;uper&longs;iciem; ita cubi replent &longs;olidum, ide&longs;t &longs;oliditatem &longs;imul vniti con&longs;tituunt, ita vt &longs;i octo cubi &longs;imul ad idem punctum coaptentur, con­&longs;tituant corpus &longs;olidum ex octo illius con&longs;latum, nihilque; inane inter ip&longs;os cubos relinquatur. & &longs;icuti planæ illæ figuræ erant conficiendis pauimentis aptæ, ita &longs;olidæ hæ muris, qui corpora &longs;unt &longs;olida, con&longs;truendis idonea &longs;unt. Notam dum præterea, quod per pyramidem debemus intelligere pyramidem regularem, quæ dicitur etiam Tetraedrum, e&longs;tque; &longs;ecunda inter quinque cor­pora regularia rectilinea, quæ alias Platonica corpora dicuntur. eorumque; defraitiones &longs;unt in 11. Elem. Tetraedrum autem &longs;ic definitur, e&longs;t figura &longs;o­lida &longs;ub quatuor triangulis æquilateris, atque inuicem æqualious contenta: de hac inquam e&longs;t &longs;ermo. quia &longs;i liceret intelligere de irregularibus figuris, infinitæ reperir entar figuræ tam planæ, quam &longs;olidæ, quæ vtrumque locum complerent. Aduertendum tandem Ari&longs;t. videri loqui de repletione loci &longs;olidi, quia tran&longs;it à planïs figuris ad &longs;olidas. & quia &longs;i hæ duæ pyramis, & cubus replent locum &longs;olummedo &longs;ecundum &longs;uas &longs;uperficies, quæ &longs;unt trian­gulum, & quadraum, iam de his cum proximè ante dixi&longs;&longs;et, quid opus fui&longs;­&longs;et idem po&longs;t modum repetere. ad hæc &longs;i in medium &longs;olida hæc duo profert, aitque; ip&longs;a replere locum, intelligens, planum, profectò non loquitur forma­liter, ide&longs;t de ip&longs;is, vt &longs;oh da &longs;unt. Quare Ari&longs;t. videretur &longs;ibi non con&longs;tare, vel perperam exi&longs;tima&longs;&longs;e plura Tetraedra complere &longs;oliditatem. deceptus fortè fuit Ari&longs;t. cò quod videret Ico&longs;aedrum con&longs;tare ex viginti pyramidi­bus, verùm illæ non &longs;unt regulares, ide&longs;t non &longs;unt Tetraedra, vt po&longs;tea o&longs;ten­dam. Verum quidem e&longs;t octo cubos &longs;imul adactos &longs;oliditatem conficere, quia ad id nece&longs;&longs;arij &longs;unt octo anguli &longs;olidi, quos octo cubi præbere po&longs;&longs;unt, cum anguli ip&longs;orum &longs;int recti, & &longs;olidi. Verum enim verò plures pyramides regulares, &longs;iue plura Tetraedra non po&longs;&longs;e replere vacuum, &longs;olidumque; con­&longs;tituere, ex eo patet, quia &longs;i id præ&longs;tarent, conflarent nece&longs;&longs;ariò, vel vnum ex quinque corporibus regularibus, de quibus in 13. Elemen. vel aliud quod­piam; non aliud, nam, vt patet ex &longs;cholio 13. Elem. non dantur, ni&longs;i illa. quinque; neque vllum ex illis, quia diameter huiu&longs;modi corporis, quod com­poneretur ex illis pyramidibus, e&longs;&longs;et dupla lateris eiu&longs;dem, vt patet, quia pyramides illæ omnes concurrerent ad centrum &longs;phæræ illas omnes com­plectentis, quare latus vnius pyramidis à &longs;uperficie &longs;phæræ incipiens de&longs;i­neret in centrum, ergo latus i&longs;tud e&longs;&longs;et &longs;emidiameter, quapropter tota dia­meter illius &longs;ph&ecedil;ræ, & con&longs;equenter huius corporis in illa in&longs;cripti, e&longs;&longs;et du­pla lateris eiu&longs;dem figuræ &longs;olidæ in&longs;criptæ, &longs;ed nullo talis proportio diame­tri alicuius ex illis quinque &longs;olidis regularibus ad latus eiu&longs;dem reperitur, quæ &longs;it nimirum dupla, vt patet ex vltimis demon&longs;trationibus 13. Elem. ini­tio facto à 13. demon&longs;tratione, in quibus nulla reperitur proportio dupla inter diametrum, & latus eiu&longs;dem alicuius ex illis &longs;olidis; ex quibus mani­fe&longs;tum e&longs;t, plures regulares pyramides quouis pacto &longs;imul vnitas nullo mo­do replere locum &longs;olidum. cum igitur animaduerterem, &longs;en&longs;um Ari&longs;t. nullo modo po&longs;&longs;e verificari de repletione &longs;olidi per plura Tetraedra, & omnes tamen commentatores auctoritate Ari&longs;t. decepti pro ip&longs;o &longs;tarent, dubius, ancepsque; diu hæ&longs;i, neque quid quam mea Minerua a&longs;&longs;erere au&longs;us &longs;um, &longs;ed P. Clauium præceptorem meum per literas con&longs;ului, qui in hunc modum hu­mani&longs;&longs;imè re&longs;pondit; cubus implet locum quater &longs;umptus, ad idem enim punctum quatuor cubi coaptantur: &longs;ic etiam pyramis &longs;exies &longs;umpta, &longs;eu &longs;ex pyramides ad idem punctum iunctæratione &longs;ub&longs;tantium triangulorum æqui­laterorum. Verum hac ratione non videntur implere locum lolidum, fa­teor; &longs;ed tamen Ari&longs;t. in co tex. non loquitur de repletione loci &longs;olidi. hæc ip&longs;e. &longs;i igitur libeat Ari&longs;totelem, quod fortè Clauius intendebat defendere, dicendum e&longs;t cum eo Ari&longs;t non loqui de repletione loci &longs;olidi: neque loqui de cubo, & Tetraedro, quatenus &longs;unt corpora, &longs;ed quatenus habent &longs;uper­ficies, cubus quidem &longs;ex quadratas, Tetraedrum autem quatuor æquilate­ras &longs;uperficies, quæ duæ figuræ, vt &longs;upra in hoc textu vidimus, replent lo­cum: atque hoc modo facimus Ari&longs;totelem non formaliter loquentem. ex­aduersò ne videamur magis Ari&longs;t. quam veritatem &longs;equi, videtur dicen­dum, Ari&longs;totilem formaliter locutum e&longs;&longs;e, & vt patet ex rationibus &longs;upra allatis de repletione &longs;olidi e&longs;&longs;e intelligendum, vt etiam intellexerunt omnes huius loci expo&longs;itores; Verumtamen ip&longs;um erra&longs;&longs;e, dum plures pyramides replere &longs;olidum exi&longs;timauit. Vtrumuis dixerimus, non tamen Ari&longs;t. ab om­ni crrore vindicabimus. Hoc tamen certum e&longs;t, ex prædictis, Græcos om­nes pariter, ac Latinos, illos &longs;equentes, lapos e&longs;&longs;e, a&longs;&longs;erentes duodecim py­ramides complere &longs;olidum locum, atque Dodecaedrum con&longs;tituere; nam py­ramides Dodecaedron con&longs;tituentes non &longs;unt regulares, ide&longs;t, non &longs;unt Te­traedra (de quibus tamen Ari&longs;t. loquitur) vt patet ex &longs;upradictis. Indul­geas Lector, &longs;i hoc loco nece&longs;&longs;e fuit in Geometriæ penetralia ingredi: ope­ræpretium enim e&longs;t aliquando ip&longs;is Mathematicis &longs;atisfacere. tu verò, &longs;i adeo es mathematicis imbutus, con&longs;ule po&longs;tremas demon&longs;tra. 13. Elem. & præcipuè &longs;cholium vltimum, vbi plura de his corporibus &longs;citu digni&longs;&longs;ima, atque huc &longs;pectantia reperies ex his omnibus Mathematica, quæ no&longs;træ &longs;unt partes, per&longs;picuè &longs;atis expo&longs;uimus.

Multo po&longs;t tempore, quàm hæc &longs;crip&longs;eram incidi fortè in cap. 38. &longs;pecu­lationem 10. Benedicti de placitis Ari&longs;t. reperique; ab eo vno Ari&longs;t. hoc loco erroris notari, dum a&longs;&longs;eruit duodecim pyramides replere locum corporeum, ide&longs;t, vt exponit ip&longs;e, &longs;ex pyramides &longs;uper hexagonam aliquam figuram &longs;uperficialem, & &longs;ex &longs;ub eadem, id præ&longs;tarent, cum potius maius vacuum remaneat ad quamlibet partium &longs;upra, & infra, quam plenum. hæc ip&longs;e. &longs;ed expo&longs;itio i&longs;ta puerili, ne dum Ari&longs;t. ingenio pror&longs;us indigna e&longs;t: vt propte­rea exi&longs;timem ca&longs;u potius eum Ari&longs;t. rectè reprehendi&longs;&longs;e, quam ex certa &longs;cientia, cum illius erratum maiori errato conetur corrigere. Incidi po­&longs;tremò in Indicem librorum, quem Maurolyius &longs;uæ Co&longs;mographiæ præpo­nit, vbi &longs;ic ait: Demon&longs;tramus autem in libello de figuris planis, &longs;olidisque; locum replentibus, cubos per &longs;e, pyramides verò cum octacdris compactas dumtaxat implere locum, qua in re Auerroem erra&longs;&longs;e pueriliter manife&longs;tum erit. Vides igitur tanti viri auctoritate confirmari no&longs;tram &longs;ententiam, py­ramides videlicet per &longs;e, non replere vacuum. cum igitur con&longs;tet vnam tan­tum ex figuris &longs;olidis, &longs;iue etiam dicas, vt perperam Ari&longs;t. & alij plures exi­&longs;timarunt, replere totum &longs;olidum; nulla ratione poterunt elementa quatuor, quatuor diuer&longs;is figuris indui, &longs;ed vnum tantummodo, quare reliqua ab&longs;que figura remanere nece&longs;&longs;e e&longs;&longs;et: quod e&longs;t omnino inconueniens.

122

Tex. 71 (Deinde &longs;i terra e&longs;t cubus &c.) lege definitiones 11. Elem. quæ &longs;unt admodum faciles, ibi reperies de&longs;initiones quinque corporum regularium, quorum figuras Plato elementis tribuebat: qua verò id ratione faceret, ha­bes in &longs;phæra Clau. Simpl. etiam hoc loco &longs;atisfacit.

Ex Quarto de Cœlo.

123

Tex. 33. (Deinde ad &longs;imiles videtur angulos ignis quidem &longs;ur&longs;um ferri, terra autem deor&longs;um, & omninò quod grauitatem babet, quare nece&longs;&longs;e est ferri ad medium. boc autem vtrum accidit ad ip&longs;um tcrræ medium, an ad vniuer&longs;i, quoniam idem ip&longs;orum &longs;it, alius &longs;ermo e&longs;t) cum vellet

probare Ari&longs;toteles dari punctum quoddam in mdio mundi, ad quod grauia de&longs;cendant, & concurrent: & à quo leuia a&longs;cndat; vtitur, præter alias, etism ratione aliqua ex parte mathematica; quæ e&longs;t huiu&longs;­modi. videmus ignem, & cætera l&ecedil;uia a&longs;cendere à terra &longs;ur&longs;um ad angulos æquales; &longs;imiliter videmus terram, & c&ecedil;tera grauia de&longs;cendere ad terram dcor­&longs;um ad angulos æquales, quod &longs;ignum e&longs;t omnia i&longs;ta idem mundi medium re&longs;picere: v.g. &longs;it terra in &longs;igu­ra præ&longs;enti circulus E C D, cuius medium, &longs;ine c­trum A. via, qua a&longs;cendit ignis &longs;it in linea A C B, quæ facit angulos in &longs;u­perficie terræ æquales, nimirum angulos B C D, B C E. &longs;imiliter terra per candem lineam faciens eo&longs;dem angulos æquales de&longs;cendit. linea autem, quæ facit tales angulos tendit ad centrum &longs;phæræ A, vt patet ad &longs;en&longs;um in figu­ra, & probari pote&longs;t geometricè ex primis tertij Elem. ex quibus patet tam læuia, quam grauia, quæ per talem lineam ferantur, re&longs;picere centrum A, &longs;phæræ. Vtrum autem i&longs;tud centrum &longs;it idem cum centro totius mundi, alius, inquit, e&longs;t &longs;ermo, hoc e&longs;t, ad a&longs;tronomum pertinet. vide igitur hac de re pulchram de&longs;&longs;ertationem apud Clauium in &longs;phæra: qui probat euidenter e&longs;&longs;e vnum, & idem.

124

Hoc loco de&longs;ideratur commentarius in cap. vlt. de Cœlo. cuius loco ìn-

terim Lector adeat Di&longs;cur&longs;um Italicum Galilæi Galilæi, de his,quæ in aqua mouentur, ac natant: ubi propè finem, plura in hu-ius capitis explicationem affert.

125

126

127

128

129

Ex Lib. 2. de Generatione, & Corruptione.

130

Tex. 56. (ldeoqué non prima latio cau&longs;a Generationis, & Corruptionis e&longs;t, &longs;ed quæ &longs;ecundum obliquum circulum, in hac enim & continuum vnum e&longs;t & moueri duobus motibus) per primam lationem intelligit mo­tum primi mobilis, qul &longs;it &longs;uper polis mundi, quo Stellæ omnes ab oriente in occidentem rectà feruntur. per obliquum verò circulum in­telligit Zodiacum, qui obliquus e&longs;t, quia poli eius &longs;unt alij à polis mundi, & quia non tendit rectà ab ortu ad occa&longs;um, &longs;ed in &longs;phæra mundi tran&longs;uer­&longs;us e&longs;t, & deflectit à &longs;eptentrione in meridiem, quamuis non rectà, vt in &longs;phæra explicari &longs;olet. motus ergo Planetarum, qui fit &longs;ecundum hunc cir­culum, & ip&longs;e obliquus, & tran&longs;uer&longs;us codem modo erit; ferrentur que per eum à Borea ad Au&longs;trum, & è conuer&longs;o; ex quo acce&longs;&longs;u, & rece&longs;&longs;u efficiunt æ&longs;tatem, & hyemem, item generationes, & corruptiones. Sol porrò, & pla­netæ, qui motibus proprijs hunc circulum peragunt, dicuntur moueri duo­bus motibus, & quidem contrarijs: quoniam dum Sol. v. g. per Zodiacum graditur motu proprio, interim etiam à primo mobili fertur ab ortu in oc­ca&longs;um: ex quibus duobus motibus fit vnus tantum Solis motus &longs;piralis, qui mixtus e&longs;t, ide&longs;t, qui fit à duobus motoribus; vnde re vera Sol non mouetur duobus motibus contrarijs re ip&longs;a di&longs;tinctis; hoc enim impo&longs;&longs;ibile e&longs;t: &longs;ed motu mixto ex duobus, qui &longs;piralis e&longs;t, circa mundum de&longs;cribens &longs;piras ab vo tropico ad alterum: qui, vt dixi, cau&longs;atur à duobus motoribus, qui &longs;unt Sol ip&longs;e, mouens &longs;e ip&longs;um per Zodiacum: & primum mobile mouens in&longs;u­per ip&longs;um Solem, & Zodiacum ab ortu in occa&longs;um circa mundum.

EX PRIMO METEORORVM.

131

Svmma 1. cap. 3. (Moles autem terræ quanta &longs;it ad ambientes magnitudi­nes, non immamfestum, iam enim vi&longs;um est per a&longs;trologica theoremata, quod multò etiam quibu&longs;dam a&longs;tris est minor) Quantitas terræ non &longs;o­lum ab&longs;olutè con&longs;iderata, ab A&longs;tronomis explorata habetur, vt vi­dere e&longs;t in &longs;phæra Clauij; &longs;ed etiam re&longs;pectiuè con&longs;iderata, ide&longs;t re&longs;pectu aliorum elementorum, & ip&longs;orum etiam a&longs;trorum; cuius demon&longs;trationes &longs;unt partim in libello Ari&longs;tarchi Samij, de magnitudine, & di&longs;tantia Solis, & Lunæ, partim apud Ptolæmeum in magna Syntaxi, &longs;iue Almage&longs;to: par­tim apud Albategnium de &longs;cientia &longs;tellarum: partim demum apud Ticho­nem Brahe. Porrò facile e&longs;t demon&longs;trare Solem e&longs;&longs;e terra multò maiorem, terram verò maiorem Luna, idque; ex eclyp&longs;i lunari, cuius imaginem habes in figura &longs;equenti; vbi vmbra terræ e&longs;t D B E, in quam Luna nigricans im­mergitur, ac lumine deficit, reliqua cognitu &longs;unt facilia: quia igitur A&longs;tro­nomi ob&longs;eruarunt vmbram terræ paulò &longs;upra Lunam pertingere, cum &longs;upe­riora a&longs;tra non adeat, hinc collegerunt eam nece&longs;&longs;ariò e&longs;&longs;e acuminatam, &longs;eu conicam, vt figura refert. Cum ergo terra vmbram proijciat turbinatam, nece&longs;&longs;ariò corpus Solis, quod ip&longs;am illuminat, eadem maior erit: quoti­diana enim experientia docemur, corpore illuminante exi&longs;tente maiore quà &longs;it illuminatum, vmbram proijci fa&longs;tigiatam: cum deinde Solem val­de a terra di&longs;tare certum &longs;it, optimè infertur, eum re&longs;pectu terræ e&longs;&longs;e maxi­mum: quanto enim duæ lineæ, &longs;iue radij B A, B C. à terra ad partes Solis

magis elongantur, tan­to maius corpus illu­minans intercipiunt. ha­ctenus de magnitudine terræ ad Solem. Cum verò Luna eclyp&longs;atio­nis tempore, aliquan­do non &longs;olum tota in vmbræ vertice lateat, verùm etiam aliquando moram trahat, euidens e&longs;t, eam e&longs;&longs;e multò mi­norem illa vmbræ par­te, in quam immergi­tur; quæ pars cum &longs;it conicæ vmbræ media, crit multò gracilior quàm &longs;it ip&longs;a terra. Ex quo manife&longs;tè apparet, Lunam, quæ illa vmbra minor e&longs;t, e&longs;&longs;e à fortio­ri multò minorem ip&longs;a terre&longs;tri mole. Atque hæc de comparatione terræ ad Lunam. harum rerum demon&longs;trationes exactioes pertractare non e&longs;t huius loci.

132

Eodem cap. (Con&longs;iderautes vtique, quæ nunc c&longs;tenduntur per Mathematica&longs;uficienter, for: è vtique de&longs;isterent ab hac puerili opinione; valde enim &longs;implex e&longs;t pure vnumquodque eorum quæ feruntur e&longs;&longs;e paruum magnitudinibus, quia vi­detur &longs;picientibus, binc nobis &longs;ic) vtinam i&longs;ta, necnon alia his &longs;imilia, quæ pa&longs;&longs;im apud Ari&longs;t. occurrunt, plerique no&longs;træ ætatis con&longs;iderarent, qui nulla ratione probari po&longs;&longs;e exi&longs;timant, Solem, v. g. terra e&longs;&longs;e centies &longs;exagies &longs;e­xies maiorem; &longs;ed c iam, quod peius e&longs;t, negant e&longs;&longs;e maiorem; ad demon­&longs;trationes autem a&longs;tronomicas dicunt &longs;e exi&longs;timare eas e&longs;&longs;e fallaces; at que impo&longs;libile e&longs;&longs;e nos res adeo à nobis di&longs;taptes &longs;ufficienter perue&longs;tigare: quanto &longs;apientius, ac prudentius eorum Magi&longs;ter Ari&longs;t. alibi &longs;æpius, &longs;ed hoc præcipuè loco; quippe qui Mathematicis &longs;ufficienter excultus erat; quibus i&longs;ti de&longs;tituti, nullo vnquam modo ve&longs;tigia præceptoris a&longs;&longs;equi poterunt.

133

Summa 1. cap. 4. (Quæ igitur astrorum e&longs;t, velox quidem; longè autem: quæ verò Lunæ deor&longs;um quidem, tarda autem: quæautem Solis ambo hæc babet &longs;uffi­cienter) quæ igitur a&longs;trorum, ide&longs;t latio a&longs;trorum e&longs;t velox, &longs;ed procul à ter­ra; Lunæ verò latio terræ quidem proxima, tarda tamen: at verò Solis la­tio medio modo &longs;e habet inter vtrumque, ide&longs;t, quia neque nimis vt a&longs;tra di­&longs;tat, neque tardè &longs;icut Luna circunfertur. exi&longs;timo Ari&longs;t. loqui de motu diur­no, quia &longs;ecundum hunc a&longs;tra inerrantia &longs;unt Sole citatiora, Sol verò ip&longs;a Luna citior. Verumenimuerò illud non prætereundum, quod plurium inua­luerit opinio exi&longs;timantium Ari&longs;t. his verbis, Solem &longs;upra Lunam proximè colloca&longs;&longs;e; quod tamen ex ip&longs;is nullo pacto deduci pote&longs;t; &longs;ed &longs;olummodo ip&longs;um &longs;upra Lunam colloca&longs;&longs;e. quod &longs;i ita &longs;en&longs;i&longs;&longs;et venia dignus haberetur, cum tunc temporis nondum fortè adinuentæ e&longs;&longs;ent demon&longs;trationes illæ a&longs;tronomicæ, quibus ordo Planetarum certi&longs;&longs;imè con&longs;tat, Solque; medius in­ter Planetas collocatur. At verò nulla ratione ferendi &longs;unt quicunque no&longs;tra hac tempe&longs;tate non &longs;olum Ari&longs;t. ita &longs;en&longs;i&longs;&longs;e, &longs;ed etiam contra firmi&longs;&longs;imas aftronomorum demon&longs;trationes, quibus adeò Ari&longs;t. deferebat, vnica, vt pu­tant ip&longs;ius auctoritate fulti, Solem &longs;ecundum à Luna locum occupare om­ni ope defendunt.

134

Summa 2. cap. 3. (Quod accidit circa Mercurij stellam, quia enim modicum &longs;upera&longs;cendis, &longs;æpè non apparet, it a vt po&longs;t tempus multum appareat) quod Mer­curius non ni&longs;i rarò con&longs;pici po&longs;&longs;it, cau&longs;a e&longs;t, quia parum à Sole elongatur, &longs;iue ip&longs;um antecedat, &longs;iue &longs;ub&longs;equatur. ex quo fit, vt diu ferè &longs;imul cum So­le cit cumferatur, & propterea &longs;iue oriatur, &longs;iue occidat, parum &longs;upra ho­rizontem eleuatus apparere pote&longs;t, quod Ari&longs;t. ait modicum &longs;upera&longs;cendit. vnde fit tum propter nimiam Solis vicinitatem, cuius lumine tegitur; tum propter vapores, qui horizonti vt plurimum incumbunt, vt rarò, & po&longs;t ma­gna temporis interualla con&longs;piciatur. non me fugit hæc omnia ab a&longs;trono­mis per epiciclum excu&longs;ari; &longs;ed ego mediocritati eorum, in quorum gra­tiam hæc &longs;cribo, con&longs;ultum volo.

135

Eodem cap. (Ad au&longs;trum autem quando feratur, copiam quidem habere talís humiditatis, &longs;ed quia parua e&longs;t &longs;ictio circuli, quæ &longs;uper terram, quæ autem deor­&longs;um multiplex, non po&longs;&longs;e vi&longs;um hominum fractum ferri ad Solem, neque ip&longs;i tropico au&longs;trino appropinquanti; neque in æ&longs;tiuis ver&longs;iombus exi&longs;tente Sole. quapropter in lis quidem locis neque fieri cometem ip&longs;um. quando verò ad Boream &longs;ubdefecerit, accipere comam, quia magna e&longs;t circun&longs;erentia, quæ e&longs;t &longs;upra horizontem; quæ au-tem e&longs;t &longs;ubtus, pars circuli parua; facilè enim vi&longs;um hominum ptingere tunc ad Solem) cur cometa in regione au&longs;trali vltra Solis, annique; vias con&longs;titutus non appareret, cau&longs;am referebat Hippocrates paruitatem circuli, qucm motu diurno cometa de&longs;cribebat, ob quam adeò parum &longs;upra horizontem attolleretur, vt non po&longs;&longs;et vi&longs;us no&longs;ter ab ip&longs;o ad Solem reflecti; quod &longs;ecun­dum ip&longs;um erat nece&longs;&longs;arium ad cometarum apparitionem. I oquitur igitur Hippocrates de circulis, quos diurna conuer&longs;ione cometes circumducir, qui omninò &longs;imiles &longs;unt ijs, quos etiam Sol, reliquaque; a&longs;tra eodem motu de &longs;i­gnant. qui quidem omnes in no&longs;tr a &longs;phæra obliqua ita &longs;e habent, vt ij, qui &longs;unt vltra æquatorem ad Capricorm tropicum, minus &longs;upra horizontem extent, quàm infra de primantur, & tanto minus, quanto magis ab æquato­re in auftrum recedunt: contra verò fciunt, qui citra æquatorem ad Can­cri conuer&longs;ionem co&longs;&longs;ocantur, quanto enim magis ab æquatore in boream remouentur, tantò eorum &longs;ectio, quæ e&longs;t &longs;upra horizontem, maior e&longs;t ea, quæ infra horizontem latet. quæ quidem omnia clara &longs;unt adhibita &longs;phæra materiali, quam &longs;i ad tuam poli eleuationem accommodaueris, illicò vi­debis tropici, Cancri &longs;ectionem, quæ e&longs;t &longs;upra horizontem multo maiorem ea, quæ e&longs;t infra. oppo&longs;itum verò in altero Capricorni tropico, cuius mini­mam portionem &longs;upra, maximam verò infra horizontem exi&longs;tere videbis. Idem proportionaliter imaginari debes de circulis, quos cometa tam vltra Capricornum, quàm citra Cancrum delineat; nam eorum, qui &longs;unt vltra Capricornum ad au&longs;trum minores adhuc &longs;ectiones &longs;upra horizontem exi­&longs;terent, quàm opus &longs;it ad cometen &longs;pectandum. Atque hæc cau&longs;a e&longs;t ex &longs;en­tentia Hippocr. cur in illa au&longs;trali plaga nunquam cometes effugat. è con­trario autem, quia ad boream &longs;ectiones illæ maximæ &longs;unt, aptæque; ad refra­ctionem vi&longs;us no&longs;tri v&longs;que ad Solem, idcircò in hac mundi parte cometas con&longs;picere &longs;olemus. Reliqua Vicomercatus, atque Alexand. optimè expli­cant, quos tu con&longs;ule, ne actum agatur.

In cap. 4. &longs;ummæ 2. lib. 1. Meteor. de Cometis.

136

In præ&longs;enti cap. Ari&longs;t. &longs;uam de Cometis &longs;ententiam exponit: Come­tam nimirum infra Lunam in elementari mundo procreari, & ignitum quoddam Meteoron, ex lenta, pingui, &longs;iccaque; materia à terra in &longs;u­premm aeris regionem attracta, exi&longs;tere; ibique; rapti aeris calore, vel elementi ignis (quod illic e&longs;&longs;e putat) vicinitate, vel etiam vi a&longs;trorum incendi, atque impelli. Hanć porrò opinionem & &longs;i probabilibus tantum ra­tionibus confirmatam vulgò tamen v&longs;que ad hanc diem receptam, cum fal­&longs;am e&longs;&longs;e a&longs;tronomi exi&longs;timent, non erit abs re rationes eas ex &longs;ecundo pro­gymn. Tichonis volumine, de&longs;umptas hic breuiter referre, quibus a&longs;trono­mus ille eos &longs;upra Lunam in ætherea regione collocauit: quas quidem ra­tiones ille ex diuturnis ob&longs;eruationibus per exqui&longs;ita organa factis adinue­nit: ea&longs;que Mathematicis linearum, ac numerorum demon&longs;trationibus explicauit.

Prim. &longs;ed vt ab auctoritate, in quam obiter incidimus initium faciamus, non e&longs;t exi&longs;timandum nonnuilos &longs;olum ex recentioribus id con&longs;tanter a&longs;&longs;e­uera&longs;&longs;e, &longs;ed &longs;uperiori etiam ætate id ip&longs;um Hieron. Cardan. libro de &longs;ubtili­tate conatus e&longs;t, neque irrito conatu, demon&longs;trare; qui præterea idem cum &longs;e ip &longs;o &longs;en&longs;i&longs;&longs;e ait Albumazar. quibus etiam ex antiquis Seneca annumeran­dus e&longs;t. pr&ecedil;dicti autem recentiores omnes varijs demon&longs;trationibus ex ac­curata ob&longs;eruatione erutis illud certò certius con&longs;irmare contendunt: idque; non in vno dumtaxat, &longs;ed in quinque cometis; quorum demon&longs;trationes apud Tychonem partim in progymn. partim in epi&longs;t. fu&longs;ius explicatas reperies.

2. Quarum poti&longs;&longs;ima illa e&longs;t, quæ ex parallaxi, &longs;eu a&longs;pectus diuer&longs;itate de&longs;umitur, certi&longs;&longs;imum enim e&longs;t lumen illud e&longs;&longs;e altero &longs;ublimius, quod mi­norem exhibet parallaxim: expertos autem &longs;e e&longs;&longs;e hi omnes, affirmant ho­&longs;ce quinque cometas multò minorem pati parallaxim, quam Lunam; imò quempiam minorem, quàm Sol ip&longs;e patiatur, quo po&longs;ito manife&longs;tè conuin­ceretur eos omnes &longs;upra Lunam in ætherea regione efful&longs;i&longs;&longs;e.

3. Ratio, qua etiam ante nouas ob&longs;eruationes vti &longs;olebant, de&longs;umitur ex motu cometæ diurno, quo &longs;cilicet oritur, & occidit, quemadmodum cæ­tera &longs;ydera, hoc e&longs;t &longs;patio 24. horarum diurnam conuer&longs;ionem circa totam terram ab&longs;oluit. &longs;i igitur comete e&longs;&longs;et in &longs;ublimiori aeris regione, vbi cæte­ra ignita meteora collocantur, mouereturque; diurno motu circa terram, &longs;e­queretur nece&longs;&longs;ariò eum tanta velocitate videri à nobis circumferri, vt po­tius fulgor quidam, &longs;eu radius pertran&longs;iens ab oriente in occidentem appa­reret, quam &longs;tella qu&ecedil;dam: idque; propter propinquitatem; a&longs;tra enim ob ni­miam di&longs;tantiam videntur tardè moueri, quamuis veloci&longs;&longs;imè moueantur.

Quod melius ex &longs;equenti figura conuincitur, vbi circulus interior e&longs;t terra, cuius &longs;emidiameter A B. cir­culus verò exterior e&longs;t cometæ gy­rus, quem ip&longs;e &longs;patio 24. horarum percurrit, qui &longs;ecundum veram pro­portionem deberet adhuc ip&longs;i terræ propinquior, ac proinde minor e&longs;&longs;e, iuxta aeris &longs;upremam partem. hori­zon e&longs;t recta D C, tangens terram in B, vbi e&longs;t oculus no&longs;ter, qui nihil in­fra ip&longs;am D C, videre pote&longs;t; quare &longs;i cometa 24. horarum totum gyrum D C E, percurrit, non videbitur, ni&longs;i quando percurret portionem D C, &longs;upra horizontem; quæ quidem por­tio, neque &longs;emihoræ re&longs;poneret, &longs;i &longs;i­gura iuxta veram proportionem con&longs;trueretur. experientia tamen con&longs;tat, cometas videri &longs;upra horizontem tot horis, quot &longs;tellæ fixæ, &longs;ub quibus mo­uentur: non ergo e&longs;t in &longs;upremo aere. Quod &longs;i &longs;iat figura, in qua exterior cometæ ambitus adeò magnus &longs;it, vt ip&longs;ius portio D C, &longs;upra horizontem exi&longs;tens, re&longs;pondeat tempori, quo cometa &longs;upra no&longs;trum pariter horizon­tem &longs;pectatur, ea figura terræ &longs;emidiametrum A B. toties multiplicabit, vt ip&longs;i Lunæ circuitui proximè accedat.

Præterea aiunt, quis &longs;anæ mentis dixerit, Meteoron vlium ex materia vaga, ac fluxa con&longs;tans, po&longs;&longs;e tanta pernicitate moueri, vt diurnam con­uer&longs;ionem ab&longs;oluat? vnde illi motus i&longs;te? præ&longs;ertim cum videamus cætera ignita mteora e&longs;&longs;e ad modum temporanea, atque euanida.

4. Comprobationem nobis &longs;uppditant ex via, &longs;eu ductus circuli, quem toto durationis tempore proprio cur&longs;u de&longs;ignarunt: prædicti namque quin­que cometæ motu &longs;ibi proprio, quo ab occidente non omninò orientem ver&longs;us, &longs;ed ad aquilonem deflectentes ab initio &longs;uæ apparitionis, v&longs;que ad vl­timum fiuem exqui&longs;iti&longs;&longs;imè portionem circuli maximi in c&ecedil;lo de&longs;ignarunt; non aiiter quàm Sol proprio motu per eclypticam in cœlo mundi &longs;phæram in duo æqualia diuidentem de&longs;cribit. necnon aliter ac Luna &longs;uum iter per circulum maximum cœlum bifariam diuidentem perficit. quapropter co­metas ho&longs;ce non minus quam Sol, vel Luna in ip&longs;o æthere &longs;patiatos e&longs;&longs;e con­tendunt. qui enim, aiunt, fieri potui&longs;&longs;et, &longs;i in mundo elementari flagra&longs;&longs;ent, vt tam regulari, atque con&longs;tanti ductu circuli maximi portionem tam exactè delinea&longs;&longs;ent, quam quidem inter elementa vagum, atque in&longs;tabilem pro ma­teriæ in&longs;tabilitate exercere debui&longs;&longs;ent?

5. Adde, quod in maximo hoc circulo de&longs;cribendo, etiam &longs;i inæquali ve­locitate vi&longs;i &longs;int moueri, inæqualitatem tamen illam regularem vbique &longs;em­per &longs;eruauerunt, in principio quidem velociores, deinde &longs;ucce&longs;&longs;iuè, & pro­portionaliter velocitatem illam &longs;imili analogia &longs;emper &longs;eruata inhibuerunt, nullo igitur pacto inordinatam inæqualitatem, qua à tardiore motu &longs;ubito in celeriorem, & rur&longs;us &longs;tatim ab hoc in illum pro&longs;ilirent exhibuerunt: prout omnia Meteora, quæ in mundi parte elementari ex flammanti materia ge­nerantur, talem di&longs;parem, atque incon&longs;tantem motum obtinere cernuntur.

6. Argumento præterea e&longs;t cometas ho&longs;ce minimè elementares fui&longs;&longs;e, quod hic eorum proprius motus, quo maximo illo tramite ferebantur, nua­quam tantus fuit, vt proprium Lunæ motum, vel tardi&longs;&longs;imum adæquauerit, quæ quidem cum lenti&longs;&longs;ima e&longs;t plus denis gradibus vna die promouetur; cum tamen cometæ initio cum veloci&longs;&longs;imi &longs;unt non multum vltra quinos gradus diurno motu progre&longs;&longs;i &longs;int, vt ob id longè &longs;upra Lunam cur&longs;um &longs;uum ab&longs;olui&longs;&longs;e manife&longs;tè comprobari po&longs;&longs;it: quo enim &longs;ydera magis à terra at­tolluntur, octauæque; &longs;phæræ propius accedunt, eò tardioribus proprijs la­tionibus proferuntur: ita vt &longs;teilæ i&longs;tæ cœlo ad&longs;cititiæ &longs;upra Lunam admo­dum euehendæ videantur. Quod &longs;i in &longs;uprema aeris regione con&longs;lagrarent, qua nam ratione vnà cum toto cœlo diurnam conuer&longs;ionem ab&longs;olui&longs;&longs;ent: neque enim putandum e&longs;t &longs;upremum hunc aeris limbum eadem pernecitate, qua cœle&longs;tes orbes, verum minori admodum imò tardi&longs;&longs;imè à diurno mo­tu, &longs;i tamen eo rapitur circumduci.

7. Tandem argumentum ex ip&longs;orum duratione de&longs;umatur. cætera nam­que meteora &longs;tatim atque apparuerint, vluti temporanea pror&longs;us, atque eua­nida extinguuntur: At verò cometæ ad men&longs;em aliquando integrum per­&longs;euerant. quì igitur fieri potuerit, vt in hac corruptibili mundi parte ex ma­teria adeò &longs;luxa, & vaga, quam illis Ari&longs;teteles &longs;upponit, tandiu perdura­re potui&longs;&longs;ent.

Atque hæ &longs;unt rationes, quibus plurimi a&longs;tronomorum recentiorum, co­metas ho&longs;ce motum æthereæ regioni conformem, contrà quam Ari&longs;t. opi­natus e&longs;t, obtinui&longs;&longs;e, munifeftum e&longs;&longs;e volunt; ac proinde eorum locum, & cur&longs;um in cœle&longs;ti mundi parte extiti&longs;&longs;e, &longs;e comproba&longs;&longs;e exi&longs;timant: qua de re prudentis Lectoris e&longs;to iudicium: neque enim, vt ille cecinit, no&longs;trum e&longs;t, tantas componere lites.

Verumenimuerò Peripatetica omnis &longs;chola reclamat; Cœlum e&longs;t inge­nerabile, & incorruptibile, mhil igitur noui cœlo pote&longs;t accidere. &longs;ed age re&longs;pondent, nonne omnium a&longs;tronomorum con&longs;en&longs;u &longs;tellæ tres nouæ no&longs;tro hoc &longs;æculo in cœlo toti mundo con&longs;picuæ illuxerunt? easque; in octaua &longs;phæ­ra re&longs;edi&longs;&longs;e conftans e&longs;t omnium a&longs;&longs;ertio? quarum prior anno 1572. in con­&longs;tellatione Ca&longs;&longs;iopeæ apparuit. Secunda anno 1600. in Cygno, quæ nec dum extinguitur. Tertia anno 1604. inter Sagittarij &longs;tellas vi&longs;a e&longs;t, de quibus vi­de P. Clauium in &longs;phæra breuiter de illis tractantem: aut &longs;i mauis, & vacat, vide quoad primam primum volumen progymna&longs;matum Tychonis Brahe, vbi etiam aliorum a&longs;tronomorum de eadem certi&longs;&longs;imas commentationes reperies. con&longs;ule etiam de reliquis duabus Ioannis Kepleri Cæ&longs;areæ Maie­&longs;tatis Mathematici commentaria; & coactus libenter fateberis noui ali­quid cœlo aduenire po&longs;&longs;e.

Po&longs;tremò tandem po&longs;&longs;et qui&longs;piam in hunc modum opponere: etiam &longs;i con­&longs;tet quinque cometas c&ecedil;lo oberra&longs;&longs;e, non propterea dicemus reliquos omnes e&longs;&longs;e pariter cœle&longs;tes, nullumque; proinde &longs;ublunarem. Huic memorati A&longs;tro­nomi &longs;ic re&longs;ponderent; id quidem mathematica, & infallibili ratione non colligi, imò aliquot parum infra Lunam extiti&longs;&longs;e, non omninò negandum videri: at verò in &longs;uperiori aeris plaga, in tam fluxa, ac in&longs;tabili mundi par­te, cometas vnquam efful&longs;i&longs;&longs;e, nemo &longs;ibi ob allatas rationes meritò per&longs;ua­dere po&longs;&longs;e.

137

Summæ 2. cap. 5. (Ad hæc autem &longs;i quemadmodum o&longs;tenditur in ijs, quæ cir­ca Astrologiam &longs;peculationibus, Solis magnitudo maior e&longs;t quàm terræ; & diftax­tia multò maior a&longs;trorum ad terram quàm So is; &longs;icut Solis ad terram quàm Lu­næ; non vtique longè alicubi à terra conus, qui à Sole, corijciet radios, neque vtique vmbraterræ, quæ vocatur nox, erit apud astra; &longs;ed ne&longs;&longs;e Solem omnia a&longs;tra cir­cun&longs;picere, & nulli p&longs;orum terram ob&longs;istere) ex dictis &longs;umma 1. cap. 3. huius, & ex figura ibi de&longs;cripta, facilè e&longs;t intelligere præ&longs;entem locum; nam cum Sol &longs;it multò maior terra, vt ibi probatur, ac minus di&longs;ter à terra quàm fixæ &longs;tellæ, magis tamen quàm Luna, vt patet ex &longs;olari eclyp&longs;i, &longs;equitur nece&longs;&longs;a­riò vmbram terræ, quæ nox e&longs;t ip&longs;a, effici turbinatam, & valdè procul à ter­ra acumen coni vmbræ a&longs;cendet, &longs;ed paulò &longs;upra Lunam conus hic vmbræ permittet radios Solis &longs;e ip&longs;um ambientes iterum &longs;imul committi, quod il­lis verbis (Conijciet radios) ide&longs;t committet radios expre&longs;&longs;it Ari&longs;t. cum igi­tur vmbra apud Lunam &longs;it &longs;atis gracilis, breui &longs;upra Lunam de&longs;inet, neque vllo pacto ad affixa &longs;ydera protendetur, neque illis renebras offundet. quod etiam experientia confirmat, cum nunquam a&longs;tra illa, quæ Soli opponuntur, quæque; vertex vmb æ colimat, vllam patiantur eclyp&longs;im. quare &longs;ine vllo ter­ræ impedimento Sol pote&longs;t af&longs;ixa omuia &longs;ydera perlu&longs;lrare. Exactiores ha­rum rerum demon&longs;trationes &longs;unt alterius loci.

138

Eodem cap. (Amplius autem e&longs;t tertia quædm opinio de ip&longs;o, dicunt enimquidam lac e&longs;&longs;e reflexionem no&longs;tri vi&longs;us ad Solem; &longs;icut & &longs;tellam comatam; im­po&longs;&longs;ibile autem e&longs;t & hoc, &longs;i enim videns quieuerit & &longs;peculum, & quod videtur omne in eodem puncto &longs;peculi eadem apparebit vtique pars imaginis, &longs;i autem mo­ueatur &longs;peculum, & quod videtur, in eadem quidem di&longs;tantia ad videns, & quie­&longs;cens; ad inuicem autem neque æquè velociter, neque in eadem &longs;emper di&longs;tantia im­po&longs;&longs;ibile eandem imaginem in eadem e&longs;&longs;e parte &longs;peculi. Quæ autem in lactis circu­lo feruntur a&longs;tra, & Sol, ad quem fit reflexio, mouentur manentibus nobis, & &longs;i­militer, & æqualiter ad nos di&longs;tantia; à &longs;e ip&longs;is autem non æqualiter: aliquando enim medijs noctibus Delphin oritur, aliquando verò diluculo. partes autem lactis eædem manent in vnoquoque; atqui non oportebat, &longs;i erat imago, &longs;ed non in ei&longs;dem adhuc e&longs;&longs;et hæc pa&longs;&longs;io locis) in his Ari&longs;t. confutat opinionem dicentium Gala­xiam apparere per quandam reflexionem vi&longs;us no&longs;tri ab illa parte c&ecedil;li, ceu, ex quodam &longs;peculo ad Solem: probat autem hoc e&longs;&longs;e impo &longs;&longs;ibile ratione de&longs;umpta ex parte Optices, quæ dicitur Catoptrica, &longs;iue &longs;pecularia, quia tractat de vi&longs;ione reflexa, quæ fit mediante &longs;peculo, quam quidem rationem &longs;i vellem mathematicè explicare, longa nimis, ac præter in&longs;titutum fieret tractatio. Pauca tamen addam, quæ Ari&longs;totelis &longs;ententiam &longs;atis per&longs;picuam reddant. &longs;i igitur inquit, Galaxia nihil aliud e&longs;&longs;et quàm reflexio no&longs;tri vi&longs;us ex illa cœli parte, in qua ip&longs;a apparet tanquam ex &longs;peculo ad Solem, ita vt nihil aliud ip&longs;a e&longs;&longs;et, quàm Sol vi&longs;us per reflexionem exilla cœli parte tan­quam &longs;peculo; &longs;equeretur eam non &longs;emper in eadem cœli parte apparere, &longs;ed modo in vna, modo in alia, ita vt &longs;patio vnius anni totum cœlum perua­garetur: quod tamen non accidit. quod autem illud con&longs;equatur manife­&longs;tum e&longs;&longs;e pote&longs;t ex ob&longs;eruatione eorum, quæ ex &longs;peculis videntur: tunc enim res per &longs;pe culum vi&longs;a in eadem &longs;peculi parte apparet, quando & videns, & &longs;peculum, & obiectum immota manent: quod &longs;i & &longs;peculum, & obiectum ad inuicem accedant, vel recedant, &longs;eruata tamen eadem ab in&longs;pectore di&longs;tan­tia, nullo modo fieri pote&longs;t, vt eadem imago, in eadem &longs;peculi parte &longs;pe­ctanti videatur, ni&longs;i obiectum &longs;peculo per eandem lineam accedat, &longs;ecun­dum quam illi incidebat. At verò partibus illis lactei circuli, &longs;iue a&longs;tris, quæ in eo fulgent, Sol perpetuò accedit, vel recedit, neque per lineam incidentiæ eandem, &longs;eruata tamen eadem à nobis di&longs;tatia, quod quidem inde patet, quia Delphini con&longs;tellatio, qui in ip&longs;o ferè lacte exi&longs;tit, aliquando medijs noctibus, aliquando verò mane, aliquando etiam ve&longs;peri oritur; quod inde accidit, quia illi Sol modò appropinquat, modò coniungitur, modò ab eo recedit, quare nece&longs;&longs;e e&longs;&longs;et, vt lacteus orbis, non &longs;emper in ij&longs;dem locis, &longs;ed perpe­tuò in alijs, atque alijs cernerecur, cuius tamen contrarium videmus. ex qui­bus con&longs;tat fal&longs;am omninò e&longs;&longs;e eorum &longs;ententiam, qui Galaxiam per huiu&longs;­modi re&longs;lexionem fieri opinabantur. Quæ dicta &longs;unt de &longs;peculo, & obiecto &longs;atius e&longs;t a&longs;&longs;umpto aliquo &longs;peculo experiri, quàm ea pluribus ob&longs;curare: qua etiam experientia Ari&longs;t. ratio confirmabiaur.

139

Ibidem (Quæ autem in lactis cir culo feruntur astra, & Sol, ad quem fit refle­xio, mouentur mancntibus nobis, & &longs;imiliter, & æqualiter ad nos di&longs;t antia à &longs;e ip&longs;is autem non æqualiter) quæ hic ab Ari&longs;totele dicuntur non &longs;unt v&longs;quequae; vera propter apogæum, ac porigæum Solis, quæ quidem duo ab omnibus a&longs;tronomis a&longs;&longs;eruatur: quando igitur Sol e&longs;t in apogæo, maiori multo in­teruallo di&longs;tat à nobis, quàm quando e&longs;t in perigæo, interuallum enim illud con&longs;tat diametris terræ duobus, & quadraginta, hoc e&longs;t milliarijs 208000. ferè, ide&longs;t octonis millibus &longs;upra ducenta millia. quæ differentia facit vt Sol manife&longs;tè appareat nobis minor apogæus, quàm perigæus. Sol præterea &longs;i­militer ip&longs;is inerrantibus &longs;tellis fit tantumdem modo remotior, modo pro­pinquior: &longs;ed fortè Ari&longs;t. i&longs;ta non occurrerunt, vel tunc temporis nondum per&longs;pecta erant.

140

Ibidem (Aliquando enim medijs noctibus Delphin oritur) vt probet, Gala­xiam non &longs;emper &longs;eruare à Sole di&longs;tantiam eandem, accipit tanquam huius rei &longs;ignum, manife&longs;tum, quod Delphini con&longs;tellatio aliquando medijs no­ctibus oriatur &longs;upra horizontem, aliquando verò diluculo; non ideò tamen putes hanc rationem &longs;upponere Delphinum e&longs;&longs;e in ip&longs;o lacteo circulo, quod tamen verum non e&longs;t, non enim e&longs;t in Galaxia, &longs;ed tamen illi proximus, vt noctu videre e&longs;t in cœlo, vel etiam &longs;i mauis in globo a&longs;tronomico: non ta­men ob id Ari&longs;t. ratio minus valida redditur, cum Delphinus &longs;emper Gala­xiæ eodem modo &longs;it proximus, eoque; moto, ip&longs;a pariter moueatur.

141

Summæ 2. cap. 6. Sunt qui velint Ari&longs;t. Galaxiam nihil aliud e&longs;&longs;e, quàm quandam refractionem lucis &longs;tellarum illarum, quæ &longs;unt in ætherea Gala­xia, quæ inquam refractio fiat circa &longs;upremam aeris regionem ex occur&longs;u exhalationum, quæ ibi perpetuò con&longs;eruantur, & vi earumdem &longs;tellarum &longs;ur&longs;um &longs;emper attrahuntur, quæ refractio fiat ad eum modum, quo halo cir­ca Solem, & Lunam. & quemadmodum halo, &longs;iue area omnibus vndecunque a&longs;picientibus &longs;emper videntur in eodem cœli loco, hoc e&longs;t è regione Solis, vel Lunæ; &longs;imiliter Galaxia in aere omnibus vndecunque intuentibus appa­reat in eadem cœli parte, ide&longs;t ex aduersò eorumdem &longs;yderum, quæ cœle­&longs;tem lacteam viam conficiunt. Porrò qui &longs;ic mentem Ari&longs;t. exponunt, nul­lo modo po&longs;&longs;unt à Mathematicis redargui per rationem de&longs;umptam à di­uer&longs;itate a&longs;pectus (quam po&longs;tea explicabo) quamuis phy&longs;icis rationibus re­fellantur. Alij &longs;unt, quorum &longs;ententia magis videtur improbanda, cò quod Ari&longs;t. &longs;ummum Philo&longs;ophum pueriliter in a&longs;tronomia lap&longs;um fateri cogan­tur. Exi&longs;timant hi Galaxiam hanc Ari&longs;totelicam nihil aliud e&longs;&longs;e, quàm ip­&longs;as tenues exhalationes in aere &longs;ubuectas, directèque infra &longs;tellas illas la­cteum circulum in cœlo con&longs;tituentes nobis obiectas. qui præter innumera, ac magna ab&longs;urda è naturali Philo&longs;ophia petita, vnum maximum ex A&longs;tro­nomia, nempè ex diuer&longs;itate a&longs;pectus de&longs;umptum, nullo modo vitare po&longs;­&longs;unt; e&longs;tque; huiu&longs;modi, quia &longs;i lacteus hic circulus e&longs;&longs;et in aere, non ab om­nibus, neque ex omni terræ loco per eadem &longs;ydera commeare cerneretur, &longs;ed è diuer&longs;is, & præcipuè ab inuicem valde di&longs;&longs;itis, circa diuer&longs;a a&longs;tra &longs;e &longs;e ocu­lis no&longs;tris obijceret: at te&longs;timonio &longs;en&longs;us con&longs;tat, Galaxiam &longs;emper in eo­dem loco; eademque; à &longs;yderibus fixis di&longs;tantia albicare, ergò nullo modo viam hanc in aere qua&longs;i pendulam fabricare debemus. rationem hanc di­uer&longs;itatis a&longs;pectus a&longs;tronomicè magis explicatam reperies apud Clauium in &longs;phæra. Porrò hæc ratio quamuis adeo certa, ac no&longs;tra tempe&longs;tate vul­gata, parum tamen à nonnullis de rebus Meteorologicis commentaria con­farcinantibus intellecta, minimè eos ab&longs;terrere potuit, quin prædictam opi­nionem, non &longs;olum Ari&longs;toteli imponerent, verum etiam ip&longs;i tanquam veram a&longs;truerent: huiu&longs;modi patiuntur incommoda, qui ab&longs;que Mathematicarum auxilio Philo&longs;ophiam aggrediuntur.

142

Eodem cap. (Ad hæc autem locus plenus e&longs;t a&longs;tris maximis, & fulgidi&longs;&longs;imis, & adhuc &longs;par&longs;is vocatis) non &longs;olum viam hanc lacteam a&longs;tris plurimis refer­ti&longs;&longs;imam e&longs;&longs;e videmus, &longs;ed præterea eandem &longs;tellarum admodum feracem appellare licebit, &longs;i quidem &longs;tellæ omnes illæ nouæ, quæ no&longs;tra tempe&longs;tate apparuerunt, omnes in hac via exortæ &longs;unt. prima enim anno 1572. efful&longs;it in Ca&longs;&longs;iopea; altera anno 1600. in Cygno. tertia demum anno 1604. in Sa­gittario, quæ omnes con&longs;tellationes intra lacteum circulum continentur. Veri&longs;&longs;imum præterea e&longs;&longs;e hoc idem confirmatur in&longs;trumenti illius mirabi­lis auxilio, quod &longs;uperiori anno in Belgio excogitatum, & po&longs;tea in Italia à Galilæo perfectius redditum e&longs;t, quodque; ip&longs;e primum Italicè Cannocchiale, Latinè verò, & quidem aptè à Græcis mutuato vocabulo alius Tele&longs;copium appellauit: hoc inquam &longs;pecillo adhibito per&longs;picuum &longs;tatim fit non &longs;olum in via lactea innumeras &longs;tellas contineri, verum quid ip&longs;a &longs;it, certò certius con&longs;tat; &longs;ed &longs;atius e&longs;t ip&longs;ius Galilæi verba ex Nuncio &longs;ydereo referre: Quod tertio inquit, loco à nobis fuit ob&longs;eruatum e&longs;t ip&longs;iu&longs;met lactei circuli e&longs;&longs;en­tia, &longs;en materies, quam Tele&longs;copij beneficio adeò ad &longs;en&longs;um licet intueri, vt & altercationes omnes, quæ per tot &longs;æcula Philo&longs;ophos excruciarunt ab oculata certitudine dirimantur, nosque; à verbo&longs;is di&longs;putationibus liberemur: e&longs;t enim Galaxia nihil aliud, quàm innumerarum &longs;tellarum coaceruatim con&longs;itarum congeries, in quancunque enim regionem illius &longs;pecillum dirigas, &longs;tatim &longs;tellarum ingens fre quentia &longs;e &longs;e in con&longs;pectum profert, quarum com­plures &longs;atis magnæ, ac valdè con&longs;picuæ videntur; &longs;ed exiguarum multitudo pror&longs;us inexplorabilis e&longs;t. hæc ille.

143

Eodem cap. (Con&longs;ideretur autem & circulus, & quæ &longs;unt in ip&longs;o a&longs;tra ex de­&longs;criptione) id e&longs;t, con&longs;ideretur Galaxia, & a&longs;tra ip&longs;ius in&longs;piciantur diligenter ex de&longs;criptione alicuius Globi a&longs;tronomici, in quo &longs;olent A&longs;tronomi omnes con&longs;tellationes, ac &longs;tellas &longs;uis locis reddere, atque etiam lacteum ip&longs;um cir­culum graphicè effingere. huiu&longs;modi globum veteres &longs;ph&ecedil;ram Aratæam di­cebant ab Arato Poeta græco, qui con&longs;tellationes omnes carmine pro&longs;e quu­tus e&longs;t, ac proinde globum hunc ordine expo&longs;uit:

144

Eodem cap. (Spar&longs;a autem vocata) putò &longs;par&longs;a hæc &longs;ydera illa e&longs;&longs;e, quæ recentiores informia appellant, eò quod ad aliorum a&longs;teri&longs;morum formas minimè reuocentur.

145

Summa 4. cap. 1. (In A&longs;ia igitur plurimi ex Parna&longs;&longs;o vocato monte videntur &longs;tuentes) rectè dubitat Alexander, qua ratione mons Parna&longs;&longs;us ab Ari&longs;t. po­natur in A&longs;ia, cum certò certius con&longs;tet, ip&longs;um in Græcia Europæ regione &longs;itum e&longs;&longs;e. fortè legendum e&longs;t, vt vult Vicomercatus, ex Paropame&longs;&longs;o, non autem ex Parna&longs;&longs;o, quamuis Græci codices aduer&longs;entur; Paropame&longs;&longs;um namque Plinius, & Strabo in A&longs;ia collocant, voluntque; ip&longs;um e&longs;&longs;e iugum quod­dam montis Cauca&longs;i: Cauca&longs;um autem &longs;upra Pontum orifi, & v&longs;que ad Hir­canum, & vltra mare per totam A&longs;iam &longs;e proferre, tradunt veteres Geo­graphi. vide The&longs;aurum geographicum Abrahami Ortelij. Strabo lib. 15. &longs;ic: Indiam à &longs;eptentrione Tauri extrema terminant, ab Ariana v&longs;que in orientale mare, quæ extrema indigenæ particulatim nominant Poropami&longs;&longs;um, Emodum, Imauum, & alijs nominibus: Macedones verò Cauca&longs;um vocant.

146

Ibidem (Apparet mare, quod e&longs;t extra) intelligit illud mare Oceanum, quod Arabiam, ac Per&longs;iam alluit, Indicoque; Oceano committitur: quodque; à pri­&longs;cis Geographis Rubrum mare appellatur, cuius alterum Rubrum mare, quod inter Africam, & Arabiam &longs;e in&longs;inuat, e&longs;t quidam &longs;inus, quem nunc communiter omnes Rubrum mare appellant. de illo inquam meritò intel­ligit Alexander, non de hoc Aegyptiaco, cum ex a&longs;pectu illius à monte Pa­ropame&longs;&longs;o, &longs;equatur ip&longs;um e&longs;&longs;e editi&longs;&longs;imum, quod non &longs;equeretur ex altero ob illius propinquitatem. Dixit autem mare, quod e&longs;t extra, ide&longs;t extra terram habitatam, ad di&longs;tinctionem maris Mediterranei, quod e&longs;t intra terram habitatam, ac propterea Mediterraneum dictum e&longs;t.

147

Ibidem (Ex hoc igitur fluunt & alij fluuij, & Bactrus, & Choa&longs;pes, & Ara­xes. ab hoc autem ab&longs;cinditur Tanais pars exi&longs;tens in Meotidem paludem fluit au­tem, & Indus ex ip&longs;o, omnium fluuiorum fluxio maxima) hæc omnia &longs;unt fal&longs;a, & impo&longs;&longs;ibilia; nam cum Bactrus Bactrianam regionem irriget, quæ e&longs;t vl­tra Per&longs;iam, Choa&longs;pes verò Per&longs;iam ip&longs;am, Indus denique in India oriatur: quì fieri pote&longs;t, vt in Regionibus adeò inuicem di&longs;&longs;itis orti fluuij ab eodem quoque Paropame&longs;&longs;o monte ortum ducant. nec minus fal&longs;um e&longs;t illud de Ta­nai, quod &longs;it qua&longs;i ip&longs;ius Araxis ramus quidam, Tanais enim ex Riphæis montibus Scythiæ delabitur in Meotidem paludem longè longius ab Araxi. eumque; terminum inter Europam, & A&longs;iam Geographi con&longs;tituunt, vnde Diony&longs;ius Afer &longs;ic cecinit:

Europam, atque A&longs;iam Tanais di&longs;terminat amnis.

verùm huiu&longs;modi errata Ari&longs;t. atque adeò Geographis illius temporis con­donanda &longs;unt, cum nondum Geographia &longs;atis exculta e&longs;&longs;et.

De altitudine montis Cauca&longs;i.

148

Eod. cap. (Cauca&longs;us autem maximus mons e&longs;t eorum qui ad orentem æ&longs;tiua­lem, & multitudine, & altitudine &longs;igna autem altitudinis quidem, quia videtur & à vocatis Profundis, & à nauigantibus in Stagnum in&longs;uper il­lu&longs;trantur à Sole ip&longs;ius &longs;ummitates, v&longs;que ad tertiam partem nocte, & ab aurora, & iterum a ve&longs;pera) Cauca&longs;us mons &longs;itus e&longs;t inter mare Euxinum, & Ca&longs;pium, &longs;upra Cholchidem, & Iberiam regiones, vbi polus eleuatur 47. circiter grad. ac re&longs;pectu Græciæ, & maris Euxini vergit ad eam mundi pla­gam, vnde illis æ&longs;tiuo tempore Sol oritur. ait Ari&longs;t. eum e&longs;&longs;e omnium mon­tium illius plagæ alti&longs;&longs;imum, quod probat primò, quia admodum à longè cernitur, nimirum ab illo Euxini loco, qui Profunda vocatur, eò quòd à Nau­tis nu&longs;quam ibi fundus reperiatur. & præterca à Nauigantibus in Stagnum, &longs;iue in Meotidem paludem, quæ quidem loca minimùm di&longs;tant a Cauca&longs;o 560. milliaribus. Secundò, probat il ius altitudinem ex eo, quòd &longs;ummi­tates ip&longs;ius v&longs;que ad tertiam partem nocte, & ve&longs;peri à Sole illu&longs;trentur. Lo­cum hunc fuè pertractat eruditi&longs;&longs;imus Iacobus Mazonius &longs;ectione 3. & 4. de Comparatione Platonis, & Ari&longs;t. quo in opere plurima habet ex Mathe­maticis de&longs;umpta, quibus naturalem Philo&longs;ophiam mirificè illu&longs;trat, mani­fe&longs;tumque; reddit, quàm nece&longs;&longs;ariæ &longs;int Mathematicæ ad philo&longs;ophicæ veri­tatis in&longs;pectionem. Is igitur &longs;ect. 3. cap. 5. de hoc Ari&longs;t. loco &longs;ie loquitur: hic locus diligenter expendendus videtur tum quia difficillimus e&longs;t, tum quia multis an&longs;am dedit reprehendendi Ari&longs;t. tanquam puerilia effutientem. tex­tus itaque Ari&longs;t. duplicem habet &longs;en&longs;um; alter à quo non abhorret Alexander; vt tertia illa pars ad montem referatur, qua&longs;i dicat, quod antequam Sol ima montis illu&longs;tret, illuminat illius cacumen v&longs;que ad tertiam montis partem: &longs;ed hæc Mazonij expo&longs;itio nulla e&longs;t, cuiu&longs;libet enim montis etiam medio­cris altitudinis Sol illu&longs;trat non &longs;olum tertiam partem, &longs;ed & dimidium, & duas tertias, & ferè totum, antequam ad planam illius ba&longs;im de&longs;cendat. Ego &longs;ic exponendum cen&longs;eo, vt Ari&longs;t. dicat, mane, ide&longs;t initio Crepu&longs;culi matutini, & ve&longs;pere, ide&longs;t, in fine Crepu&longs;culi ve&longs;pertini ip&longs;ius tertiam par­tem illuminatam con&longs;pici ab ijs, quorum horizonti tunc incipit, vel de&longs;init Crepu&longs;culum; ex quibus illi nece&longs;&longs;ariò re&longs;pectu Cauca&longs;i &longs;unt occidentales, quì manè hoc vident, vti &longs;unt ij, qui in Euxino, &longs;eu Ponto, & Meotide naui­gant, vel loca proxima inhabitant: illi verò, qui in fine Crepu&longs;culi ve&longs;per­tini hoc cernunt, nece&longs;&longs;ariò re&longs;pectu Cauca&longs;i erunt orientales. Alter huius loci &longs;en&longs;us e&longs;t, ait Mazonius, vt non de tertia montis parte, &longs;ed de tertia noctis portione loquatur, ita vt manè. v. g. initio tertiæ, & vltimæ noctis parte, cacumen Cauca&longs;i illuminetur. hæc ille. vbi animaduertendum expo­&longs;itionem hanc parùm differre à no&longs;tra modò allata, cùm vtraque in idem tem­pus recidat; nam &longs;i dixerimus initio Crepu&longs;culi matutini illuminari ter­tiam partem Cauca&longs;i, tempus hoc coincidit cum initio tertiæ partis noctis, quantitas enim Crepu&longs;culi in poli eleuatione 47. grad. qualem habet Cau­ca&longs;us, per totam æ&longs;tatem tres horas plus minus continet, vt patet ex tabu­la quantitatis Crepu&longs;culi, quæ e&longs;t apud Nonium, & apud Clauium in &longs;phæ­ra vltimæ editionis; quæ quantitas reperiri geometrico calculo pote&longs;t, vt docent Nonius, Clauius, & Maginus lib. 10. primi mob. quod quidem trium circiter horarum tempus e&longs;t tertia ferè noctis pars in ijs regionibus, quibus polus eleuatur 47. grad. &longs;iue ergo dicamus id contingere initio Crepu&longs;culi, &longs;iue initio tertiæ partis noctis, erit idem tempus, trium &longs;cilicet horarum. &longs;i ergo, inquit Mazonius, &longs;equamur priorem declarationem, nece&longs;&longs;arium e&longs;t dicere, quod ea tertia pars montis, quæ initio auroræ Solis lumine per­funditur, &longs;it ea montis altitudo, qua ip&longs;e exuperat illam aeris regionem, vnde Crepu&longs;culum incipit apparere. quo po&longs;ito aptè, ac &longs;agaciter altitudi­nem Cauca&longs;i inue&longs;tigat hoc pacto. præmittit autem &longs;eptem propo&longs;itiones apud Mathematicos manife&longs;tas, quas ego mi&longs;&longs;as facio cum non mihi nece&longs;­&longs;ariæ videantur. po&longs;tea &longs;ic di&longs;currit; His ergo ita &longs;e habentibus, dico nos in­uenire po&longs;&longs;e viam, qua &longs;altem rudi Minerua, montis altitudinem comper­tam habeamus. &longs;i enim in principio Crepu&longs;culi v. g. matutini (ita enim, vt &longs;upra annotaui intelligendus e&longs;t Ari&longs;t.) illuminatur tertia pars, nece&longs;&longs;arium vidctur tertiam illam partem &longs;upra cam regionem collocari, ex qua Cre­pu&longs;culum in planitie apparere incipit, &longs;ed illa regio ex Alhazino, & Vitell. de Crepu&longs;culis milliaribus 52. à terra recedit, ergo duæ tertiæ montis par­tes, quæ Solem initio auroræ non vident, &longs;unt 52. milliaria ad perpendicu­lum, & tertia alia pars illuminata e&longs;t ad perpendiculum 26. milliaria: ita vt totius montis altitudo perpendicularis &longs;it 78. mill. &longs;ed papè in quos acu­leos imprudens me conieci? rident enim hoc Ari&longs;t. dictum Mathematici, putant enim eum pueriliter lap&longs;um e&longs;&longs;e. Cæterum ego pro præceptoris tu­rela, dico eum &longs;equutum e&longs;&longs;e famam. hæc Mazonius, quorum nonnulla in­digent con&longs;ideratione cuiu&longs;modi, &longs;unt illa, quando dicit, nece&longs;&longs;arium vi­detur, quod ea pars &longs;upra eam regionem attollatur, vnde Crepu&longs;culum in planitie apparere ineipit. videtur enim his verbis velle dicere, quod quan­do habitantibus planitiem, quæ e&longs;t ad pedem montis Cauca&longs;i, vel horizon­tem eiu&longs;dem, incipit Crepu&longs;culum, ij&longs;dem etiam tunc tertia montis pars appareat illuminata; in quo &longs;en&longs;u errat po&longs;tea in colligenda montis altitu­dine, quamuis enim verum e&longs;&longs;et partem illuminatam eminere totam &longs;upra 52. milliaria, non tamen &longs;equitur ip&longs;am &longs;olam eminere, &longs;ed alia etiam pars eminere pote&longs;t, quod &longs;ic geometricè demon&longs;trabo. de&longs;cribatur enim figura

illa, qua ad vaporum altitudines indagandas vtuntur Alhazenus, Vitellio, & Clauius, in qua terræ globus e&longs;t F L G E, regiò vaporum, & exhalatio­num M X N T. horizon a&longs;tronomicus O P. phy&longs;icus Q R, tangens terram in puncto F, vbi etiam ponendus e&longs;t huius horizontis habitator, vnà cum. Cauca&longs;o F V. Sol A B C, qui initio Crepu&longs;culi infra horizontem O P, depri­mitur gr. 18. vti ab A&longs;tronomis compertum e&longs;t, hoc e&longs;t, arcum D P, e&longs;&longs;e grad. 18. radius autem C I K, tangens terram, incipit illuminare halitus, qui &longs;unt ad K, in extremo horizonte &longs;en&longs;ibili F K. quique po&longs;&longs;unt videri ab oculo in F, ide&longs;t ab huius horizontis habitatore. Cæterùm prædicti autho­res po&longs;t longam ratiocinationem ex calculo planorum triangulorum tandem o&longs;tendunt in triangulo H F K, latus H K, continere milliaria 3631. ex quo detracta H L, &longs;emidiametro terræ, quæ e&longs;t milliar, 3579. reliqua L K, &longs;um­ma halitunm eleuatio relinquatur 52. milliar. quibus ab ip&longs;is demon&longs;tra­tis, &longs;i H F, terræ &longs;emidiameter, quæ continet milliar. 3579. ponatur &longs;inus totus 100000. & latus F K, ponatur tangens anguli ad H, quem pr&ecedil;dicti au­thores probant e&longs;&longs;e grad. 8. 54. erit F K, tangens partium 15659. fiat igi­tur per 2. pro. trjang. rectil. Clauij;

vt H F, &longs;inus totus,ad milliar.ita tangens F K,ad milliar.100000.3579.15659.560.

& inueniemus per auream regulam latus F K, continere milliar. 560. quan­ta &longs;cilicet e&longs;t di&longs;tantia ab oculo no&longs;tro ad exhalationes Crepu&longs;culi initium efficientes. Con&longs;ideremus iam triangulum F K V, vt ip&longs;ius latus F V, quæ e&longs;t Cauca&longs;i altitudo, in milliaribus innote&longs;cat. iam ip&longs;ius latus F K, inno­tuit, angulus verò ad F, e&longs;t rectus; at angulus ad K, &longs;ic manife&longs;tabitur; in quadrilatero F K I H, quatuor anguli &longs;unt æquales 4. rectis ex 32. primi. duo autem F, & I, &longs;unt recti ex 18. 3. ergo reliqui duo H, & K, æquales erunt duo­bus rectis, quorum alter H, e&longs;t gr. 17. 48. vt præditi Mathematici o&longs;tendunt, reliquus igitur ad K, erit gr. 162. 12. vt compleat duos rectos. qui &longs;i detra­hatur à duobus rectis, qui &longs;unt deinceps ad lineam F K, reliquus angulus F K V, erit gr. 17. 48. &longs;i ergo latus F K, notum ponatur &longs;inus totus 100000. latus verò F V, tangens anguli noti, erit ip&longs;a 32100. fiat igitur,

vt F K, &longs;inus totus,ad milliar.ita F V, tangensad milliar.100000.560.32100.180.

inueniemusque; latus F V, continere milliar. 180. cuius pars F X, quæ e&longs;t in­fra habituum altitudinem continet milliar. 52. quibus detractis ex 180. re­manent 128. pro tota X V, quæ tota e&longs;t &longs;upra vapores, nondum tamen illu­minata. vnde patet Mazonium erra&longs;&longs;e in colligenda hoc modo Cauca&longs;i al­titudine, ex prima Crepu&longs;culi illuminatione in horizonte Cauca&longs;i facta, cum ex præmi&longs;&longs;o calculo con&longs;tet partem montis F V, totam tunc temporis e&longs;&longs;e tenebro&longs;am, quamuis &longs;uperet multò regionem vaporum, contrà quàm ip&longs;e putabat, &longs;uperat enim eam milliar. 128. quare duæ tertiæ montis erunt non 52. mill. vt ip&longs;e ait, &longs;ed mill. 180. & proinde tota altitudo erit mill. 270. quod &longs;anè ridiculum e&longs;t, cum nullius montis altitudo &longs;e&longs;quimilliare tran­&longs;cendat. Quod &longs;i &longs;equamur alteram expo&longs;itionem, vt nimirum Ari&longs;tor. lo­quatur non de tertia montis parte, &longs;ed noctis, ita vt dicat, circa initium tertiæ partis noctis apicem montis illu&longs;trari, altitudo eius erit tantum­modo 180. quot continet latus F V. vt vidimus, quæ quamuis illa minor &longs;it, adhuc tamen ab&longs;urda e&longs;t.

Si vrò dixerimus Ari&longs;t. intelligere hæc omnia, non re&longs;pectu horizontis Cauca&longs;i, &longs;ed alterius, cuius habitator in principio &longs;ui Crepu&longs;culi tertiam Cauca&longs;i partem iam illu&longs;tratam videat, vti accideret &longs;i Cauca&longs;us &longs;tatuere­tur in L K, vbi incipit Crepu&longs;culum habitanti in F. tunc e&longs;&longs;et altitudo tanta, quanta colligit Mazonius, &longs;i tamen Ari&longs;t. intelligatur de tertia montis par­te; e&longs;t enim L K, altitudo habituum 52. mill. & duæ tertiæ montis, quare totus mons erit 78. &longs;i autem intelligatur circa tertiam noctis partem, mon­tis apicem illuminatum videri ab habitatore F, &longs;ic altitudo eins erit tan­tummodo 52. mill. quæ tamen adhuc omnem veritatem nimium &longs;uperat. Cum ergo hinc inde &longs;equantur ab&longs;urda, putat Mazonium excu&longs;andum e&longs;&longs;e Ari&longs;tot. dicendo eum &longs;equutum e&longs;&longs;e famam, loquutumque; e&longs;&longs;e populariter. Verumenimuerò &longs;apientiores iudicent num rectè philo&longs;ophus, cuius e&longs;t re­condita, atque abdita docere, excu&longs;etur, &longs;i dicatur, eum, popularem famam &longs;equutum e&longs;&longs;e.

Tandem monendus mihi Lector e&longs;t, in demon&longs;tratione Magini, quæ e&longs;t apud Mazonium &longs;ect. 4. citati operis; a&longs;&longs;umi radium Solis tangentem terræ globum, qui cum horizonte faciat angulum gr. 18. quod fal&longs;um e&longs;t, &longs;olus enim radius centralis, qui à centro Solis ad centrum terræ ducitur talem facit angulum, atque hac de cau&longs;a ip&longs;e colligit altitudinem no&longs;tra maiorem; no&longs;tra e&longs;t 270. mill. &longs;ua verò 276. vbi etiam, &longs;icut & nos a&longs;&longs;umit horizon­tem Cauca&longs;i.

Aduertendum tandem Mazonium admodum aduer&longs;antia loquutum e&longs;&longs;e, &longs;ect. enim 3. demon&longs;tratinè concludit altitudinem 76. mill. &longs;ect. verò 4. &longs;i­mul cum Magino demon&longs;tratiuè pariter colligit altitudinem eiu&longs;dem 276. m. quæ nimis ab innicem di&longs;crepant, cum tamen vtrobique demon&longs;tret, & ve­ritas &longs;it vna. At verò cau&longs;a huius di&longs;crepantiæ e&longs;t, quòd &longs;ect. 3. accipit Cre­pu&longs;culum non horizontis Cauca&longs;i, &longs;ed illius, in cuius extremitate orientali, vbi incipit Crepu&longs;culum, Cauca&longs;us &longs;itus &longs;it, di&longs;tetque; ab habitatore 560. m. vt &longs;upra o&longs;tendimus. &longs;ect. verò 4. accipit horizontem ip&longs;ius Cauca&longs;i, vt ex figura illic de&longs;cripta videre e&longs;t. ex hac igitur horizontum varia &longs;uppo&longs;itio­ne, varia etiam altitudo colligitur, quamuis vtrobique ex vtraque &longs;uppo&longs;itio­ne vtramque altitudinem rectè concludat. Atque hæc de Cauca&longs;o &longs;ufficiant.

149

Eodem cap. (Ex Pyreneo autem, hic autem est mons ad occidentem æquino­ctiaiem in Gallia, flaunt l&longs;ter, & Tarte&longs;&longs;us, iste quidem extra columnas, I&longs;ter au­tem per totam Europam in Pontum Euxmum) Ari&longs;t. fortè &longs;equutus e&longs;t Herodo­tum, qui falsò tradit I&longs;trum, &longs;ine Dannbium ex Pyreneis de&longs;luere, nam Iu­ce clarius con&longs;tat ip&longs;um ex ijs Alpibus, quæ Heluetiorum montes dicuntur, propè Ba&longs;ileam ex Adula monte ortum ducere. neque verum e&longs;t Tarte&longs;&longs;um, quem & Bœtim alij nominant ex Pyreneis de&longs;cendere. Tarte&longs;&longs;um hunc Ma­ginus putat e&longs;&longs;e Tagum, cui fauet vocabulorum quali&longs;cunque &longs;imilitudo. extra tamen columnas Herculis qui&longs;quis &longs;it in Oceanum occidentale illa­bitur. Igno&longs;cenda &longs;unt i&longs;ta Ari&longs;t. tunc enim Geographia nondum adoleuerat.

150

Ad finm eiu&longs;dem cap. (Et circa Ligu&longs;ticam non minor Rhodano ab&longs;orbetur quiam &longs;lus, & iterum egreditur &longs;ecundum alium locum) incompertum & hoc Ari&longs;t. vt &longs;uperiora, ob Geographiæ illius &longs;eculi imperfectionem, nu&longs;quam enim in tota Liguria quidpiam tale reperitur.

De Terræ rotunditate.

151

Svmma 4. cap. 2. quod e&longs;t de permutatione, & vici&longs;&longs;itudine aquarum, & continentis. Pergratum Lectori fore exi&longs;timaui, nec alienum ab in&longs;tituto, &longs;i occa&longs;ione huius permutationis maris, ac terræ, rem ex­po&longs;uero &longs;citu digniffimam, quam pridem ob&longs;eruare cœpi, ac in dies ob&longs;eruo, præ&longs;ertim cum nullus præteritorum &longs;criptorum, quod &longs;ciam, eam literis mandauerit: Terræ &longs;cilicet totius molem paulatim reduci ad perfe­ctam &longs;phæricitatem, ita vt aliquando nece&longs;&longs;e &longs;it futurum ip&longs;am à mari inun­dari, atque omninò inhabitabilem reddi. Prrmum igitur illud ex &longs;acris lite­ris &longs;tatuendum, orbem terræ in &longs;uo primordio fui&longs;&longs;e ab opifice rerum om­nium, figura &longs;phærica donatum, hoc e&longs;t ab&longs;que montium eminentijs, atque vallium depre&longs;&longs;ionibus. quod patet ex eo, quia tunc tota Mari obtegebatur, ita vt minimè apta e&longs;&longs;et animantibus ad inhabitandum. redditam verò ha­bitabilem, cum ip&longs;ius conditor quandam ip&longs;ius partem humiliorem, & quan­dam eminentiorem effeci&longs;&longs;et; transferendo nimirum maximam terræ por­tionem ex vno loco in alium, vnde illic maris concauitas, i&longs;tic verò mon­tium &longs;ublimitas emer&longs;it. quo facto aquæ omnes in loca illa decliuiora &longs;ua &longs;pontè rece&longs;&longs;erunt, quæ aquarum congregatio Mare appellatum e&longs;t. Hine nonnulli auctores graui&longs;&longs;imi a&longs;&longs;erere non dubitarunt, montes conflatos fui&longs;­&longs;e ex terra illa, quæ locum illum occupabat, quem po&longs;tea maria inua&longs;erunt. quæ cum ita &longs;int. &longs;equitur terram nunc e&longs;&longs;e extra naturalem &longs;uam figuram, & propterea in quodam &longs;tatu violento, violentum autem nullum perpetuum. præ­terea cum terra &longs;it grauior quàm aqua, nulla ratione deberent terræ partes &longs;uperiores a quæ &longs;uperficiem &longs;uperare, cuius tamen contrarium accidit, nam &longs;uperficies ip&longs;a terræ, & multò magis montana loca &longs;uperficiem maris cuiu&longs;­uis non parum &longs;uperant; quæ altera violentia terræ, & aquæ ine&longs;t, & ideò minimè mirum e&longs;t, imò vtriu&longs;que naturæ valdè conueniens terram redire ad pri&longs;tinam, ac primigeniam figuram, ex qua con&longs;ectarium erit aquam quoque &longs;uam pariter illam &longs;ibi primæuam recuperaturam e&longs;&longs;e figuram. cau&longs;am au­tem re&longs;tauratri huius terrenæ rotunditatis e&longs;&longs;e aquas tum pluuiales, tum fluuiales iamdiù ob&longs;eruauimus, vt ex &longs;equentibus ob&longs;eruationibus patebit.

Primò, videmus flumina quotidie montium radices corrodere, ac qua&longs;i &longs;uffodere, ita vt pa&longs;&longs;im ex hoc, vel illo monte magnas faciant ruinas, ac pr&ecedil;­cipitia, atque hiac inde prærupti appareant montes, vt meritò legamus apud Iob cap. 14. allunione paulatim terra con&longs;umitur. humum porrò illam ex montibus delap&longs;am &longs;emper ad loca humiliora fluuij &longs;ecum detrahunt. Ex continua etiam hac inter montes corro&longs;ione facta manife&longs;tè apparet, flumi­num alueos in montanis modò e&longs;&longs;e humiliores quàm olim, quamuis contra­rium accidat alueis &longs;luuiorum per plana decurrentium, qui modò altiores &longs;unt quam exordio mundi, vt paulò po&longs;t o&longs;tendam. Illud autem liquidò apparet ex &longs;ignis, &longs;eu &longs;ymbolis, &longs;eu ex &longs;imilitudine terræ, aut lapidis, quæ in alti&longs;&longs;imis fluminum ripis hinc inde pa&longs;&longs;im videntur, quæ indicio &longs;unt montes illos iam olim fui&longs;&longs;e continuos, atque vnam, eandemque; terram continentem, ante quaflumen eos ab inuicem &longs;epararet; flumenque; ip&longs;um olim altius, vbi &longs;unt &longs;igna illa ambula&longs;&longs;e; quemadmodum in Pyramo Ciliciæ amne ob&longs;eruauit Strabo, dum libro 12. de illius ripis hæc tradit, mira præterea e&longs;t montis cæ&longs;ura, per quam alueus ducitur; nam quemadmodum in petris per medium &longs;ci&longs;&longs;is contingit, alterius partis depre&longs;&longs;ioribus ita conuenire alterius partis emi­nentias, vt coniungi po&longs;&longs;int: &longs;ic videre e&longs;t imminentes flumini petras vtrin­que ferè v&longs;que ad montis &longs;umma pertendentes duorum, triumuè iugerum &longs;patio concauitates qua&longs;dam eminentijs oppo&longs;itas habere. hæc Strabo de vno, quod nos in pluribus ob&longs;eruauimus. Pr&ecedil;terea videmus quotidie pluuias aquas, idem quantum po&longs;&longs;unt efficere, &longs;uperficies montium, eorum maxi­mè, qui coluntur, perpetuò ab&longs;umentes, atque ad loca conuallium deducen­tes. hinc videre e&longs;t, montes cæteris duriores, vt &longs;unt lapido&longs;i, cæteris altio­res reman&longs;i&longs;&longs;e; quippe qui magis & pluuijs, & fluuialibus aquis &longs;ua duritie ob&longs;titerunt. idem montani incolæ omnes confirmant, qui omnes aiunt &longs;ibi hanc montium demolitionem iampridem innotui&longs;&longs;e, ex eo quod nonnulli montes olim &longs;ibi impedimento erant, ne arcem, turremuè in vlteriore mon­te &longs;itam con&longs;picerent, quam deinde plures po&longs;t annos intermedio monte depre&longs;&longs;o, commodè videbant. Ad hæc; antiqua in montium verticibus con­&longs;tituta ædeficia, propterea intercidunt, quia terra hinc, & inde ab aquis paulatim confumpta, deor&longs;umque; delap&longs;a, fundamenta ip&longs;orum nuda primò relinquit; deindé terra etiam ip&longs;a, qua fundamenta innitebatur &longs;en&longs;im de­lap&longs;a, ip&longs;a quoque fundamenta vnà cum toto ædeficio nece&longs;&longs;e e&longs;t collabi, hu­ius &longs;igna infinita propemodum videri po&longs;&longs;unt; vnum tamen, quod toti orbi confpicuum e&longs;t, non ommittam; Capitolium videlicet Romanum, cuius modo fundamenta tota extant, quæ olim altè &longs;ub terram de&longs;cendebant. vi­de pulcherrimam hac de re tractationem apud Georgium Agricolam lib. 3. cap. 1. qui amplius addit illud, quod & mihi maximè probatur; flumina ni­mirum producere montes, collesque; hoc modo; vult enim initio mundi non extiti&longs;&longs;e tot particulares montes ab inuicem di&longs;cretos, &longs;ed fui&longs;&longs;e perpetua quædam terræ iuga eminentia quidem, &longs;ed non tot vallibus di&longs;&longs;ecta: v. g. mons no&longs;ter Apenninus erat iugum, &longs;iue dor&longs;um quoddam terræ eminens quidem, &longs;ed nullis vallibus in tot particulares colles, aut montes di&longs;&longs;ectum; &longs;ed po&longs;tquam flumina à &longs;ummitate ip&longs;ius deor&longs;um fluere cœperunt; paula­tim corrodentes humum in dies magis, ac magis effecerunt valles, atque hac ratione in colles, montesque; plurimes totus Apenninus diui&longs;us e&longs;t. hæc de montibus &longs;ufficiant, nunc ad plana de&longs;cendamus.

Contrarium igitur omninò accidere videmus in planis, quoniam eædem aquæ, quæ ex montibus quotidie terram &longs;ecum deducunt, eam ad humilio­ra loca, vt &longs;unt plana, & campe&longs;tria, &longs;iue ibi &longs;int maria, &longs;iue arida, compor­tant, eamque; ibidem deponunt. hinc videmus antiqua ædeficia in planis locis ex&longs;tructa, e&longs;&longs;e iam penè tota &longs;epulta, contra quam in montanis, cuius exem­plum habes etiam Romæ propè ip&longs;um Capitolium, in Arcu triumphali Sep­timij, qui iam ferè totus ruino&longs;a vndique terra obruitur. &longs;ic Pantheon. &longs;ic etiam templa Epi&longs;copalia, quæ plerunque &longs;atis peruetu&longs;ta &longs;unt, admodum infra terram con&longs;piciuntur. Idem affirmant cœmentarij, & architectores omnes, quibus vbique terrarum, dum in planis ædeficiorum fundamenta ex­canant, occurrit primò terra quædam, quam ip&longs;i motam appellant, quæ li­gnis, ruderibus, ferramentis, numi&longs;matis, &longs;epulturis, varijsque; rebus per­mixta e&longs;t; qua eruta, reperitur terra alia, quam nunquam fui&longs;&longs;e motam, ap­paret, ex eo quod &longs;olida, ac benè compacta &longs;it, neque vllis externis rebus, præ&longs;ertim artificiatis admixta, terra illa, quam motam dicunt, variam va­rijs in locis &longs;ortita e&longs;t altitudinem, prout aquæ plurimum, vel minimum montanæ terræ huc, vel illuc comportarunt: alicubi vt hic Parmæ erit &longs;ex vlnarum, alibi viginti, vt Mutinæ; alibi triginta, vt Romæ, nonnullis in lo­cis. Comprobatur tandem hæc no&longs;tra ob&longs;eruatio ex arte illa, qua per ea&longs;­dem fluuiales aquas &longs;olent, tam loca depre&longs;&longs;iora per aggerationem paula­tim replere, atque eleuare: quàm etiam altiora per aquarum earumdem cor­ro&longs;ionem deprimere. qua in arte exercitati&longs;&longs;imum P. Augu&longs;tinum Spernac­ciatum no&longs;træ Societatis videmus modo de mandato Summi Pontificis Pa­dum, ac Renum Bononien&longs;em ob aggerationem &longs;tagnantes in mari emitte­re; cui totus hic no&longs;ter di&longs;cur&longs;us maximè probatur. Ex quibus omnibus &longs;e­quitur &longs;uperficiem terræ tam montium, quam planorum quotidie variari. illam nimirum deprimi, hanc attolli. vnde aliud maximum notandum &longs;e­quitur, videlicet hac tempe&longs;tate non e&longs;&longs;e eandem agrorum &longs;uperficiem, quæ erat antiquitus, cum in montanis agris &longs;it multò humilior, in campe&longs;tribus verò altior, quàm antiqua illa, ac primigenia; quapropter mirum videri non debet, &longs;i quorumdam locorum adeò immutata natura e&longs;t, vt quæ olim genero&longs;a vina ferebant, vel quouis alio e&longs;&longs;ent prædita munere, adeò dege­nerauerint, vt & vina, & alia nullius modò valoris, vel in para copia pro­ferant. Quod verò ad marium aggerationem &longs;pectat, dicimus ij&longs;dem aquis magnam arenarum copiam perpetuò impertantibus, fieri aggerationem, hoc e&longs;t littora quotidie magis cre&longs;cere, &longs;eu in mare ingredi, & con&longs;equen­ter mare recedere. quod primò Ari&longs;t. te&longs;timonio in hoc cap. comprobatur, cum quo pariter &longs;entiunt veteres Geographi, & Hi&longs;torici omnes. Ari&longs;t. igi­tur in comprobationem huius adducit primò magnam Aegypti aggeratio­nem; pars enim illa Aegypti, quæ Delta, Nilique; donum appellatur ab He­rodoto, ex arenis, & limo, ex Aethyopiæ montibus &longs;imul cum Nilo in mare delabentibus, e&longs;t conflata, atque antiquo littori addita, cui locum paulatim mare ce&longs;&longs;it; e&longs;tque; propterea donum Nili appellata, quod ab ip&longs;o illuc are­nas importante &longs;it facta. &longs;ecundum, Ari&longs;t. exemplum e&longs;t Ammonia Regio, cuius humiliora loca. f. maritima, palam e&longs;t, inquit, quod aggeratione facta, fiunt &longs;tagna, & continens: &longs;uccedente autem tempore, &longs;tagnans aqua ob nouam aggerationem de&longs;iccata e&longs;t, & iam annihilata. tertium e&longs;t Meotidis Paludis; At verò, ait, & quæ &longs;unt circa Meotidem Paludem creuerunt allu­uione fluuiorum tantum, vt multò minores magnitudine naues, nunc innare po&longs;&longs;int, quàm anno ab hinc &longs;exa ge&longs;imo. quare ex hoc facilè e&longs;t ratiocinari, quod & primò, vt multa &longs;tagnorum, ita & hoc opus e&longs;t fluuiorum, & tan­dem nece&longs;&longs;e e&longs;t totum fieri &longs;iccum. quartum e&longs;t illi Bo&longs;phorus Tracius; quod vnà cum præcedentibus &longs;atius e&longs;t apud ip&longs;um, vel potius apud eius expo&longs;i­torem Vicomercatum videre, vt breuitati con&longs;ulatur. Accedit & Plinij te­&longs;timonium, qui tradit multas terras na&longs;ci, non &longs;olum fluminum inuectu, &longs;d etiam marium rece&longs;&longs;u; &longs;ic mare ab Ambraciæ portu 10. millia pa&longs;&longs;uum; ab Athenarum verò quinque millia, & alijs in locis plus minu&longs;uè rece&longs;&longs;i&longs;&longs;e &longs;cri­bit. Huc facit locus quidam Strabonis ex lib. 12. de Pyramo Ciliciæ fluuio: &longs;ic; montes verò egre&longs;&longs;us tantum limum in mare deducit, partim ex Ca­taonia, partim ex Ciliciæ campis, vt huiu&longs;modi de co oraculum feratur;

Tempus erit rapidis olim cum Pyramus vndis In &longs;acram veniet conge&longs;io litore, Cyprum:

hic enim fluuius è regione Cypri in&longs;ulæ in mari influit, &c. hæc Strabo.

Verùm recentiora non de&longs;unt exempla. Rauenna olim erat in extremo littore &longs;ita, nunc paulatim aggeratione aucto litore, mare multum ab ea rece&longs;&longs;it. Patauium pariter, vt fertur mare alluebat, quod modo 25. pa&longs;&longs;uum millibus ab eo di&longs;tat. Aæ&longs;tuarium ip&longs;um Venetum, ob arenas à varijs &longs;lu­minibus in ip&longs;um immi&longs;&longs;as adeò fundum extulit, vt vix amplius nauigatio­ni &longs;it aptum, periculamque; &longs;it ne Venetiarum mirabilis locus, ex maritimo fiat terre&longs;tris. demum exemplum &longs;it Bononien&longs;ium Renus, qui quamuis exi­guus &longs;it torrens, paucis tamen annis Padum ip&longs;um, in quem immi&longs;&longs;us fue­rat arena ita repleuit, vt & &longs;ibi, & Pado magno vicinorum agrorum damno viam in mare ob&longs;truxerit. Cum igitur mare ob hanc adaggerationem co­gatur &longs;e quotidie magis recipere, fiatque; propterea alueus ip&longs;ius angu&longs;tior, atque clatior, nece&longs;&longs;e e&longs;t etiam ip&longs;am quoque maris aquam quotidie magis coangu&longs;tari, atque attolli, & aliquando futurum, vt exundare incipiat. quod iam pleri&longs;que in locis accidit, vt in littore Baltico, Danico, & Hollandico, quibus in locis &longs;ut hac tempe&longs;tate extructi prælongi, ac præalti aggeres contra maritimas innundationes: quibus antiquitus minimè fui&longs;&longs;e opus hi­&longs;toricorum, ac Geographorum &longs;ilentium comprobat. Hoc igitur modo ter­ra, qua montes, collesque; con&longs;tant paulatim ab aquis in maris concauitates deportata, cau&longs;a e&longs;t, vt mare &longs;en&longs;im modo hac, modo illac, terræ &longs;uperfi­ciei &longs;uperfundatur, terraque; iterum, quemadmodum exordio mundi inhabi­tabilis reddatur: quod tunc maximè accidct cum aquæ tam fluuiales, quàm pluuiæ, &longs;uper faciem terræ perpetuò di&longs;currentes, totam illam montanam terram in pri&longs;tinum locum, vbi ab initio fuerat, vndeque; &longs;ublata fuit, re&longs;ti­tuerint; tunc terra erit iterum rotunda, & &longs;phærica, hoc e&longs;t &longs;uæ primigeniæ iterum figuræ re&longs;tituetur: quapropter mare etiam rur&longs;us &longs;icut initio mundi totam terræ faciem circumquaque innundabit, quod probare volebam.

Tantum æui mutare potest longæua vetu&longs;tas.

Hinc nonnulla colligi po&longs;&longs;unt non minus notatu, ac &longs;citu, quàm præceden­tia digni&longs;&longs;ima, quibus Ethnicorum Philo&longs;ophorum error redarguatur, &longs;ides verò no&longs;tra magis roboretur: mundum nimirum ab æterno neutiquam ex­titi&longs;&longs;e, vel &longs;altem terram ab æterno non fui&longs;&longs;e hac figura præditam, qua nunc videmus, ncc mundum perpetuò duraturum. nam &longs;i hæc montuo&longs;a illi figu­ra ab æterno ine&longs;&longs;et, iampridem tota illa montium tubero&longs;itas fui&longs;&longs;et ab aquis exæ&longs;a, & con&longs;umpta: neque æterna erit, quia &longs;ucce&longs;&longs;u temporis, vt pro­bauimus, reducetur ad rotunditatem, atque à mari innun dabitur, & idcircò inhabitabilis, vnde nece&longs;&longs;ariò mortalium genus interibit. Quapropter ni&longs;i igne illo, quem &longs;acræ literæ innuunt catacly&longs;mus ille præueniatur, aqua mundus interiturus e&longs;&longs;et. &longs;ed de his hactenus.

Quoad magnum illud Diluuium, quod Ari&longs;t. hoc capite exi&longs;timat po&longs;t multa &longs;ecula reuolui, hoc veritati e&longs;&longs;e con&longs;entaneum argumento &longs;unt, ac pariter admirationi varia conchiliorum genera, quæ tùm in Apennino mon­te, tùm in Alpibus ob&longs;eruaui; Ìdemque; in alijs mundi partibus inueniri pu­to; præ&longs;ertim in tam immen&longs;a copia, atque intra vi&longs;cera montium colloca­ta, quæ nulla vis humana illuc contuli&longs;&longs;er, ni&longs;i temporibus catacly&longs;mi ebul­lientibus aquis maris &longs;uper terram facta fui&longs;&longs;et hæc varia rerum maritima­rum cum terre&longs;tribus commixtio: quæ quidem optimè ex Pomponio Mela comprobantur, qui libro 1. de Numidia &longs;ic narrat: interius, & longè &longs;atis à litore, &longs;i fides res capit, mirum admodum, &longs;pinæ pi&longs;cium, Muricum, O&longs;treo­rumque; fragmenta, &longs;axi atritu, vti &longs;olent fluctibus, & non differentia mari­nis, infixæ cautibus anchoræ, aliaque; huiu&longs;modi &longs;igna, & ve&longs;tigia effu&longs;i olim v&longs;que ad ea loca pelagi, in campis nihil alentibus e&longs;&longs;e inuenirique narrantur. neque locus ille Ouid. Met. 15. extra rem:

Vidi ego, quod fuerat olim &longs;olidi&longs;&longs;ima petra E&longs;&longs;e fretum, vidi fact as ex æquore terras: Et procul à Pelago conchæ iacuere marinæ, Et vetus inuenta e&longs;t in montibus anchora &longs;ummis.

Nos autem Chri&longs;tiani ad Noemi Diluuium i&longs;ta referre debemus.

Ex Secundo Meteororum.

152

Cap. 1. ait multa e&longs;&longs;e maria, quæ ad inuicem non communicant. Eorum rubrum mare vnum e&longs;&longs;e; quod cum Oceano Atlantico, qui e&longs;t extra Herculeum fretum ad occidentem parum videtur com­mi&longs;ceri &longs;iue Ari&longs;t. pro Rubro mari intelligat Oceanum illum, qui Arabiam, ac Per&longs;iam alluit, &longs;iue illius &longs;inum, qui Arabiam, atque Aethiopiam interluit, fal&longs;um e&longs;t ip&longs;um parum communicare cum occidentali Oceano, vt quotidianis Lu&longs;itanorum nauigationibus ad Indos patet. &longs;ed meritò hoc Ari&longs;tot. condonandum, cum tunc temporis nondum tota Africa e&longs;&longs;et certò circumlu&longs;trata, neque iter ab Hi&longs;pania ad Indos maritimum, adeo nunc fre­quens, patefactum e&longs;&longs;et.

153

Summæ 2. cap. 2. (Quapropter & circa Orionis orturm maximè fit tranquilli­tas) quando Medici, Philo&longs;ophi, Poetæ, ac reliqui auctores loquuntur de ortu a&longs;trorum fixorum, aut con&longs;tellationum, quæ &longs;unt in firmamento, vti e&longs;t Orion (& Canis, de quo po&longs;tea) intelligunt &longs;emper de ortu ip&longs;orum, qui fit matutino tempore, quando &longs;cilicet vel &longs;imul cum Sole, vel paulò ante Solem emergunt, ita vt videantur à nobis; qui ortus dicitur Co&longs;micus, tunc propriè, quando &longs;imul a&longs;trum cum Sole oritur; quando autem incipit appa­rere manc ante Solem, dicitur ortus Heliacus. i. &longs;olaris, quia oritur quodam­modo ex radijs Solis, &longs;ub quibus antea latebat. A&longs;tra verò incrrantia, & planetæ Sole tardiores oriuntur vtroque modo. nam cùm ip&longs;a Sol, quippe il­lis velocior primum a&longs;&longs;equitur, ea &longs;uo lumine obtegit, e&longs;tque; hic occa&longs;us eo­rum heliacus: cum verò eadem præterierit, ac po&longs;t &longs;e reliquerit fit, vt mo­tu diurno toto cœlo conuer&longs;o, mane ante Solem effulgeant, &longs;iue heliacè oriantur: & cum quotidie magis Sol ab illis recedat, ip&longs;aque magis à Sole elongentur, fit, vt quotidie magis ortum Solis anticipent, & citius mane au­te Solem videantur. &longs;icque; tanto in dies citius, vt deinde media etiam nocte oriantur; tum ante mediam noctem po&longs;tea paulò ante occa&longs;um Solis. de­mum cum fuerint Soli oppo&longs;ita, occidente Sole oriantur, qui ortus dicitur Ve&longs;pertinus, vel Acronicus. po&longs;tea oriuntur &longs;emper in die ante Solis occa­&longs;um, donec Sol ip&longs;a iterum a&longs;&longs;equatur, eaque; radijs &longs;uis offu&longs;cet, quod e&longs;t he­liacè occidere; & mox cum ip&longs;o Sole occumbant, quod Acronicè e&longs;t occi­dere. Totum porrò illud tempus, quo per diem oriuntur, non eorum ortui, &longs;ed occa&longs;ui deputatur, eò quod non cernuntur oriri, vt &longs;equenti loco expli­cabitur. Quæ omnia adhibito Globo a&longs;tronomico, in quo con&longs;tellationes omnes depictæ &longs;unt, eoque; ad tui poli eleuationem con&longs;tituto, appo&longs;itoque Sole &longs;uo loco in Zodiaco, qui paulatim per Zodiacum orientem ver&longs;us gra­diatur, & interim diurno motu globus conuertatur, ad &longs;en&longs;um manife &longs;ta apparebunt. In &longs;umma auctores intelligunt de ortu, qui mane fit ante So­lem, quia tunc primum po&longs;t diuturnas latebras incipit apparere. non autem intelligunt de ortu Acronico, quia ante hunc ortum videbatur noctu, itaque ortu Acronico non fit noua apparitio; ideo de hoc non intelligunt. fit au­tem ortus hic Orionis, heliacus, & matutinus, de quo Ari&longs;t. hoc loco, & alij auctores, no&longs;tra hac tempe&longs;tate paulò ante Solis ingre&longs;&longs;um in Cancrum, &longs;i­ue ante &longs;ol&longs;titium æ&longs;tiuum circa 22. Iunij.

154

Eodem cap. (Incertus autem, & mole&longs;tus Orion e&longs;&longs;e videtur & occumbens, & oriens, quia in tran&longs;mutatione temporis accidit occa&longs;us, & ortus, a&longs;tate, aut hye­me, & propter magnitudinem a&longs;tri dierum &longs;it aliqua pluralitas) hoc loco Vico­mercatus ex &longs;ententia a&longs;tronomorum occa&longs;um Orionis fieri autumni tem­pore, Sole Scorpionem ob&longs;idente docet, quod & verba Ari&longs;t. clarè &longs;ignifi­cant, cum dicat ortum ip&longs;ius fieri æ&longs;tate; in tran&longs;mutatione verò temporis, videlicet in autumno fieri occa&longs;um. Porrò occa&longs;us hic fieri incipit primum mane oriente Sole, diciturque; occa&longs;us co&longs;micus, quia dum Sol e&longs;t in oriente, Orion e&longs;t in occidente, & infra orizontem cadit: deinde paulò ante Solis or­tum, &longs;ed tamen nocturno tempore, ita vt occa&longs;us eius videri po&longs;&longs;it, donec occidat parum po&longs;t Solis occa&longs;um, & tandem cum Sole ip&longs;o heliacè euane­&longs;cat. Scriptores autem ferè &longs;emper cum loquuntur de occa&longs;u inerrantium &longs;yderum, de eo, qui noctu videatur, intelligunt: &longs;icuti ortum intelligunt eum, qui noctu fit, noctuque; videtur. affixa namque &longs;ydera per fex fermè men­&longs;es noctu oriuntur, oririque; ea con&longs;picimus, & propterea totum illud tem­pus, ortui ip&longs;orum deputamus: Reliquum verò tempus, quo per diem oriun­tur, & idcircò ortus illorum minimè apparet, nulla ratione ortui debuit a&longs;cribi: totum verò tempus, quo noctu occidunt, & occidere cernuntur, oc­ca&longs;ui illorum meritò attribuitur. & quemadmodum temporis illius initium, quo primo de nocte apparere incipiunt, dicitur ab&longs;olutè ortus cuiu&longs;uis &longs;y­deris; &longs;ic etiam initium temporis illius, quo primum per noctem ea occide­re videmus, &longs;impliciter occa&longs;um appellamus.

155

Eodem cap. (Ete&longs;iæ autem flant post ver&longs;iones, & Canis ortum) per ver&longs;io­nes intelligit tropicos, quod & tropici etymon confirmat, cum tropicus idem valeat, ac conuer&longs;iuus. circa Canis ortum eadem &longs;unt notanda, quæ &longs;upra de ortu Orionis annotaui; intelligit enim eum Canis ortum, qui mane fiat primum paulò ante Solis ortum, cum &longs;cilicet incipit apparere.

Cum porrò in c&ecedil;lo &longs;it Canis maior, & Canis minor, qui & Procyon, ide&longs;t Anticanis dicitur, exi&longs;timo Canem maiorem e&longs;&longs;e eum, qui vulgò Canicula nominatur, &longs;oletque; vehementes, ac noxios calores excitare. de quo etiam putò Ari&longs;t. intelligere. eius porrò ortus in no&longs;tra poli eleuatione quadra­ginta quinque graduum, circa diem tertium Augu&longs;ti contingit, Sole autem 10. gradum Leonis occupante. Ex Magini tabulis ante ephemerides.

156

Eodem cap. (Duobus enim exi&longs;tentibus &longs;egmentis habitabilis regionis: vno quidem ad &longs;uperiorem polum, qui no&longs;ter e&longs;t; altero ad alterum, & ad meridiem: eaque, tympani &longs;peciem habeant, talem enim figuram terræ excidunt ex centro ip&longs;ius ductæ lineæ, & faciunt duos conos, bunc quidem habentem ba&longs;im tropicum, alte­rum autem habentem ba&longs;im circulum &longs;emper manifestum, verticem autem in me­dio terræ. eodem autem modo ad inferiorem polum alij duo coni terræ &longs;egmenta fa­ciunt) vt benè duas ha&longs;ce terræ portiones, quas &longs;olas habitabiles putat Ari­&longs;tot. concipias, reliquaque huius loci intelligas, in&longs;pice &longs;equentem figuram.

Maior circulus &longs;it cœlum, in quo polus L, articus; M, antarticus, ille eleua­tus &longs;upra no&longs;trum horizontem S N, 45. gradibus, i&longs;te verò totidem infra depre&longs;&longs;us. &longs;intque; diametri circuli &longs;emper apparentium maximi S R, necnon diametri &longs;emper occultorum maximi Y N: tropicorum item T Q, Cancri, X O, Capricorni, vt vides in figura. Terra &longs;it A B C H G F E D Z K. à cu­ius centro Z, educantur primo duæ lineæ rectæ Z R, Z S. ad circulum &longs;em­per apparentium maximum, quæ in terra tran&longs;eant per puncta B, K. & iun­gatur linea B K: iam vides conum S R Z, cuius ba&longs;is e&longs;t circulus &longs;emper ap­parens S R, vertex autem Z, in centro terræ, vt ait Ari&longs;tot. educantur nunc duæ aliæ rectæ ad tropicum Cancri Z T, Z Q, quæ in terra faciant puncta I, C, iungaturque; recta I C; hic pariter vides conum alterum T Q Z, cuius ba­&longs;is e&longs;t circulus Cancri, vertex verò centrum terræ Z. con&longs;idera iam figuram B K I C, inter duas rectas B K, I C, & duos circuli terræ arcus contentam; hanc Ari&longs;t. appellat tympanum vnum terræ habitabile, quod e&longs;t ad Vr&longs;am, ide&longs;t in &longs;eptentrionali plaga, in qua &longs;umus nos: quæ quidem portio &longs;i con&longs;i­deretur vt &longs;olida, & à reliqua terra præci&longs;a, erit corpus rotundum, vtrinque tamen duobus planis circulis ad in&longs;tar tympani terminatum: Ductis dein­de &longs;imiliter alijs quattuor lineis à centro Z, ver&longs;us polum antarticum fit al­terum tympanum H D E G, au&longs;tralis terræ habitabilis, vt in figura manife­&longs;tum e&longs;t. fui&longs;&longs;e autem huiu&longs;modi habitabilis terræ &longs;egmenta figuræ tympa­ni &longs;imilia, optimè declarant veteres figuræ geographicæ Ptol&ecedil;mei, & patet etiam ex longitudine, & latitudine, vt benè ait Ari&longs;t. quas Geographi por­tioni terræ habitabili attribuebant, longitudinem enim dixerunt eius di­men&longs;ionem ab occa&longs;u ad ortum: latitudinem autem à &longs;eptentrione in meri­diem, eò quòd illa multò hac longior e&longs;&longs;et. Ex quibus apparet habitatam fui&longs;&longs;e veluti Zonam, terram ab occa&longs;u ad ortum præcingentem. quæ Zona &longs;i &longs;umatur cum &longs;oliditate, quam ambit, ab Ari&longs;t. tympano a&longs;&longs;imilatur.

157

Eodem cap. (Hæ autem habitari &longs;olæ po&longs;&longs;ibiles: & neque vltra ver&longs;iones; vm­bra enim non vtique e&longs;&longs;et ad Vr&longs;am: nunc autem inhabitabilia prius fiunt loca, quàm &longs;ubdeficiat, aut permutetur vmbra ad meridiem. Quæ autem &longs;ub Vr&longs;a, è frigore inhabitabilia) quod ait vltra ver&longs;iones, ide&longs;t intra tropicos in ip&longs;a &longs;cilicet Zona torrida, non po&longs;&longs;e habitari, fal&longs;um e&longs;&longs;e o&longs;tendunt plurimæ regiones tam veteris, quam noui orbis, &longs;uperiori &longs;eculo patefactæ, in quibus magna in amœnitate, ac fertilitate, &longs;ummisque; delicijs viuitur. Quoad vmbram il­lam, intellige meridianam. i. quam Sole circa meridiem exi&longs;tente, nos qui Boreales &longs;umus, &longs;emper ad &longs;eptentrionem proijcimus. Quod &longs;i ad meridiem perrexerimus, occurret inhabitabilis (vt falsò putat) terra, prius quam. vmbra meridiana in Boream vergens deficiat. quæ &longs;igna &longs;unt no&longs;tram habi­tationem e&longs;&longs;e citra Zonam torridam, in Boreali parte. Quæ autem &longs;ub Vr­&longs;a, ide&longs;t &longs;ub polo arctico, ob nimium frigus inho&longs;pita omninò habetur, nam

Quod latus mundi nebulæ, malusque; Iupiter vrget.

Verumtamen, quæ &longs;ub vtroque polo partes &longs;unt adhuc incognitæ manent.

158

Eodem cap: (Fertur autem, & corona &longs;ecundam hunc locum, videtur enim &longs;u­per caput e&longs;&longs;e nohis, cum fuerit &longs;ecundum meridianum) con&longs;tellatio videlicet, quæ corona Ariadnæ dicitur, hæc cum in cœlo manife&longs;tè &longs;it Borealis, no­&longs;troque; vertici noctu, quando meridianum pertran&longs;it, incumbat: clarè indi­cat nos quoque e&longs;&longs;e Boreales.

159

Eodem cap. (Et quidem ad latitudinem v&longs;que ad inhabitabilia &longs;cimus hahita-tam, hic enim propter frigus non amplius habitant, illic autem propter æ&longs;tum)illic autem, ide&longs;t &longs;ub Zona torrida, compertum autem e&longs;t nunc totam ferè torridam Zonam, & quidem alicubi percommodè habitari, cuius cau&longs;æ &longs;unt quatuor, quæ ip&longs;um latuerunt. prima eaque; toti Zonæ torridæ communis, e&longs;t perpetuum æquinoctium, quo Sol tantum &longs;upra, quantum infra terram immoratur. accedit, quòd Sol nocturno tempore maximè ad imum cœli fe­ratur, plurimumque; ab horizonte, &longs;uperoque; hemi&longs;pherio recedat. atque ob hanc &longs;olam rationem Campanus in &longs;ua &longs;phæra Zonam hanc putat maximè e&longs;&longs;e habitabilem: quamuis hæc &longs;ola cau&longs;a, vt quotidiana docet experientia, non &longs;ufficiat. &longs;ecunda &longs;unt pluuiæ, quæ alicubi quotidie &longs;tata hora decidunt. tertia venti, qui veluti flabella quædam aerem agitant. quarta præalti mon­tes perpetuis niuibus ob&longs;iti. quæ quatuor torridam hanc pa&longs;&longs;im refrigerant, atque habitabilem reddunt.

160.a

Summæ 2. cap. 3. de ventis (Oportet autem de &longs;itu &longs;imul rationes ex de&longs;criptio ne con&longs;iderare) ide&longs;t rationes ventorum ex de&longs;criptione, ide&longs;t in figura ali­qua, vt in &longs;equenti con&longs;iderare; &longs;olet enim Ari&longs;t. figuras, imò demon&longs;tratio­nes ip&longs;as Mathematicorum, de&longs;criptiones appellare, vt &longs;æpius in Logicis monuimus.

De&longs;criptus &longs;it igitur, vt clarior res euadat horizontis circulus quapropter, & rotundus) vt in &longs;equenti figura circulus A G B H, de&longs;criptus horizontem referret,

Oportet autem ip&longs;ius alteram portionem intelligere, quæ nobis habitatur; quæ eodem modo diuidi poterit) ide&longs;t oportet intelligere ip&longs;ius horizontis, vel ter­ræ habitatæ partem, quæ quamuis rotunda non &longs;it, poterit tamen, ac &longs;i ro­tunda e&longs;&longs;et in figura circulari repre&longs;entari, atque in plures partes eo modo, quo circulus &longs;ecatur, &longs;ecari.

Supponatur autem primò contraria &longs;ecundum locum, e&longs;&longs;e plurimum di&longs;tantia &longs;ecundum locum; &longs;icut &longs;ecundum &longs;peciem contraria, plurimum di&longs;tant &longs;ecundum &longs;peciem. plurimum autem di&longs;tant &longs;ecundum locum, quæ per diametrum opponuntur, &longs;it igitur vbi A, occidens æquinoctionalis, contrarius autem huic locus vltimus B, ortus æquinoctionalis) ide&longs;t in &longs;equenti figura ducta diametro B A. in altera ip&longs;ius extremitate vbi A. &longs;it occa&longs;us æquinoctialis, qui fit Sole exi&longs;tente in alterutro æquinoctio; huic igitur per diametrum opponatur ortus æquino­ctialis in B. qui pariter contingit tempore æquinoctiorum: linea autem B A, refert ip&longs;um æquatorem.

Alia autem diameter hanc perpendiculariter &longs;ecet, cuius punctum illud, in quo G, &longs;it Vr&longs;a: huic autem contrarium ex oppo&longs;ito illud, in quo H, meridies) hæc dia­meter erit ip&longs;a linea meridiana. pro Vr&longs;a verò intelligit &longs;eptentrionem, quod ibi &longs;it Vr&longs;æ con&longs;tellatio.

Id autem, in quo F, ortus æ&longs;tiualis; in quo verò E, occidens æ&longs;tiualis) quæ duo puncta iunguntur linea F E, quæ refert &longs;ectionem tropici, Cancri cum ho­rizonte: ortus enim, & occa&longs;us æ&longs;tiualis contingunt Sole Cancri tropicum percurrente.

Id autem, in quo D, oriens byemalis; vbi verò C, occidens hyemalis) linea au­tem D C, erit &longs;ectio tropici Capricorni, & horizontis; Sole enim hunc tro­picum attingente ortus, & occa&longs;us hybernus fiunt.

Ab F, autem ducatur diameter ad C, & à D, ad E. quoniam igitur plurimum di&longs;tantia &longs;ecundum locum, contraria &longs;unt &longs;ecundum locum: plurimum autem di­stantia, quæ &longs;ecundum diametrum; nece&longs;&longs;arium e&longs;t, & flatuum hos inuicem con­trarios e&longs;&longs;e, quicunque &longs;ecundum diametrum exi&longs;tunt. vocantur autem &longs;ecundum po­&longs;itionem locorum venti &longs;ic; Zephyrus quidem ab A, hoc enim e&longs;t occidens æquino­ctialis. Boreas autem, & Aparetias à G. hic enim Vr&longs;a, contrarius autem huic Notus ab H. Meridies enim e&longs;t hic, à quo flat, & H, ip&longs;i G, contrarium e&longs;t; &longs;ecun­dum enim diametrum &longs;unt. Ab F, autem Cæcias; hic enim oriens æ&longs;tiuus e&longs;t; cui contrarius est, non qui flat ab E, &longs;ed qui à C. Libs, i&longs;te enim ab occidente hyemali flat; estque, illi contrarius, quia &longs;ecundum diametrum illi opponitur. Qui verò à D, Eurus, i&longs;te enim ab horiente hyberno flat, vicinus existens Noto, vnde & &longs;æpè Eu­ronoti flare dicuntur: contrarius autem huic, non qui à C. Libs, &longs;ed qui ab E, quem vocant, hi quidem Arge&longs;ten, hi autem Olympium, alij verò Scironem; iste enim ab occidente æ&longs;tiuo flat, & &longs;ecundum diametrum ip&longs;i &longs;olus opponitur. Venti igitur, qui &longs;ecundum diametrum po&longs;iti &longs;unt, & quibus alij aduer&longs;antur, ij &longs;unt. Alij autem &longs;unt, &longs;ecundum quos non &longs;unt contrarij venti, ab I, quem vocant Tra&longs;ciam, qui me­dius e&longs;t inter Argesten, & Apparitiam, à K, autem, quem vocant Me&longs;en, Mtdius enim e&longs;t Cæciæ, & Aparetiæ. Diameter autem K I, iuxta circulum &longs;emper con&longs;pi­cuum e&longs;&longs;e &longs;olet, non tamen exactè) ide&longs;t linea K I, &longs;olet in horizonte referre diametrum circuli omnium &longs;emper apparentium maximi, eo quod &longs;it ferè &longs;ub diametro illius, in qualibet enim &longs;phæra obliqua, ide&longs;t, in qua polus cle­natur, intelligunt A&longs;tronomi circulum quendam &longs;emper apparentium ma­ximum, quem de&longs;cribunt ex ip&longs;o polo, tanquam centro, & interuailo v&longs;que ad horizontem, circa ip&longs;um polum: hunc appellant &longs;emper apparentium, maximum, quia intra hunc alios quamplurimos concipiunt circa eundem polum, quorum minores &longs;emper &longs;unt polo propinquiores. huius igitur dia­metrum vult Ari&longs;t. per lineam, quæ à K, in I, duceretur (quamuis non exa­ctè) repre&longs;entari.

Contrarij autem non &longs;unt his &longs;latibus, neque ip&longs;i Me&longs;e, &longs;piraret enim vtique aliquis ab eo, in quo M. hoc enim illi e&longs;t &longs;ecundum diametrum; neque Tra&longs;ciæ ab N, enim, quod punctum per diametrum aduer&longs;um illi e&longs;t, &longs;piraret. Ni&longs;i ab eo veniat, qui ta­men non longè progreditur ventus quidam, quem accolæ Phæniciam vocant. maxi­mè igitur præcipui, & definiti venti hi &longs;unt: hocque, modo di&longs;po&longs;iti) &longs;upradicta por­rò omnia ex &longs;equenti figura optimè poterunt intelligi, quam diligenti ope­ra ad mentem Ari&longs;t. ex græcis codicibus re&longs;tituere conatus &longs;um, cum ani­maduerterem figuras val dè deprauatas pa&longs;&longs;im apud commentatores reperiri. Porrò ad literam M, in figura &longs;crip&longs;i ventum Libonotum, quem Ari&longs;t. qui­dem non ponit propter ip&longs;ius paruitatem; imò apertè dicit Hele&longs;pontum non habere contrarium: &longs;ed feci, vt completum ventorum numerum, quem alij tradunt, haberemus.

Ex Tertio Meteororum.

160.b

Antequam textuum explicationem aggrediar, illud animaduerten dum e&longs;t, vbicunque interpretatio antiqua vtitur verbis, refractio, & refrangere; ibi Vicomercatum in &longs;ua interpretatione meritò, & propriè v&longs;um e&longs;&longs;e verbis; reflexio, & reflecti: differunt enim valdè apud Opticos refractio, & reflexio, vt etiam refrangere, & reflectere. propterea optimè hoc loco Olympiodorus di&longs;tinguit inter anaxlasin, xai diaxladi, reflexionem, & refractionem. Reflexio enim fit ex repercu&longs;&longs;o, vt quando lumen Solis incidens in aliquod &longs;peculum, inde re&longs;ilit in oppo&longs;itum parietem, illud re&longs;ilire e&longs;t propriè per&longs;pectiuis reflecti, vnde reflexio. Re­fractio autem fit ex tran&longs;pectu: vt quando lapis, qui e&longs;t in aqua, emittit fuam &longs;peciem ad oculum, qui e&longs;t in aere, tunc enim, quia &longs;pecies lapidis re­pre&longs;entatiua non tendit recta ad oculum, &longs;ed in confinio aquæ, & aeris fran­gitur, dicitur fieri refractio, & refrangi, in refractione igitur requiruntur duo media, per quæ &longs;iat vi&longs;io, quæ &longs;int diuer&longs;æ den&longs;itatis, vt &longs;unt aqua, & aer: vapor, exhalatio, & aer: vitrum, & aer, &c. quando igitur videmus Solem, aut Lunam per vapores, aut exhalationes fit refractio, quia den&longs;ior e&longs;t vapor, & exhalatio, quam aer.

Notandum etiam Aream, de qua mox dicam explicari po&longs;&longs;e tam per re­flexionem, quàm per refractionem: per reflexionem, quia &longs;upponunt Philo­&longs;ophi e&longs;&longs;e in acre rorido innumcra &longs;pecula parua inuicem valdè proxima, ide&longs;t guttulas, per quas re&longs;lectatur ad oculum no&longs;trum &longs;pecies &longs;yderis. per re&longs;ractionem verò, vt vult Vitellio, quia &longs;umit totum illum aerem humi­dum magis den&longs;um e&longs;&longs;e aere paro, qui e&longs;t circa oculos no&longs;tros, & hoc modo con&longs;tituit diucr&longs;a media in den&longs;itate, per quam fiat vi&longs;io; corpus inquam illud humidum den&longs;ius, & aerem deinde circa oculum rarius. Vicomerca­tus igitur quamuis vtatur voce reflexionis in Halone, non tamen ex prædi­ctis videtur reprchenden dus.

161

Summæ 2. cap. 2. De Areæ figura (Refrangitur autem à con&longs;i&longs;tente caligine circa Solem, aut Lunam vi&longs;us; quapropter non ex oppo&longs;ito &longs;icut iris, apparet. Vn­dique autem &longs;imiliter refracto, nece&longs;&longs;e e&longs;t circulum e&longs;&longs;e, aut circuli partem. ab co­dem enim &longs;igno ad idem &longs;ignum æquales frangentur &longs;uper circuli lineam &longs;emper. &longs;it

enim à puncto, in quo A, ad B, fracta, & ea, quæ est A C B, & quæ A F B, & quæ A D B, æquales autem & hæ A C, A F, A D, inuiccm. & quæ ad B, inui­cem &longs;cilicet C B, E B, D B. & protrahatur A E B, quare trianguli æquales, etenim &longs;uper æqualem, quæ e&longs;t A E B, ducantur autem perpendiculares ad A E B, ex angulis; à C, quidem, quæ e&longs;t C E; ab F, autem, quæ e&longs;t F E; à D, autem, quæ e&longs;t D E, æquales itaque hæ, in æqualibus enim triăgulis, & in vno plano om­nes, ad rectum emm omnes ei, quæ e&longs;t A E B. & ad vnum punctum E, copulantur, circulus igitur erit de&longs;cripta, centrum autem E. &longs;it autem B, quidem Sol, A, autem vi&longs;us, quæ autem e&longs;t circa C D F, circun­ferentia nubes, à qua refrangitur vi&longs;us ad Solem)quia &longs;uppono Aream, &longs;iue Halonem fieri per re­fractionem, vt vult etiam Vitellio, propterea præmittendum e&longs;t principium quoddam, quo tra­ctatio de refractione innititur; e&longs;t autem huiu&longs;­modi; ea, quæ videntur per refractionem, &longs;iue &longs;ub aliquo refractionis angulo, manentibus nobis & a&longs;tro, & medio ij&longs;dem in locis, non po&longs;&longs;unt vide­ri &longs;ub diuer&longs;o angulo à priori, ncc per con&longs;quens alibi apparere. v. g. Sol (vt in præ&longs;enti figura) videatur ab oculo A, media nube C D F, &longs;ub an­gulo refractionis B C A, vel B F A, & alijs &longs;imilibus angulis in eadem nube; manente igitur oculo A, & a&longs;tro B, necnon nube C D E. eodem in loco, im­po&longs;&longs;ibile e&longs;t Solem videri ab eodem oculo &longs;ub diuer&longs;o angulo à priori, nec con&longs;equenter alibi apparere, quam in B. Nunc ad textus declarationem, in quo continetur Geometrica demon&longs;tratio rotunditatis Areæ, quam &longs;ic bre­uiter prius veteres excogitarunt: Viderunt primò Solem in Area apparere in orbem, & con&longs;imiliter: hinc intulerunt nece&longs;&longs;e e&longs;&longs;e apparere etiam per con&longs;imiles, &longs;iue æquales refractionis angulos; quia diuer&longs;i anguli, diuer&longs;am etiam apparentiam efficiunt: atqui con&longs;imiles, &longs;iue æquales refractionis an­gulos nece&longs;&longs;e e&longs;t in circulum con&longs;titui, vt mox con&longs;tabit; cau&longs;a igitur rotun­ditatis huius, e&longs;t angulorum refractionis æqualitas. Sed iam textum Ari&longs;t. qui geometricam huius rci continet demon&longs;trationem, explicemus. Suppo­nit igitur primò Ari&longs;t. lineas vi&longs;uales à &longs;ydere B, ad oculos no&longs;tros A, per nubem roridam C D F, procedentes, in nube con&longs;imiliter refrangi, ide&longs;t vn­dique circa Solem, Lunamuè facere angulos refractionis æquales. quod etiam patet ex 48. 10. Vitellionis; vt in figura, in qua &longs;ydus B, oculus A, nubes C D F, radij vi&longs;uales tres refracti in nube &longs;int B C A, B D A, B E A, facien­tes con&longs;imilem refractionem, ide&longs;t angulos refractos B C A, B D A, B E A, æquales in punctis C, D, F: atque hoc e&longs;t con&longs;imilem facere refractionem. Supponit &longs;ecundò lineas à &longs;ydere ad nubem, v&longs;que exten&longs;as e&longs;&longs;e æquales, vt &longs;unt B C, B D, B F: &longs;imiliter reliquas tres à nube ad vi&longs;um A. pares e&longs;&longs;e C A, D A, F A. his &longs;uppo&longs;itis, &longs;i deinde protrahatur recta A B, ab oculo ad &longs;ydus, exurgunt tria triangula omninò æqualia, & &longs;imilia, cuni duo latera vnius &longs;int æqualia duobus alterius vtrunque vtrique, & angulus angulo, & præterea ba&longs;is &longs;it communis; ideò per quartam primi &longs;unt omninò æqualia. ducan­tur nunc ex angulis C, D, F, tres perpendiculares ad rectam A B, quæ &longs;int C E, D E, F E, in figura; quæ tres nece&longs;&longs;ariò erunt æquales, cum &longs;int ductæ ab angulis æqualibus æqualium triangulorum ad communem ba&longs;im, & di­uident nece&longs;&longs;ariò ba&longs;im in eodem puncto E, cum diuidant triangula æqua­lia proportionaliter; eruntque; propterea hæ tres rectæ in eodem plano, quod in nube concipitur ex 5. 11. Quare &longs;i concipiamus &longs;uperficiem, &longs;iue planum delineari circa E, ad interuallum linearum æqualium C E, D E, F E, de­&longs;criptus erit circulus per 9. tertij, cuius circumferentia C D F. Ex quibus patet tria illa puncta C, D, E, per quæ Sol tran&longs;paret e&longs;&longs;e in orbem di&longs;po&longs;i­ta. cau&longs;a igitur rotunditatis Areæ, e&longs;t &longs;imilitudo angulorum refractionis, quibus Sol tran&longs;paret: vel ideo rotunda e&longs;t, quia &longs;imiles anguli nece&longs;&longs;ariò in orbem con&longs;tituuntur, vt o&longs;ten&longs;um e&longs;t. Eadem ratione omnia alia puncta eiu&longs;dem circunferentiæ &longs;unt puncta, per quæ Sol videtur refractè; & hoc mo­do ad &longs;imilitudinem trium linearum A C B, A D B, A F B, refractarum, in­finitæ vndique intelligendæ &longs;unt, quarum aliæ refrangantur in circunferentia prædicta, aliæ verò in alia periphæria maiori, aliæ etiam in minori, ita vt ex tota nube fiant refractiones circulares plurimæ, ex quibus in nube area con&longs;tituatur. Atque hæc cur Halonis figura orbicularis videatur, rationem reddunt, vnaque; textui lucem afferunt.

Summæ 2. cap. 4. De Iridis figura.

162

Qvod autem neque circulum po&longs;&longs;ibile &longs;it fieri Iridis, neque maiorem &longs;emicir­culo portionem, & de alijs accidentibus circa ip&longs;am, ex de&longs;criptione erit con&longs;iderantibus manife&longs;tum) In Logicis &longs;æpius monui Ari&longs;t. per de&longs;criptiones intelligere geometricas demon&longs;trationes, quod etiam hoc loco confirmatur, vbi Geometrica demon&longs;tratione quam de&longs;cri­ptionem appellat, Iridis figuræ accidentia o&longs;tendit; nimirum cur &longs;it quidem circularis, nunquam tamen circulus integer, imò neque &longs;emicirculo vnquam maior, &longs;ed tamen &longs;emicirculo minor.

163

Ibidem (Hemi&longs;pberio enim exi&longs;t exte &longs;uper horizontis circulum in quo A. cen­tro autem K, alio autem quodam oriente puncto, in quo G, &longs;i lineæ, quæ à K, &longs;ecun­dum conum excidentes faciant velut axem lineam in qua G K, & à K. ad M, co­pulatæ refrangantur ab hemi&longs;phærio ad G, &longs;uper maiorem angulum, circuli circun­ferentiam incident lineæ, quæ à K, & &longs;i quidem in ortu, aut in occa&longs;u a&longs;tri reflexio fiat, &longs;emicirculus ab horizonte a&longs;&longs;umetur &longs;uper terram factus. &longs;i autem &longs;upra, minor

&longs;emper &longs;emicirculo, minus autem, cum in meridie fuerit a&longs;trum) quod &longs;upra monui, iterum moneo, re­tinendam vocem reflexionis, quan­uis in antiqua tran&longs;latione lega­tur refractio, e&longs;t enim apud om­nes in confe&longs;&longs;o Iridem fieri per reflexionem. E&longs;t igitur in &longs;upe­riori figura, quam textui, vt par erat re&longs;titui, horizon G K O. cuius centrum K. in quo e&longs;t vi&longs;us no&longs;ter, &longs;itque; hemi&longs;phærium no&longs;trum in arcu G A M O, repræ&longs;entatum, &longs;itque; nubes rori­da, in qua Iris appareat, vbi M, quod punctum M, nubem referens, in figu­ra ponitur in hemi&longs;phærij ambitu, quod cœlum repræ&longs;entat, cum tamen nubes parum à terra &longs;ubuchatur; id enim ad demon&longs;trationem ferè perinde e&longs;t. in oriente G, &longs;it a&longs;trum. &longs;i ergò lineæ vi&longs;uales à K, ad M, nubem tenden­tes reflectantur &longs;uper maiorem angulum M K G, ad G, erit reflexarum vna veluti M G. Porro omnes lineæ viluales, quæ adnubem M, incidunt, nece&longs;­&longs;ariò, vt probabo, cadent in ambitum circularem. debemus enim innume­ras lineas im aginari à K, in coni figuram excidentes, cuius vertex &longs;it in K, & axis G K O, quas omnes repræ&longs;entat vna K M, meliusque; repræ&longs;entabit, fi cogitemus axem G K O, circa polos G, O, manentes circumuolui, &longs;ecumque; lineam K M, circumducere. in hac etiam giratione linea K M, tran&longs;ibit per omnes illas lineas, quas imaginabamur; de&longs;cribetque; conum, quem illæ con­formare debebant. In prædicta autem axis volutatione, extremum M, li­neæ K M, nece&longs;&longs;ariò de&longs;cribit circulum, qui e&longs;t circulus Iridis, & e&longs;t ba&longs;is memorati coni.

Si igitur oriente, vel occidente a&longs;tro fiat iris, Iris erit &longs;emicirculus, ide&longs;t illa &longs;emi&longs;&longs;is circuli pr&ecedil;dicti (quem horizon bifariam diuidit) quæ &longs;upra ter­ram extabit. &longs;i autem a&longs;trum eleuatum &longs;upra horizontem fuerit, quando fit iris, erit &longs;emper arcus Iridis &longs;emicirculo minor; tuncque; minimus cum a&longs;trum meridianum circulum occupauerit. h&ecedil;c tria &longs;unt, quæ deinceps probanda recipit.

264

Ibidem (Sit enim in oriente pri­mum vbi G, & refracta &longs;it K M, ad G, & planum erectum &longs;it in quo A, à triangulo in quo G K M, cir­culus igitur erit &longs;ectio &longs;phææ, qui maximus &longs;it in quo A, differet enim mbil &longs;i quodŭque eorum, quæ &longs;uper G K, &longs;ecundum triangulŭ K M G, erectum fuerit planum. lineæ igitur ab ijs, quæ G, K, ductæ in bac ratio­ne non cen&longs;tituentur ad aliud, & aliud punctum, quàm &longs;emicirculi in quo A. Quoniam enim puncta G, K, data &longs;unt, & quæ K M, vtique data erit; & quæ M G, ad M K; datam igi­ur circunferentiam tanget M, fit itaque bæc in qua M N, quare &longs;ectio circunferen-tiarum data e&longs;t. apud autem aliud punctum, quam ip&longs;ius M N, circunferentiæ, ab ij&longs;dem punctis, eadem ratio in eodem plano non con&longs;i&longs;tit) eorum omnium, quæ demon&longs;tranda &longs;unt, præmittenda &longs;unt duo nece&longs;&longs;aria fundamenta. Primum e&longs;t; ea, quæ videmus per reflexionem &longs;ub quopiam angulo, manentibus no­bis &longs;peculo, & obiecto ij&longs;dem in locis, non po&longs;&longs;unt videri &longs;ub alio diuer&longs;o angulo, nec alibi con&longs;equenter apparere. v. g. in &longs;uperiori figura, quam textui re&longs;tituimus exi&longs;tente Sole in G, oculo in K, & nube in M. ex qua ra­dius Solis G M, re&longs;lectatur ad vi&longs;um in K, per lineam M K, &longs;ub angulo G M K, impo&longs;&longs;ibile e&longs;t manentibus illis, vt dixi, videri Solem in nube M, &longs;ub diuer­&longs;o angulo à priori, nec alibi apparere. Alterum e&longs;t apud Opticos vulga­tum; ea &longs;cilicet, quæ per reflexionem (de quorum numero e&longs;t Iris) viden­tur, videri, tunc &longs;olum, quando angulus incidentiæ fuerit æqualis angulo reflexionis, quia tunc breui&longs;&longs;imis lineis fit vi&longs;io; quibus &longs;oli, natura (&longs;i fieri

pote&longs;t) vtitur. v. g. in figura præ&longs;enti &longs;it &longs;pe­culum C D E, obiectum A, oculus B, linea in­cidentiæ e&longs;t A D, & angulus pariter inciden­tiæ e&longs;t A D C. linea verò D B, e&longs;t linea refle­xionis, & angulus pariter reflexionis e&longs;t B D­E, qui duo anguli ni&longs;i fuerint æquales, nun­quam videbitur obiectum A, ab oculo B, hinc e&longs;t, quod aliquando po&longs;ito &longs;peculo, obiectum quamuis illi aduer&longs;um, à nobis pariter ante &longs;peculum con&longs;titutis, videri nequit, quia &longs;ci­licet in tali po&longs;itione &longs;peculi, obiecti, & no&longs;tri, nulla linea incidentiæ, ide&longs;t, quæ ab obiecto in &longs;peculum tendit, facere pote&longs;t angulum cum &longs;peculo, qui dicitur angulus incidentiæ, æqualem angulo illi, quem facit linea eadem re­flexa à &longs;peculo ad oculum, quem dicunt angulum re&longs;lexionis. Cum ergo in Iride videamus colorem Solis per reflexionem, tunc &longs;olum apparebit Iris, quando Sol, nubes, & oculus fuerint in ea con&longs;titutione, qua radius incidens nubi, & radius à nube repercu&longs;&longs;us faciant pares angulos. Et quia quando nubes ro&longs;cida perpendiculariter opponitur Soli, & nobis, po&longs;&longs;unt &longs;ieri præ­dicti anguli æquales non in vno loco nubis, &longs;ed in pluribus, con&longs;titutis ta­men in circuli periphæria, hinc fit, quod Solis color reflectatur ex pluribus locis in orbem con&longs;titutis, quæ reflexio e&longs;t ip&longs;ius Iridis arcus. ex Vitellion 63. 10. Totam autem figuræ Iridis demon&longs;trationem &longs;ic breuiter puto ad­inuentam e&longs;&longs;e. cum Sol in Iride videatur in orbem, atque con&longs;imiliter, ne ce&longs;­&longs;e e&longs;t id prouenire ex angulis reflexionum con&longs;imilibus, &longs;iue æqualibus: di&longs;­&longs;imiles enim anguli, di&longs;&longs;imilem vtique efficiunt Solis apparentiam. atqui con­&longs;imiles anguli, &longs;iue æquales, non ni&longs;i in orbem po&longs;&longs;unt con&longs;titui; igitur an­gulorum æqualitas cau&longs;a erit rotundationis arcus. h&ecedil;c e&longs;t &longs;umma totius di­&longs;cur&longs;us, quem pluribus, & nimis ob&longs;curè Ari&longs;t. explicat.

Inquit igitur Ari&longs;t. &longs;it enim in oriente, &c. vbi aggreditur probare vnum ex tribus illis, quæ &longs;upra propo&longs;uit, nimirum tunc Iridem e&longs;&longs;e &longs;emicircu­lum, quando a&longs;trum fuerit in oriente, &longs;iue in horizonte, vbi G. &longs;i igitur per triangulum G M K, intelligamus planum exten&longs;um, in quo A, in figura, adeo magnum, vt totum &longs;ece hemi&longs;phærium, faciet in &longs;uperficie hemi&longs;phærij &longs;e­ctionem, quæ erit portio maximi circuli, per 6. Theodo&longs;ij, cum planum &longs;e­cans hemi&longs;phærium, tran&longs;eat per centrum ip&longs;ius, quæ &longs;ectio, &longs;iue circuli por­tio repræ&longs;entatur in figura, per &longs;emicirculum in quo A, &longs;iue in quo G A M­R O. nihil autem refert quodcunque intelligas planum &longs;uper axem G K O, tran&longs;iens &longs;iue per triangulum G K M, &longs;iue per aliud illi &longs;imile. Præmitten­dum præterea non po&longs;&longs;e in &longs;emicirculo &longs;uperiori, quod e&longs;t planum, & &longs;ectio trianguli G K M, poni alias duas lineas. v. g. G R, K R, ad aliud punctum, vti e&longs;t R, quæ habeant eandem inuicem proportionem, quam habent prio­res duæ G M, K M, quod probatur, quia &longs;i &longs;int vt G M, ad K M, ita G R, ad K R, cum G R, &longs;it centro K, propinquior quam G M, erit etiam eadem G R, longior ip&longs;a G M, per 15. 3. & tamen deberet e&longs;&longs;e æqualis illi; quemadmo­dum K M, e&longs;t æqualis alteri K R; nequeunt autem duæ lineæ inæquales inui­cem, habere eandem rationem ad duas inuicem æquales: ergo non habent eandem rationem G M, & K M, quam habent G R, & K R. quod &longs;i punctum R, &longs;umatur &longs;upra M, erit &longs;imilis demon&longs;tratio, &longs;i literæ M, & R, loca permu­tent. his po&longs;itis, ait (Quoniam enim G, K, puncta data &longs;unt, & c.) ide&longs;t data &longs;unt po&longs;itione, cum notum &longs;it vbi &longs;int. G, enim e&longs;t in ortu. K, verò in centro horizontis, &longs;equitur, quod etiam linea G K, cuins ip&longs;a &longs;unt extrema, data &longs;it, & po&longs;itione, & magnitudine, per 26. Datorum Euclidis. eadem quoque ratione data erit K M, linea; &longs;iue quia e&longs;t æqualis ip&longs;i G K, &longs;iue quia per a&longs;trolabium po&longs;&longs;umus ip&longs;ius longitudinem, & po&longs;itionem inue&longs;tigare; qua­re & punctum M, datum erit per 27. Datorum, quare & linea G M, data erit quoad &longs;itum, & magnitudinem per 26. Datorum. Quare per primam Datorum erit data proportio linearum G M, M K, punctum itaque M, tange t ambitum datum, qui ba&longs;is e&longs;t coni, quem linea K M, de&longs;cribit in reuolutio­ne axis G K O, &longs;uper polis G, O. cum enim data &longs;it K M, po&longs;itu, & magni­tudine, eaque; &longs;it latus prædicti coni, &longs;equitur periphæriam, vel ambitum ba­&longs;is coni e&longs;&longs;e datum per &longs;imilem definitionem 5. definitioni Datorum. &longs;it au­tem ambitus ille in figura &longs;equenti notatus literis L M N. qui ambitus L M N, non e&longs;t concipiendus in eodem plano &longs;emicirculi G A N O, quemadmodum falsò pingitur in figura; &longs;ed debemus ip&longs;um concipere tanquam erectum ad angulos rectos cum prædicto &longs;emicirculo, necnon cum horizonte G K O. Iam &longs;i triangulum G M K, prioris figuræ circumuoluatur circa axem G K O, punctum ip&longs;ius M, de&longs;cribit prædictum ambitum L M N. hunc ambitum inquit Ariltot. linea K M, attinger, eritque; hic ambitus datus, vt dictum e&longs;t.

Erit præterea &longs;ectio circunferentiarum ho­rizontis, & huius amb tus data, cuius extre­ma puncta e&longs;&longs;ent L, & N. &longs;i enim concipiamus in figura non &longs;olum horizontis iametrum G K O, &longs;ed etiam circunferentiam (in qua circunferentia e&longs;&longs;ent duo illa puncta L, & N, vt in præ&longs;enti de&longs;criptione melius intelli ge­tur, in qua horizon G N O L, & ambitus prædictus e&longs;t L M N, qui debet intelligi ele­uatus &longs;upra horizontem perpendiculariter) tunc &longs;ectio ip&longs;ius mutua cum horizonte e&longs;&longs;et linea N P L, cuius extrema puncta &longs;unt L, N, quæ data erunt, cum &longs;int ex­trema lineæ K M, circumlatæ; & quemadmodum dabatur &longs;uperius punctum M. eadem ratione ex Datis, dabitur punctum N, & L. quare etiam &longs;ectio N P L, quæ inter data puncta continetur, data erit ex 26. Datorum.

Illud nunc in memoriam reuocandum, quod paulò ante probaui, nimirum proportionem linearum G M, K M, non po&longs;&longs;e &longs;eruari in alijs lineis, quæ &longs;int in eodem plano trianguli G M K, &longs;i ducantur ab ij&longs;dem punctis G, K. pote&longs;t tamen &longs;eruari in alijs duabus, quæ cadant in prædictum ambitum, &longs;iue cir­cunferentiam L M N, quæque; &longs;int in alio plano, quam in plano trianguli G M K, quod tamen tran&longs;eat per axem G K O, &longs;itque; vnum ex planis illis, de quibus &longs;upra dictum e&longs;t. Verumenimuerò ad quid probatio hæc? non po&longs;&longs;e duas alias lineas in eodem plano, &c.? exi&longs;timo Ari&longs;t. idcircò hoc proba&longs;&longs;e, quia &longs;i aliæ duæ lineæ habentes eandem rationem, po&longs;&longs;ent collocari in eodem plano; e&longs;&longs;ent permutando illæ duæ (in priori figura) G R, R K. vtraque vtrique æquales prioribus G M, M K, per quas videtur Iris, cum enim K R, &longs;it æqua­lis ip&longs;i K M, erit, & G M, æqualis ip&longs;i G R, per 7. 5. & in eius &longs;cholio. qua­re natura ageret tam per lineas breui&longs;&longs;imas agendo per has, quam per illas, hocque; pacto perhas etiam Iris videri po&longs;&longs;et. cum ergò con&longs;tet non po&longs;&longs;e has e&longs;&longs;e prioribus proportionales, &longs;ed maiorem, vel minorem, alteram illarum, quàm &longs;it G M, &longs;equitur, quod non faciunt angulum æqualem angulo G M K, &longs;ub quo videtur Iris, nimirum angulum G R K, qui &longs;it æqualis angulo G M K; habet enim Iris hunc angulum determinatum, ita vt &longs;ub maiori, vel mino­ri videri nequeat; ex 10. Bapti&longs;ta Porta. &longs;i autem punctum R, e&longs;&longs;et infra M, angulus G R K, e&longs;&longs;et minor angulo Iridis G M K, &longs;i verò &longs;upra e&longs;&longs;et maior eodem, quod vel ad &longs;en&longs;um patere pote&longs;t in quouis circulo, idque; &longs;ufficiat, ne longior euadat hæc tractatio. Fortè etiam addi pote&longs;t, quod alibi exi&longs;ten­te puncto R, quàm in M, non po&longs;&longs;ent anguli incidentiæ, & reflexionis e&longs;&longs;e æquales, quæ cau&longs;a e&longs;&longs;et cur &longs;ub alio angulo, quam prædicto G M K, Iris non appareret.

Prædicta omnia &longs;unt &longs;ecundum Ari&longs;tot. di&longs;cur&longs;um, & figurationem dicta, nam &longs;ecundum veritatem po&longs;&longs;nt in eadem nube con&longs;titui plures anguli æquales, nec tamen in eodem orbe, &longs;ed vnus &longs;upra alterum; vt in figura præ­

&longs;enti, &longs;i nubes e&longs;&longs;et vbi B D. oculus in C, Sol in A. e&longs;&longs;ent duo anguli A B C, A D C, æ­quales per 33. 3. qui tamen non &longs;unt in gyrum con&longs;tituti, po&longs;&longs;et igitur, per illorum vtrun­que Sol Iridem efficere. atque animaduer&longs;io h&ecedil;c videtur ma­gni momenti e&longs;&longs;e, ad Iridis de­mon&longs;trationem con&longs;tituendam: cum hinc v&longs;itatæ demon&longs;tra­tiones infringatur. Fortè confu giendum e&longs;t ad illud, quod Maurolycus, & 10. Bapti&longs;ta Porta ob&longs;eruarunt; debere nimirum di&longs;tantiam ab oculo ad cen­trum Iridis e&longs;&longs;e æqualem altitudini, &longs;iue &longs;emidiametro Iridis. Ita vt non &longs;o­lum requiratur idem angulus, &longs;ed etiam tanta Iridis altitudo, quanta requi­ritur vt angulus in orbem con&longs;tituatur, ex quo Iris po&longs;&longs;it apparere. hæc à nemine hactenus animaduer&longs;a placuit addere, vt ex ijs demon&longs;tratio Iridis omnibus numeris aliquando ab&longs;olui po&longs;&longs;it, quod infra (ni fallor, fauente Deo) præ&longs;tabimus.

165

Ibidem (Extraponatur igitur quædam linea, quæ D B, & &longs;eindatur vt M G, ad­M K, &longs;ic quæ D, ad B, maior autem quæ M G, ea quàm M K, quoniam &longs;uper ma­iorem angulum reflexio coni, maiori enim angulo &longs;ubtenditur trianguli M K G. Maior igitur e&longs;t & ip&longs;a D, ip&longs;a B. addatur igitur ad eam, quæ B, ea in qua F, vt &longs;it quod D, ad B, quæ B F, ad D. Deinde quod F, ad K G, quæ B, ad aliam fiat, quæ K P. & à P, ad M, copuletur quæ P M, erit igitur P. polus circuli, ad quem lineæ, quæ à K, incidunt) hucu&longs;que o&longs;tendit lineas vi&longs;uales cadere ad M, pun­ctum in Iridis periphæriam, pergit deinceps inue&longs;tigare polum, & po&longs;tea centrum eiu&longs;dem ambitus, vtraque autem exi&longs;tere in horizonte reperit, vt hinc inferat Iridis portionem illam, quæ oriente Sole &longs;upra horizontem ap­paret, e&longs;&longs;e &longs;emicirculum, vt propo&longs;uerat. Differt autem polus circuli à cen­tro eiu&longs;dem circuli. polus e&longs;t punctum extra planum circuli, ex quo tamen vt centro adhibito circino circuli periphæria de&longs;cribi pote&longs;t; &longs;ic polus æqua­toris e&longs;t idem, qui polus mundi: centrum verò e&longs;t in plano &longs;ui cir culi, &longs;ic cen­trum æquatoris e&longs;t idem cum centro mundi, cum æquator per illud incedat.

Dicit itaque Ari&longs;t. cum data &longs;it proportio linearum K M, & M G, in &longs;upe­riori &longs;ecunda figura numeri 164. quam nunc iterum in&longs;picere opertet; ex­

ponatur alia linea recta B D. quæ diui­datur in partes B, & D. proportionales cum lineis K M, G M, per 10. 6. cum ergo K M, &longs;it minor quàm G M, per 19. primi, quia in triangulo G M K, oppo­nitur minori angulo, erit quoque B, minor quàm D, addatur iam ip&longs;i B. linea nea F, ita vt &longs;it tota F B, tertia proportionalis ad duas B, & D, per 11. 6. hoc ordine, vt F B, ad D. ita D, ad B. Deinde vt &longs;e habet F, ad K G. ita &longs;it B, ad aliam, quæ &longs;it K P, in eadem figura per 12. 6. & à puncto P, ad M, iun­gatur recta P M. Dico P, e&longs;&longs;e polum circuli, quem dixi Iridis, & in quem li­neæ à K, procedentes turbinis formam effingunt, probatur autem ab Ari&longs;t. in &longs;equentibus.

166

Ibidem (Erit etiam, quod quæ F, ad K G. & quæ B, ad K P. & quæ D, ad P M. non enim &longs;it, &longs;ed aut ad minorem, aut ad maiorem ea, quæ P M, nibil emm differet. &longs;it enim ad P R. eandem ergo rationem G K, & K P, & P R, inuicem habebunt, quam quæ F, B, D: quæ autem F, B, D, proportionales crant, quod quidem D, ad B. quæ F B, ad D: quare quod quæ P G, ad P R, quæ P R, ad eam, quæ P K. &longs;i igi­tur ab ijs, quæ K G, quæ G R, & K R, ad R, coniungantur, coniunctæ hæ eandem habebunt rationem, quam quæ G P, ad eam, quæ P R, circa eundem enim angulum P, proportion aliter, & quæ trianguli G P R, & eius, qui K R P. quare & quæ G R, ad eam quæ K R, eandem rationem habebit, quam & quæ G P, ad eam quæ P R, habet autem & quæ M G, ad M K, eam rationem, quam quæ D, ad eam quæ B, quare ambæ à punctis G K, non &longs;olum ad circun&longs;erentiam M N, con&longs;tituentur ean­aem habentes rationem, &longs;ed & alibi, quod quidem impo&longs;&longs;ibile) incipit, vt dixi, probare P, e&longs;&longs;e polum prædicti ambitus, &longs;ic. Primò enim &longs;ciendum in præ­mi&longs;&longs;a con&longs;tructione e&longs;&longs;e, vt F, ad G K, & B, ad K P, ita D, ad P M. nam &longs;i non &longs;it eadem ratio D, ad P M, cum alijs prædictis, erit eadem ratio eiu&longs;dem D, ad aliam maiorem, vel minorem ipfa P M. &longs;it ad minorem P R. nihil enim refert &longs;iue dixeris habere eandem rationem ad minorem, &longs;iue ad maiorem, ergo permutando erunt G K, K P, P R, proportionales cum F, B, D. &longs;ed li­neæ F, B, D, erant proportionales componendo hoc modo, vt F B, ad D, ita D, ad B: quare &longs;imiliter erunt vt G P, ad P R, ita P R, ad P K. per 18. 5. &longs;i igi­tur à punctis G, & K, figuræ nu. 164. iungantur lineæ ad R, quæ &longs;int G R, K R, erit vt G R, ad K R, ita G P, ad P R. quia orta sunt duo triangula G P R, K P R, quæ habent eundem angulum ad P. & latera proportionalia circa dictum angulum. e&longs;t etiam vt G P, ad P R, in maiori triangulo, ita P R, ad K P, in minori, ex con&longs;tructione, quare per 6. 6. erunt illa duo triangula æquian­gula; ergò per 4. 6. erunt latera circum æquales angulos proportionalia; quare erit vt G P, ad P R. ita G R, ad R K: erat autem vt K M, ad G M, ita B, ad D. & ita etiam G P, ad P R; ergò per 11. 5. vt K M, ad M G. ita K R, ad R G, intra eandem circunferentiam, & in eodem plano: quod e&longs;&longs;e im­po&longs;&longs;ibile &longs;upra o&longs;tendimus, hoc autem impo&longs;&longs;ibile, &longs;equitur &longs;i neges e&longs;&longs;e vt F, ad G K; & B, ad K P, ita D, ad P M.

167

Ibidem (Quoniă igitur quæ D, neque ad minorem ea, quæ P M, neque ad maiorem (&longs;imiliter enim demon&longs;ir abimus) palam e&longs;t, quod ad ip&longs;am vtique erit, in qua P M, quare erit, quod quæ M P, ad P K, quæ P G, ad M P. Si igitur eo in quo P, polo vtens, di&longs;tantia autem ea, in qua P M, circulns de&longs;cribatur, omnes angulos attin­get, quos reflexæ faciunt, quæ à K, G. &longs;i autem non, &longs;imiliter o&longs;tendentur eandem babere rationem, quæ alibi, quam in &longs;emicirculo con&longs;tituuntur; quod quidem erat impo&longs;&longs;ibile) quoniam igitur, inquit, linea D, neque ad minorem, neque ad ma­iorem quam P M, habet eam rationem, quæ e&longs;t ip&longs;ius F, ad G K, aut ip&longs;ius B, ad K P. &longs;imiliter enim demon&longs;tratur ab&longs;urdum &longs;equi. palàm e&longs;t, quoniam erit D, ad P M, vt prædictæ ad prædictas: quare componendo, & permu­tando, erunt tandem vt G P, ad P M, ita P M, ad P K, & ita G M, ad M K, a&longs;&longs;ump&longs;imus enim in con&longs;tructione e&longs;&longs;e G M, ad M K, ita F B, ad D, & D, ad B. quare cum &longs;it vt G M, ad M K, ita F B, ad D. & G P, ad P M. & P M, ad K P; erunt per 11. 5. vt G M, ad M K. ita G P, ad P M. & P M, ad P K. &longs;i quis igitur vtens puncto P, tanquam polo, & interuallo P M, circulum de&longs;cribat, omnes angulos reflexionis attinget, quos faciunt lineæ productæ à K, & re­flexæ ab M, ad G. harum enim infinitam multitudinem debemus imaginari à K, ad infinita puncta M, produci in ambitu illo con&longs;tituta, re&longs;lectique; ad G. &longs;i enim non attingat omnes illos angulos, &longs;equitur, vt &longs;upra, in eodem &longs;emi­circulo con&longs;titui po&longs;&longs;e duas alias rectas proportionales prioribus G M, M K, quod e&longs;t impo&longs;&longs;ibile. Porrò &longs;ub angulo G M K, linearum G M, M K, Iris apparet: quare apparebit etiam &longs;ub alijs omnibus, quæ à punctis G K, duci po&longs;&longs;unt ad extremum lineæ P M, quia erunt in eadem ratione cum illis; cum non de&longs;inant in eundem &longs;emicirculum, &longs;ed in ambitum Iridis M N, in quo M, punctum imaginamur circumduci. Ex quibus pater P, e&longs;&longs;e polum Iridis, ex quo per puncta M, vbi &longs;it reflexio, de&longs;cribitur arcus attingens omnes Iridis reflexiones.

168

Ibidem (Si igitur circumducas &longs;emicirculŭ, in quo A, circa diametrum in qua G K P, que à G, K, reflexæ ad id in quo M; in omnibus planis &longs;imiliter &longs;e habebunt, & æqualem facient angulam, qui K M G, & quem etiam facient angulum, quæ K P, & P M, &longs;uper eam, quæ G P, &longs;emper æqualis erit. Trianguli igitur &longs;uper eam, quæ G P, æquales ei, qui G M P. con&longs;i&longs;tunt. horum autem perpendiculares ad idem &longs;ignum cadent eius, quæ G P, & æquales erunt, cadunt ad w, centrum ergò circuli w &longs;emicirculus autem, qui circa M N, ab&longs;ectus e&longs;t ab horizonte) hac vitima textus parte concludit Iridis portionem &longs;upra horizontem a&longs;tro oriente exi­&longs;tentem e&longs;&longs;e &longs;emicirculum, hoc modo; &longs;i igitur imaginatione circumducas &longs;emicirculum, in quo A, circa diametrum horizontis G K P, in hac circum­uolutione duæ lineæ G M, M K, in omnibus planis con&longs;titui po&longs;&longs;ibilibus cir­ca prædictam diametrum, quæ &longs;upra etiam fieri à triangulis infinitis dixi­mus, &longs;ucce&longs;&longs;iuè erunt; &longs;iue percurrent &longs;imiliter omnia illa plana, & facient vbique angulum Iridis K M G, eundem: pariter duæ lineæ K P, P M, facient vndique eundem angulum K P M. quare omnia triangula in predictis planis imaginata, & con&longs;tituta &longs;uper linea G P, &longs;imilia ip&longs;i G M P, & æqualia erunt; &longs;i igitur ab angulis ip&longs;orum, in quibus M, ductæ &longs;int perpendiculares ad la­tus G P, omnes cadent in idem punctum w, vt in figura; quarum vna erit M w,quæ tamen cæteras omnes repre&longs;entabit, eisque; omnibus in volutatione axis G K w, coincidit; erunt autem omnes æquales, quandoquidem &longs;unt trian­gulorum æqualium. eruntque; in eodem eiu&longs;dem circuli plano, & punctum w,erit centrum ip&longs;ius. &longs;imilia dicta &longs;unt in Halone. Cum ergò ip&longs;ius centrum a, &longs;it in diametro horizontis G K w P O, manife&longs;tum fit portionem eius, quæ &longs;upra horizontem eminet, e&longs;&longs;e &longs;emicirculum, qui in figura notatur lineis L M N. Atque hoc accidit Sole, vel Luna in horizonte exi&longs;tentibus; quod erat primo loco demon&longs;trandum.

Porrò &longs;ciendum po&longs;&longs;e nos breuius polum prædictum inuenire, &longs;i nimirum

ad M, ducatur M P, faciens angulum K P M, æqua­lem angulo G M K, per 23. primi, erunt enim duo triangula æquiangula G P M, K P M, angulus enim P, e&longs;t communis, angulus verò M K P, e&longs;t æqualis duobus G, & G M K, per 32. primi, ergo etiam duobus ad M, &longs;iue toti G M P, & reliquus K M P, reliquo, quare per 4.6. latera circa angulos æqua­les proportionalia erunt, & omologa G M, ad M K, ita G P, ad P M, quæ æqualibus augulis &longs;ubtenduntur. ea&longs;dem autem proprietates habcbant etiam triangula Ari&longs;t. in figura, de qua paulò ante dicebam. Verba illa (Quæ ali­b quam in &longs;emicirculo constituuntur) &longs;unt perperam in antiqua tran&longs;latione tran&longs;lata, nam Græcè &longs;ic, ai alloqi tou_ hmixoxlnou/ sunisamenai, transferenda e&longs;&longs;ent, quæ in alio circuli loco concurrunt.

169

Ibidem (Iterum &longs;it horizon quidem in quo A C. oriatur autem &longs;upra hunc G, axis autem &longs;it nunc in quo G P. Alia igitur omnia &longs;imiliter o&longs;tendentur vt & prius. Polus autem circuli, in quo P, erit &longs;ub horizonte eo, in quo A C, eleuato puncto, in quo G. in eadem autem & polus, & centrum circuli, & terminantis nunc ortum, e&longs;t enim i&longs;te, in quo G P. Quoniam autem &longs;upra diametrum, quæ A C, quod K G, centrum vtique erit &longs;ub horizonte priori eius, in quo A C, in linea K P, in quo w,

Quare minor erit &longs;uperior &longs;ectio &longs;emicir­culo, in qua S T, (nam Q S T, &longs;emicir­culus est, nunc autem inter&longs;ectus e&longs;t ab horizonte A C; itaque Q S, di&longs;parens erit) eleuato ip&longs;o Sole) demon&longs;trat propo&longs;i­tionem &longs;ecundam nimirum Sole &longs;upra horizontem elcuato, ambitum Iridis e&longs;&longs;e minorem circuli portionem, &longs;iue &longs;emicirculo minorem. &longs;it igitur in fi­gura &longs;uperiori, quam textui congruen­tem re&longs;tituimus, linea A C, horizon­talis, &longs;upra quam Sol &longs;it eleuatus in circulo altitudinis in loco G, axis au­rem coni, quem reflexè faciunt &longs;it G K w P. alia igitur omnia, quæ &longs;upra exi&longs;tente in ortu a&longs;tro o&longs;ten&longs;a &longs;unt, hic pariter o&longs;tendi po&longs;&longs;unt, &longs;cilicet Iridem fieri tantum per lineas proportiona­les, & æquales lineis G M, M K, quia Iris videri nequit, ni&longs;i in tali, ac deter­minata reflexione, & angulo, vt initio &longs;uppo&longs;ui; & quia lineæ illis propor­tionales non po&longs;&longs;unt alibi con&longs;titui, quam in ambitu circulari, & in diuer&longs;is planis, &longs;equitur, vt &longs;upra Iridem e&longs;&longs;e circularem M N L; eiusque; polum P, & centrum w, inueniemus &longs;imiliter in axe G K w P, & quia axis hic &longs;ecat hori­zontem in K, in hac vltima figura propter eleuationem Solis &longs;upra A C, in G, &longs;equitur partem axis, in qua w, & P, exi&longs;tunt, infra horizontem deprimi. & quia (vt pater ex 64. 10. Vitell.) & P, polus, & centrum w, Iridis, & cen­crum K, circuli horizontis, cuius &longs;cilicet diameter e&longs;&longs;et A K S, & Sol, &longs;unt in eadem linea G K w P, &longs;i centrum Iridis w, &longs;it infra horizontem, patet mi­norem circuli portionem, quam &longs;it &longs;emicirculus &longs;upra horizontem eminere, in qua po&longs;ui literas S L T, nam Q S L T R, e&longs;t &longs;emicirculus, cuius pars con­tenta inter duos arcus Q S, & T R, e&longs;t infra horizontem. debemus autem hunc &longs;emicirculum, & hanc portionem ip&longs;ius S L T, extantem &longs;upra hori­zontem imaginari erectam e&longs;&longs;e, vt planum ip&longs;ius circuli faciat angulos re­ctos &longs;iue &longs;it perpendiculare cum axe G K P; & circulum altitudinis A G M N, modo fungi vice horizontis. &longs;ic enim &longs;ola portio S L T, appareret nobis, e&longs;­&longs;etque; rationabiliter con&longs;tituta. Ex quibus 2. Ari&longs;t. propo&longs;itio manife&longs;ta e&longs;t.

180

Ibidem (Minima autem cum in meridie, quanto enim &longs;uperius G, tanto in&longs;e­rius & polus, & centrum circuli erit) probat tertiam propo&longs;itionem, nimi­rum Sole exi&longs;tente in meridie minimam omnium e&longs;&longs;e Iridis arcus portionem: ratio autem e&longs;t, quia tunc G, &longs;iue Sol, e&longs;t alti&longs;&longs;imus &longs;upra horizontem, & con&longs;equenter w; centrum Iridis e&longs;t depre&longs;si&longs;&longs;imum, quare tunc maxima cir­culi Iridis portio ab&longs;condetur, & proinde minima apparebit, quod erat vl­timo demon&longs;trandum. Non me latet has Ari&longs;t. figurationes e&longs;&longs;e apud Olym­piodorum nonnullis obiectionibus obnoxias, &longs;ed cum facilè dilui po&longs;&longs;int, & etiam &longs;i non diluantur, &longs;aluetur tamen veritas Ari&longs;totelicæ demon&longs;tratio­nis, breuitati &longs;tudens, con&longs;ultò eas prætermitto.

Aduertendum præterea Vicomercatum inordinatè citare librum Dato­rum Euclidis, & quandoque etiam malè citare Euclidem ip&longs;um. peius verò faciunt ij, qui has demon&longs;trrationes ab&longs;que vlla libri Datorum mentione ex­plicare conantur, cum manife&longs;tè illo innitantur.

Cæterum &longs;i quis breues, ac dilucidas harum rerum demon&longs;trationes re­quirat, is legat 74. 75. 76. propo&longs;itiones 10. Vitell. vel &longs;equentem no&longs;tram de Iride additionem. ego enim longiorem hanc, atque impeditam Ari&longs;t. tra­ctationem in gratiam textus illius, vt in&longs;tituti mei ratio po&longs;tulabat, per&longs;e­quutus &longs;um.

181

Ibidem (Quod autem in minoribus quidem diebus ijs, qui po&longs;t æquinoctium au­tumnale contingit &longs;emper fieri Iridem: in longioribus aurem diebus ijs qui ab æqui­noctio altero, ad æquinoctium alterum circa meridiem non fit Iris, can&longs;a est, quia quæ ad Vr&longs;am &longs;ectiones omnes maiores &longs;unt &longs;emicirculo, & &longs;emper ad matere quod autem e&longs;t occultum, paruum: quæ autem ad æquatoris meridiem &longs;ectiones, quæ qui­dem &longs;upra &longs;ectio, parua; quæ autem &longs;ub terra magna, & &longs;emper maiores, quæ lon­gius. quare in ijs, qui ad æ&longs;tiuas ver&longs;iones diebus propter magnitudinem &longs;ectionis, antequam veniat G, ad medium &longs;ectionis, infra iam pœnitus fit P; propterea quod longè di&longs;tat à terra meridies propter magnitudinem &longs;ectionis. In ijs autem diebus, qui ad hyemates ver&longs;iones, quia non multŭ &longs;unt &longs;upra terram &longs;ectiones cir culorum, contrarium nece&longs;&longs;arium fieri, modicum enim eleuato in quo G, in meridie fit Sol)quærit cur po&longs;t æquinoctium autumnale v&longs;que ad vernum, hoc e&longs;t hyemali tempore, Iris appareat etiam Sole meridiem occupante: reliquo autem tempore æ&longs;tiuo, quod e&longs;t ab æquinoctio verno ad autumnale appareat tan­tum Sole vel in ortu, aut occa&longs;u exi&longs;tente, vel parum &longs;upra terram &longs;ublato. cau&longs;a autem huius refert in &longs;ectiones parallelorum circulorum, quos Sol diurno motu inter vtrunque tropicum de&longs;cribit: nam &longs;ectiones parallelorum, qui &longs;unt ad Vr&longs;am, ide&longs;t in parte &longs;phæræ Boreali, qui omnes &longs;unt inter æqua­torem, & tropicum Cancri; &longs;ectiones inquam horum circulorum, quæ &longs;unt &longs;upra horizontem, maiores &longs;unt &longs;ectionibus infra horizontem depre&longs;&longs;is, & &longs;emper eò maiores, quò propiores &longs;unt Cancro, ita vt magna yaldè &longs;it ea portio, quæ e&longs;t &longs;upra terram, exigua verò admodum, quæ infra (intelligan­tur hæc in &longs;phæra obliqua, cuius polus eleuetur grad. 45. circiter) quare quando a&longs;trum G, con&longs;cenderit meridiem, adeò P, polus Iridis, & etiam w,centrum eius infra terram deprimitur, vt aut nihil, aut in&longs;en&longs;ibile quid de Iridis ambitu &longs;upra terram eleuari po&longs;&longs;it, contrarium accidit in parallelis meridionalibus, quia eorum &longs;ectiones &longs;uperiores &longs;unt &longs;emper inferioribus minores, quapropter etiam &longs;i a&longs;trum ad meridiem eleuetur, parum tamen attollitur, & con&longs;equenter centrum w, Iridis parum infra horizontem de&longs;cendit, ac propterea etiam in meridie pars ip&longs;ius &longs;atis ma­gna con&longs;picitur. quæ omnia adhibita &longs;phæra materia­li, eaque a&longs;tronomicè ad &longs;uam eleuationem accommodata, nullo negotio li­cebit intueri.

Additio de Iride.

Cvm &longs;uperior Ari&longs;tot. de Iride tractatio ob&longs;cura, ac tricis pluribus impedita eua&longs;erit, cumque; aliorum etiam demon&longs;trationes aliqua ex parte vacilient, vi&longs;um e&longs;t breuiter expeditam, atque ab&longs;olutam ip&longs;ius apponere demon&longs;trationem. Cum igitur in cœle&longs;ti arcu duo poti&longs;&longs;imum &longs;int, quæ &longs;ui admiratione Philo&longs;ophorum animos in &longs;ui con­templationem alliciant, colores, &longs;cilicet, & figura: nos mirabilem illam co­lorum triadem, tanquam alienam, phy&longs;icis relinquentes, de figura ip&longs;ius iu­re mathematico di&longs;&longs;eremus: rotunditatis &longs;cilicet Iridis cau&longs;am opticis ra­tionibus venabimur, cur aliquando &longs;emicirculus, aliquando &longs;emicirculo mi­nor appareat. vt igitur ordine procedamus.

Primo loco aduertendum e&longs;t tria ad Iridis vi&longs;ionem e&longs;&longs;e nece&longs;&longs;aria, So­lem, oculum, & nubem tenuem, ac ro&longs;cidam, quæ &longs;cilicet minutis guttulis iam &longs;cateat; hac enim ratione guttulæ illæ innumera erunt veluti parua &longs;pecula, quæ lumen Solis ob paruitatem imperfecto quodam modo repre­&longs;entare po&longs;&longs;int, ex tali enim repre&longs;entatione Iris apparet. quæ tria debent e&longs;&longs;e ita di&longs;po&longs;ita, vt Sol, oculus, & centrum Iridis &longs;int in eadem recta linea con&longs;tituta, oculusque; medium locum, inter Solem, & Iridis centrum obtineat, vt in prima figura videre e&longs;t, in qua Sol vbi A, oculus in C. nubes verò G H L E, in qua apparet Iris in arcu E B F, quem debemus concipere e&longs;&longs;e in rece&longs;&longs;u, vt pictores aiunt, depictum. i. non in hoc &longs;itu, & ouali figura, &longs;ed

e&longs;&longs;e perfectè &longs;emicircularem, habereque; talem po&longs;itionem, vt pars ip&longs;ius B F, &longs;it citra chartam eleuata, ip&longs;ique; perpendicularis, pars verò E B, vltra pagi­nam rectà recedat, &longs;icque; diameter Iridis E F, faciat angulos rectos cum linea horizontali A C L, in quo &longs;itu oculo C, totus ex oppo&longs;ito directè &longs;pe­ctaretur, non aliter ac Iridem ip&longs;am con&longs;picere &longs;olemus. Quod autem ne­ce&longs;&longs;aria &longs;it nubes ro&longs;cida, pulcherrima hac experientia comprobatur: &longs;i enim in Sole po&longs;iti ore aquam efflantes leui a&longs;pergine aerem Soli, ac nobis ad­uer&longs;um irroremus, actutum Iridis arcum guttulis illis, quamuis volitanti­bus inhærcntem &longs;umma voluptate &longs;pectabimus. Quod præterea oculus no­&longs;ter, cum Iridem videmus, medius &longs;it inter Solem, & Iridis centrum, expe­rimento diuturno, manife&longs;tum e&longs;t.

Secundò, notandum e&longs;t, arcum per reflexionem fieri: quod quidem pri­mo eadem experientia, qua præcedens conclu&longs;io confirmatur: deinde, quia Iridem &longs;emper in oppo&longs;ita Soli, ac nobis parte con&longs;picimus; quemadmodum in eadem figura o&longs;tenditur, quod aliter quàm per reflexionem fieri nequit.

Tertiò, &longs;ciendum e&longs;t ex Maurolyco, & 10. Bapti&longs;ta Porta, tantam e&longs;&longs;e di­&longs;tantiam C D, ab oculo ad centrum arcus, quanta e&longs;t altitudo, &longs;eu &longs;emidia­meter D B, ob&longs;eruarunt enim ip&longs;i angulos D C B, & C B D, e&longs;&longs;e &longs;emirectos, & proinde æquales, & con&longs;equenter duo latera C D, D B, trianguli C D B, per 6. 1. æqualia &longs;unt.

Quartò, con&longs;iderandum e&longs;t lineas A B, A D, ob maximam Solis ab Iride di&longs;tantiam in&longs;en&longs;ibiliter differre; & ideò &longs;upponi po&longs;&longs;unt æquidi&longs;tantes, quare angulus A B C, qui æqualis e&longs;t alterno B C D, &longs;umi pote&longs;t ab&longs;que vllo errore pro &longs;emirecto. hic autem angulus A B C, dicitur angulus reflexionis Iridis, &longs;ub tali enim reflexione lumen Solis occurrens nubi in B, reflectitur ad oculum C.

Quintò, &longs;equitur ex prædictis arcum videri &longs;emper &longs;ub &longs;tato, ac determi­nato reflexionis angulo, &longs;cilicet &longs;ub &longs;emirecto, neque po&longs;&longs;e per alium videri. quod etiam probari pote&longs;t ex Ari&longs;t. quia nimirum videmus arcum apparere con&longs;imiliter in ambitu circulari, ergò nece&longs;&longs;ariò apparebit vbique in toto il­lo ambitu per con&longs;imilem reflexionem, &longs;iue per æquales reflexionis angulos, pro quibus omnibus vnus cernitur in figura angulus A B C.

Sextò, ad Iridis vi&longs;ionem, præter ea, requiri aeris rorantis multiplica­tionem; &longs;icuti enim nebulam videre nequimus, ni&longs;i aer exhalatione illa in­fectus multus &longs;it ante oculum no&longs;trum: &longs;ic etiam exi&longs;timo ad Iridis appari­tionem, opus e&longs;&longs;e plurima nube rore&longs;cente, vt ex multiplicatione guttula­rum, quarum aliæ po&longs;t alias &longs;int, totus tandem Iris appareat. quia paucæ guttulæ, etiam &longs;i quælibet illarum aliquid Iridis efficeret, ob paruitatem tamen illarum, nulla arcus figura &longs;pectaretur. Quod &longs;i ante oculum pluri­mæ &longs;int in toto aere aliæ po&longs;t alias, tunc &longs;e mutuò iuuantes, obiectum &longs;atis &longs;en&longs;ibile, quoc Iris e&longs;t, efficere po&longs;&longs;unt. Adde, quod etiam ex tali guttula­rum multiplicatione, aer opacatur, quæ opacatio plurimum iuuat ad Iri­dem &longs;pectandam.

Septimò, Iridis rotundationis cau&longs;am ex præmi&longs;&longs;is con&longs;tare poti&longs;&longs;imum ex duabus. primò, ex angulo reflexionis determinato, qui videlicet &longs;it ferè &longs;emirectus. &longs;ecundò, ex paribus di&longs;tantijs C D, D B, huiu&longs;modi enim plures anguli, qui ad Iridem &longs;unt nece&longs;&longs;arij (debent enim &longs;ingulæ Iridis partes &longs;ub huiu&longs;modi angulo repre&longs;entari) non po&longs;&longs;unt aliter quàm in gyrum con&longs;titui, quem gyrum optimè concipiemus, &longs;i imaginemur triangulum A B C, cir­cumuerti circa lineam horizontalem A C L, fixam, tanquam circa axem. in hac enim conuer&longs;ione angulus Iridis B, de&longs;cribet circulum, qui erit Iris, & pertr an&longs;ibit omnes angulos, qui in tali Solis, oculi, ac nubis &longs;itu, arcum ef­ficere &longs;unt idonei.

Sed contra prædicta de angulo Iridis determinato eadem nobis obijcies, quæ nos &longs;upra ad finem numeri 164. Ari&longs;t. & alijs obiecimus, plures nimi­rum po&longs;&longs;e con&longs;titui angulos æquales angulo Iridis B, in plano trianguli A B C, qui non &longs;int in eodem orbe con&longs;tituti, in quo &longs;unt omnes anguli B. Iridem reflectentes, quique reflexionem faciant ad eundem oculum C, vnde &longs;equitur prædictam Iridis altitudinem non e&longs;&longs;e, vti diximus, determinatam, cum po&longs;&longs;it angulus B, alios &longs;ibi æquales tam &longs;upra, quàm infra habere, qua ra­tione deberet etiam Iris, & altius, & inferius apparere.

Huic dubitationi re&longs;pondeo, quod quamuis huiu&longs;modi plures anguli æquales fiant, non tamen Iridis generationi ob&longs;tant, quinimò ad eam valdè nece&longs;&longs;arij &longs;unt; cum enim omnes &longs;int in circunferentia circuli A C D B, quar­tæ figuræ num. 164. quæ modo in&longs;picienda e&longs;t, vt &longs;unt in ea anguli A D C, A B C; quæ circunferentia ob &longs;ui circuli immen&longs;itatem ad &longs;en&longs;um e&longs;t in&longs;tar lineæ rectæ, fit vt omnes illi anguli tàm qui &longs;upra B, quàm qui infra &longs;unt, &longs;int quoad &longs;en&longs;um in eadem recta C D B, ante vi&longs;um proten&longs;a, &longs;icque; Iris, qui apparet in D, & in B, &c. ob medij rorantis multiplicationem vnam tantùm oculo Iridem repre&longs;entet. locus tamen, in quo apparet, & vbi e&longs;t angulus B, qui propriè Iridis appellatur, e&longs;t in tanta di&longs;tantia à centro arcus, quan­ta e&longs;t ab eodem centro ad oculum, vt &longs;upra dictum e&longs;t.

Quod verò alibi extra circunferentiam illius circuli, poni nequeat angu­lus æqualis angulo B, præ&longs;entis figuræ, qui re&longs;lectat ad C. patet &longs;ic, &longs;it enim angulus A N O, &longs;emirectas, & ideò æqualis angulo B, erunt ergo B C, N O, parallelæ, quare non corcurrent mbæ ad C, &longs;ed altera ad E, altera verò ad O, quæ propterea oculo in O, to Iridem efficeret, non autem oculo C: &longs;icque; oculus C, & ocu O, erent diuer&longs;s arcus. eodem modo o&longs;tendi pote&longs;t, neque in &longs;apemorparce nubis vbi P, con&longs;titui po&longs;&longs;e angulum æqualem angulo B, qui oculo C, Iridem valeat o&longs;tendere. Ex quibus &longs;atis patefacta e&longs;t cau&longs;a rotunditatis arcus, angulus &longs;cilicet determinatus cum di&longs;tantia­rum C D, D B, paritate, necnon cum medij rorantis &longs;ufficienti multiplica­tione. Ex his etiam Iridis definitio in hunc modum concinnari pote&longs;t, Iris e&longs;t arcus multicolor in nube rorida, ex radiorum Solis, aut Lunæ reflexio­ne &longs;ab &longs;tatuto angulo effulgens.

Octauo loco Problemata nonnulla re&longs;oluemus.

Problema Primum.

Cur oriente, aut occumbente Sole, Iris &longs;emicirculus e&longs;t?

Cau&longs;a huius hæc e&longs;t; &longs;upra enim dictum e&longs;t, in omni Iridis appari­tione tria hæc, Solem, oculum, & Iridis centrum e&longs;&longs;e in eadem re­cta linea, v. g. in linea A C D, præcedentis figuræ, cum igitur Sol tam oriens, quam occidens &longs;it in horizonte, v. g. in A, horizontis puncto, &longs;imiliter oculus &longs;it in C, horizontis centro, con&longs;ectarium e&longs;t, cen­trum etiam Iridis D, e&longs;&longs;e pariter in horizontis &longs;uperficie, quare &longs;ecabitur ab horizonte per centrum, vnde etiam &longs;equitur ip&longs;ius Iridis portionem E B F, quæ &longs;upra horizontem extat e&longs;&longs;e &longs;emicirculum. Quod &longs;i horizon non ob&longs;taret, integrum Iris compleret orbem, cernereturque; toto ambitu B F M E.

An quandoque; maior &longs;emicirculo appareat?

Problema Secundum.

Maior quidem, imò etiam integer circulus, &longs;ed ab oculo in &longs;ummitate montis con&longs;tituto, Soleque; iam multum eleuato videri pote&longs;t, vt in hac &longs;ecunda figura cernitur, vbi euecto Sole ad locum E, &longs;upra horizontem

A B, poterit oculus in vertice montis C, po&longs;itus Iridem F G H I, comple­tam videre, quia infra lineam E C D, in qua exi&longs;tunt Sol, oculus, & Iridis centrum, nihil e&longs;t ad partes D, vbi nubes irrorat, quod Iridis apparitioni &longs;it impedimento.

Cur quanto Sol altior e&longs;t, tanto inferior, tantoque; &longs;emicir­culo minor appareat Iris?

Problema Tertium.

Qvia eleuato Sole ad E, vt in hac tertia figura, nece&longs;&longs;ario centrum Iri­dis D, infra horizontem A B, deprimetur, cum in eadem recta E C D.

Sol E, oculus C, centrunque; Iridis D, exi&longs;tant: vnde nece&longs;&longs;ariò &longs;equitur Iridis portionem F G H, &longs;upra horizontem extantem, &longs;emicirculo minorem e&longs;&longs;e.

Cur Iris in&longs;equentes fugit, fugientes verò in&longs;equitur?

Problema Quartum.

Pvlcherrimum i&longs;tud phænomenon primus omnium Philippus Mendæus Platonis di&longs;cipulus, ob&longs;eruauit; Cuius ratio e&longs;t, quia arcus non ni&longs;i &longs;ub determinato angulo, di&longs;tantijs etiam illis paribus, ac tandem idone a a&longs;per­gino&longs;æ nubis multiplicatione &longs;pectatur; quapropter &longs;i quis per aerem to­tum vndique ro&longs;cidum inambulet, vbicunque illi anguli, illæque; conditiones af­fuerint Iris apparebit: quod &longs;i in aperta planitie obequitans arcu con&longs;pe­cto, additis equo calcaribus citatum cur&longs;um ad eum direxerit, fugientem ante &longs;e Iridem &longs;umma cum iucunditate mirabitur.

Ex dictis pr&ecedil;tere a patet, &longs;impliciter nimis eos hallucinari, qui exi&longs;timant in plana, aut concaua nubis &longs;uperficie Iridem tantummodo apparere po&longs;&longs;e.

Curlunares Irides fiunt rariores?

Problema Quintum.

Qvoniam iuxta plenilunia tantum, cum &longs;cilicet Luna plurimo lumine abundat, quod Iridem efficere debet, contingunt: præterea quia cum lunare lumen debile &longs;it, ni&longs;i aliæ cau&longs;æ perfectæ admodum concur­rant, quod rarò accidit, Iris nullo modo effulgere valet. Hactenus de Iri­dis figura &longs;it &longs;atis.

Summa 2. cap. 5. De Parelio.

182

Textus (Fiunt autem vt diximus, & Virgæ, & Parelia in ortu, & oc­ca&longs;u, & nec &longs;upra Solem, nec infra, &longs;ed ex lateribus, nec propè admo­dum, nec procul omninò. propinquam enim concretionem Sol di&longs;&longs;oluit: &longs;i autem procul ab&longs;it, a&longs;pectus non reflectetur, &longs;i enim à paruo &longs;peculo procul protenditur imbecillus fit. quare, & Coronæ è regione Solis non fiunt. &longs;i igi­tur &longs;upra fuerit, & proxima; eam Sol di&longs;&longs;oluet: &longs;i vrò procul a&longs;pectus minor quam vt reflecti po&longs;&longs;it in Solem non-incidet; à latere autem fieri pote&longs;t, vt &longs;pecu­lum ita distet à Sole, vt non &longs;oluatur, & a&longs;pectus totus ad eum perueniat, eo quod ad terram dum fertur, qua&longs;i per immen&longs;um feratur, peruenire nequeat. &longs;ub Sole verò non fit, quia cum ad terram propius acce&longs;&longs;erit à Sole di&longs;&longs;oluitur, cum medium cœli tenuerit a&longs;pectus di&longs;trahitur. omninò ne à latere quidem, Sole medium cœli tenente, efficitur, quia a&longs; pectus &longs;ub terram non fertur, quare exiguus ad &longs;peculum producitur, & qui reftectitur pror&longs;us imbecillis redditur) ibi (propinquam enim concretionem Sol di&longs;&longs;oluit) rationes, quas affert circa Parelia videntur (auda­cter loquar) admodum debiles. præ&longs;ens ea e&longs;t, vt Parelium non fiat propè Solem, quia illa nubis concretio, quæ Parelio nece&longs;&longs;aria e&longs;t, nequit adeo So­li propinqua e&longs;&longs;e, quia nimirum Sol ob propinquitatem eam di&longs;&longs;olueret; &longs;ed quis non videt eam nubem, quam vulgò exi&longs;timamus e&longs;&longs;e Soli propinquam, &longs;eu qua&longs;i inter nos, & Solem tantum, imò etiam minus aliquando à Sole ve­rè di&longs;tare, quàm alia, quàm vulgò remotiorem à Sole putabimus? præte­rea omnes nubes no&longs;tri horizontis re vera æquidi&longs;tare à Sole certum e&longs;t, ob maximam enim Solis di&longs;tantiam totus no&longs;ter horizon phy&longs;icus e&longs;t in&longs;en&longs;i­bilis quantitatis ad Solem, & vnius puncti vicem gerit.

Ibi verò (Si autem procul ab&longs;it, &c.) reddit rationem, cur parelium non appareat in nube à Sole valde remota &longs;ecundum vulgarem æ&longs;timationem, vnde vulgarem etiam rationem affert, ait enim, nubem illam e&longs;&longs;e veluti &longs;pe­culum Solis repre&longs;entatiuum, &longs;peculum autem tàm longè à Sole po&longs;itum, reddi debile, & proptereá non po&longs;&longs;e Solis imaginem referre: Verùm ratio hæc nulla e&longs;&longs;e videtur, quis enim ignorat non propterea e&longs;&longs;e remotius à So­le, quamuis maiorem habere videatur à Sole lateralem di&longs;tantiam, vt pau­lò ante dixi? Eandem rationem illi dubitationi accommodat, cur neque vi­deatur &longs;upra Solem, quamuis non ei quadret, pote&longs;t enim aliqua nubes vi­deri &longs;upra Solem, quæ tamen remotior &longs;it à Sole, quam illa, in qua Parclium gignitur. Ait po&longs;tea (A latere autem, &c.) cur appareat in nube fatis Soli à latere vicina, in di&longs;tantiam à Sole refert: &longs;ed quæ dudum dicta &longs;unt, i&longs;tud quoque refellunt. Verba illa (Eo quod ad terram dum fertur qua&longs;i per immen&longs;um feratur, peruenire nequeat) videntur alieno loco dicta; &longs;imilia præcedentibus &longs;unt reliqua, præ&longs;ertim quæ ibi (Sub Sole verò non fit, quia cum ad terram pro­pius acce&longs;&longs;erit) cur non videatur infra Solem, rationem quandam, quæ fortè inanis e&longs;t reddit; nunquid enim non po&longs;&longs;umus tam infra Solem, quàm &longs;upra ita &longs;peculum accommodare, vt Solem no&longs;tris vi&longs;ibus remittat? huic certè Optice tota repugnat. Cum igitur Mathematica ratione hæ rationes non con&longs;i&longs;tant, alias alij excogitent. Mirum tamen e&longs;t, omnes, quos viderim commentatores, eas tanquam optimas admittere.

In quarto Meteororum nihil Mathematicum occurrit.

EX LIB. PRIMO DE ANIMA.

183

Tex. 11. (Videtur autem non &longs;olum ip&longs;um quid e&longs;t cogno&longs;cere vtile e&longs;&longs;e ad cogno&longs;cendas cau&longs;as accidentium &longs;ub&longs;tantijs: &longs;icut in Mathemati­cis quid rectum, & quid obliqaum, aut quid linea, & planum, ad co­gno&longs; cendum quot rectis, trianguli anguli &longs;unt æquales) quid &longs;it vnum­quodque ex prædictis patet tum ex definitionibus primi Elem. tum ex com­mentarijs ip&longs;arum; quamuis autem ibi non definiatur rectum, nec obliquum in genere, definitur tamen linea recta, & obliqua, & plana &longs;uperficies, &longs;iue planum, ex quibus facilè definitio recti, & obliqui colligi pote&longs;t: quæ defi­nitiones nece&longs;&longs;ariæ &longs;unt ad cogno&longs;cendum quot rectis angulis æquales &longs;int tres anguli cuiufuis trianguli. vide quæ de hac æqualitate &longs;crip&longs;i lib, primo Priorum, &longs;ecto 3. cap. 1.

184

Tex. 13. (Si igitur e&longs;t aliqua animæ operatio, aut pa&longs;&longs;io propria, continget vti­que ip&longs;am &longs;eparari: &longs;i verò nulla e&longs;t propria ip&longs;ius non vtique erit &longs;eparabilis. &longs;ed &longs;icut recto in quantum rectum multa accidunt, vt tangere æeam &longs;phæram &longs;ecun­dum punctum, non tamen tanget hoc, rectum ip&longs;um &longs;eparatum: in&longs;eparabile enim, &longs;i quidem cum corpore quodam &longs;emper e&longs;t) Propo&longs;itio 2. tertij Elem. &pacute;robat li­

neam rectam, duo quælibet puncta quantumuis pro­pinqua in circuli ambitu a&longs;&longs;umpta coniungentem cadere intra circulum. v. g. puncta A B, quantum­uis &longs;ibi inuicem propinqua fnerint, attamen &longs;i line a A B, ea coniungat, ip&longs;a cadet intra circulum, & veluti chorda &longs;ubtendet arcum A B, quantulum­cunque. ex qua demon&longs;tratione colligitur in corol­lario eius lineam rectam tangentem circulum ip­&longs;um in vnico puncto tangere. v. g. rectam C D, tan­gere circulum in puncto E. &longs;i enim dixeris tangere in duobus admodum propinquis, vt in E F, tunc non erit amplius tangens, &longs;ed &longs;ecans, quia vt modo dixi, pars lineæ rectæ, quæ coniungeret puncta E F, intra circulum per &longs;ecundam præallegatam caderet, quod e&longs;t ab&longs;urdum, quia contra hypothe&longs;im, cum &longs;upponamus illam &longs;olùm tangere, non autem &longs;ecare circulum. Ex hac Euclidis doctrina Theodo&longs;ius primo &longs;phæricorum, propo&longs;itione 3. probat planum, &longs;iue &longs;uperficiem planam tangere &longs;phæram in vnico puncto, vt hoc loco innuit Philo&longs;ophus. probat autem hac ferè ra­
tione. &longs;it &longs;phæra A B C, quæ tangat quodpiam planum in duobus punctis A, B, &longs;i fieri pote&longs;t. per quæ duo pun­cta intelligatur ducta recta linea A B, intelligatur etiam circulus A B C, qui &longs;ecet &longs;phæram per centrum C. & per puncta A, B, ergo ex demon&longs;tratis ab Euclide li­nea A B, quæ coniungit puncta A B, cadet intra prædi­ctum circulum; &longs;ed linea hæc e&longs;t in plano tangente ex &longs;uppo&longs;itione, circulus verò in &longs;phæra; ergò cum linea cadat intra circulum, cadet etiam nece&longs;&longs;ariò planum in quo e&longs;t linea, & cum linea cadat intra circulum, cadet etiam nece&longs;&longs;ariò intra &longs;phæram; idemque; faciet planum, quod eam nece&longs;&longs;ariò &longs;equatur, ergò planum &longs;ecat &longs;phæram, non autem tangit, quod e&longs;t ab&longs;urdum, quia contra hypothe&longs;im, &longs;upponunt autem Mathematici, entia hæc mathematica e&longs;&longs;e perfecta, qualia in &longs;ublunaribus fortè non reperiuntur; ænea enim &longs;phæra nulla erit perfectè rotunda, vel planum aliquod perfectè complanatum, vt ip&longs;i &longs;upponunt, eò quod materiæ imperfectio, ac ruditas id nequaquam pa­tiatur. quare cum huiu&longs;inodi entia non reperiantur ab&longs;tracta ab impura hac materia, nullum erit inquit Ari&longs;t. ab&longs;tractum planum, quod po&longs;&longs;it mathe­maticè, atque adeò in vnico puncto mathematico &longs;phæram tangere. hucu&longs;que nece&longs;&longs;aria &longs;unt mathematica ad huius loci intelligentiam. ex quibus ea etiam, quæ ad phy&longs;icum &longs;pectant manife&longs;ta fiunt, nimirum &longs;icut entia mathemati­ca à materia non exi&longs;tunt &longs;eparata, quia &longs;ic nullam haberent operationem; ita etiam anima, &longs;i nullam habet propriam operationem non exi&longs;tet à cor­pore &longs;eparata.

Ex Secundo de Anima.

185

Tex. 12. (Non enim &longs;olum ip&longs;um, quod&longs;it, oportet definitiuam rationem oftendere, &longs;icut plures definitionum dicunt, &longs;ed & cau&longs;am ine&longs;&longs;e, & ap­parere. nunc autem, vt conclu&longs;iones rationes definitionum &longs;unt, vt quid tetragoni&longs;mus? æquale altera parte longiori rectangulum æquilaterum e&longs;&longs;e, talis autem definitio ratio conclu&longs;ionis. dicens autem, quod tetragoni&longs;mus e&longs;t medij inuentio rei cau&longs;am dicit) aggre&longs;&longs;urus Ari&longs;t. animæ definitionem præ­mittit duplicem e&longs;&longs;e definitionem, alteram &longs;cilicet, quæ explicat &longs;olum rei e&longs;&longs;entiam, quam dicunt formalem definitionem; alteram verò, quæ præte­rea explicat etiam rei cau&longs;am, quam dicunt cau&longs;alem definitionem: vtram­que autem exemplo Geometrico explicat.

In cap. igitur de relatione plura &longs;crip&longs;i de tetragoni&longs;mo, &longs;eu qua dratio­ne circuli, quæ huc &longs;pectant. propterea nunc tantum propria huius loci de­claranda re&longs;tant. loquitur igitur hic Philo &longs;ophus non de quadratione circuli, &longs;ed figuræ rectilineæ illius, quæ dicitur Altera parte longior, qualis e&longs;t præ­&longs;ens figura A B C D, cuius quadrandæ ratio e&longs;t huiu&longs;modi. per 13. 6. inue­

niatur recta linea media proportionalis inter duo latera figuræ A B, B C, eaque; &longs;it B D, in &longs;e­quenti figura. e&longs;&longs;e autem mediam proportio­nalem nihil aliud e&longs;t quam ita e&longs;&longs;e A B, ad B D, &longs;icut B D, ad B C. diciturque; media proportio­nalis, quia in hac habitudine medium locum obtinet. quadratum autem li­neæ B D, æquale e&longs;t rectangulo dato A B C D, per 17.6. Inuentio porrò hu­ius mediæ proportionalis, quia facilis e&longs;t, & &longs;citu iucunda, eam &longs;ic habeto.
accipe duo latera A B, & B C, quadrandi rectan­guli, eaque; in directum con&longs;titue, vt vnicam re­ctam con&longs;tituant A C, vt apparet in figura; de­inde diui&longs;a tota A C, bifariam in E, facto cen­tro in E, de&longs;cribe &longs;emicirculum &longs;uper lineam A C, demum à puncto B, in quo duo latera con­iunguntur, erigatur linea perpendicularis v&longs;que ad periphæriam, quæ &longs;it B D. hæc enim B D, e&longs;t media proportionalis inter latera A B, B D, quam nimirum habitudinem habet A B, ad B D, eam quo­que obtinet B D, ad B C. Quadratum igitur huius B D, hoc e&longs;t quadratum, cuius quatuor latera &longs;iut æqualia lineæ B D, quale e&longs;t præ&longs;ens, æquale erit
dato &longs;uperiori rectangulo A B C D, atque hoc modo per­acta erit quadratio, &longs;eu tetragoni&longs;mus dati quadrilateri A B C D. Vides igitur, qua ratione quadratum con&longs;ti­tuatur æquale dato quadrilatero; & qua rationem inuen­tio illius mediæ proportionalis &longs;it cau&longs;a quadraturæ re­ctanguli, & proinde &longs;i quis dicat quadrationem hanc e&longs;&longs;e effectionem rectanguli æquilateri, ide&longs;t quadrati, æqualis dato quadrilate­ro, hic definitionem formalem &longs;olum afferet: quæ definitio, vt dixit in Lo­gicis, e&longs;t in&longs;tar conclu&longs;ionis. &longs;i quis verò dicat tetragoni&longs;mum hunc quadri­lateri dati e&longs;&longs;e mediæ prædictæ inuentionem cau&longs;alem afferet definitionem, cum rei cau&longs;am dicat. Aduerte 10. Grammaticum immeritò accu&longs;are Ale­xandrum, quod dicat quadrationem hanc per inuentionem mediæ propor­tionalis tradi in 2. Elem. nam verè in 14. 2. traditur talis inuentio, quam­uis enim ibi nulla fiat expre&longs;&longs;a mentio huiu&longs;modi mediæ, in ip&longs;a tamen ereperitur, ac per eam figuræ rectilineæ quadrantur: quod patet ex figura 14. prædictæ, quæ eadem e&longs;t cum figura 13. 6. qua docemur prædictam in­uentionem.

186

Tex. 86. (Acutum mouet &longs;en&longs;um in tempore pauco multùm: graue autem in multo parùm; non igitur velox e&longs;t acutum, graue autem tardum, fed fit illius qui­dem propter velocitatem motus huiu&longs;modi, huius autem propter tarditatem) vide quæ de hac re primo topic. cap. 13. dicta &longs;unt, illa enim omnia in hunc lo­cum quadrant. Verum occurrit illa dubitatio; quod cum Ari&longs;t. ibi dicat (Vox acuta quidem velox) hic autem (Non igitur velox e&longs;t acutum) repugnan­tia dicere videtur. cui dubitationi &longs;ic occurrendum; vt dicamus ibi Philo­&longs;ophum dicere vocem acutam e&longs;&longs;e velocem, quatenus acumen vocis oritur ex velocitate motus aerem impellentis. hic verò di&longs;tinguere acutum à ve­loci, tanquam effectum à cau&longs;a.

187

Tex. 159. (Apparent autem, & fal&longs;a, de quibus &longs;imul exi&longs;timationem veram habet, vt apparet &longs;ol vnius pedis, per&longs;ua&longs;um autem e&longs;t, eum maiorem e&longs;&longs;e babitata)habitata, ide&longs;t terra habitata. Vide, quæ cap. 3. &longs;ummæ 1. primi Meteor. Item capite 5. &longs;ummæ 2. de Solis magnitudine &longs;crip&longs;i, ea enim huic loco abundè &longs;atisfaciunt.

Ex Tertio de Anima.

188

Tex. 21. (Vt incommen&longs;urabile, & diameter) vide, quæ de incom­men&longs;uratione diametri, & co&longs;tæ &longs;cripta &longs;unt lib. 1. Priorum, cap. 23. vnde &longs;atis huic loco fieri pote&longs;t.

189

Tex 25. (Punctum autem, & omnis diui&longs;io, & &longs;ic indiui&longs;ibile mon­&longs;tratur &longs;i cut priuatio) punctum enim cum &longs;it terminus lineæ, e&longs;t negatio vl­terioris lineæ (Et omnis diui&longs;io) innuit his verbis præter punctum, lineam etiam, & &longs;uperficiem, nam quemadmodum punctus oritur ex diui&longs;ione li­neæ, ita linea ex diui&longs;ione &longs;uperficiei, & &longs;uperficies ex di&longs;ione corporis. & quamuis punctum, linea, &longs;uperficies, &longs;int indiui&longs;ibilia, mon&longs;trantur ta­men quatenus &longs;unt priuationes, &longs;eu negationes, illud vlterioris lineæ, i&longs;ta vlterioris &longs;uperficiei, hæc tandem vlterioris corporis.

190

Tex. 32. (Sit igitur vt A, quidem album, ad B, quod nigrum; &longs;ic C, ad D; qua­re & prmutatim) ide&longs;t, quare & permutando (vt aiunt Geometræ) erit vt A, ad C, ita B, ad D, hunc argumentandi modum à permutata proportio­ne explicaui in primo Po&longs;ter. cap. 5. tex. 13. dicitur etiam alterna ratio; & definitur ab Euclide definitione 12, 5.

Ex Libro de Sen&longs;u.

191

Cap, 6. (Et qui in Die&longs;i &longs;onus latet, quamuis continum exi&longs;tentem audit omnem cantum, di&longs;t antia enim eius ad extremos &longs;onos latet) quid &longs;it Die&longs;is apud Mu&longs;icos explicatum e&longs;t primo Po&longs;ter. tex. 38. cum autem Die&longs;is &longs;it minima di&longs;tantia, &longs;eu vt loquuntur Mu&longs;ici, mini­mum interuallum inter duas voces, hinc fit vt hæc minima di&longs;tantia inter ex­tremos &longs;onos non exaudiatur, quemadmodum nec minima particula alicu­ius magni corporis à longè vi&longs;i non percipitur, &longs;ed latetinter extrema illius.

192

Cap. 8. (Vnumquodque magis e&longs;t &longs;entire &longs;implex xi&longs;tens, quàm mixtum, velut vinum non temperatum, quàm temperatum; & mel, & colorem, & neten &longs;olam. quàm in diapa&longs;on, quia ob&longs;curant &longs;e inucem) nete apud veteres mu&longs;icos erat in mu&longs;icis in&longs;trumentis omnium chordarum acuti&longs;&longs;ima, cuiu&longs;modi apud nos e&longs;t, quam vulgò canto appellant. Hypate verò eav chorda omnium graui&longs;&longs;ima, qualis e&longs;t ea, quam modo Ba&longs;&longs;o vocant. hæ duæ &longs;imul pul&longs;atæ edebant conionantiam, quæ Diapa&longs;on dicitur, & vulgò octaua. ex quibus &longs;en&longs;us verberum Ari&longs;t. manife&longs;tus e&longs;t.

193

Eodem cap. (Velut Diapa&longs;on, & Diapente) quid &longs;it con&longs;onantia Diapa­&longs;on, explicaui in primo Po&longs;ter. tex. 1. Diapente verò e&longs;t con&longs;onantia ex duo­

bus &longs;onis coale&longs;cens, quorum proportio &longs;it vt 3. ad 2. quæ dicitur &longs;e&longs;quialtera. v. g. &longs;int duæ chordæ æqualis cra&longs;fitiei, atque æquè ten&longs;æ: vna tamen habeat ad alteram proportionem &longs;e&longs;­quialteram, vt in figura apparet; &longs;i &longs;imul pul­&longs;entur, edent con&longs;onantiam Diapente. vulgò autem quint

Ex Libro de Memoria, & remini&longs;centia.

194

Cap. 1. (Sic meminit eos, qui trianguli, quod duobus rectis æquales) ide&longs;t &longs;ic meminit tres angulos cuiu&longs;uis trianguli &longs;imul &longs;umptos æqua­les e&longs;&longs;e duobus angulis rectis &longs;imul &longs;umptis. lege annotata primo Po&longs;ter. &longs;ecto 3. cap. 1.

195

Cap. 3. (Sunt facilè remini&longs;cibilia, quæcunque habent ordinationem aliquam, vt mathemata) h&ecedil;c Philo&longs;ophus dicensfp ectabat ad mirabilem illam, ac per­petuam de mon&longs;trationum connexionem, qua Geometræ omnes, & præci­puè Euclides opera &longs;ua ab initio ad finem v&longs;que, diuino planè ingenij acu­mine deduxerunt.

Ex Libro de Somnijs.

196

Cap. 2. (Cur autem fallimur, cau&longs;a e&longs;t, quoniam non &longs;olum cum &longs;en&longs;ibile mouetur apparent quælibet, &longs;ed etiam cum &longs;en&longs;us ip&longs;e mouetur, &longs;i eodem modo moueatur, quemadmodum à &longs;en&longs;ibili. dico autem velut terra vi­detur nauigantibus moueri, dummodo vi&longs;us ab alio) reddit rationem, cur nauigantibus videatur terra ip&longs;a moueri, ac retrocedere, non autem ip&longs;i nauigantes, quin potius ip&longs;i fibi &longs;tare videantur. cau&longs;am igitur eam e&longs;­&longs;e ait, quia ex motu nauis, terra ip&longs;a manente, accidit, vt eodem modo im­mutetur &longs;en&longs;us vi&longs;us, ac &longs;i terra ip&longs;a moueretur, vi&longs;us verò quie&longs;ceret. At cur eodem modo afficitur &longs;en&longs;us? Per&longs;pectiuirationem e&longs;&longs;e dicunt, quia ea, quæ circa oculum &longs;unt, vt nauis, & ea, quæ in naui &longs;unt, non mutant &longs;i­tum re&longs;pectu oculi, quemadmodum facerent, &longs;i nos ip&longs;i &longs;ine naui progrede­remur. arbores autem, & reliqua, quæ in terra &longs;unt, variant &longs;itum re&longs;pectu oculi, non &longs;ecus, ac &longs;i ip&longs;æ arbores retro deferrentur. propterea igitur vi&longs;us tunc arbores remeare iudicat, quia quæ circa oculum &longs;unt re&longs;pectu ip&longs;ius oculi non mouentur, &longs;iue non variant &longs;itum ad ip&longs;um; ex variatione enim &longs;itus rei re&longs;pectu oculi, percipimus cuiu&longs;uis rei localem motum.

197

Cap. 3. (Quemadmodum igitur, &longs;i quem lateat &longs;uppo&longs;itus oculo digitus, non &longs;olum app trebit, &longs;ed etiam putabitur duo, quod e&longs;t vnum. Si verò non lateat appa­rebit quidem, non putabitur tamen) e&longs;t hæc optica deceptio, quæ tunc accidit, cum aliquod obiectum intuentes, interim digito alterum oculum &longs;ur&longs;um pellimus, ita vt oculi propterea varient &longs;itum re&longs;pectu obiecti, &longs;iue non eo­dem &longs;itu vterque obiectum intueatur, hoc e&longs;t, vt optici aiunt, axes vi&longs;uales non amplius concurrunt &longs;imul in rem vi&longs;am. Vnde &longs;equitur &longs;peciem rei in­tentionalem oculis vario &longs;itu affectis imprimi, ac proinde eam eundem &longs;i­tum in vtroque oculo minimè obtinere, &longs;ed ea, quæ oculo à &longs;uo naturali &longs;latu dimoto accidit ab altera alterius oculi differt; quapropter vario ctiam modo, duplici nimirum, obiectum repre&longs;entant. atque hæc ip&longs;a cau&longs;a e&longs;t, cur illud, quod vnum tantum e&longs;t, duo tamen emoto oculorum altero, videatur. Vide Alhaze­num lib. 3. propo&longs;it. 11. & 12. & infra Problem. 7. &longs;ectionis 31.

EX PRIMOMETAPHYSICAE.

198

Capite 1. (Cirea Aegyptum Mathematicæ artes constitutæ &longs;unt; illic enim gens Sacerdotum vacare permittitur) Notanda maximè no­bilis Mathematicarum origo, cum ab Aegyptiorum Sacerdoti­bus te&longs;te Philo&longs;opho fuerint adinuentæ, quibus occa&longs;ionem præ­buit anniuer&longs;aria agrorum ob Nili innundationem, diui&longs;io: cum enim iam perplures dimetiendorum agrorum rationes repertæ fui&longs;&longs;ent, Sacerdotes ip&longs;i, quibus per otium licebat, illarum praxium demon&longs;tr ationes cœperunt perue&longs;tigare, &longs;icque; paulatim po&longs;tea Geometria amplius exculta adoleuit; quæ deinde ij&longs;dem ad res a&longs;tronomicas per&longs;crutandas adiumento fuit, hacque; ratione reliquas etiam in mathematicas inciderunt.

199

Cap. 2. (Sicut de præ&longs;tigio&longs;is, quæ per &longs;e mouentur, illi qui nondum &longs;peculati &longs;unt cau&longs;am) verbis illis (Quæ per &longs;emouentur) vnica dictio Græcare&longs;pondet, Automata. erant autem Automata apud veteres Gr&ecedil;cos machinæ qu&ecedil;dam, quæ à Mathematicis Mechanicæ artis occultis quibu&longs;dam ingenijs, ea arte con&longs;truebantur, vt à &longs;eip&longs;is de loco ad locum, ac &longs;i viuæ e&longs;&longs;ent &longs;pontè pro­grederentur; vnde, & automata, qua&longs;i &longs;pontanca dicebantur. Extat adhuc de huiu&longs;modi machinis liber Heronis Alexandrini, quem nuper ex græco latinum reddidit docti&longs;&longs;imus Abbas Gua&longs;tallenfis. de huiu&longs;modi artificio&longs;is operibus, quibus &longs;æpè pri&longs;ci ita admirationi fuere, vt præ&longs;tigia quædam ar­tificium ignorantibus, viderentur, intelligit hoc loco Ari&longs;t.

200

Cap. 3. (Aut de &longs;ol&longs;titijs) quid &longs;ol&longs;titium, cur dicatur &longs;ol&longs;titium, & cur Sol in vtroque topico, quoad dierum incrementum, ac decrementum, & quoad eleuationem eius, aut depre&longs;&longs;ionem meridianam, videatur moras trahere, quamuis no&longs;trum &longs;it explicare, ob rei tamen facilitatem omittantur. Hoc tantum &longs;cias velim &longs;ol&longs;titiorum cau&longs;am e&longs;&longs;e Zodiaci ad Tropicos longio­rem adhæ&longs;ionem, ide&longs;t, quòd Zodiacus propè contactum tropicorum ab ijs parum recedat, cum ergo Sol motu proprio &longs;emper per Zodiacum inam­bulet, fit vt ip&longs;e quoque pariter modicum à tropicis remoueatur, imò pluri­mum &longs;ecus illos incedat, ita vt eo tempore, quo ad eos paulatim accedit, aut ab eis paulatim recedit, qua&longs;i &longs;tare, &longs;iue quie&longs;cere apud eo&longs;dem videa­tur: atque hinc etiam quantitas dierum, ac noctium videatur ferè nihil variari; & noua elcuatio, aut depre&longs;&longs;io Solis &longs;upra horizontem nuila ferè appareat.

201

Ibidem (Aut de diametri incommen&longs;ur abilitate, admirabile enim omnibus vi­detur, &longs;i quid, cum non &longs;it minimum non men&longs;uretur, decet autem in contrarium, & in melius &longs;ecundum prouerbium con&longs;umare, quemadmodŭ in his fit, cum di&longs;cant, nihil enim magis vir Geometricus admiraretur, quàm &longs;i diamcter commen&longs;urabi­lis &longs;ieret) vide quæ de hac commen&longs;urabilitate &longs;crip&longs;i lib. 1. Priorum, &longs;ect. 1. cap. 1. Videtur inquit mirum à principio Geometriam aggredienti diame­trum, & latus eiu&longs;dem quadrati non commen&longs;urari, cum in neutro eorum detur minimum, &longs;eu indiui&longs;ibile, videtur enim omne diui&longs;ibile po&longs;&longs;e men&longs;u­rari. po&longs;tea tamen cum in Geometria ver&longs;atus fuerit, maximè admirare­tur, &longs;i audiret diametrum e&longs;&longs;e lateri commen&longs;urabilem.

202

Summa 2. cap. 3. (Pythagorici primi Mathematicis operam dedere, hæc præpo­nebant, & in cis enutriti, eorum principia, entium quoque cunctorum putant e&longs;&longs;e principia) vtinam no&longs;trates Philo&longs;ophi Pythagoricos imitarentur; enimue­rò multò melius & &longs;ibi, & Philo&longs;ophiæ con&longs;ulerent. At verò non &longs;ine ma­gno artium, atque di&longs;ciplinarum omnium di&longs;pendio à plurimis hac tempe­&longs;tate de&longs;pectui habentur; &longs;ed quid mirum cum quas &longs;cientiarum omnium alumni Pythagorei omnibus &longs;cientijs anteferebant; eas no&longs;tri &longs;eculi quam­plures omnibus alijs facultatibus po&longs;thabeant.

203

Tex. 47. (Qui Geometriam di&longs;cit aliqua præ&longs;cire contingit) ide&longs;t definitio­nes, po&longs;tulata, axiomata, quæ &longs;unt tria principiorum genera, ex quibus to­ta Geometria deducitur.

Ex Secundo Metaphy&longs;icæ.

204

Tex. 14. (Quantam verò vim con&longs;uetudo habeat, leges declar ant, in qui­bus fabulo&longs;a, ac puerilia plus po&longs;&longs;unt propter con&longs;uetudinem, quàm &longs;i ea cogno&longs;ceremus) per leges intelligit cantilenas illas, quas vete­res Mu&longs;ici leges appellabant, eò quòd eas &longs;olas, cæteris abroga­tis liceret lata lege decantari. Vide declarationem problematis 15. & 28. &longs;ect. 19. problematum vbi tanquam in proprio loco i&longs;ta fu&longs;ius pertractabuntur.

Ex Tertio Metaphy&longs;icæ.

205

Tex. 3. Verba huius textus, cum &longs;atis per&longs;picua &longs;int, ac parum ma­thematicis indigeant, omittenda duxi. Quod ad mathematicas attinet, ait, eas non demon&longs;trare, nec per cau&longs;am finalem, nec per efficientem (quod intelligendum e&longs;t de Mathematicis puris, & &longs;peculatiuis nam mathematicæ practicæ reliquas etiam cau&longs;as, efficien­tem, & finalem nece&longs;&longs;ariò habere debent, quapropter &longs;ophi&longs;ta quidam no­mine Ari&longs;tippus, eas irridebat, atque adeo illiberalibus, ac &longs;edentarijs arti­bus po&longs;thabebat, quæ cau&longs;am efficientem, quia &longs;cilicet operantur, & fina­lem &longs;cilicet quæ&longs;tum &longs;ibi proponunt. fuit autem i&longs;te ex Plutarcho, & Laer­tio primus, qui pacto pretio doceret, philo&longs;ophiamque; faceret quæ&longs;tuo&longs;am: ideoque; mathematicas paruipendebat, quòd neglecta cau&longs;a efficiente, nihil efficerent; & finali, nihil lucrarentur. videas igitur quales &longs;int pulcherrima­rum facultatum contemptores, ij nimirum, qui philo&longs;ophiæ, aut lucri, aut ambitionis cau&longs;a dant operam. Quod autem Mathematicæ nihil efficiant, nihilque; lucrentur, ne videamur vtile paruifacere, e&longs;t omninò fal&longs;um: &longs;unt enim plures mathematicæ practicæ, quæ innumera, atque admiranda efficiunt opera, quæque; magnos quæ&longs;tus quotidie faciunt. huiu&longs;modi &longs;unt Geometria practica, qua men&longs;urationes omnes vel &longs;olo vi&longs;u perficiuntur. Arithmeti­ca, cuius v&longs;us quàm latè patet? Mu&longs;ica practica, qua quotidie ip&longs;i oblecta­mur; Deoque; Optimo Maximo laudes debitas concinimus. Mechanica pra­ctica, cuius opgentia pondera, vel exigua vi, inuitaque; natura &longs;u&longs;g; deque; commouentur. Per&longs;pectiua, quæ Pictoribus, & Architectoribus adeo in&longs;er­uit, vt ab&longs;que ea nihil fermè audeant. A&longs;tronomia tandem, &longs;i in praxim de­ducatur, ex vna &longs;olum eclyp&longs;ium prædictione, quantam vniuer&longs;o orbi ad­mirationem parit? mitto hanc &longs;olam dierum, men&longs;ium, & annorum di&longs;tri­butionem, ac temporum emendationem exhibere, rem adeò Reipublicæ Chri&longs;tianæ nece&longs;&longs;ariam.

206

Eodem tex. 3. (Item & in cæteris tunc &longs;cire vnumquodque arbitramur torum, quorum &longs;unt demonstrationes, cum quid e&longs;t &longs;ciamus, vt puta quid tetragoni&longs;mus, quòd inuentio mediæ) eadem reperies &longs;uperius in &longs;ecundo de Anima, tex. 12. fu&longs;ius explicata.

207

Tex. 8. (Si enim in hoc differret &longs;olum Geometria à Geodæ&longs;ia, quod hæc quidem eorum e&longs;t, quæ &longs;entimus, illa verò non &longs;en&longs;ibilium e&longs;t) Geodæ&longs;ia e&longs;t pars Geo­metriæ practicæ, ea &longs;cilicet, quæ circa diui&longs;ionem &longs;uperficierum ver&longs;atur. audi Pedia&longs;mum de men&longs;uratione: Terræ inquit men&longs;uratio in duas partes diuiditur, Geometriam &longs;cilicet, & Geodæ&longs;iam: Areæ namque &longs;ecundum ar­tem men&longs;uratio, & terræ men&longs;uratio e&longs;t, & meritò Geometria vocatur. Vnius verò, & eiu&longs;dem areæ, &longs;eu loci diui&longs;io inter diuer&longs;as per&longs;onas, parti­tio quædam e&longs;t terræ, & iure optimo Geodæ&longs;ia appellatur. hæcille. dicitur autem Geodæ&longs;ia à gea, terra, & da/iw, diuido. Vocabulum tamen i&longs;tud Geo­dæ&longs;iæ fuit po&longs;tea ad latiorem tran&longs;latum &longs;ignificationem: extat enim Geo­dæ&longs;ia Heronis Mechanici antiqui &longs;criptoris, quampridem Baroccius lati­nitate donauit, quæ quidem ars e&longs;t eadem cum Geometria practica, cum non &longs;olum diui&longs;iones, &longs;ed men&longs;urationes omnes etiam per dioptricam f­cultatem, &longs;eu per lineas vi&longs;uales doceat inue&longs;tigare.

Ex Quarto Metaphy&longs;icæ.

208

Tex. 4. (Philo&longs;ophus namque e&longs;t, vt ille, qui Mathematicus dicitur, & bæc enim habet partes: ac prima quædam, & &longs;ecunda &longs;cientia e&longs;t: cæ teræ quoque con&longs;equenter in mathematibus) inter mathematicas pri­mæ &longs;cientiæ &longs;unt Geometria, & Arithmetica, quia ip&longs;æ à cæteris nulla ratione dependent; imò cæteræ ip&longs;is innituntur, quæ &longs;ecundæ hoc lo­co appellantur, hæ &longs;unt Per&longs;pectiua, Mu&longs;ica, Mechanica, A&longs;tronomia. illas duas recentiores &longs;ubalternantes, has verò &longs;ecundas &longs;ubalternatas vocant. Exempla &longs;ubalternationum varia attuli in Logicis tex. 20. & 23. primi Po­&longs;ter. vbi clarè licet intueri quid &longs;it &longs;ubalternatio, vnde etiam præ&longs;ens lo­cus illu&longs;tratur.

209

Tex. 28. (Vti diametrum commen&longs;urabilem e&longs;&longs;e) legenda &longs;unt ea, quæ libro primo Priorum, &longs;ecto 1. cap. 23. de hac commen&longs;urabilitate, & incommen­&longs;urabilitate tractata &longs;unt.

Ex Quinto Metaphy&longs;icæ.

210

Tex. 2. (Alia verò cau&longs;a e&longs;t forma, & exemplar: hæc autem e&longs;t ratio ip­&longs;ius quid erat e&longs;&longs;e, & borum genera, vt ip&longs;ius Diapa&longs;on duo ad vnum, & &longs;impliciter numerus, & partes, quæ in ra ione &longs;unt) affert exem­plum cau&longs;æ formalis ex Mu&longs;ica petitum; aitque; cau&longs;am formalem illius con&longs;onantiæ, quæ Diapa&longs;on dicitur, e&longs;tque; omnium perfecti&longs;&longs;ima, e&longs;&longs;e duplam proportionem, ide&longs;t, quæ e&longs;t inter duo, & vnum, id, quod omnes Mu&longs;ici fatentur. quod vtinelius intelligas, repete, quæ in 2. Po&longs;ter. ad tex. 1. &longs;cripta &longs;unt: necnon quæ in libro de Sen&longs;u in cap. 8. Amplius inquit can&longs;am formalem genericam eiu&longs;dem Diapa&longs;on e&longs;&longs;e numerum, & partes numeri, &longs;ub numero enim continentur & duo, & vnum. Occurrit hoc loco vnum magnopere notandum, videlicet tam con&longs;onantias, quam di&longs;&longs;onantias ha­bere proportiones numerorum, hoc tamen di&longs;crimine, quod con&longs;onantiæ habent &longs;olùm proportiones numerorum eorum, qui quaternario continen­tur, ex veterum præ&longs;ertim Pythagoreorum &longs;ententia, qui propterea vltra quaternarium progredi vetabant. Recentiores tamen y&longs;que ad &longs;enarium procedunt, quippe, qui omnes vocum con&longs;onantias admittunt, quæ pro­portionibus numerorum &longs;enario contentorum præditæ &longs;int. Di&longs;&longs;onantiæ verò &longs;eoundum pri&longs;cos habent proportiones numerorum extra quaterna­rium progredientium, iuxta no&longs;tros autem extra &longs;enarium. qua de re pluri­bus Zarlinus colloquio 2. definit. 3.

211

Tex. 3. (Partes quoque totius) ide&longs;t &longs;unt inateria; loquitur enim de cau&longs;a materiali. libuit locum hunc annotare in gratiam Geometricarum demon­&longs;trationum, quorum media &longs;æpè &longs;unt ex cau&longs;a materiali &longs;umpta, quod ta­men non ita ab omnibus ob&longs;eruatur, quotie&longs;cunque enim probant affe ctio­nem quampiam de aliquo &longs;ubiecto, ex eo, quod &longs;ubiectum illud &longs;it, vel di­midium alicuius, vel duplum, vel reliquum, vel tertia pars, & his &longs;imilia, erit talis ratio in genere cau&longs;æ materialis. neque e&longs;t cur recentiores quidam, naturalibus &longs;cientijs a&longs;&longs;ueti, negent huiu&longs;modi materiam veram e&longs;&longs;emate­riam, ac proinde neq, Geometricas demon&longs;trationes veras e&longs;&longs;e demon&longs;tra­tiones; dicendum enim talem quidem materiam non e&longs;&longs;e veram materiam phy&longs;icam, & proinde illas demon&longs;trationes non e&longs;&longs;e veras naturales demon­&longs;irationes, e&longs;&longs;e tamen veram materiam intelligibilem, quæ Geometriæ &longs;u­bijcitur, & proinde demon&longs;trationes illas veras e&longs;&longs;e demon&longs;trationes Geo­metricas; id quod Ari&longs;t. &longs;æpius in libris Po&longs;ter, apertè &longs;ignificat, tum a&longs;&longs;er­tionibus, tum exemplis quamplurimis. Quapropter cauendum e&longs;t illis, ne ingrati animi notam incurrant, dum pulcherrimam artem re&longs;olutoriam, quam Ari&longs;t. à Mathematicis acceptam omnibus &longs;cientijs accommodauit (vt initio Priorum o&longs;ten&longs;um e&longs;t) eam ip&longs;i ita alijs facultatibus adaptent, vt Mathematicis ip&longs;is, ex quibus orta, & &longs;ub quibus adoleuit, pulla ratione conuenire poi&longs;it. De hac materia fu&longs;ius infra in additamento de natura Ma­thematicarum.

212

Tex. 3. (Et ip&longs;ius Diapa&longs;on duplum, & numerus) &longs;cilicet cau&longs;æ formales &longs;unt, quemadmodum &longs;upra tex. 2. huius cap. explicatum e&longs;t.

213

Tex. 4. (Similiter autem figurationum quoque elementa dicuntur, ac &longs;impliciter demon&longs;trationum primæ enim demon&longs;trationes, quæ in pluribus demonstr ationbus in&longs;unt, hæc elementa demon&longs;trationum dicuntur) verbo (Figurationum) &longs;iue de­&longs;criptionum, Ari&longs;t, intelligere demon&longs;trationes Geometricas, &longs;æpius dictum e&longs;t, præ&longs;ertim in Logicis, & ex hoc loco pariter confirmatur. Ex hoc por­rò loco illud innote&longs;cit dignum, quod præcipuè à Mathematico non igno­retur, quæ nam &longs;int demon&longs;trationes illæ, quæ nomine elementorum debeant appelllari, necnon cau&longs;a cur Euclides &longs;uum opus elementa nuncupauerit, &longs;unt enim illæ, quæ in pluribus demon&longs;trationibus in&longs;unt, ide&longs;t, quæ &longs;æpius in alijs demon&longs;trationibus citantur, vti &longs;unt præcipuè &longs;ex priores libri Eu­clidis: atque hac ratione elementa appellantur.

214

Tex. 12. (Principium itaque &longs;cibilis, circa vnumquodque ip&longs;um vnum, non e&longs;t au­tem idem in cunct is generibus vnum, &longs;ed hic quidem die&longs;is, hic verò vocalis, aut muta) ide&longs;t, in Mu&longs;ica quidem principium omnium, & elementum e&longs;t die­&longs;is, quæ e&longs;t minima vox, aut &longs;onus, qui &longs;ub Mu&longs;ici con&longs;iderationem cadat. Porrò ad tex. 38. primi Po&longs;ter. de die&longs;i plura &longs;unt dicta.

215

Tex. 17. (Veluti diametrum commen&longs;urabilem e&longs;&longs;e impo&longs;&longs;ibile est) huius expo­&longs;itionem inuenies 1. Priorum, &longs;ecto 1. cap. 23.

216

Tex. eodem (Metaphoricè autem, quæ in Geometria po­tentia dicitur) potentiam vnius lineæ appellant Geometræ quadratum illius, ide&longs;t quadratum &longs;uper ip&longs;am con&longs;tru­ctum. v. g. quadratum in quo C, dicitur potentia lineæ D B, quia &longs;uper illam con&longs;tructum e&longs;t.

217

Tex. 34. (Quemadmodum dicitur diametrum e&longs;&longs;e commen&longs;urabilem) vide an­notata 1. Priorum, fecto 1. cap. 23.

218

Tex. 35. (Vt triangulo duos rectos habere) ide&longs;t affectio trianguli e&longs;t habe­re tres angulos æquales duobus rectis angulis. Vide declarationem huius lib. primo Priornm, &longs;ecto 3. cap. 1.

Ex Sexto Metaphy&longs;icæ.

219

Tex. 1. (Mathematicorum quoque principia, elementa, & cau&longs;æ &longs;unt) notanda &longs;unt hæc aduer&longs;us quo&longs;dam, qui negant in Mathemati­cis cau&longs;as reperiri, vt hinc quoque illis &longs;cientiam auferant. enim­uerò apertè patet eos falli ex toto hoc Ari&longs;t. di&longs;cur&longs;u.

Ex Nono Metaphy&longs;icæ.

220

Vt &longs;i quis dicat diametrum po&longs;&longs;e commen&longs;arari, non tamen commen&longs;u­rabitur) & paulò infra (Commen&longs;urari enim impo&longs;&longs;ibile e&longs;t) expo&longs;i­tionem horum reperies 1. Priorum, &longs;ecto 1. cap. 23.

221

Tex. 20. (De&longs;eriptiones quoque actu inueniuntur, diuidentes nanque inuenirent, quod &longs;i diui&longs;æ e&longs;&longs;ent, manife&longs;i è e&longs;&longs;ent, nunc autem in&longs;unt potentia, cur triangulus duo recti? quia qui circa vnum punctum anguli duobus rectis æquales&longs;unt, &longs;i igitur quæ ad latus educeretur, videnti mox e&longs;&longs;et manife&longs;tum) per de&longs;cri­ptiones, vel figurationes, vel de&longs;ignationes intelligendas e&longs;&longs;e demon&longs;tra­tiones Geometricas &longs;æpius &longs;upra dictum e&longs;t, & pariter ex hoc loco com­probatur. Dicit igitur, quod demon&longs;trationes &longs;uas Geometræ inueniunt, reducendo ad actum ea, quæ erant in potentia, diuidentes enim educunt in actum, figuras, angulos, lineas, & cætera huiu&longs;inodi, quæ prius &longs;olùm erat in potentia, ex quibus po&longs;tea &longs;uas demon&longs;trationes perficiunt (Cur triangu­lus duo recti) affert exemplum eius, quod proximè dixerat, &longs;cilicet Geome­tras demon&longs;trare producendo ad actum entia quædam Mathematica, quod exemplum, vt intelligas ijs opus habes, quæ primo Priorum, &longs;ecto 3. cap. 1. con&longs;cripta &longs;unt (Cur triangulus duo recti?) ide&longs;t, cur triangulus habet tres angulos æquales duobus rectis angulis (Quia qui circa vnum punctum anguli duobus rectis angulis æquales &longs;unt) ni&longs;i hoc dictum ad bonum trahatur &longs;en&longs;um,

fal&longs;um e&longs;t, nam omnes anguli, qui circa vnum punctum, v. g. A, &longs;unt con&longs;tituti, æquales &longs;unt non duobus, vt e&longs;t in textu, &longs;ed quatuor rectis, vt patet ex corollario 2. 15. primi Elem. quot­quot enim anguli con&longs;tituantur ad punctum A, omnes &longs;imul erunt æquales quatuor rectis, quos faciunt præ&longs;entes lineæ B C, D E. vniuer&longs;i enim illi congruent his quatuor rectis: &longs;ed Ari&longs;t. &longs;en­&longs;us e&longs;t omnes angulos ad ea&longs;dem partes con&longs;ti­tutos, v. g. ad partes &longs;uperiores lineæ B C, e&longs;&longs;e æquales duobus rectis B A D, D A C, vt o&longs;tenditur in 13. primi, necnon etiam patere pote&longs;t ex corollario 2. 15. eiu&longs;dem. tales &longs;unt quatuor anguli ad &longs;uperiores partes lineæ B C, & ad punctum A, con&longs;tituti, qui, vt patet,
&longs;unt æquales duobus rectis B A D, D A C, tales etiam &longs;unt in hac &longs;ecunda figura tres anguli B C A, A C D, D C E, qui quidem æquales &longs;unt duobus rectis angulis. hoc &longs;en&longs;i&longs;&longs;e Ari&longs;t. patet ex demon&longs;tratione 32. primi, quæ demon&longs;trat memoratam ab Ari­&longs;tot. trianguli affectionem, & ad quam propterea ip&longs;e &longs;pectabat, cuius figura e&longs;t eadem cum hac &longs;ecunda, in qua Euclides o&longs;tendit prædictos tres angulos æquari duobus rectis. &longs;ubdit po&longs;tea, &longs;i igitur linea C D, quæ ad latus A B, parallela e&longs;t in potentia, educeretur in actum, videnti mox e&longs;&longs;et manife&longs;tum tres angulos trianguli A B C, e&longs;&longs;e pares duobus rectis. ducta enim C D, pa­rallela lateri B A, apparet &longs;tatim angulus A, æqualis angulo A C D, & an­gulus B, angulo D C E; cum reliquus verò trianguli angulus B C A, &longs;it apud prædictos duos ad idem punctum C, con&longs;tit utus; atque omnes hi tres duobus rectis æquentur, mox in&longs;picienti talem figur ationem manife&longs;tum fit tres an­gulos illius trianguli e&longs;&longs;e duobus rectis æqu ales.

222

Ibidem (Cur in &longs;emicirculo vniuer&longs;aliter rectus? quia &longs;i tres æquales, & quæ ba&longs;is e&longs;t duo, & quæ ex medio &longs;upra stat recta, videnti manifestum erit ei, qui illud &longs;ciat) In 2. Po&longs;ter. tex. 11. inuenies hu ius loci expo&longs;itionem. nunc &longs;olùm

hæc addenda &longs;unt. Re&longs;pondet Ari&longs;t. quæ­&longs;ito pr&ecedil;cedenti, cur &longs;cilicet angulus in &longs;e­micirculo &longs;it rectus, qualis e&longs;t in figura angulus A C B, dicitque; cau&longs;am e&longs;&longs;e, quia in figura tres lineæ &longs;unt æquales, duæ ni­mirum, in quas ba&longs;is B A, diuiditur, quæ &longs;unt B D, D A, & tertia, quæ ex medio ba&longs;is erigitur, e&longs;tque; D C, cum omnes &longs;int &longs;emidia metri ciu&longs;dem circuli. educta itaque linea D C, de potentia in actum, &longs;i cuipiam trium harum linearum æqualitas innote&longs;cat, continuò ei etiam manife&longs;tum erit angulum A C B, in &longs;emicirculo, e&longs;&longs;e rectum. quia &longs;tatim ap­parent duo i&longs;o&longs;celia B D C, A D C, quorum anguli ad ba&longs;es B C, A C, &longs;unt æquales inuicem; & anguli duo ad D, &longs;unt dupli duorum angulorum A C D, D C B, ex quibus conflatur totus angulus A C B, ergo duo anguli ad D, &longs;unt dupli anguli B C A, &longs;ed duo anguli ad D, &longs;unt æquales duobus rectis, ergo duo recti &longs;unt dupli anguli A C B, ergo angulus B C A, e&longs;t dimidium duo­rum rectorum. cum autem omnes recti &longs;int æquales, con&longs;ectarium e&longs;t dimi­dium duorum rectorum e&longs;&longs;e angulum rectum. patet igitur, qua ratione ex ductu linearum prædictarum actu, manife&longs;tum fiat angulum in &longs;emicirculo A C B, e&longs;&longs;e rectum. ne mireris &longs;i vulgatam tran&longs;lationem antiquam non &longs;um &longs;equutus, indigebat enim correctione, quam iuxta græcum exem­plar adhibui.

223

Tex. 22. (Vt puta &longs;i triangulum non putet mutari, non opinabitur modo duos rectos habere, modo non, mutaretur enim) quia nimirum huius habemus &longs;cien­tiam per demon&longs;trationem 32. primi Elementorum. quomodo autem tri­angulus habeat duos rectos, ide&longs;t tres angulos æquales duobus rectis angu­lis, explicatum e&longs;t primo Priorum, &longs;ecto 3. cap. 1.

224

Ibidem (Verum aliquid quidem, aliquid verò non, vt puta parem numerum primum nullum e&longs;&longs;e; aut quo&longs;dam quidem, quo&longs;dam verò non) definitione 11. 7. Elem. &longs;ic numerus ille, qui à Mathematicis dicitur primus, definitur, pri­mus numerus e&longs;t, quem vnitas &longs;ola metitur, vnde patet inter numeros pa­res &longs;olum binarium e&longs;&longs;e primum, cum ip&longs;um &longs;ola vnitas bis replicata men­&longs;uraret. quaternarium autem, &longs;enarium, &c. pares, non e&longs;&longs;e primos, cum eos non &longs;ola vnitas, &longs;ed alius numerus metiatur: quaternarium enim bina­rius bis replicatus men&longs;urat: &longs;enarium men&longs;urat & binarius, & ternarius: quare verum erit exi&longs;timare inter pares numeros aliquos e&longs;&longs;e primos, ide&longs;t binarium, aliquos verò non, ide&longs;t cæteros pares vltra binarium.

Ex Decimo Metaphy&longs;icæ.

225

Tex. 4. (Ac etiam motum &longs;implici, & veloti&longs;&longs;imo motu men&longs;urant, mi­nimum enim tempus hic habet. quapropter in A&longs;trologia tale vnŭ prin­cipium, & men&longs;ura e&longs;t. motum æqualem, & veloci&longs;&longs;iniŭ œli &longs;up­ponunt, ad quem cæteros tudicant) intelligit motum diureum, quam primo cœlo, &longs;eu mobili a&longs;eribunt, hic enim veloci&longs;&longs;imus e&longs;t omnium reli­quorum cœle&longs;tium motuum, ac &longs;impliciffimus, & valdè vniformis, ac regu­laris, & propterea minimum habet tempus, ide&longs;t tempus vnius diei natura­lis, quo tempore totum primum mobile circulationem integram perficit. per minimum tempus, po&longs;&longs;uut etiam intelligi partes diei, quæ &longs;unt horæ, & horarum partes. con&longs;iderant hunc motum in circulo æquàtoris, quia æqua­tor motu primi mobilis, &longs;eu diurno vniformiter, ae maximè regulatiter mouetur: hac de cau&longs;a hunc motum tanquam reliquorum men&longs;uram, ac normam meritò a&longs;&longs;ump&longs;erunt.

226

Ibidem (Et in Mu&longs;ica Die&longs;is primus &longs;en&longs;ibilis &longs;onus, quia minimum) ide&longs;t mi­nimum interuallum, quod à Mu&longs;icis con&longs;ideretur, e&longs;t men&longs;ura maiorum in­teruallorum. ad tex. 38. primi Po&longs;ter. &longs;atis dictum e&longs;t de Die&longs;i, quæ videas.

227

Eodem tex. &longs;ed cap. 3. (Nox &longs;emper autem men&longs;ura numero vnum e&longs;t, verum aliquando plura, vt puta die&longs;es duæ, non quidem &longs;ecundum cuditum, &longs;ed in ratio­nibus, & voces plures, quibus men&longs;uramus, & diameter duobus men&longs;uratur, & la­tus, & omnes magnitudines) ita corrigenda e&longs;t antiqua tran&longs;latio. quid die&longs;is dictum &longs;it ad tex. 38. primi Po&longs;ter. quando autem ait (Vt puta duæ die&longs;es)ide&longs;t duæ die&longs;es &longs;unt men&longs;ura vnius interualli mu&longs;ici, qui tonus appellatur: quæ quidem duæ die&longs;es non &longs;unt men&longs;ura &longs;en&longs;ibilis, quæ &longs;cilicet auribus per­cipiatur, &longs;ed tantummodò exi&longs;tunt in numerorum proportionibus, ibi per intellectum excogitatis, quando ait (Et voces plures quibus men&longs;uramus)quando vtimur eodem interuallo, &longs;iue eadem voce ad cantus men&longs;uram, tunc &longs;unt plures men&longs;uræ numero, quamuis vna tantam &longs;pe Ait (Et dia­meter duobus men&longs;uratur) v. g. duobus &longs;emidiametris: v pedibus. & latus pariter quadrati, duobus. v. g. pedibus me mque; mo­do reliquæ omnes magnitudines po&longs;&longs;unt ab ea me replica­ta men&longs;urari.

228

Eodem tex. (Semper autem men&longs;ura eiu&longs;de agnitudinum nam­que magnitudo, & &longs;ecundum vnumquedque, do) ex his ratio manife&longs;ta apparet, cur Geometræ practici me longitudines per ali­quam longitudinem, vt puta per vlnam, digitum, vnciam, &c. &longs;uperficies etiam per aliquam &longs;uperficiem, &longs;ed quæ &longs;it quadrata, vt puta per vlnam qua­dratam, palmum quadratum, &c. corpora quoque per corpus, quod tamen &longs;it cubus, vt per vlnam cubicam, palmum cubicum, vnciam cubicam, &c.

229

Tex. 11. (Similia verò &longs;i cum non &longs;int eadem &longs;impliciter, nec &longs;ecundum &longs;ab&longs;t an­tiam &longs;ubiectam in d. fferentia &longs;ecundum formam eadem &longs;it: quemadmodum quadra­tum maius minori &longs;imile e&longs;t, & lineæ inæquales, hæ enim &longs;imiles quidem, verŭ non cædem &longs;impliciter &longs;unt) Prima definitio &longs;exti definit &longs;imiles figuras eas e&longs;&longs;e, quæ &longs;unt æquiangulæ inuicem, & quæ habent latera proportionalia circa æquales angulos. cum ergò quadratum maius, & minus &longs;int æquiangula, quia habent omnes angulos rectos; & præterea habeant latera circa æqua­les angulos proportionalia, &longs;icut enim latera maioris quadrati circa vnum angulum rectum &longs;unt in proportione æqualitatis; ita quoque latera minoris circa vnum angulum rectum &longs;unt illis proportionalia, cum &longs;int inuicem pa­riter in proportione æqualitatis, erunt nece&longs;&longs;ariò &longs;imilia hæc duo quadrata. duæ ctiam, exempli gratia, lineæ rectæ &longs;unt inuicem &longs;imiles, quamuis vna &longs;it maior altera.

230

Eodem tex. (Tertium &longs;icut illa, quæ in Mathematicis) tertium &longs;cilicet mo­dum diuer&longs;i, ponit in entibus Mathematicis, &longs;icut enim po&longs;uit idem e&longs;&longs;e in Mathematicis, quando duæ figuræ &longs;unt &longs;imiles, & æquales: ita ex oppo&longs;ito diuer&longs;um erit in Mathematicis, quando duæ figuræ fuerint di&longs;&longs;imiles, & in­æquales, dicenturque; diuer&longs;æ, in quo con&longs;i&longs;tat &longs;imilitudo figurarum dictum e&longs;t in præcedenti expo&longs;itione.

Ex Vndecimo Metaphy&longs;iæ.

231

Svmma r. cap. 2. (Si quis verò lineas, aut quæ has &longs;equuntur, dico autem primas &longs;uperficies principia e&longs;&longs;e ponat. bæc non &longs;unt &longs;ub&longs;tantiæ &longs;eparabiles, verùm &longs;ectiones, & diui&longs;iones, illæ quidem in &longs;uperficierum, hæc verò cor­porum, puncta verò linearum &longs;unt, & etiam ip&longs;arum earumdem termini; hæc autem omnia in alijs &longs;unt, & nihil &longs;eparabile e&longs;t) ait puncta oriri ex &longs;ectio­ne lineæ, quamuis &longs;int etiam termini illius; lineas verò oriri ex diui&longs;ione &longs;uperficierum, quamuis &longs;int etiam termini illarum. &longs;uperficies quoque oriri ex diui&longs;ione corporum, quamuis &longs;int etiam termini, illorum. Hæc placuit annotare propter ip&longs;orum conuenientiam cum ijs, quæ à Geometris traduntur.

232

Summa 3. cap. 2. (Vt puta &longs;ub Cane fiat frigus) ideft &longs;ub ortum Canis cœ­læ&longs;tis, &longs;eu Caniculæ. Vide quæ libro &longs;ecundo Meteororum, &longs;umma 2. cap. 2. de hac &longs;tella &longs;crip&longs;imus.

Ex Duodecimo Metaphy&longs;icæ.

233

Tex. 44. (Pluralitatem verò lationum ex peculiari&longs;&longs;ima Philo&longs;ophie Mathematicarum &longs;cientiarum, videlicet ex A&longs;tronomia con&longs;iderandum est: hæc enim de &longs;ub&longs;tantia &longs;en&longs;ibili quidem, ac &longs;empiterna &longs;peculatur)pluralitatem nimirum cœle&longs;tium motuum petendam e&longs;&longs;e a&longs;&longs;erit ex præcipua totius Philo&longs;ophiæ parte, quam ait e&longs;&longs;e A&longs;tronomiam. dignum porrò con&longs;ideratione e&longs;t, quanti faciat Ari&longs;t. Mathematicas di&longs;ciplinas, ac præcipuè &longs;yderalem &longs;cientiam.

234

Tex. 45. (Eudoxus igitur Solis, & Lunæ lationem po&longs;uit fieri à tribus orbibus, quorum primus quidem e&longs;&longs;et, qui inerrantium &longs;iellarum; &longs;ecundus verò &longs;ecunduns id, quod per medium Zodiacum; tertius tandem, &longs;ecundum quem qui in latitudine Zodiaci obliquatur. in maiori autem latitudine obliquari eum &longs;ecundum quem Lu­na, quàm eum &longs;ecundum quem Sol &longs;ertur) Eudoxi tempore nondum &longs;atis ex­culta fuerat A&longs;tronomia, vt propterea minimè mirandum &longs;it, eum hoc lo­co imperfecta admodum circa c&ecedil;le&longs;tia tradere. omittit enim in Sole orbem motum augis conficientem; necnon duos eccentricos, qui &longs;olis anomaliam, atque eccentricitatis variationem excu&longs;ant. attribuit præterea Soli motum quendam in latitudinem, quod fal&longs;um e&longs;t omninò, cum Sol perpetuò directè &longs;ub eclyptica incedat. In Luna pariter plures nece&longs;&longs;arios illi orbes ad motus ip&longs;ius &longs;aluandos prætermittit. Ex &longs;ententia tamen Tychonis Brahe hos or­bes, ac circulos tanquam ab inuicem di&longs;tinctos abrogare debemus.

235

Tex. 46. (Errantium verò &longs;tellarum vniu&longs;cuiu&longs;que in quatuor &longs;phæris, quarura primam quidem, & &longs;ecundam eandem illis e&longs;&longs;e: etenim, quæ fix arum eft eam illam e&longs;&longs;e, quæomnes fert: at cam, quæ &longs;ub ip&longs;a ordinata e&longs;t, ac quæ &longs;ecuxdum Zodiacum lationem habet, communem omnibus e&longs;&longs;e. Tertiæ verò omnium polos in eo, quod per medium Zodiacum e&longs;t. Quartæ autem lationem &longs;ecundum eum, qui obliquatus ad medusm eius e&longs;t; e&longs;&longs;e verò tertiæ &longs;phæræ polos aliarum quidem proprios, Veneris autem, & Mercurij eo&longs;dem) pergit tradere theoriam reliquorum errantium quinque &longs;yderum, &longs;ecundum mentem Eudoxi, qui propriè Planetæ dicuntur: Sol autem, & Luna hoc nomine non e&longs;t complexus, eo quod ip&longs;a mereantur potius duo mundi luminaria appellari, quàm cum c&ecedil;teris &longs;tellis in ordinem redigi. Reliquis igitur quinque erronibus &longs;ingulis quatuor &longs;phæris attribue­bat, quarum prima, & &longs;ecunda eodem modo &longs;e habebant, ac in Sole, & Lu­na, etenim octaua &longs;phæra, &longs;eu firmamentum, quod affixa &longs;ibi &longs;ydera differt communicabat, &longs;ecundum ip&longs;um reliquis inferioribus &longs;phæris motum &longs;uum peculiarem, videlicet diurnum, quo ab oriente in occidentem tota c&ecedil;li ma­china conuertebatur. fecundam eam facit, quæ Planetas omnes &longs;ecundum Zodiaci longitudinem ab occidente in orientem vehebat, quæ pariter eodem modo &longs;e habet in &longs;ingulis. Tertiam verò eam confinxit, cuius poli e&longs;&longs;ent in eclyptica, in quibus cita, ab eclyptica vltrò, citroque; dilataretur. Quartam demum po&longs;uit, quæ tertiam bifariam &longs;ecaret, eamque; tali motu cieret, ne ab eclyptica plus iu&longs;to ver&longs;us mundi polos exorbitaret. porrò in reliquis vo­luit polos tertij orbis e&longs;&longs;e peculiares, Veneri autem, & Mercurio eo&longs;dem e&longs;&longs;e, ide&longs;t e&longs;&longs;e in eadem linea. Ex mente igitur Eudoxi cœle&longs;tes orbes in vniuer&longs;um 27. numerantur, in Sole &longs;imul, ac Luna 6. in reliquis quinque er­rantibus 20. atque octauæ &longs;phæræ 1. Non me later, has Eudoxi po&longs;itiones, ob ratas po&longs;teriorum a&longs;tronomorum ob&longs;eruationes non &longs;ub&longs;i&longs;tere. at verò hic non ip&longs;ius placita, &longs;ed præcipuè textus intelligentiam per&longs;equor.

236

Tex. 47. (At Calippus &longs;itum quidem &longs;phærarum eundem Eudoxo ponebat, hoe e&longs;t di&longs;tantiarum ordinem. pluralitatem autem &longs;tellæ quidem Iouis, ac Saturni ean­dem illi attribuebat. Solis verò, & Lunæ duas adbuc putabat &longs;phæras addendas e&longs;&longs;e, &longs;i quis eorum, quæ &longs;en&longs;ibilitcr apparent, can&longs;as a&longs;&longs;ignare debeat. Cæteris ve­rò errantium vnicuique vnam. nece&longs;&longs;e verò e&longs;&longs;e, &longs;i debent omnes &longs;imul po&longs;itæ, quæ apparent reddere, &longs;ecundam vnamquamque errantium alteras &longs;phæras vna paucie­res e&longs;&longs;e, quæ reuoluant, & ad idem po&longs;itione &longs;emper primam eius astri &longs;phæram, quod inferius ordinatum e&longs;t, con&longs;tituant. boc enim modo &longs;olùm contingit errantium lationem omnia facere. Cùmigitur, in quibus ip&longs;a quidem feruntur &longs;phæris, hæ quidem octo, bæverò vigintiquinque &longs;int. horum &longs;ane non oportet illas &longs;olas reuo­lai, in quiòus fertur, quod infimè ordinatum e&longs;t. quæ quidem duarum &longs;phærarum primas reuoluant, &longs;ex erunt. quæ verò pe&longs;teriorum quatuor, &longs;exdecim. cunctarum verò numerus, tùm earum quæ ferunt, tùm quæ reuoluunt eas, quinquaginta quin­que. quòd &longs;i Lunæ, & Soli, non addat aliquis quos diximus motus, omnes &longs;phæræ erunt &longs;eptem, & quadraginta. pluralitas itaque &longs;phærarum tanta &longs;it) textum hunc per paraphra&longs;im &longs;ic explico; Calippus igitur eundem quidem ordinem, at­que di&longs;tantiam &longs;phærarum cum Eudoxo ponebat: eandemque; pluralitatem orbium mouentium Saturnum, ac Jouem; quatuor nimirum vnicuique eorum. &longs;ed putabat &longs;oli duas addendas, ac Lunæ &longs;imiliter, &longs;i quis eorum apparentias &longs;aluare vellet. cæteris verò errantium, Marti, Veneri, & Mercurio vnicuique vnam. nece&longs;&longs;e præterea exi&longs;timabat e&longs;&longs;e, vt prædictæ omnes &longs;phæræ &longs;imul apparentias omnes excu&longs;arent, addendas e&longs;&longs;e alias &longs;ingulis planetis toti­dem &longs;phæras vna minus, quas Reuoluentes appellabat; ita vt qui quatuor Mouentes &longs;phæras habuif&longs;et, tribus præterea reuoluentibus opus haberet: quæ &longs;phæræ reuoluentes id præ&longs;tabant, vt qua&longs;i priores Mouentes ita in of­ficio continerent, vt priori po&longs;itioni a&longs;trum, quod interiori orbi affigebur &longs;uo tempore re&longs;tituerent, vt Alexander exponit. hoc enim &longs;olummodo po&longs;­&longs;ibile putabat omnes errantium lationes nos imitari po&longs;&longs;e. Cum igitur mo­uentes &longs;phæræ illæ quidem Saturni, ac Iouis &longs;int octo; reliquorum verò vi­gintiquinque, nam reliqui Planetæ quinque &longs;inguli &longs;phæras quinque mouentes habent, quæ omnes &longs;imul numerum vigintiquinque explent: quarum omnium &longs;olæ inferiores, quibus a&longs;trum affixum volebat, non indigebant reuoluente, &longs;equitur duorum &longs;uperiorum Saturni, & Iouis, quorum octo erant mouen­tes, &longs;ex debere e&longs;&longs;e reuoluentes. Inferiorum verò quatuor planetarum re­uoluentes erunt &longs;exdecim: &longs;ed hoc loco Ari&longs;t. memoria fallit, deberet enim dicere, reliquorum quinque planetarum reuoluentes erunt vigintì, &longs;unt enim planetæ &longs;eptem, quorum Saturno, ac Ioui &longs;upremis &longs;ex reuoluentes attri­buit habita ratione &longs;phæratum mouentium; reliquis igitur quinque planetis habita ratione &longs;uorum orbium mouentium, 25. cum &longs;inguli habeant quinque mouentes, habebunt ex prælcripto Calippi &longs;inguli 4. reuoluentes; ac pro­inde 20. in vniuer&longs;um erunt reuoluentes. Omnium igitur &longs;phærarum tam mouentium, quàm reuoluentium &longs;ummam ait, &longs;ed perperam, e&longs;&longs;e quinqua­gintaquinque; cum enim mouentes Saturni, & Iouis &longs;int 8. reliquorum au­tem 25. reuoluentes verò Saturni, & Iouis &longs;int 6. reliquorum autem, vt ip­&longs;e memoria fal&longs;us ponit, &longs;exdecim, conflant quidem &longs;ummam prædictam, &longs;ed illi in memoria reuocandus e&longs;t, planeta ille, quem oblitus e&longs;t, cuius &longs;unt quatuor reuoluentes, qui prioribus additi &longs;phærarum errantium numerum quinquaginta nouem con&longs;tituent: quibus etiam addenda e&longs;t octaua &longs;phæra, &longs;eu firmamentum, quod inerrantium &longs;edes e&longs;t, non enim &longs;olum errantium, &longs;ed omnium cœle&longs;tium orbium numerum inue&longs;tigare volebat, &longs;icque; e&longs;&longs;ent omnes &longs;ecundum Calippum &longs;ph&ecedil;ræ &longs;exaginta. Quod &longs;i Lunæ, & Soli non ad­dantur &longs;ingulis duo mouentes, vt facit Calippus, neque con&longs;equenter quatuor illis debiti reuoluentes non erunt omnes, 55. verùm, detractis octo prædi­ctis, erunt tantum 47. &longs;eu vt melius loquatur non erunt in vniuer&longs;um, 60. &longs;ed 52. tantum. Hactenus de numero cœlorum.

Ex Decimotertio Metaphy&longs;icæ.

237

Svmma 1. cap. 3. (Qui dicunt Mathematicas &longs;cientias nihil de bono, vel pulchro dicere, fal&longs;um dicunt. dicunt. n. & maximè o&longs;tendunt. nam & &longs;i non nominant, quia tamen opera, & rationes ostendunt, non ne dicunt de eis? pulchra namque maximè &longs;pecies &longs;unt, ordo, commen&longs;uratio, & definuŭ, quæ maximè à Mathematicis &longs;cientijs o&longs;tenduntur, &c.) placuit hæc in Mathemati­carum commendationem, ac defen&longs;ionem apponere, cum non de&longs;int hac no&longs;tra tempe&longs;tate ageometrcti complures, qui cas libenter &longs;ugillare &longs;olent.

IN MECHANICAS QVÆSTIONES.

Qvidquid Mathematicum in his quæ&longs;tionibus occurret, illud, vt plurimum per paraphra&longs;im exponemus, ita tamen, vt tex. Ari&longs;t. & figuræ textui re&longs;pondentes per eam, quantum fieri poterit re­&longs;tituantur, & &longs;i quæ &longs;e offerent difficilia, pro viribus &longs;oluantur. E&longs;t autem nonnullis in locis textus tam græcus, quàm latinus adeò corrup­tus, ac deprauatus, vt nullo modo emendari queat.

Caput Primum.

Quæ &longs;it artis Mechanicæ facultas.

238

Eorum, quæ miraculo &longs;unt, alia quidem natura contingunt, &longs;untque; ea, quorum ignorantur cau&longs;æ: alia verò &longs;unt, quæ præter naturam per artificium aliquod ad hominum vtilitatem perficiuntur, in multis namque natura ei, quod nobis v&longs;ui e&longs;&longs;e pote&longs;t, contrarium facit, quod inde oritur, quia natura eundem &longs;emper, ac &longs;implicem &longs;eruat modum: quod autem nobis vtile e&longs;t, plurimas &longs;ubit varietates. quando igitur quippiam præter naturam facere opportuerit, illud, quod faciendum e&longs;t, difficultate &longs;ua nos remoratur, arteque; propterea indigemus. quamobrem eam artis partem, quæ huiu&longs;modi &longs;uccurrit difficultatibus, Mechanicam appellamus. Cæterùm optimè Antiphon Poeta in hunc modum cecinit;

Arte &longs;uperamus ea, in quibus à natura vincimur.

Quemadmodum accidit, cum minora &longs;uperant maiora, & quæcunque exi­guam vim habentia, magna tamen mouent pondera, & omnia ferè illa, quæ &longs;ub ea cadunt problemata, quæ mechanica nuncupari &longs;olent. &longs;unt autem hæc neque naturalibus omninò quæ&longs;tionibus eadem, neque &longs;eiugata valde: verùm mathematicarum contemplationum, naturaliumque communia. Po&longs;tea in græcis codicibus hæc &longs;equuntur (to\ men ga\r w_c di\a twn maqhmatixw_n dh/log: to\ de pevi\o\, di\a tw_n fuszxw_n) ide&longs;t, &longs;i quidem quomodo &longs;int, &longs;eu qua ratione exi&longs;tant, manife&longs;tum e&longs;t per Mathematica: illud verò circa quod ver&longs;antur, hoc e&longs;t obiectum, de quo pertractant Mechanicæ quæ&longs;tiones per &longs;cientias phy&longs;icas habetur, ide&longs;t res naturalis e&longs;t; e&longs;t enim pondus, & vis, aut poten­tia pondus ip&longs;um mouens, quatenus quanta &longs;unt; &longs;iue dixeris e&longs;t quantitas ponderum, atque potentiarum. Mathematicæ enim mediæ, de quorum nu­mero e&longs;t facultas Mechanica, con&longs;iderant quantitatem rei alicuius determinatæ, &longs;ic A&longs;tronomia circa cœle&longs;tium corporum, mo­tuumque; quantitates, Per&longs;pectiua circa linearum vi&longs;ua­lium; Mu&longs;ica circa &longs;onorum quantitates ver­&longs;antur. quæ placuit annotare, vt &longs;cien­tiæ huius naturam per&longs;pectam haberemus.

De dignitatibus, admirandisque; Circuli proprietatibus.

Cap. Secundum.

239

Cvm vellet Ari&longs;t. mirabilium effectuum, quos in Mechanicis admi­ramur, cau&longs;am referre in circulum: meritò ante omnia de admi­randa ip&longs;ius circuli natura di&longs;&longs;erit, quo minus mirum deinde vi­deatur prædictas mirabiles-operationes exip&longs;o procedere. quan­doquidem exadmiranda cau&longs;a admirabiles effectus prodire debeant. qua­lia &longs;unt ea, quæ circa yectem, cum magna omnium admiratione contingunt. videmus enim exiguam pror&longs;us vim ingens pondus, quod ab&longs;que vecte mini­mè mouere po&longs;&longs;et, addito etiam ip&longs;ius vectis pondere, facilè quocunque vo­luerit propellere. quod quidem auditu ab&longs;urdum foret, ni&longs;i vi&longs;u con&longs;taret. omnium autem huiu&longs;modi cau&longs;æ principium circulus obtinet: & hoc qui­dem meritò, ex admirabili enim, quippiam mirandum accidere rationi omninò con&longs;entaneum eft.

Primò igitur maximè admirandum e&longs;t contraria &longs;imul fieri, aut exi&longs;terecirculus tamen ex contrarijs e&longs;t con&longs;titutus, oritur enim circulus ex com­moto, & manente, quæ quidem naturaliter &longs;untinuicem contraria. &longs;it au­tem circulus ex commoto, & manente, quia oritur ex circumuolutione vnius rectæ lineæ, cuius alterum extremum fixum manet, alterum verò cir­cumagitur; quamobrem i&longs;thæc cernentes minus admirari conuenit reliquas, quæ in ip&longs;o &longs;unt contrarietates. cuiu&longs;modi e&longs;t hæc, quod cum linea, quæ cir­culi orbem complectitur, quæque; circunferentia appellatur, nullam habeat latitudinem, ei tamen contraria quodammodo in&longs;unt, concauum &longs;cilicet, & curuum; quæ quidem eo modo &longs;unt contraria, quo etiam magnum, & pa­ruum, horum enim medium e&longs;t æquale; illorum verò rectum. & &longs;icuti quan­do magnum, & paruum inuicem commutantur, ita vt quod magnum e&longs;t fiat paruum, quod verò paruum fiat magnum, nece&longs;&longs;e e&longs;t, vt perueniant ad æquale priu&longs;quam ad extremum alterutrum; ita linea curua antequam fiat concaua, debet prius fieri recta: & ex concaua, vt tran&longs;eat ad conuexam, & circularem, debet &longs;imiliter prius e&longs;&longs;e recta.

Alterum contrarium, quod circulo ine&longs;t, e&longs;t &longs;imul contrarijs motibus mo­neri: &longs;imul enim ad anteriorem mouetur locum, & ad po&longs;teriotem. & eo­dem modo linea illa, quæ ex vno extremo manens, ex altero verò circum­lata circulum de&longs;cribit, &longs;e habet; contraria enim &longs;imul contipet, primum &longs;cilicet, & extremum. Ex quo enim primo loco circumagi incipit ad eun­dem rur&longs;us po&longs;tremò reuertitur, ita, vt primum ip&longs;ius, & po&longs;tremum idem &longs;int; quapropter, vt prius dicebamus non e&longs;t inconueniens, ip&longs;um circulum miraculorum omnium e&longs;&longs;e principium. Admiranda igitur ea, quæ circa li­bram &longs;iunt, ad circulum tanquam cau&longs;am referuntur, quæ verò circa vectem ad ip&longs;am libram: alia autem ferè omnia, quæ circa mechanicas contingunt motiones, ad vectem reducuntur.

Præter prædicta aliud tandem mirum ip&longs;i ine&longs;t, quia nimirum cum innu­mera &longs;int puncta in vna eademque; linea, quæ &longs;emidiameter e&longs;t, omnia tamen quando &longs;emidiameter circa centrum mouetur, quamuis cum ip&longs;a mouean­tur, inæquali veiocitate mouentur; Nam punctum illud &longs;emper velocius mouetur, quod remotius e&longs;t à centro circuli, &longs;eu à manente &longs;emidiametri termino, & proinde illud tardius, quod centro proximius e&longs;t. Atque ex hac mira circuli proprietate, pleraque miraculorum accidunt circuli motioni­bus, vt in &longs;equentibus quæ&longs;tionibus manife&longs;tum erit.

Quoniam autem &longs;ecundum contrarias &longs;imul motiones mouetur circulus, & alterum quidem diametri extremum vbi A, in figura præ&longs;enti antror&longs;um

mouetur; alterum verò vbi B, retror­&longs;um, efficiunt nonnulli, vt ab vnica mo­tione multi contrariò &longs;imul mouean­tur denticulati circuli: vt &longs;unt ij, quos in locis proponunt &longs;acris, quorum alij &longs;unt ænei, alij ferrei. &longs;i enim circulus A B, alterum circulum C D, contige­rit, mota diametro A B, ita vt A, an­tror&longs;um eat, commouebit alteram dia­metrum C D, ita vt C, retror&longs;um, hoc e&longs;t in contrarium ip&longs;i A, veniat, in contrarium igitur mouebitur &longs;ecundus circulus C D, ad circulum A B, & rur&longs;us circulus E F. in contrarium ip&longs;i C D, commouebitur ab ip&longs;o C D, ob eandem rationem. eodem etiam modo &longs;i plures fuerint, idem facient vno &longs;olo tanquam primo motore commoto. hanc igitur circuli naturam animad­uertentes Architecti, in&longs;trumentum artificiosè fabricant, motus principium occultantes, vt machinæ &longs;olù manife&longs;tum &longs;it illud, quod admirationem parit, cau&longs;a verò lateat: quod genus machinarum Automata dicebantur, quia &longs;pontè à &longs;e ip&longs;is mouebantur.

In primis igitur, quæ circa libram accidunt, dubitare faciunt, quamnam ob cau&longs;am maiores libræ minoribus &longs;int exactiores: huius autem rei prin­cipium e&longs;t illud, quod &longs;upra innuimus, quod &longs;cilicet, quæ à centro plus di­&longs;tat linea, &longs;iue quæ longior e&longs;t, eadem vi commota citius fertur, quam illa, quæ minus à centro di&longs;tat, &longs;eu quæ minor e&longs;t. Porrò citius bifariam dicitur; &longs;iue enim in minori tempore æquale pertran&longs;it &longs;patium: &longs;iue in æquali tem­pore, maius conficit interuallum; citius feci&longs;&longs;e dicitur. &longs;i autem duæ lineæ circa idem centrum moueantur vna maior, & altera minor in æquali tem­pore; maior maiorem circulum de&longs;cribet, quam minor; quia circulus à ma­iori de&longs;criptus, alterum à minori delineatum circumple ctetur, atque intra &longs;e continebit; maius autem e&longs;t continens, quàm contentum. horum autem cau­&longs;a, quoniam quæ circulum de&longs;cribit linea, duabus fertur lationibus, quæ nul­lam inuicem obtinent analogiam: quod antequam probemus, &longs;ciendum e&longs;t, quod, quidquid duobus motibus inuicem proportionatis, mouetur, ne­ce&longs;&longs;e e&longs;t, quod motu exillis mixto progrediatur per lineam rectam, quæ dia­meter e&longs;t quadrilateri, cuius latera habeant illam proportionem, quam duo illi motus. &longs;it enim in figura proportio lateris A B, ad latus A C, quam ctiam habent duo motus, &longs;ecundum quos latum quodpiam feratur, &longs;itque; la­tum illud A, & feratur motu vno ver&longs;us B, per lineam A B, altero verò mo­tu feratur ver&longs;us C. quod fiet &longs;i cogitemus latus A B, de&longs;cendere ver&longs;us M C,

ip&longs;i æquidi&longs;tanter, dum punctum A, mouetnr ad B. his duabus lationibus A, latum. nece&longs;&longs;a­niò motu mixto progre dietur per diametrum A M, quod &longs;ic probari pote&longs;t; &longs;it iam A, mo­tum primo motu v&longs;que ad D, linea verò ex &longs;e­cundo motu &longs;it in G F E, quo motu punctum A, quod erat in D, tractum erit in F. quod pun­ctum e&longs;t in diametro A M, quoniam enim mo­uetur duobus motibus, cum lineis A B, A C, proportionalibus, motus au­tem hucu&longs;que &longs;unt A D, A E, quæ debent e&longs;&longs;e proportionales, cum A B, A C compleatur rectangulum A D F E, erunt &longs;imiliter proportionalia F E, D E, cum &longs;int æqualia duobus D A, A E, quare per 26. 6. cum quadrilaterum paruum A D F E, &longs;it &longs;imile toti A B M C, erit A M, vtriu&longs;que diameter, ergò punctum F, in quo e&longs;t A, e&longs;t in diametro A M. eodem modo, de quouis pun­cto in linea A B, ad quod A, perueniat, probabitur ab altero motu de&longs;cen­di&longs;&longs;e v&longs;que ad diametrum. &longs;emper ergò latum A, per rectam A M, diame­trum quadrilateri, cum illis motibus proportionalibus progreditur, quod probandum erat. è conuersò manife&longs;tum etiam e&longs;t, quod &longs;i quid &longs;ecundum diametrum duabus fertur lationibus, eas lationes e&longs;&longs;e proportionales late­ribus quadrilateri, cuius e&longs;t illa diameter, &longs;i enim illæ lationes non &longs;unt la­teribus proportionales, latum illud non feretur &longs;ecundum diametrum il­lam, &longs;ed &longs;ecundum aliam alterius quadrilateri.

Quod &longs;i quid duabus lationibus nullam habentibus proportionem per­petuò ferratur, impo&longs;&longs;ibile e&longs;t ip&longs;um motu mixto lineam rectam de&longs;cribere. &longs;i enim dixeris illud po&longs;&longs;e de&longs;cribere rectam lineam, tunc circa rectam il­lam tanquam diametrum de&longs;cribam quadrilaterum, & po&longs;tea o&longs;tendam, vt proximè o&longs;ten&longs;um e&longs;t, illud latum e&longs;&longs;e &longs;ecundum laterum illius proportio­nem, quare impo&longs;&longs;ibile e&longs;t id, quod mouetur duabus lationibus nullam in­uicem rationem habentibus, ferri per lineam rectam: quapropter dicendum e&longs;t hoc modo latum, nece&longs;&longs;ariò ferri circulariter, &longs;iue per lineam circularem. Quod autemea, quæ de&longs;cribit circulum linea, dum altero eins manente extremo circumagitur, duabus &longs;imul feratur lationibus, ex quibus motus orbicularis oriatur, manife&longs;tum e&longs;t ex &longs;uperioribus, quia & antror&longs;um, & retror&longs;um impellitur; tùm etiam, quia &longs;i rectà tenderet recta de&longs;cribens cir­

culum, nunquam ad diametri perpendiculum perueniret, &longs;ed tamen peruenit, ita vt &longs;it ip&longs;a à centro perpendicularis diametro. &longs;it circuli figura A B C D, in qua extremum diametri B, feratur ad alterum extremum vbi D, per ip&longs;ius diametri B D, circumuolutionem circa centrum F, nece&longs;&longs;e e&longs;t aliquando B, perueniat ad C. &longs;i igitur B, feretur duabus lationibus aliquo modo proportionatis, v. g. vt e&longs;t pro­portio lateris B E, ad E C, latus, &longs;equeretur ex demon&longs;tratis ip&longs;um B, ferri per rectam B C, quæ diameter e&longs;&longs;et quadrilateri B E C G. &longs;ed quia in nu&longs;la proportione fertur, propterea per circularem lineam B E C, progreditur ad C, ita vt ip&longs;a diameter B D, in po&longs;itione A C, fiat perpendi­cularis priori diametro B D. ex quibus &longs;equitur eam moueri duobus moti­bus nullam rationem habentibus; quod erat intentum.

Hoc modo Ari&longs;t. probare conatur, lineam circulum de&longs;cribentem, dua­bus ferri lationibus, quæ nullam habeant analogiam: Yerùm, vt liberè fa­tear nullo modo mihi videtur intentum a&longs;&longs;equi, nam neque ex dictis pater, ip&longs;am duobus motibus ferri, quibus opus e&longs;&longs;et: neque patet eos (quamuis concedantur) nullam inuicem habere analogiam: qui enim fieri pote&longs;t, vt duo motus reperiantur, quì nulla &longs;e mutuò habitudine re&longs;piciant? Præte­rea &longs;i B, ferretur illis motibus, non &longs;equitur debere moueri per lineam cir­cularem, cum præter lineam rectam &longs;int plures curuæ, quæ tamen non &longs;unt circulares, vt &longs;unt &longs;ectiones parabolicæ, & lineæ &longs;pirales. Deinde pergit.

241

Vt autem cau&longs;a appareat, cur ea, quæ à centro longior e&longs;t linea velocius moueatur, &longs;iue quod in eadem &longs;emidiametro remotiora puncta à centro ve­locius moueantur, vt &longs;upra dictum e&longs;t, &longs;ciendum e&longs;t, Quod &longs;i duo mouean­tur ab eadem potentia, quorum vnum à quopiam alio mouente plus repel­latur à motu priori, alterum verò minus, rationi con&longs;entaneum e&longs;&longs;e, tardius moueri id, quod plus, eo quod minus impeditur; quod videtur accidere maiori, & minori illarum, quæ à centro egre&longs;&longs;æ circulos delineant. quoniam enim propius e&longs;t manenti eius, quæ minor e&longs;t extremum, quàm extremum maioris, propterea plus à centro, cui propius e&longs;t, retrahitur à priori mo­tu, hincque; motus eius tardior redditur, ide&longs;t, quia centro propius e&longs;t; hinc fit, vt extremum illud de&longs;cribat lineam circularem quidem, &longs;ed tamen curuiorem quam de&longs;cribat extremum longioris lineæ, quæ circulum minus curuum, &longs;eu magis ad rectam lineam accedentem delineat. omni quidem igitur lineæ circulum de&longs;cribenti i&longs;tud accidit, vt duobus feratur motioni­bus; vna quidem, quæ illi naturalis, ac &longs;ecundum circunferentiam, qua re­ctà tenderet ni&longs;i impediretur: altera verò, quæ illi innaturalis, qua in tran&longs;­uer&longs;um agitur, &longs;eu &longs;ecus centrum, ob quam cogitur in gyrum duci, minor autem linea &longs;ecundum hanc motionem innaturalem plus fertur, quàm ma­ior, ide&longs;t plus ip&longs;ius progre&longs;&longs;io inflectitur in orbem; quia enim e&longs;t centro

vicinior, quod quodammodo retra­hit à motu naturali, propterea ma­gis vincitur, quàm remotior. Quod ex his erit manife&longs;tum. &longs;it circulus vbi B C E D, & alter in eo minor, vbi N M O P, circa idem centrum A. & proijciantur diametri in magno qui­dem C D, B E, in minori verò M O, N P. & altera parte longius quadri­laterum compleatur D K R C. &longs;i igi­tur &longs;emidiameter A B, circumacta de&longs;cribit circulum maiorem, reuer­titur tandem ad locum B A, vnde di­gre&longs;&longs;a e&longs;t. &longs;imiliter M A, circumuoluta redibit ad priorem po&longs;itionem in M A. Tardius autem fertur M A, quàm B A, vt dictum e&longs;t, quia maior illi fit retractio à recta progre&longs;&longs;ione. Sit igi­tur linea A B, mota v&longs;que ad locum A L F, & à puncto L, ducatur L Q, per­pendicularis ip&longs;i A B, in minori circulo. & rur&longs;us ducatur L S, parallela ei­dem A B, & à puncto S, in maiori circulo ducatur S T, perpendicularis ei­dem B A, necnon F X. erunt igitur S T, L Q, latera rectanguli T L, æqualia per 34. primi. erit po&longs;tea B T, minor quam M Q, quia æquales rectæ S T, L Q, ductæ à circunferentia ad diametrum perpendiculares in circulis in­æqualibus, ea quæ e&longs;t in maiori circulo minorem re&longs;ecat diametri portio­nem, quàm quæ in minori.

In quanto autem tempore ip&longs;a A L, lata e&longs;t per circunferentiam M L, in tanto temporis &longs;patio in maiori circulo B, extremum ip&longs;ius B A, latum erit per maiorem arcum quàm &longs;it B S; iam con&longs;ideraudum e&longs;t motus vtriu&longs;que lineæ in hoc ca&longs;u æquales e&longs;&longs;e, &longs;unt enim de&longs;cripti per lineas æquales T S, Q L, quæ &longs;unt rectæ; tam enim linea B A, quàm M A, naturali motu recta tenderet, vt dictum e&longs;t, peragra&longs;&longs;etque; illa rectam T S: hæc verò rectam Q L. Verum lationes innaturales &longs;unt impares, latio enim B T, breuior e&longs;t M que quantitate autem B T, retracta e&longs;t B A, à motu &longs;ibi naturali, & recto: quan­titate verò M Q, retracta e&longs;t M A, vnde apparet motu hoc violento magis retractam e&longs;&longs;e minorem M A, quàm maiorem B A, quod erat primo de­clarandum.

Quod autem ob id A B, maior c&ecedil;lerius mota &longs;it motu naturali, quàm mi­nor M A, palàm fiet. quia enim oportet vtramque lineam maiorem, & mi­norem eadem vi motam, confeci&longs;&longs;e binos illos motus proportionales, ide&longs;t ita &longs;e debet habere motus naturalis maioris ad motum innaturalem eiu&longs;­dem, quemadmodum &longs;e habet motus naturalis minoris ad motum innatu­ralem eiu&longs;dem: Oportet ergo, vt &longs;i A B, & A M, &longs;unt eadem vi commotæ, vt &longs;it eadem ratio T S, ad Q L, quæ e&longs;t B T, ad M Q, non e&longs;t autem, vt o&longs;ten­&longs;um e&longs;t; ergo linea A B, eadem vi commota, ac M A, conficit plu&longs;quam B S, &longs;ed nece&longs;&longs;ariò peruenit ad F. hoc enim in puncto erunt prædicti motus proportionales, vt oportet, erit enim motus naturalis in maiori perpendi­cularis F X, & innaturalis B X, in minori verò naturalis L Q, innaturalis M que quod &longs;i ducantur rectè B F, M L, apparebunt duo triangula æquian­gula B X F, M Q L, & erunt per 4. 6. vt F X, ad B X. ita L Q, ad M Q, & permutando erunt etiam vt F X, ad L Q, ita B X, ad M que ide&longs;t, vt motus naturalis ad naturalem, ita innaturalis ad innaturalem. In alio autem lo­co præter F, non erunt eædem proportiones.

Ex quibus patere &longs;atis pote&longs;t, cur A B, longior à centro velocius mouea­tur quàm minor M A, &longs;eu cur puncta eiu&longs;dem B A, velocius vertuntur, quo longius ab&longs;unt à centro A, ide&longs;t maiorem arcum B F, peractum e&longs;&longs;e à B, quàm &longs;it arcus M L, peractus ab M, quod erat o&longs;tendendum.

Atque hic e&longs;t di&longs;cur&longs;us ille Ari&longs;t. quo putat &longs;e cau&longs;am aperui&longs;&longs;e, cur lon­gior &longs;emidiameter velocius moueatur: quod num rectè attigerit, non puto operæpretium e&longs;&longs;e hoc loco di&longs;cutere, præ&longs;ertim cum ad naturalem Philo­&longs;ophum &longs;pectet.

Mihi tamen maximè con&longs;iderandum videtur hoc ip&longs;um quod a&longs;&longs;eruit, & ex &longs;e patet, remotiores &longs;cilicet partes diametrorum à centro velocius mo­ueri, quàm viciniores; ex hac enim maiori velocitate &longs;equitur maiore etiam vi moueri, vnde & potentiæ mouenti in extremo eius vis augebitur, & plus poterit quam &longs;ola &longs;ine vecte, e&longs;t enim vectis duæ &longs;emidiametri altera alte­ram longior; ex quibus fortè apparet vnde vectis vires oriantur.

His igitur tanquam huius Mechanicæ facultatis principijs po&longs;itis, ad va­rias Quæ&longs;tiones di&longs;cutiendas accedit.

QVÆSTIO PRIMA

De Libra.

242

Cvr autem maiores libræ minoribus &longs;int exactiores, palàm e&longs;t ex præmi&longs;&longs;is principijs. con&longs;iderare enim oportet, quod in motu li­bræ de&longs;cribitur quidam circulus, cuius diameter &longs;unt ip&longs;a libræ brachia, centrum verò e&longs;t fpartum, &longs;iue trutina; hoc enim pun­ctum in motu libræ manet: duo verò brachia &longs;unt veluti duæ &longs;emidiametri

à centro exeuntes, vt in figura cerne­re e&longs;t, in qua centrum, &longs;iue &longs;partum e&longs;t vbi C, reliqua &longs;unt manife&longs;ta. In eadem porrò figura libra maior &longs;it A B. minor verò circa idem &longs;partum C, &longs;it F G. Iam vt præmi&longs;&longs;um e&longs;t, ea­dem vi, vel eodem onere in lance B, po&longs;ito, mouebitur velocius brachium libræ maioris, quàm minoris &longs;it ma­ior tran&longs;lata ad locum D E, ergò com­mota e&longs;t per arcum B E, vel A D. Minor autem libra acta e&longs;&longs;et per mino­rem arcum G I, vel F H, melius autem apparet arcus B E, maior, quam mi­nor G I, atque hoc e&longs;t, quòd maiores libras exactiores facit. hincque; etiam e&longs;t, quòd nonnulla pondera in minimis libris adeò paruam brachiorum aper­tionem faciant, vt ægrè percipi po&longs;&longs;it; in magnis verò propter brachiorum longitudinem valdè &longs;en&longs;ibilem efficiant. quædam verò benè, & in magnis, & in paruis apparent, &longs;ed tamen &longs;emper melius in magnis ob dictam ratio­nem. Quamobrem machinantur ij, qui purpuram vendunt, vt pendendo defraudent, tum in medio libræ non ponentes &longs;partum, vt hoc modo bra­chium ex vna parte longius factum facilius moueatur, & proinde à minori purpuræ pondere; tum etiam plumbum in lancem illam infundentes inquam merces imponitur, vel partem illam lancis, quam magis grauitare cu­piunt ex ligno radici proximo, vel ex nodo&longs;o facientes: lignum enim, quod radici proximum e&longs;t, graue admodum e&longs;t, quemadmodum etiam nodus; quia nodus e&longs;t, quædam radix. Atque hæc e&longs;t huius pri­mæ quæ&longs;tionis paraphra&longs;is.

QVÆSTIO SECVNDA

De Libra

243

Cvr &longs;i quidem &longs;ur&longs;um fuerit &longs;partum, quando deor&longs;um lato pondere, qui&longs;­piam id amouet, rur&longs;um a&longs;cendit libra? Si autem deor&longs;um constitutum fuerit, non a&longs;cendit, &longs;ed manet? An quia &longs;ur&longs;um &longs;parto quidem exi&longs;ten­te plus libræ extra perpendiculum fit, &longs;partum enim e&longs;t perpendiculum, quare nece&longs;&longs;e est deor&longs;um ferri id, quod plus est, donec a&longs;cendat, quæ bifariam li­bram diuidit ad ip&longs;um perpendiculŭ, cum onus incumbat ad libræ partem tractam.

&longs;it libra vbi recta B C, &longs;partum autem A D: hoc igitur &longs;ur&longs;um erecto, perpendi­culum erit vbi A D M. &longs;i igitur in ip&longs;o B, ponatur onus, B, quidem de&longs;cendet vbi E; C, autem a&longs;cendat vbi H, quamobrem ea, quæ bifariam libram &longs;ecat, primò quidem erit D M, ip&longs;ius perpendiculi; incumben­te autem onere erit D G, quare libræ ip­&longs;ius vbi E H, quod extra A M, perpendi­culum e&longs;t, vbi e&longs;t D D H, maius e&longs;t dimidio. &longs;i igitur amoueatur onus ab ip&longs;o E, ne­ce&longs;&longs;e e&longs;t H, deor&longs;um ferri, minus enim e&longs;t ip&longs;um E D. &longs;i quidem igitur &longs;ur&longs;um ha­buerit &longs;partum, propter hoc a&longs;cendit libra. &longs;i autem deor&longs;um fuerit, id quod &longs;ub­stat, contrarium facit; plus enim dimidio fit libræ, quæ deor&longs;um e&longs;t, pars, quàm quod perpendiculum &longs;ecet; quapropter non a&longs;cendit, pars enim eleuata leuior e&longs;t.
&longs;it libra vbi N G, perpendiculum autem K L M, bifariam igitur &longs;ecatur N G. im­po&longs;ito autem onere in ip&longs;o N, erit quidem N, vbi O, ip&longs;um autem G, vbi R; K L, au­tem vbi K P, quare maius e&longs;t L P O, quàm L R, ip&longs;o P L. Ablato igitur onere, ne­ce&longs;&longs;e e&longs;t manere; incumbit enim, ceu onus exce&longs;&longs;us medietatis in quo P L.) Aduer­te textum græcum e&longs;&longs;e mendo&longs;um, la­tinum vero mendo&longs;i&longs;&longs;imum. Ego partim ex certa rei intelligentia, vti vi­des re&longs;titui. Idemque; circa figuras præ&longs;titi. Porrò quoniam Piccolomineus, & &longs;i plurimum, vt ip&longs;e fatetur, in&longs;udauerit, non tamen &longs;olutionem huius quæ&longs;tionis e&longs;t a&longs;&longs;ecutus, eam tibi ex Mechanicis Guidibaldi tradam. Ari&longs;t­igitur ponit duas libræ &longs;pecies, &longs;iue potius duas eiu&longs;dem libræ po&longs;itiones, vnam, quæ haber &longs;partum, &longs;iue perpendiculum &longs;upra; alteram, quæ infra.
vt in præ&longs;enti figura, &longs;it libra B C, cuius &longs;partum, &longs;iue perpendiculum A D, &longs;it &longs;ur­&longs;um, ita vt in puncto A, &longs;it affixum perpen­diculum, & circa idem punctum A, tan­quam circa centrum tota libra circum­uertatur. hæc e&longs;t prima libræ collocatio. &longs;it deinde libra B C, cuius &longs;partum, &longs;iue perpendiculum A D, &longs;it deor&longs;um, vt in altera figura, &longs;itque; circa pun­
ctum A, tanquam circa centrum, aut axem ita fixum, vt ip&longs;i libræ conuer&longs;io innita­tur, quæ e&longs;t altera libræ po&longs;itio. Quærit igitur, cur &longs;i in libra &longs;ur&longs;um habente per­pendiculum, & centrum, ponatur ex vna parte onus quodpiam, v. g. in parte B, vt in prima textus figura factum e&longs;t, libra de primo &longs;itu B C, mouetur ad &longs;itum E H, &longs;ed tamen ablato pondere reuertitur &longs;ua &longs;pontè ad pri&longs;tinum &longs;itum B C. &longs;i autem in libra, cuius per­pendiculum, ac centrum deor&longs;um &longs;it, vt in &longs;ecunda figura textus, pondus imponatur, ip&longs;a quidem à &longs;itu B C, ad &longs;itum O R, transferretur; verumta­men ablato onere, non amplius ad priorem po&longs;itionem, vti prior, reucrtitur.

Huic quæ&longs;tioni, vt re&longs;pondeat, tacitè &longs;upponit omne graue tendere de­or&longs;um, hoc pacto, vt centrum grauitatis ip&longs;ius tendat per lineam rectam ad mundi centrum ab ip&longs;o grauitatis centro protractam, quam lineam Di­rectionis Recentiores appellant. &longs;ciendum autem centrum grauitatis e&longs;&longs;e punctum quoddam in quolibet graui, ex quo &longs;i graue illud &longs;u&longs;pendatur, &longs;em­per manet in æquilibrio, nec vnquam po&longs;itionem re&longs;pectu &longs;uarum partium mutat, quamuis ita &longs;u&longs;pen&longs;um huc illuc transferatur. Ita Pappus Alexan­drinus initio octaui libri Mathematicarum collectionum. Totius igitur li­bræ ab&longs;que onere centrum grauitatis e&longs;&longs;et circa punctum D, quod e&longs;&longs;et di­&longs;tinctum à centro circumuolutionis A. quod grauitatis centrum, &longs;emper quantum fieri pote&longs;t, &longs;i nihil ob&longs;tet, centro mundi appropinquat; & propte­rea facit, vt prior libra &longs;ine onere &longs;u&longs;pen&longs;a in A, in æquilibrio, atque hori­zonti parallela permaneat, &longs;tante enim D, centro mundi maximè propin­quo, &longs;iue in loco humillimo, erit inter punctum A, & centrum mundi, ac con&longs;equenter in linea directionis. quæ linea directionis in prima figura textus e&longs;&longs;et eadem cum perpendiculo A D M, manente libra &longs;ine pondere horizonti parallela; in &longs;ecunda autem figura textus coincideret pariter cum perpendiculo K L M, antequam libra ob impo&longs;itum onus ab æquilibrio di­moueretur. per hanc enim lineam centrum grauitatis libræ, quod e&longs;t propè puncta D, & L, tenderet ad mundi centrum, &longs;i libra liberè ad centrum mun­di dilaberetur. his præmi&longs;&longs;is &longs;ic quæ&longs;tioni &longs;atisfacit, & primò primæ parti, quando nimirum &longs;partum &longs;upernè collocatum e&longs;t. Ratio igitur, cur tunc li­bra amoto pondere ad horizontis æquilibrium reuertatur e&longs;t, quia pondus libræ impo&longs;itum in altera tantum libræ parte, grauitando impellit libram ad alium &longs;itum E H, ita vt maior pars libræ con&longs;tituatur ex altera parte li­neæ directionis prioris A D M, in qua etiam parte exi&longs;tit centrum granita­tis libræ ip&longs;ius, e&longs;t enim circa D, quod centrum vi ponderis incumbentis in E, cogitur paulùm a&longs;cendere, atque contra ip&longs;ius naturalem inclinationem à mundi centro recedere, vt &longs;i in libra B C, appendatur onus in B, vt in pri­ma textus figura; B, de&longs;cendet ad E, & C, a&longs;cendet ad H, & centrum graui­tatis D, paulùm a&longs;cendet à centro mundi, & linca A D M, quæ libram bi­fariam &longs;ecabat modo tran&longs;lato perpendiculo in A D G, non amplius cam bifariam &longs;ecabit; &longs;ed libræ E H, maior pars erit vltra perpendiculum A D­M, quæ maior pars e&longs;t D D H.

Si igitur nunc onus amoueatur libræ E H, centrum grauitatis, quod e&longs;t ad D, remanet vltra priorem Directionis lineam; & quia pondus non am­plius illi æ que ponderat, grauitabit, & quia libra cùm affixa &longs;it ad A, nequit deor&longs;um recta tendere, circumferretur circa A, trahente ip&longs;am grauitatis centro, cum nihil ob&longs;it, donec iterum perpendiculum A D G, priori &longs;itui A D M, congruat: hac enim ratione centrum grauitatis, quantum pote&longs;t, iuxta naturam &longs;uam de&longs;cendet, libraque; ad pri&longs;tinum æquilibrij B C, &longs;itum re&longs;tituetur. Si autem deor&longs;um fuerit &longs;partum in &longs;ecunda figura textus, im­po&longs;ito pondere contrarium accidit, quia maior pars libræ, & in qua cen­trum grauitatis e&longs;t, in tali motu de&longs;cendit: altera autem pars minor, ac læ­uior &longs;ur&longs;um tollitur. & quia graue natura &longs;ua nequit a&longs;cendere, propterea ablato pondere non reuertitur ad æquilibrium B C, cum centrum grauita­tis a&longs;cendere ne queat, quod tunc oporteret.

Sit libra N G, in &longs;ecunda figura, cuius perpendiculum, &longs;imulque; directio­nis linea &longs;it K L M, quæ libram in prima po&longs;itione diuidit bifariam; impofi­to autem onere in N. N, trahetur ad O, & G, ad R, & K L, vbi K P. quare maior e&longs;t O L, in quo centrum grauitatis, & propterea grauior quàm &longs;it L R: &longs;uperat enim O L, ip&longs;am L R, exce&longs;&longs;u duplæ P L, quod facilè apparet &longs;i po­natur tota O R, 10. & dimidia O P, & O R, 5. & P L, ponatur 2. erit enim tunc O L, 7. & L R, 3. quæ hanc &longs;uperat 4. duplo &longs;cilicet ip&longs;ius P L, 2. qua­re ne&longs;cio cur Ari&longs;t. dicat, ip&longs;am O L, &longs;uperare ip&longs;am L R, &longs;olùm quantitate P L. Quapropter etiam &longs;i onus auferatur, nece&longs;&longs;e e&longs;t ibi libram manere, quia maior, & grauior ip&longs;ius pars deor&longs;um e&longs;t, nec pote&longs;t natura &longs;ua læui­tare, vel a&longs;cendere, vt oporteret, &longs;i ad pri&longs;tinum &longs;itum N G, re&longs;titui debe­ret. remanebit igitur in O R.

Ex his, quæ&longs;tionis &longs;olutionem, textus explicationem, ac re&longs;titutio­nem habeto.

Aduertendum quoad &longs;ecundam libram, ne &longs;imul cum 10. Bapti&longs;ta Bene­dicto in libro &longs;peculationum immeritò Ari&longs;t. erroris arguamus: ip&longs;e enim, quia libram hanc non agnouit, au&longs;us e&longs;t affirmare, Ari&longs;tot. hoc loco fal&longs;um pror&longs;us dixi&longs;&longs;e, cum dixit libram &longs;patto infimè collocato, non redire ad pri&longs;tinam po&longs;itionem.

QVÆSTIO TERTIA

De Vecte.

244

Cvm textus tam græci, quàm latini mendis &longs;cateant, neque hi textus maioris &longs;int momenti, eos per paraphra&longs;im explicabo, in qua ta­men totus textus continebitur, atque emendabitur. Cur exiguæ vires (quemadmodum à principio dictum e&longs;t) adhibito vecte, ma­iora mouent pondera, quam ab&longs;que vecte? contrarium enim videtur debere fieri, nam mouenti additur grauitas vectis, & ideò pondus augetur, ergò difficilius ip&longs;um cum vecte, quàm &longs;ine eo mouere deberet.

Vectis porrò e&longs;t in&longs;trumentum oblongum, quo ad &longs;ubleuandum graue quodpiam vtuntur opifices, quod innititur cuidam fulcimento, quod græcè hypomoclion dicitur: hypomoclion antem oncri leuando, quanrum &longs;ieri pote&longs;t proximum e&longs;&longs;e debet, vt vectis pars longior &longs;it ad partes potentiæ mouentis. vt plurimum verò fulcimentum e&longs;t inter pondus, & potentiam: aliquando etiam e&longs;t ex altero vectis extremo, ita vt onus &longs;it inter fulturam, & potentiam; aliquando potentia e&longs;t inter vtrunque, vnde tres vectis &longs;pe­cies exi&longs;tunt. vt in &longs;ubiectis figuris apparet. In prima, vectis e&longs;t A B, fultu­

ra E, onus C. potentia autem &longs;eu vis, &longs;eu aliud pondus mouens &longs;it vbi D. quæ deor&longs;um in D, præmens eleuabit &longs;ur­&longs;um ex altera parte onus C. & vectis circa fulturam E, tanquam centrum conuertetur. In altera figura pondus e&longs;t inter fulturam, & potentiam, ful­tura autem in altera extremitate, vt patet in figura, hic autem potentia non præmit deor&longs;um in D: &longs;ed &longs;ur&longs;um vectem eleuando pondus C, attollitur. In tertia tandem figura potentia, e&longs;t inter vtrunque, e&longs;t enim in D, ibique &longs;ur&longs;um vrget. verum tamen e&longs;t hunc vectem artificibus e&longs;&longs;e inutilem, quip­pe qui nullo modo iuuet potentiam, imò verò pondus ip&longs;um grauius reddit: neque hoc genere in his Mechanicis indigemus.

Re&longs;pondet igitur dubitationi, dicens rationem huius incrementi poten­tiæ motricis, quod fit a&longs;&longs;umpto vecte fortè inde oriri, quod vectis &longs;it quæ­dam libra, cuius alterum brachium &longs;it altero longius; in prima autem quæ­&longs;tione explicatum e&longs;t, cur libra maior, maiorem vim habeat, eam ad cir­culum reducendo; vectis autem fit libra, hypomoclion enim e&longs;t loco &longs;parti, tam enim &longs;partum, quam hypomoclion veluti centra manent. quoniam ve­rò ab eodem pondere, c&ecedil;lerius, &longs;iue maiori vi mouetur linea, quantò lon­gior à centro fuerit, vt dictum e&longs;t de admiranda circuli natura; hinc fit, vt cum duæ &longs;int in vecte potentiæ, &longs;iue duo pondera, mouens, & motum, illud facilius ac maiore vi moueat, &longs;iue vires ex vecte acquirat, quod longiorem vectis partem pre&longs;&longs;erit. quemadmodum igitur pars vectis longior, quæ &longs;pe­ctabat ad mouentem potentiam, &longs;uperat minorem partem, in qua e&longs;t mo­tum; ita etiam maius e&longs;t pondus motum, quàm mouens. &longs;emper autem quan­to ab hypomoclio magis di&longs;tabit potentia, tantò facilius mouebit, cuius cau&longs;a &longs;upra reddita e&longs;t, quoniam nimirum, quæ plus à centro elongatur ma­iorem de&longs;cribit circulum, qui magis ad lineam rectam accedit: quare ab eadem potentia adhibito vecte, tantò facilius pars vectis mouens dimoue­bitur, quantò magis à fulcimento di&longs;tabit. Exempli gratia &longs;it in &longs;uperiori prima figura vectis A B, pondus C, mouens D, hypomoclion E, in qua præ­dicta poteris contemplari. vltima illa textus verba (Quod autem vbi D, mo­uens, vbi F, motum autem vbi C, pondus in G,) videntur &longs;uperuacanea, atque mendosè addita.

In hac quæ&longs;tione re&longs;pexit Ari&longs;t. &longs;olùm ad primam vectis &longs;peciem. Illud demum, quod dixit eandem habere rationem potentiam ad pondus, quàm partes vectis inuicem demon&longs;tratum e&longs;t po&longs;tea acuti&longs;&longs;imè ab Archimede propo&longs;itione 6. & 7. de æqueponderantibus: & no&longs;tra tempe&longs;tate alio quam­uis modo, & vnica demon&longs;tratione à Guido Vbaldo in &longs;uis Mechanicis pro­po&longs;itione 1. de Vecte, quæ e&longs;t huiu&longs;modi; Potentia &longs;u&longs;tinens pondus vecti appen&longs;um, eandem ad ip&longs;um pondus proportionem habet, quam vectis di­&longs;tantia inter fulcimentum, ac ponderis &longs;u&longs;pen&longs;ionem, ad di&longs;tantiam, à fulci­mento ad potentiam interiectam. quod de omni vecte ab eo demon&longs;tratur, cuius propo&longs;itionis &longs;en&longs;us e&longs;t hic; in &longs;uperiori prima figura &longs;i pars vectis E B, fuerit, v.g. qua drupla partis A E; etiam pondus C, erit quadruplo ma­ius pondere, &longs;eu vi in D, quæ ip &longs;um C, ope vectis &longs;u&longs;tinet. quod etiam trans­ferre debes ad &longs;ecundam figuram.

QVÆSTIO QVARTA

De Remo.

245

EI, qui &longs;uperiora intellexerit &longs;atis clara videtur. Illud tamen non omittendum, &longs;cilicet dicendum potius Remum e&longs;&longs;e vectem &longs;ecundi generis, quàm primi, quod fortè Ari&longs;t. non animaduertit, nec Pic­colomineus, nam mare e&longs;t hypomoclion, re&longs;pectu enim nauis non mouetur, &longs;ed manet, &longs;calmus autem &longs;imul cum tota naui e&longs;t pondus motum; verè enim nauis ip&longs;a mouetur. mouens e&longs;t ip&longs;e remex. Reliqua in textu &longs;unt clara.

QVÆSTIO QVINTA

De Temone Nauis.

246

Qvemadmodum in præcedenti quæ&longs;tione Ari&longs;t. vectem &longs;ecundi ge­neris ad &longs;olutionem non adhibuit, vt par erat, & propterea ob&longs;cu­rior eua&longs;it, ita etiam in præ&longs;enti, qu&ecedil;&longs;tionem ad ve ctem primi ge­neris reducit, quæ ad alterum reducendà erat: atque hinc ob&longs;curi­tas, atque prolixitas &longs;olutionis manauit. E&longs;t enim propriè Temo, &longs;iue gu­bernaculum nauis, vectis &longs;ecundi generis, vt mox explicabo, e&longs;t enim temo

in&longs;trumentum in extrema nanis par­te, &longs;eu puppi affixum, vt in figura prç­&longs;enti vides tabellam, in qua B C D, cuius manubrium A B, intra nauim recipitur, quæ tabella, &longs;eu temo in duobus cardinibus, vbi C, & D, cir­cumuertitur à Nauis gubernatore, manubrium vbi A, tractante; ex qua conuer&longs;ione nauigium, quò vult ip&longs;e gubernator facilè dirigit, ip&longs;umque nauigium huc illuc quamuis adeò magnum ip&longs;e &longs;olus impellit, & agitat. e&longs;t enim temo vectis, cuius auxilio vires mirum in modum augentur, nam to­ta A B, e&longs;t ip&longs;a Vectis longitudo, cuius hypomoclion e&longs;t mare, cui contra­nititur tabella B E; onus autem e&longs;t puppis, quod onus præ&longs;ertim in cardini­bus C D, mouenti re&longs;i&longs;tit, & quod præcipuè mouere gubernator intendit. cum igitur motum onus &longs;it intra vectis extrema, hypomoclion in extremo ad B E, vbi in motu temonis tabella mare vrget, quod minimè cedit, ip&longs;aque; in hoc motu ferè maneat, & fiat qua&longs;i centrum, circa quod totus temo cir­cumducitur, patet temonem e&longs;&longs;e vectem &longs;ecundæ &longs;peciei, vt dicebam. quod etiam hinc patere pote&longs;t, quia temo e&longs;t veluti remus, cuius &longs;calmus &longs;int car­dines C, D. &longs;icut ergo remus e&longs;t vectis &longs;ecundi generis, cuius pondus e&longs;t &longs;ealmus, & mare hypomoclion; ita temo erit vectis eiu&longs;dem generis, cuius pondus erit vbi cardines, fultura verò mare.

Quærit igitur Ari&longs;t. vnde nam tantas vires paruus nauis temo guberna­tori &longs;uggerat, re&longs;pondetque; propterea id contingere, quod temo vectis na­turam obtineat, cuius inquit onus e&longs;t mare, melius autem, vt dixi, dixi&longs;&longs;et onus e&longs;&longs;e nauim, mare autem hypomoclion, mouens autem e&longs;t gubernator. Differunt autem remus, & temo, quamuis vterque &longs;it vectis, quoniam remus &longs;ecundum latitudinem nauis, &longs;eu ad latera nauis mari obnititur. temo au­tem in directum ferè nauigij con&longs;titutus mare &longs;cindit. hinc fit, vt remus ad nauem antror&longs;um rectà agitandam, gubernaculum verò ad eam in latera, & obliquè contor quendam idoneum &longs;it. quoniam enim mare e&longs;t hypomo­clion, fit vt dum gubernator mouet an&longs;am temonis in A, &longs;eu ad dextram, &longs;eu ad &longs;ini&longs;tram &longs;ecum ad eandem partem trahat nauigium, quod temoni e&longs;t connexum; ad contrariam tamen partem trahit ei, &longs;ecundum quam mare impingit. atque hoc pacto remus antror&longs;um, temo verò obliquè nauim agit.

Po&longs;thæc &longs;equuntur huiu&longs;modi verba (In extremo autem, & non in medio iacet, quoniam mouenti facillimum est ab extremo motum mouere: prima enim pars celerrimè fertur, quoniam quemadmodum in ijs, quœ feruntur in fine deficit latio, &longs;ic ip&longs;ius continui in fine imbecili&longs;&longs;ima e&longs;t latio, imbecili&longs;&longs;ima autem ad expellendum est facilis, propter hœc igitur in puppi gubernaculum ponitur) quorum &longs;en&longs;us videtur difficilis, neque græcus textus excu&longs;andus e&longs;t, benè enim tran&longs;lata &longs;unt. Piccolominæus quidem plura quàm Ari&longs;t. fatur, &longs;ed non clariora. dif­ficultas e&longs;t in verbis illis (Prima enim pars celerrimè fertur) & in illis (Sic ip­&longs;ius continui in fine imbecili&longs;&longs;ima eft latio) videtur velle dicere, quod quando continuum aliquod proiectum fertur per aera, pars ip&longs;ius anterior ea e&longs;t, quæ præ cæteris partibus principaliter mouetur, & ad cuius motum reliquæ po&longs;teriores tanquam &longs;ub&longs;e quentes moueantur; qua&longs;i dicat tota vis lationis e&longs;t in anteriori parte: &longs;iue ip&longs;i impetus maior ine&longs;t: videmus enim proiecta, quorum vna pars e&longs;t cæteris grauior, quia ei parti melius imprimitur mo­tus, eam etiam fieri anteriorem in latione, quamuis initio fuerit po&longs;terior. &longs;ic etiam quando graue fertur deor&longs;um, dicimus ip&longs;um ferri &longs;ecundum cen­trum grauitatis ip&longs;ius, ibique; maiorem vim grauitandi exi&longs;tere, &longs;ic in proie­ctis partem anteriorem dicere po&longs;&longs;umus e&longs;&longs;e, &longs;ecundum quam totum conti­nuum fertur: ibique; totum e&longs;&longs;e impetum lationis, & propterea etiam maio­ri impetu, atque celerrimè ferri: & con&longs;equenter partem po&longs;teriorem, quam­uis priorem æqua velocitate con&longs;equatur, non tamen tanto impetu, cum ip­&longs;a ad alterius impetum moueatur, & propterca latio ip&longs;ius e&longs;t admodum imbecillis.

Si quis &longs;agittam per aerem latam à &longs;uo motu vellet deflectere, eam faci­lius in po&longs;teriore parte à &longs;uo cur&longs;u deuiaret, quàm in anteriore. hunc con­cinui corporis motum continuo proiectorum motui a&longs;&longs;imilat: quemadmo­dum enim motus proiectorum in fine debilior lente&longs;cit: &longs;ic totum conti­nuum in po&longs;trema parte &longs;egnius impellitur. Quia igitur nauis e&longs;t continuum, quod vi remorum recta antror&longs;um fertur, & propterea maiore vi prora, quàm puppis, facilius e&longs;t à &longs;uo directo cur&longs;u nauem deflectere, eam in pup­pi, quàm in prora commouendo. hac igitur de cau&longs;a, gubernaculum puppi affigitur. quæ quidem ratio, & quantum valcat, & an naui quadret, & num benè &longs;it explicata, phy&longs;icorum e&longs;t iudicare.

Ego tamen aliam huius rationem video, quia nimirum &longs;i temo in priori parte e&longs;&longs;et, quando à rectitudine ip&longs;ius nauis ad dextram, aut ad &longs;ini&longs;tram e&longs;&longs;et inclinandus, tunc quia aqua in vnam tantum ipfius partem, &longs;eu faciem tota impingeret, in eam &longs;cilicet, quæ antror&longs;um re&longs;piceret, eam aqua re­tror&longs;um &longs;imul cum tota naui auerteret, &longs;icque; totam nauim inuerteret, ita vt prora, cui adhæreret temo extrema fieret. impetus igitur aquæ, & naui­gij temonati, cogit temonem e&longs;&longs;e po&longs;tremum non primum, nec medium. atque hinc oritur nece&longs;&longs;itas eum po&longs;teriori parti affigendi. &longs;ubdit po&longs;tea aliam eiu&longs;dem rationem, quia nimirum parua motione facta in puppi multo ma­ius interuallum cogitur mutare prora; nam idem angulus, quo eius lineæ &longs;unt longiores, eò maiorem &longs;ubten&longs;am &longs;ibi lineam re&longs;picit, quod facilè in

ad&longs;cripta figura intueri licet; in qua duæ lineæ A B, A C, continent angulum A, cui angulo &longs;ubtenduntur tres lineæ parallelæ F G, D E, B C, quarum B C, maxima e&longs;t, quia ibi maiores, &longs;iue remotiores &longs;unt ab angulo A, duæ rectæ A B, A C, ip&longs;um con­tinentes, quod Geometricè per 4. 6. pro­bari pote&longs;t. &longs;ic etiam facta motione, vel parua in puppi, tota nauis transfertur ad alium &longs;itum, ita vt prora multum aliò transferatur, quod non accideret, &longs;i eadem motio fieret ad medium nauigij. propterea igitur apti&longs;&longs;imè puppi gubernaculum connectitur.

247

Ex ij&longs;dem etiam rationibus mathematicis patet, cur magis antror&longs;um procedit nauigium, quàm remi ip&longs;ius palmula retror&longs;um: eadem enim ma­gnitudo, ij&longs;dem mota viribus in aere plus, quàm in aqua progreditur. Sit igitur A B, remus, G, verò calmus. A, autem in nauigio &longs;it remi initium. B, verò in mari palmula. &longs;i igitur A, vbi D, transferatur, per totum &longs;pa­tium A D, non permeabit tantumdem &longs;patij B, v&longs;que ad E. B E, enim ponitur æqualis ip&longs;i A D, &longs;ed minus interuallum propter re&longs;i&longs;tentiam aquæ ex &longs;up­po&longs;itione percurret, quale e&longs;t B F, quod minus e&longs;t quàm A D, quare etiam li­nea B G, abbreuiabitur, eritque; veluti F Y, quæ etiam erit minor ip&longs;a D G, quæ facta e&longs;t D Y, propter duo &longs;indlia triangula D Y A, B Y F, &longs;imilia au­tem triangula &longs;unt ea, quorum anguli vnius &longs;unt æquales angulis alterius, quo po&longs;ito &longs;unt etiam latera vnius proportionalia lateribus alterius, vt pa­tet ex prima definitione 6. necnon ex quarta eiu&longs;dem demon&longs;tratione. hæc

quidem duo triangula &longs;unt &longs;imi­lia, & rectè concluditur F Y, mi­nus e&longs;&longs;e quàm D Y, &longs;ed tamen non videntur i&longs;ta propo&longs;itum o&longs;tendere, quod erat, plus nauim procedere, quàm palmulam re­trocedere. Fateor quidem tex­tum hunc e&longs;&longs;e ob&longs;curi&longs;&longs;imum, idque; propterea fortè quia e&longs;t admodum corruptus, præ&longs;ertim circa chara­cteres, qui corrigendi &longs;unt vti nos facimus. ne&longs;cio qua ratione Piccolomi­neus videatur &longs;ibi locum hunc explica&longs;&longs;e. For&longs;itan addenda &longs;unt nonnulla hoc pacto; cum initio remigationis ponamus remum in &longs;itu A B, in fine ve­rò primæ impul&longs;ionis in D F, &longs;calmum verò circa medium remi in G, pri­mo; vltimo erit etiam circa medium D F, vbi H, quare &longs;calmus tran&longs;latus e&longs;t à G, ad H, totaque; G H, perficit, quam deberet Ari&longs;tot. vt &longs;ibi con&longs;taret probare e&longs;&longs;e maiorem ip&longs;a B F, quam palmula obiuit, & con&longs;equenter pro­ba&longs;&longs;et nauigium plus proce&longs;&longs;i&longs;&longs;e, quàm palmula rece&longs;&longs;erit: quod propo&longs;ue­rat. Verum hoc non demon&longs;trat; neque ex præmi&longs;&longs;is deduci pote&longs;t. po&longs;tea &longs;ubdit (Stans autem erit medium vbi e&longs;t G, in contrarium enim ip&longs;i, quqd in mari e&longs;t, extremo B, procedit, vbi extremum in nauigio e&longs;t A, non procederet autcm vbi est D, ni&longs;i commoueretur nauigiŭ, & eò transferretur vbi e&longs;t remi principium)vbi in textu mendosè legitur C, pro G.

Sen&longs;us porrò horum verborum e&longs;t hic; &longs;i remus cirea &longs;calmum G, verte­retur, & tamen nauis ab eo non propelleretur, &longs;ed &longs;taret, tunc medium na­uis maneret vbi G, per motum enim remi impellitur in contrarias partes ip&longs;i palmulæ B, quæ e&longs;t in mari, quia &longs;equitur motum alterius extremi A, manubrij &longs;cilicet remi, qui e&longs;t in naui: quod autem nauigium à remo mo­neatur, &longs;ignum e&longs;t, quia manubrium A, non procederet vbi e&longs;t D, ni&longs;i pari­ter cum remo nauigium illor&longs;um con&longs;equeretur. Hæc quidem Ari&longs;t. circa motum nauigij imperfectè admodum ni&longs;i textus corruptionem cau&longs;etur, di­xi&longs;&longs;e videatur. Quapropter operæpretium me facturum exi&longs;timo, &longs;i Petri Nonij acuti&longs;&longs;imi Mathematici, &longs;ubtili&longs;&longs;imas, &longs;cituque; digni&longs;&longs;imas in præ&longs;ens problema anuotationes hoc loco de&longs;crip&longs;ero, ex quibus perfectè, ac ma­thematicè toti huic quæ&longs;tioni fit &longs;atis, quæ &longs;ic &longs;e habent.

In Problema Mechanicum Arist. de motu Nauigij ex remis, annotatio Petri Nonij.

Cvm olim di&longs;cipulis no&longs;tris mechanicas Ari&longs;t. quæ&longs;tiones interpre­taremur, nonnulla circa problema illud annotauimus, cur magis procedat nauigium, quam remi palmula in contrarium. Ari&longs;tot. enim ratiocinatio ob&longs;cura e&longs;t; quam nos tamen, vt aliquid lucis haberet, ad hunc modum explicauimus; & propter materiæ &longs;imilitudinem hi&longs;ce no&longs;tris libris de nauigandi ratione adiunximus. Supponit autem ip&longs;e auctor remi palmulam retrocedere, quoties nauigium in anteriora progre­ditur, locumque; &longs;calmi, &longs;uper quo circulari motu remus vertitur, in medio ip&longs;ius remi po&longs;itum e&longs;&longs;e, vt &longs;cilicet tantum di&longs;tet à manubrio, quantum à palmula. Duæ itaque rectæ lineæ ponantur æquales A B, & D E, quæ quidem in C, puncto medio &longs;e inuicem &longs;ecent, & connectantur A B, & D E: remus autem in initio vnius remigationis po&longs;itionem habeat rectam lineam A B, &longs;itque; A, manubrium; B, palmula; C, verò &longs;ealmus. Cum igitur A, remi ca­put in fine ip&longs;ius remigationis eò tran&longs;latum fuerit D, non erit B, vbi E; &longs;i

enim ibi fuerit; remus igitur po&longs;itionem habebit rectam lineam D E; & quoniam contrapo&longs;iti anguli, qui ad C, æquales &longs;unt, & duo latera A C, & D C, trianguli A D C, duobus lateribus B C, & C E, trianguli B­E C, æqualia etiam &longs;unt: reliqui igitur an­guli, atque ba&longs;es ip&longs;orum triangulorum æqua­les erunt per 4. propo&longs;itionem primi libri Euclidis, & propterea tantum &longs;patium per­curret B, quantum A: &longs;calmus verò C, im­motus omninò erit: & nauigium idcircò, in quo ip&longs;e &longs;calmus, immotum etiam erit con­tra hypothe&longs;im. &longs;upponitur enim in que&longs;tio­ne, quod nauigium illa remigatione in anteriora moueatur, remi verò pal­mula retrocedat. Scalmus porrò quamquam circularis remi motus expers &longs;it; motu tamen nauigij commouetur. Remus igitur po&longs;itionem habeat in fine ip&longs;ius remigationis rectam lineam D Z, quæ quidem rectam A B, &longs;ecec in T, inter B, & C; rectam verò B E, in Z. Et quoniam duo coalterni anguli C A D, & C B E, æquales o&longs;ten&longs;i &longs;unt, & angulus A T D, contrapo&longs;ito B T Z, æqualis e&longs;t: duo igitur triangula A T D, & B Z T, æquiangula erunt per 32. primi, & communem &longs;ententiam. Similia itaque erunt ip&longs;a triangula, late­raque; habebunt proportionalia per 4. 6. &longs;icut A T, ad B T, ita D A, ad B Z. Maior e&longs;t autem A T, quàm B T: maior igitur D A, quàm B Z, quod etiam per communem &longs;ententiam neglecta triangulorum &longs;imilitudine concludi pote&longs;t.

Maius itaque &longs;patium decurrit manubrium, quàm remi palmula, atque illuc tran&longs;uehetur nauigium, quò remi capulus deportatus fuerit: nauigium igi­tur in diuer&longs;a procedens, plus &longs;patij, quàm remi palmula tran&longs;mittet. Vti­mur aurem tralatione, atque demon&longs;trationis figura Victoris Fau&longs;ti. Aduer­tendum e&longs;t tamen, quod cum remus po&longs;itionem habuerit D Z, remi palmu­la erit infra Z. Nam quoniam trianguli A D C, duo latera A C, & D C, æqua­lia po&longs;ita &longs;unc: duo igitur anguli, qui ad D, & A, æquales erunt: angulus igitur A D T, angulo D A T, maior erit: & idcircò latus A T, trianguli A­T D, latere D T, maius erit per 19. primi. Aæqualis porrò o&longs;ten&longs;us e&longs;t an­guius B Z T, angulo A D T, præterea angulus D A T; angulo T B Z, æqua­lis: angulus igitur B Z T, angulo T B Z, maior erit, & propterea latus B T, trianguli B T Z, latere T Z, maius erit: tota igitur recta linea A B, tota D Z, maior erit: & idcircò cum remus po&longs;itionem habuerit rectam lineam D Z palmula erit vltra Z. E&longs;to igitur in K, & connectantur rectæ lineæ B D, & B K: &longs;patium igitur decur&longs;um ab ip&longs;a palmula non erit B Z, &longs;ed B K: quod quidem minus etiam o&longs;tendemus e&longs;&longs;e ip&longs;o D A. Nam quoniam duo latera B D, & D K, trianguli B D K, duobus lateribus B D, & D E, trianguli B E D, æqualia &longs;unt, &longs;ed minor e&longs;t angulus B D K, angulo B D E: minorigitur erit ba&longs;is B K, ba&longs;e B E, per 24. primi, quod demon&longs;trandum erat

Præterea, quod Ari&longs;t. ratiocinando &longs;umit tantum &longs;patium conficere na­uigium, quantum remi manubrium, ambiguum e&longs;t. Nam remi manubrium duabus fertur motionibus: vna propria, circularique; &longs;uper &longs;calmo: altera verò, qua vnà fertur cum ip&longs;o nauigio. &longs;patium igitur, quod omninò decur­&longs;um e&longs;t à remi manubrio, eo quod à nauigio confectum e&longs;t, mains erit. At &longs;i paria &longs;patia decur&longs;a e&longs;&longs;e intelligat à remi manubrio motu proprio, & à nauigio, neque hoc difficultate caret. Nam nauiginm interdum maius &longs;pa­tium percurret, interdum minus, iuxta remigum vires, & prout mari remi palmula immer&longs;a fuerit: remi verò manubrium tamet&longs;i ab exiguis viribus moueatur haud minorem tamen ambitum de&longs;cribet, quàm &longs;i à multo ma­iore virtute moueretur. Quapropter, vt huiu&longs;modi Ari&longs;t. &longs;ententiam exa­minaremus, Theoremata, quæ &longs;equuntur, demonftrauimus.

PROPOSITIO PRIMA.

Si Remiges nauigium mouere po&longs;&longs;unt, maius &longs;emper &longs;pa­tium remi manubrium percurrit, quàm nauigium.

Sit enim remus A C, manubrium A, &longs;calmus B, qui propter nauigij motum &longs;patium percurrat à B, in D, in quo loco ip&longs;eremus A C, &longs;i­

tum rectitudinis habeat E F. Spatium itaque, quod A, conficit, curna linea &longs;it A E, cui recta linea re&longs;pondeat A Z, in re­ctam E F, perpendieularis. Nauigium verò idem &longs;patium conficiet, quod &longs;ealmus B: aio igitur ip&longs;am A Z, rectam lineam, recta B D, maiorem e&longs;&longs;e. &longs;ecet enim recta A C, rectam E F, in G: æquiangula &longs;unt igitur bina trian­gula A G Z, & B G D, quapropter &longs;icut A G, ad B G, &longs;ie A Z, ad B D, per. 4. 6. libri Eucli­dis: maior e&longs;t autem A G, ipfa B G, & maior igitur erit A Z, quam B D. & proinde maius &longs;patium remi manubrium percurrit, quam nauigium, quod demon&longs;trandum erat.

Quod &longs;i à puncto B, rectam lineam vtrinque ducamus H K, ad remi men&longs;uram, rectos facientem angulos cum B D, re­ctamque; A Z, &longs;ecantem in I, manife&longs;tè intelligemus ip&longs;am rectam A Z, con­&longs;tare ex A I, & I Z, quarum prior re&longs;pondet curuæ A H, quæ motu proprio manubrij de&longs;cripta e&longs;t; po&longs;terior verò æqualis e&longs;t rectæ B D, quæ motu na­uigij decur&longs;a e&longs;t.

PROPOSITIO SECVNDA.

Si remi manubrium motu proprio, & nauigium, æqualia &longs;patia pertran&longs;ierint, fieri non poterit, vt palmula mo­ueatur: &longs;ed veluti centrum immota manebit.

Esto iterum remus A C, manubrium A, &longs;calmus B: tantum autem &longs;pa­tium conficiat nauigium; quantum motu proprio A. Dico, quod C, remi palmula immota manebit. Nam &longs;i a loco &longs;uo dimota fuerit: &longs;patium igitur permeet C D, ad po&longs;teriora: quo quidem decur&longs;o, remus A C, po&longs;itionem rectitudmis habeat F D, &longs;calmus itaque B, tran&longs;latus erit in G. Excitetur autem à puncto B, in vtramque partem linea E B R, ad

rectos angulos &longs;uper B G, & à puncto A, recta A H, &longs;uper D F: itemque à puncto E, recta C E, &longs;uper E R; ip&longs;arum verò rectarum linearum E R, & A H, &longs;ectio &longs;it in K, &longs;ed C F., & D F, &longs;it in Z, & quo­niam A K, id &longs;patium e&longs;t, quod motu proprio re­mi manubrium permeauit, curuilineo enim re­&longs;pondeat A R, recta autem B G, id &longs;patium e&longs;t, quod nauigium confecit: ip&longs;æ igitur rectæ lineæ H K, & B G, æquales erunt. Atqui in duobus æqui­angulis triangulis E B C, & B A K, vel per 26. propo&longs;itionem primi Euclidis, vel 4. 6. æquales e&longs;&longs;e concludes A K, & E C, rectas lineas: quapro­pter æqualis erit E C, rectæ B G, per communem &longs;ententiam: eidem autem B G, æqualis e&longs;t E Z, in parallelogrammo, per 34. propo&longs;itionem ip­&longs;ius primi libri: æqualis igitur erit recta E Z, re­ctæ E C, pars toti, quod e&longs;t impo&longs;&longs;ibile. Et pro­pterea immota manebit palmula C, quod erat à nobis o&longs;tendendum.

PROPOSITIO TERTIA.

Si remi manubrium motu proprio duplum confecerit &longs;pa­tium, quàm nauigium, tantum prouehetur ea remiga­tione nauigium, quantum palmula retroce&longs;&longs;erit.

Remus enim incipiente motu po&longs;itionem habeat A C, de&longs;inente verò rectitudinis &longs;itum F G. &longs;calmus igitur B, propter nauigij motum, &longs;patium con&longs;iciet B D. Excitetur à puncto B, in vtramque partem perpendicularis E Z, in quam veniant a punctis A, & C, ad rectos angulos rectæ lineæ A E, & C Z: &longs;patium autem A E, à manubrio

decur&longs;um motu proprio &longs;patij B D, duplum &longs;it: recta verò linea C H, curuæ re&longs;pondeat C G, quæ à remi palmula de&longs;cripta e&longs;t. Di­co ip&longs;as rectas lineas B D, & C H, æquales e&longs;&longs;e. Nam in duobus triangulis B A E, & C B Z, duæ rectæ lineæ A E, & C Z, æqua­les &longs;unt. In parallelogrammo autem B H, duæ B D, & H Z, æquales, atqui recta A E, dupla e&longs;t rectæ B D, per hypothe&longs;im; dupla e&longs;t igitur, & C Z, rectæ H Z, quapropter C H, & H Z, æquales erunt, Duæ igitur C H, & B D, æquales per communem &longs;en­tentiam.

Et quia nauigium tantum &longs;patium de­currit &longs;emper, quantum &longs;calmus: &longs;i igitur remi manubrium motu proprio duplum confecerit &longs;patium, quàm nauigium, tan­tum prouehetur nauigium, quantum pal­mula retroce&longs;&longs;erit, quod demon&longs;trandum erat.

PROPOSITIO QVARTA.

Si nauigium minus &longs;patium decurrat, quàm remi manu­brium, &longs;ed &longs;upra dimidium, magis prouehetur, quàm pal­mula retrocedat; &longs;i verò citra dimidium, minus.

In de&longs;cripta enim figura ponatur B D, minor quam A E, &longs;ed eius dimi­dio maior. Dico, quod ip&longs;a B D, maior e&longs;t quàm C H. Nam B D, & H Z, æquales &longs;unt: Ad hæc A E, & C Z, æquales &longs;unt rectæ lineæ; ma­ior igitur erit H Z, dimidio ip&longs;ius A E: quapropter reliqua C H, mi­nor dimidio erit eiu&longs;dem A E, & minor igitur erit C H, quàm B D. Spa­tium autem B D, id e&longs;t, quod nauigium conficit, &longs;patium verò C H, remi palmula in contrarium decurrit; idcircò prior pars Theorematis vera e&longs;t. Po&longs;terior autem &longs;imiliter o&longs;tendetur. &longs;i enim B D, minor e&longs;t dimidio ip&longs;ius A E: minor igitur erit, & H Z, dimidio eiu&longs;dem A E; & quoniam A E, & C Z, æquales &longs;unt: reliqua igitur C H, dimidio eiu&longs;dem A E, maior erit: & proinde minor erit B D, quàm C H. Nauigium igitur minus &longs;patium de­curret in anteriora, quam remi palmula in contrarium, quod demon&longs;tran­dum &longs;u&longs;cepimus.

Corollarium.

Ex hac, & præcedenti infertur, quod &longs;i remi manubrium motu proprio maius &longs;patium decurrat, quàm nauigium, &longs;iue id &longs;it duplum, &longs;iue mi­nus duplo, &longs;iue maius duplo, &longs;patium, quod nauigium interim decurrit ad anteriora, & quod palmula remi in contrarium &longs;imul iuncta, ei quod ip&longs;um remi manubrium motu proprio conficit, æqualia erunt. &longs;emper enim B D, æqualis e&longs;t H Z: tota verò C Z, quæ æqualis e&longs;t A E, ex &longs;uis partibus C H, & H Z, con&longs;tabit.

Propo&longs;itionis conuer&longs;io.

Si nauigium longius progrediatur, quàm remi palmula re­trocedat, &longs;patium conficiet plu&longs;quam dimidium eius, quod motu proprio remi manubrium decurrit: &longs;i minus, citra dimidium.

Huius demonctratio ex &longs;upradictis facilè colligi poterit.

PROPOSITIO QVINTA.

Si celerius feratur nauigium, quàm remi manubrium, mo­uebitur palmula in vlteriora, nilque; vnquam retroce­det, idque; &longs;patium decurret, quo nauigij motus motum manubrij &longs;uperat.

Habeat enim remus incipiente motu po&longs;itionem A C: de&longs;inente

verò &longs;itum rectitudinis F G. &longs;cal­mus igitur B, propter nauigij motum tran&longs;latus, erit in D, &longs;it itaque &longs;patium B D, maius quàm A H, à re­mi manubrio motu proprio decur&longs;um: &longs;ic enim celerius dicetur ferri nauigium, quàm manubrium. Dico, quòd palmula C, in vlteriora mouebitur. Nam cum &longs;calmus B, prouectus fuerit in D: tran&longs;lata erit ip­fa palmula C, vbi G, in rectitudinis &longs;itu, &longs;patiumque; conficiet C G, curuilineum, cui re&longs;pondet C K: mouebitur igitur palmula in vlteriora. Nihil autem vnquam retro­cedere, o&longs;tendetur in hunc modum. eadem enim celeritate mouentur A, in H, & C, ver&longs;us I, circa &longs;calmum. Atqui per hypo­the&longs;im celerius fertur nauigium, quam A. in H, celerius igitur ip&longs;um nauigium fer­tur, quàm C, ver&longs;us I. &longs;ed mouetur idem C. ip&longs;a nauigij celeritate ver&longs;us K; celerius igitur ferretur C, ad K, quam ad I, quapropter nihil vnquam retrocedet ip&longs;um C, imò verò in vlteriora progredietur, &longs;patiumque; decurret C K, quod quidem relinquitur detracto I C, ex I K. &longs;i enim remi palmula tota ip&longs;a nauigij celeritate moueretur, vl­tra K, progrederetur, cum B, perueniret ad D: &longs;ed retrahitur interim, pro­pter eum motum, qui fit circa B. Sic igitur palmulæ celeritate, quæ à mo­tu nauigij prouenit retardata, decur&longs;um &longs;patium erit C K. Videtur autem &longs;olo remorum impul&longs;u hoc fieri non po&longs;&longs;e, &longs;ed alia in&longs;uper virtute impel­lente opus e&longs;&longs;e, vt venti, vel aquæ.

Ex his Theorematis liquet, inquit Nonius, quàm incerta interroget Ari­&longs;toteles, & quàm in&longs;citè re&longs;pondeat. Nam non continuò &longs;i nauigium in an­teriora mouetur, remi palmula retroceder; neque etiam &longs;i retrocedat, mi­nus &longs;patìum tran&longs;mittit in contrarium, quàm nauigium progrediatur. De­mon&longs;trant hoc &longs;ecunda, & tertia propo&longs;itio. Remi verò manubrium motu proprio, qui circa &longs;calmum fit, & vnà cum nauigij motu maius &longs;patium con­ficit quàm nauigium. &longs;olo autem proprio motu, &longs;i contingat tantum &longs;pa­tium conficere, quantum nauigium, fieri non poterit, vt palmula mouea­tur. fru&longs;tra igitur conatur in vniuer&longs;um demon&longs;tr are remi manubrium ma­ius &longs;patium decurrere, quàm palmulam in contrarium. Præterea quando nauigium longius progreditur, quàm remi palmula regrediatur, minus &longs;pa­tium decurrit, quam manubrium: igitur hon æquale. Et proinde con&longs;tat neque veritatem in propo&longs;ito, neque demon&longs;trationem in ijs, quæ conge­rit, reperiri.

Hucu&longs;que Petrus Nonius:

Reliqua huius textus vtinam quemadmodum &longs;unt clara, ita etiam vera e&longs;&longs;ent: &longs;ed quia quæ modo dixit de remo, eadem temoni applicat propte­rea ij&longs;dem etiam obnoxia &longs;unt difficultatibus.

QVÆSTIO SEXTA

De Antenna.

248

Qværit cur quanto Antenna &longs;ublimior fuerit, ij&longs;dem velis, & vento eodem celerius ferantur nauigia. Re&longs;pondet inde id prouenire, quia malus, &longs;iue arbor nauis in huiu&longs;modi ventorum impul&longs;u ve­ctis euadit, cuius auxilio idem ventus, qui mouens e&longs;t, maiorem vim acquirit, quanto longior fuerit pars vectis, quæ inter hypomoclion, & vim mouentem intercipitur: quando autem altior fuerit antenna, tunc ea vectis pars longior euadit, & propterea accidit, vt vires ventorum augean­tur. &longs;ed i&longs;ta melius in figura in&longs;piciamus. &longs;it nauis A B, cuius arbor C D E, antenna F C G, velum F G H, vectis e&longs;t arbor, cuius fultura e&longs;t in E, extre­mo mali in fundo nauis, onus autem in D, vbi malus exit è carina. mouens potentia e&longs;t ventus, qui mouet in antenna F C G. quanto igitur &longs;ublimior e&longs;t antenna, tanto longior euadit vectis E C, tantoque; maiores fiunt venti vires. dixi autem onus e&longs;&longs;e in D, quia &longs;i nauis vento ob&longs;i&longs;teret, ip&longs;a inuerte­retur hac ratione, vt puppis A, eleuata, prora B, demergeretur, manente

veluti centro parte E. quia ve­rò ob maris liquiditatem na­uis minimè obfi&longs;tit, &longs;ed facilè cedens à ventis vrgetur, hinc fit, vt meritò dixerim pondus nauis e&longs;&longs;e ad D, fulcimentum verò ad E.

Quæ&longs;tio &longs;eptima, & &longs;atis pec &longs;e clara e&longs;t; neque Mathemati­ci e&longs;t eam exponere.

QVÆSTIO OCTAVA

De Rota.

Cur ex figurarum genere quæcun que rotundæ &longs;unt, & cir­culares facilius mouentur?

249

Tribus autem modis circulum rotari contingit; aut enim &longs;ecun­dum ap&longs;idem, &longs;iue curuaturam centro &longs;imul moto, quemadmo­dum plau&longs;trorum rotæ vertuntur: aut circa manentem axem, tanquam centrum veluti rotulæ illæ, ex quibus trochlea compo­nitur; vel quibus ad puteos vtimur, quæ quidem rectæ ad horizontem &longs;o­lent con&longs;titui. aut quem ad modum rota figuli, quæ pariter circa manens cen­trum gyratur, &longs;ed qua&longs;i pro&longs;trata horizonti æquidi&longs;tans collocata e&longs;t. Quæ igitur primo modo mouentur, fortè facilius quam figuræ rectilineæ, vt &longs;unt triangulares, quadratæ, pentagonæ, &c. mouentur, quia circulares figuræ parua &longs;ui parte, & qua&longs;i in puncto planum, &longs;eu pauimentum contingunt, vn­de fit, vt neque offen&longs;ent, neque impingant; cuius cau&longs;a e&longs;t, quia à terra &longs;emo­tus e&longs;t angulus, ide&longs;t tali angulo planum contingunt, vt ab eo &longs;tatim rotæ curuatura à terra eleuari incipiat, & propterea parum terræ hæreat: in fi­guris verò rectilineis, in quadrata. v. g. &longs;ecus accidit, quia ab angulo ad an­gulum linea recta tenditur, vnde in ip&longs;ius volutatione po&longs;t contactum vnius anguli tota recta linea &longs;equens, plano adaptabitur, & non &longs;emouebitur &longs;ta­tim in altum, & ideò multum offen&longs;abit, & impinget, tardeque; idcircò mo­uebitur. Præterea circulares etiam, &longs;i cui obulam fiunt corpori, illud &longs;imi­liter &longs;ecundum pu&longs;illum tan gunt: rectilineæ verò figuræ, rectitudine &longs;ua plani multum contingerent. Ad hæc motor mouens huiu&longs;inodi rotas, eas mouet, quò nutant: nam quando rota erecta e&longs;t &longs;uper pauimentum, dia­meter ip&longs;ius, quæ à contactu pauimenti ad angulos rectos, ad &longs;upremum rotæ perducitur totum rotæ pondus in duas æquas partes diuidit, ita vt ta­le pondus in æquilibrio con&longs;tituatur, cum ex vna parte tantum &longs;it, quantum ex altera; ex quo fit, vt vel exigua vis ip&longs;am impellere valeat: quando enim duo æqualia pondera &longs;unt in æquilibrio, quelibet vis pote&longs;t ea ab æquilibrio dimouere. quando po&longs;tea rota e&longs;t in motu, vel cum primum ei motus fuerit à motore inditus, &longs;emper nutat ad partes illas, ad quas primum fuit incita­ta per impre&longs;&longs;am motionem, quapropter nullo negotio ad ea&longs;dem partes, &longs;eu antror&longs;um mouetur; quò enim vnumquodque vergit, illuc facillimè fer­tur: quemadmodum è contrario difficillimum e&longs;t in contrariam nutus &longs;ui partem vnumquodque pellere. Huc etiam pertinet, quod nonnulli dicunt, circuli nimirum periphæriam perenni ver&longs;ari motu, atque hinc facilius mo­ueri. &longs;icuti etiam dicunt, quod manentia propterea manent, quia contrani­tuntur, & ob&longs;i&longs;tunt mouenti: quod fortè dicebant propter maximam circu­li ad motum aptitudinem. & quia &longs;icut diameter ad diametrum, ita maio­ris circuli periphæria ad minoris periphæriam (vt po&longs;tea o&longs;tendam) & quia quo longior diameter e&longs;t, eò facilius, vt initio probaui, mouetur, fit vt etiam periphæria maioris facilius, quàm minoris moueatur, &longs;iue dixeris, quod an­gulus maioris circuli ad angulum minoris nutum quendam habet; & quia facilius mouetur angulus maioris, quàm minoris, fit, vt maior rota adhi­beatur ad minorem mouendam: & quia intra maiorem infinitæ circa idem centrum concipi po&longs;&longs;unt, hinc fit, vt rotæ maiores facilius moueantur, & motæ moueant cæteras intra &longs;e contentas. quod dictum e&longs;t de nutu anguli maioris circuli ad angulum minoris ex appo&longs;ita figura facilè patebit, vbi

pro minore angulo intelligendus e&longs;t arcus C B, pro maiore autem arcus D E, quorum vterque vo­catur angulus, quoniam angulo A, qui e&longs;t in cen­tro opponuntur. Atque hæc &longs;ufficiant deijs, quæ primo modo moueutur.

Nunc ad ea, quæ reliquis duobus modis cieri &longs;olent, quæ &longs;cilicet non mouentur &longs;ecundum ap&longs;i­dem, &longs;ed aut iuxta planitiem, ide&longs;t, quæ æquidi­&longs;tanter pauimento collo cantur, vt rotæ figulorum, aut quæ in loco à terra eleuato, vt troclearum or­biculi. rotæ hæ facilius ip&longs;æ, & ea etiam, quæ ip&longs;is annectuntur commouen­tur, quam &longs;i rectilinea figura con&longs;tarent; non quia parua &longs;ui portione vel tangant planum, vel offen&longs;ent, &longs;ed ob aliam inclinationem, de qua initio huius operis ante quæ&longs;tiones dictum e&longs;t, vbi diximus circulum duas incli­nationes ad motum obtinere, &longs;ecundum quas à motore mouetur; vna e&longs;t, quam diximus naturalem, qua &longs;olet cieri &longs;ecundum periphæriam, motor enim &longs;emper mouet circulum in periphæria, & &longs;ecundum hanc inclinatio­nem extremum diametri rectà, non circulariter moueretur: hanc inclina­tionem fortè habet à materia grauitante, & in ip&longs;o circulo con&longs;tituta in æquilibrio: quæ autem in æquilibrio, facillimè cedunt; & qui talia mouent, qua&longs;i prius mota mouent, & ideò facillimè. Secundum igitur inclinatio­nem hanc, quæ in obliquum e&longs;t, ide&longs;t, quæ &longs;ecundum circunferentiam &longs;it, ip&longs;am rotam mouens facillimè mouet. altera latio e&longs;t, &longs;ecundum quam cir­culus à &longs;eip&longs;o &longs;ecundum diametrum mouetur, ide&longs;t circa &longs;uum centrum re­trahit continuò extrema diametri; ne recta &longs;ecundum naturalem lationem ferantur, &longs;ed in orbem circulariter circa centrum gyrentur. hæc Ari&longs;t. Re­&longs;tat vt &longs;atisfaciam promi&longs;&longs;is.

Dictum e&longs;t ab Ari&longs;t. in textu (Sicut diameter ad diametrum, ita maior circu­lus ad maiorem) quæ verba intelligenda e&longs;&longs;e non de circulis, &longs;ed de periphæ­rijs, vti expo&longs;ui, manife&longs;tum e&longs;t ex 11. propo&longs;it. 5. Pappi Alexandrini, quæ talis e&longs;t: Circulorum circunferentiæ inter &longs;e &longs;unt vt diametri. quam etiam Pater Clauius demon&longs;trat propo&longs;. 2. lib. 8. & propo&longs;. 1. lib. 4. Geom. pract. &longs;i autem de ip&longs;is circulis intelligerentur fal&longs;a e&longs;&longs;ent, non enim e&longs;t circulus ad circulum, vt diameter ad diametrum; &longs;ed circuli &longs;unt inter &longs;e, quemad­modum à diametris ip&longs;orum quadrata per &longs;ecundam 12. Elem. quadrata autem &longs;unt inter &longs;e in duplicata ratione laterum per 20. 6. eiusque corolla­rium; hoc e&longs;t &longs;i fiat, vt latus maioris quadrati ad latus minoris, ita latus mi­noris ad aliam tertiam lineam, erit quadratum maius ad minus, vt latus ip&longs;ius ad tertiam illam lineam; non autem vt ad latus minoris. cum ergo circulus &longs;it ad circulum, vt quadratum diametri ad quadratum diametri, & quadrata non habeant rationem laterum, &longs;eu diametrorum prædictorum, &longs;ed illorum duplicatam, neque circuli inuicem illam habere poterunt.

Illud demum non ignorandum, quod Guidus Vbaldus propo&longs;it. 1. de Tro­chlea, demon&longs;trat, quod nimirum potentia &longs;u&longs;tinens pondus per rotulam, cui funis &longs;upernæ fuerit circumductus, qualis ea e&longs;t, qua ad hauriendam ex puteis aquam vtimur, talis inquam potentia e&longs;t æqualis ponderi; cuius ra­tio e&longs;t, quia tunc trochlea fit vectis, cuius fulcimentum e&longs;t in medio vectis, pondus verò, & potentia in extremitatibus &longs;unt, & æquidi&longs;tant ab hypomo­clio, & propterea cum &longs;it eadem proportio ponderis ad potentiam, quæ di­&longs;tantiæ ad di&longs;tantiam, vt &longs;upra qu&ecedil;&longs;t. 3. probatum e&longs;t ex Archimede, & Gui­do Vbaldo, di&longs;tantiæ autem &longs;int æquales, ernt etiam pondus, & potentia æqualia, ide&longs;t, &longs;i pondus e&longs;&longs;et vnius libræ, &longs;u&longs;tineretur à tanta vi, quanta opus e&longs;t ad libram vnam &longs;u&longs;tinendam, & non amplius. vt autem clarè appareat vectis in trochlea, & hypomoclion, & æquales di&longs;tantiæ, &longs;it figura, in qua

pondus D, ductario funi D C B E, alligatum. poten­tia &longs;u&longs;tinens E. axis autem erit diameter rotulæ B A C, nam potentia premit rotulam in B, & pondus in C, & cum rotula &longs;u&longs;tineatur in A, à &longs;u&longs;pen&longs;orio F A. erit punctum A, hypomoclion, quia in motu vectis eua­dit centrum, e&longs;tque; punctum manens. æquales autem di&longs;tantiæ vtrinque ab hypomoclio &longs;unt B A, A C, &longs;unt enim ex centro eodem. ex quibus manife&longs;tum e&longs;t hu­iu&longs;modi rotulam nullam vim mouenti addere, &longs;ed &longs;o­lum illud præ&longs;tat, vt omne tollat impedimentum, quemadmodum ait Ari&longs;t. manife&longs;tum etiam e&longs;t ma­iorem vim quamlibet, quam &longs;it ea, quæ &longs;u&longs;tinet, po&longs;&longs;e idem pondus &longs;ur&longs;um mouere. hæc & præ&longs;enti loco, & &longs;equentibus lucem afferre po&longs;&longs;unt.

QVÆSTIO NONA

De Trochleis, & Scytalis.

250

Cvr ea, quæ per maiores circulos tollantur, & trahuntur facilius, & ci­tius mouentur? veluti per maiores trochleas, quàm per minores, & &longs;cy­talas &longs;imiliter? An quanto maior fuerit illa, quæ à centro e&longs;t, in æquali temporis &longs;patio maius &longs;patium conficit? quamobrem æqualì inexi&longs;tente onere, idem faciet, &longs;icuti diximus maiores libras minoribus exactiores e&longs;&longs;e; &longs;par­tum enim in illis centrum e&longs;t: partes verò libræ vtrinque à &longs;parto &longs;unt veluti lineæ ex centro) Cum textus huius quæ&longs;tionis fatis clarus &longs;it, præ&longs;ertim &longs;i prius legantur, quæ dicta &longs;unt de libra in prima quæ&longs;t. & quæ de rota, & trochlea in proxima præcedenti, à paraphra&longs;i ip&longs;ius &longs;uper&longs;edebo. Illud tamen, quod magis nece&longs;&longs;arium e&longs;t, non omittam, vt &longs;cilicet difficultatibus quibu&longs;dam occurram. Et primo, quod Ari&longs;t. ait, ea quæ per maiores circulos veluti trochleas, &longs;eu rotulas trahuntur, facilius trahi, quàm ea, quæ per minores, non videtur ex omni parte verom. nam &longs;icuti in præcedenti qnæ&longs;tione o&longs;ten­&longs;um e&longs;t ex Guido Vbaldo, trochlea &longs;implex, &longs;iue rotula illa &longs;triata, cui funis &longs;upernè inditur, vt in &longs;uperiori figura; nullas addit vires potentiæ, quia re­ducitur ad vectem, cuius fultura &longs;it in medio ip&longs;ius. &longs;iue igitur rotula illa magna fuerit, &longs;iue parua, &longs;emper in talem vectem re&longs;oluetur, & propterea, vt etiam experientia con&longs;tat eodem labore aquam hauriunt, &longs;iue rotula illa magna fuerit, &longs;ine parua. nec minus vera videtur re&longs;pon&longs;io, cum ait (An quia quanto maior fuerit illa, quæ à centro e&longs;t, in æquali tempore maius mouetur (patium)quæ quidem vera &longs;unt, &longs;i intelligantur hoc modo, nimirum, quod quando plures circul&longs;concentrici, atque inuicem connexi fuerint, ita vt vans &longs;ine alijs moueri nequeat, tunc quanto maior fuerit diameter, & con&longs;equenter cir­cunferentia, tanto velocius mouebitur. &longs;i autem intelligantur de duobus circulis ab inuicem &longs;eparatis, quorum vnus ab&longs;que altero moueri pote&longs;t, vt &longs;ie quando vtimur modo rotula magna, modo parua ad aquam hauriendam non videntur vera, in quo &longs;en&longs;u manife&longs;tè loquitur Ari&longs;t. Quapropter vt &longs;in­cerè loquar, nunc ne&longs;cio, qua ratione Ari&longs;t ab errore excu&longs;are valeam, alijs fortè occurret.

Secundo loco videndum quid &longs;int &longs;cyntalæ. Vt autem con&longs;tat ex &longs;equenti quæ&longs;tione 11. &longs;cyntala erat in&longs;trumentum quoddam vectorium, quod ro­tas, &longs;icut currus, aliter tamen factas, habebat, porrò sxutalh\, ide&longs;t &longs;cytala inter alia &longs;ignificat baculum, &longs;iue hgnum oblongum, ac teres, qualia ea &longs;unt, quibus vtimur in &longs;ucculis, vulgò Na&longs;pe; & in axe in peritrochio, vt videre e&longs;t apud Guidum Vbaldum. hinc factum e&longs;t, vt apud Lacædemonios &longs;cytala &longs;ignificaret quoddam genus epi&longs;tolæ, quam &longs;cytalem laconicam dicebant, quia in charta in&longs;tar zonæ oblonga, & circa &longs;cytalam, hoc e&longs;t circa bacillum quendam &longs;piratim circumuoluta exarabatur; ita vt yer&longs;us &longs;cripturæ &longs;ecun­dum &longs;urculi longitudinem ducerentur, ex quo &longs;iebat, vt per iuncturas mem­branæ, literæ, ac verba procederent, membranam hanc ex &longs;cytala reuolu­tam, & aliter complicatam Imperatori mittebant, re&longs;olutio autem mem­branæ literas truncas, atque mutilas reddebat; cum partim continerentur citra iuncturas, partim vltra: eæquè partes, quæ &longs;imul fuerant &longs;criptæ, & continuatæ, po&longs;t re&longs;olutionem erant ab innicem valde di&longs;&longs;itæ. quapropter Imperator commenti totius con&longs;cius, eandem membranam &longs;cytali alteri priori omninò &longs;imili, æqualique; eodem modo, quo prius circumponebat, &longs;icque; iuncturæ priores redibant, quæ literas, ac verba mutila, & imperfecta in integrum re&longs;tituebant, vt facilè legi po&longs;&longs;ent. hoc illi vtebantur &longs;ecreto, cum literas ad Imperatores &longs;uos mi&longs;&longs;as, ho&longs;tibus occultas e&longs;&longs;e volebant.

Ex quibus conijcere licet &longs;cytalam fui&longs;&longs;e lignum oblongum, & teres, &longs;iue vt Geometræ dicunt, Cylindrum; in cuius tamen extremitatibus e&longs;&longs;ent margines duo aliquantulum prominentes, ceu binæ rotæ, cum ip&longs;o tamen continuæ, & connexæ, vt cum ip&longs;o &longs;imul conuoluerentur; non tamen tan­

quam circa axem. cuius hanc accipe fi­guram. Quærit igitur Ari&longs;t. cur huiu&longs;­modi &longs;cytalæ facilius moueantur, quo maiores ip&longs;arum &longs;unt rotæ. Cui quæ­&longs;tioni &longs;imul, ij&longs;demque verbis, quibus quæ&longs;tioni de maioribus rotulis re&longs;pondet, &longs;ed non &longs;atisfacit ob eandem ra­tionem, quam ibi attuli. Crediderim tamen maiores &longs;cytalas, & maiores curruum rotas, & alia id generis, quæ volutantur, ita vt motu progre&longs;&longs;iuo mutent locum, facilius moueri, &longs;ed ob aliam cau&longs;am, quia nimirum maio­res rotæ minus &longs;i quid obuiam fiat, offen&longs;ant, quia &longs;ua magnitudine quem­libet obicem facilè &longs;uperare po&longs;&longs;unt; cuius cau&longs;a e&longs;t angulus acuti&longs;&longs;imuns, quem cum terra facit; at verò exiguæ rotæ, &longs;i cui maiori ob&longs;taculo obuia­rint, ip&longs;um nequeunt &longs;uperare, aut &longs;upera&longs;cendere, quia angulum cum ter­ra faciunt in&longs;to maiorem, vnde facilè ip&longs;orum cur&longs;us inhibetur, ip&longs;æque; pro­pterea præ maioribus tardiores euadunt. Atque hæc in hanc quæ&longs;tionem dicta &longs;ufficiant.

QVÆSTIO DECIMA

De libra vacua, & alijs &longs;imilibus.

251

Cvr libræ, quæ omni incumbente pondere &longs;unt vacuæ ab impo&longs;ito pondere facilius mouentur, quàm &longs;i quopiam inexi&longs;tente pondere aliud rur&longs;us onus &longs;uperaddatur. &longs;imiliter etiam rota, & huiu&longs;modi quippiam, quod grauius quidem e&longs;t, difficilius commouetur quàm læue, v. g. rota ferrea difficilius, quàm lignea. &longs;imiliter quæ maiora &longs;unt, etiam &longs;i ex eadem materia con&longs;tent difficilius mouentur quàm minora, vt rota maior ferrea, quàm minor etiam ferrea. Habet hæc quæ&longs;tio tres par­tes, quibus Ari&longs;t. re&longs;pondet dicens, quod graue e&longs;t ægrè moneri non &longs;olum contra nutum &longs;uum, idc&longs;t &longs;ur&longs;um, &longs;ed etiam in obliquum, &longs;eu ad latera, quia grauia deor&longs;um nutant, non &longs;ur&longs;um, nec in tran&longs;uer&longs;um: ideo libræ cum one­re, quia &longs;unt grauiores, & rota ferrea quàm lignea, & ferrea ctiam maior, quàm minor grauior e&longs;t, ideò difficilius agitatur.

Contra quam re&longs;pon&longs;ionem &longs;ic fortè obijcies; in præcedenti enim quæ­&longs;tione dictum e&longs;t ab Ari&longs;t. maiores trochleas, & &longs;cytalas, minoribus facilius commoueri, hic autem dicit maiorem rotam difficilius quàm minorem mo­ueri. Hanc obiectionem Piccolomineus di&longs;&longs;imula&longs;&longs;e videtur, cui ego, inge­nuè fateor, me &longs;atisfacere ne&longs;cire, vt enim in præcedenti annotaui, nulla mihi ratio Ari&longs;t. excu&longs;andi occurrit, alijs fortè occurret. In præ&longs;enti au­tem benè quidem re&longs;pondet, &longs;ed tamen intimam rei cau&longs;am non attingit.

Sciendum igitur e&longs;t id, quod Guidus Vbaldus in tractatu de libra pluri­bus demon&longs;trauit: quod &longs;i quoduis graue &longs;u&longs;pendatur pror&longs;us in centro gra­uitatis, ita vt in perfecto &longs;it æquilibrio, tunc &longs;iue magnum, &longs;iue paruum, &longs;iue graue, grauiu&longs;uè fuerit, à quauis exigua vi poterit ab æquilibrio dimo­ueri. cur ergo in libris, & rotis grauioribus, aut maioribus experientia con­trarium o&longs;tendit? ratio e&longs;t, quia hæc omnia communiter non collocantur, ita vt circa centrum &longs;uum, quod etiam centrum grauitatis e&longs;t, conuerti po&longs;&longs;int: verum aptantur circa axem, & quidem iu&longs;to maiorem, laxiu&longs;que circa ip&longs;um conuertuntur, vnde fit, vt ip&longs;a ob in&longs;itam grauitatem premant axem in &longs;uperiori parte, vnde quando ab aliquo gyrantur, non propriè gy­rant, &longs;ed in &longs;uperiori axis parte hærentes ip&longs;um atterunt; ex qua attritione fit, vt retardentur, idque; eò magis, quo graniora magis premunt; hærent, difficiliusque; propterea raptantur potius, quàm gyrentur.

Ex his, & textus, & ratio Ari&longs;totelis &longs;atis clara redduntur.

QVÆSTIO VNDECIMA

De Scytala, & Curru.

252

Cvr &longs;uper &longs;cytalas facilius portantur onera quàm &longs;uper currus, cum tamen currus magnas habeant rotas, &longs;cytalæ verò pu&longs;illas?

Quidnam &longs;cytala e&longs;&longs;et explicatum e&longs;t in 9. quæ&longs;t. Quo autem modo per &longs;cytalas onera portentur, &longs;ic, accipe: exi&longs;timo binas &longs;cy­talas inuicem æquidi&longs;tantes, & aliquantulum &longs;emotas inuicem &longs;ic di&longs;poni, vt efficiant in&longs;trumentum vectorium currus in&longs;tar, & fortè veteres vteban­tur his &longs;cytalis eo modo, quo nunc architectores vtuntur duobus illis lignis longis, ac rotundis, quæ vulgò dicuntur Ruccioli.

Re&longs;pondet igitur id accidere, quia rotæ &longs;cytalarum &longs;imul &longs;unt cum &longs;uo axe coinpactæ, ita vt &longs;imul cum ip&longs;o rotentur: rotæ autem curruum, quia &longs;eiunctæ &longs;unt ab earum axe, ita vt &longs;ine illius rotatione ip&longs;æ voluantur, fit vt illæ firmius incedant, nechuc, illucque; nutent, veluti rotæ plan&longs;tri: neque illæ ad ip&longs;um axem offen&longs;ent, quemadmodum i&longs;tæ. addit aliam rationem, quia currus nimia oneris grauitate premens rotas ip&longs;as ferè &longs;i&longs;tit, quod &longs;cytalis non accidit, cum rotæ ip&longs;arum vnum, & idem cum &longs;uo &longs;int axe. quæ ratio quantum valeat, ne&longs;cio, nam quamuis rotæ &longs;cytalarum non premantur ab axe, premitur tamen axis ip&longs;arum ab onere, à quo &longs;imiliter &longs;i&longs;ti debe­rent &longs;cytalæ.

Crediderim ego facilius portari magna onera per &longs;cytalas, propter ip&longs;a­rum firmitatem, currus enim ip&longs;orumque rotæ &longs;unt multò debiliores, neque maioribus oneribus &longs;ufficiunt. Concludit po&longs;tea quæ&longs;tionem dicens, quia igitur &longs;cytalæ ab ip&longs;o onere non ita premuntur quin moueri melius po&longs;&longs;int quàm currus, imò ab ip&longs;o onere iam commoto, ip&longs;æ quoque incitentur, & præterea à potentia per planum infernè, benè &longs;ub&longs;tratum, & complanatum trahantur, fit, vt qua&longs;i in duobus locis ip&longs;arum rotæ impellantur ab onere &longs;upra, & à potentia infra; &longs;icque facilius quam currus ingentia præ&longs;ertim onera vehunt.

De Funda.

QVÆSTIO DVODECIMA.

Non videtur declaratione indigere.

QVÆSTIO DECIMATERTIA

De Iugo, & Succula.

253

Declarandum prius quid &longs;it hoc loco iugum: e&longs;t igitur iugum li­gnum illud cylindricum, quod vulgò dicitur Subbio. quoum bi­na ponuntur in ea machina textoria, quam vulgò dicunt Telaio, qua&longs;i telarium, eo quod in ip&longs;a telæ texantur. alteri autem iugo conuoluitur &longs;tamen: alteri verò contexta iam tela &longs;ubinde cum opus e&longs;t cir­cumponitur: quæ duo textores faciunt ip&longs;a iuga conuertendo. quæ vt faci­lius conuertant, iugis vtrinque in&longs;erunt per bina foramina binos collopes. qui collopes &longs;unt duo ligna oblonga &longs;atis gracilia vnius vlnæ ferè in longi­tudinem; quibus appræhen&longs;is, motisque; iugum facilè ver&longs;atur. quanto autem collopes &longs;unt longiores, facilius iugum circumagitur. cuius cau&longs;a e&longs;t, quia collops ad vectem reducitur, cuius fultura e&longs;t circa medium iugi, pondus verò e&longs;t extima iugi &longs;uperficies è qua telæ, aut &longs;taminis pondus pendet: in altera verò extremitate collopis, quæ extra iugum multum prominet, e&longs;t potentia: ibi enim textoris manus premit, vel trahit. quando ergò longior e&longs;t collops, ea pars, quæ e&longs;t inter fulturam, & vim, augetur; altera non mu­tata; quia &longs;emper inter fulturam, &longs;eu centrum iugi, & vltimam iugi &longs;uper­ficiem continetur; quanto autem illa hanc &longs;uperar, tantum virium po­tentiæ addi.

Secundò, videndum quid &longs;it &longs;uccula: hanc vulgò Na&longs;pa appellant, ni fal­lor à verbo græco a)gaspa/w, oriunda, quod &longs;ur&longs;um extrahere &longs;ignificat. cum quo, & voce, & &longs;ignificatione conuenit; e&longs;t enim in&longs;trumentum, quo &longs;æpius architectores in extrahendis &longs;ur&longs;um ruderibus effo&longs;&longs;is vtuntur. e&longs;t autem compago quædam cylindrica non admodum longa, cuiex vna parte poti&longs;­&longs;imum prominent plures collopes non mobiles, vt in iugo, verum &longs;tabiles, ac cum ip&longs;a &longs;uccula compacti, quibus manu appræhen&longs;is &longs;uccula &longs;upra bi­nos polos ver&longs;atur, eique; interim ductarius funis circumuoluitur, &longs;ecumque &longs;ur&longs;um pondus educit. cuius imaginem qualcmcunque in&longs;pice. quærit igitur, cur quanto gracilius fucrit corpus &longs;ucculæ A B, tanto facilius vertitur. Ratio e&longs;t, quia collops, quemadmodum etiam iugum, reducitur ad vectem,

cuius hypomoclion e&longs;t in medio &longs;ucculæ, &longs;iue in axe ip&longs;ius &longs;ucculæ; potentia verò e&longs;t in &longs;ummitatibus collopum, vt in C, E, F, D, pon­dus verò e&longs;t vbi funis ductarius cum onere pendet è &longs;uccula in &longs;u­perficie nimirum, vt vbi L, quare pars vectis inter axim, & &longs;uperfi­ciem &longs;ucculæ eadem e&longs;t, quæ inter hypomoclium, & pondus. quanto igitur &longs;ucculæ corpus gracilius fuerit, tanto hæc pars minuetur; & con&longs;e­quenter altera inter hypomoclium, & potentiam productior euadet: eaque propter facilius à motore ver&longs;abitur.

De ligno ad genu fracto.

QVÆSTIO DECIMAQVARTA.

Satis per&longs;e clara videtur.

QVÆSTIO DECIMAQVINTA

De Vmbilicis.

254

Notandum primò, quæ Græcis *krexai, ide&longs;t Crocæ dicuntur, Latinis Vmbilicos appellari; de his enim loquitur Cic. 2. de Oratore, vbi &longs;ic, non audeo dicere de talibus viris, &longs;ed tamen ita narrare &longs;ole­bat Sceuola, conchas, eos, & vmbilicos ad Caietam, & ad Lucri­num legere con&longs;ueui&longs;&longs;e. hos autem vmbilicos exponunt Grammatici e&longs;&longs;e lapillos paruos, acrotundos, polito&longs;que, de quibus etiam Ari&longs;t. loquitur. Quare decipitur Piccolomineus dum negat, nos harum crocarum latinum nomen habere. Cæterùm, & quæ&longs;tio, & re&longs;pon&longs;io, ex &longs;uperioribus &longs;atis per&longs;picua e&longs;&longs;e videntur.

QVÆSTIO DECIM ASEXTA

De ligno oblongo.

255

Ex appo&longs;ita figura totus huius problematis textus, alioquin &longs;atis cla­rus patebit. &longs;int duo ligna oblonga, vnum altero longius, & cra&longs;&longs;ius. in eleuatione maioris, fulcimentum e&longs;t in B, vbi manus altera ferè manens appræhendit; in C, verò, vbi altera manus mouens premit e&longs;t potentia, &longs;iue maius onus. in A, verò onus ip&longs;ius ligni, deor&longs;um tendens premit, quod nunc e&longs;t in&longs;tar potentiæ motricis, quare A, & C, &longs;unt &longs;ibi in­uicem, & potentiæ, & pondera. In minori autem ligno, onus ligni in D,

fultura manus in E, potentia alterius ma­nus in F. iam inquir Ari&longs;t. maius lignum A B C, magis flectitur, quamuis cra&longs;&longs;ius &longs;it, quàm lignum D E F, quod e&longs;t tenuuius, &longs;ed multò breuius; quia in maiori onus ip&longs;ius ligni, quod circa A, deor&longs;um pre­mit longius di&longs;tat ab hypomoclio B, quàm in minori ligno. Ex quo &longs;equitur iuxta ip&longs;ius principia, vt onus A, facilius lignum mouere, aut inflectere po&longs;&longs;it.

Cæterùm exi&longs;timo, quod &longs;i maioris ligni longitudo ad eiu&longs;dem cra&longs;&longs;itiem haberet eandem proportionem, quàm minoris longitudo ad eiu&longs;­dem cra&longs;&longs;itiem, &longs;icque; vtrumque e&longs;&longs;et ab hypomoclio in eadem ratione diui­&longs;um, fore, vt vtrunque eodem modo inflecteretur, quia haberent pondera eandem rationem ad di&longs;tantias ab hypomoclio, oportet igitur vt &longs;int non analoga, &longs;ed aloga, vt eis præ&longs;ens problema Ari&longs;totelis vnà cum eiu&longs;dem &longs;olutione competat.

QVÆSTIO XVII.

De Cuneo.

256

Cvr paruo cuneo magna finduntur onera, & corporum moles, adeoque valida fit impre&longs;&longs;io? fortè, quia cuneus duobus vectibus &longs;ibi inui­cem oppo&longs;itis con&longs;tat; quorum vterque, & potentiam mouentem, & hypomoclion, & pondus habet. hypomoclion autem illud ip&longs;um e&longs;&longs;e ait, quod cuneo diuellitur; hoc autem dicit Ari&longs;tot. quia non agnouit alium, præter primi generis vectem, vt &longs;upra etiam dixi.

Verum &longs;atius e&longs;t cum Guido Vbaldo reducere cuneum ad duos &longs;ecundi generis vectes, quorum fultura &longs;it in cunei apice extremo, pondus verò in­tra vectem, ea nimirum pars ligni, que à cuneo vrgetur, ac diuellitur. cuneo præterea vires adduntur ex valida mallei percu&longs;&longs;ione; malleus autem ip&longs;e magna vi percutit, quia motus mouet, &longs;eu quia mouens malleum, mouet ip&longs;um etiam dum e&longs;t in ip&longs;a latione, vnde ip&longs;a lationis celeritate malleus fit valentior: hocque; modo paruos cunci vectes maiores con&longs;equuntur vires,

quàm ip&longs;a vectium magnitudo po&longs;tulet. &longs;it cuneus A B C. lignum autem &longs;cinden­dum D E F G, vectesque duo &longs;int A C, & B C, quorum commune hypomoclion e&longs;t in C, onus autem vectis B C, e&longs;t pars li­gni G, hæc enim ip&longs;i contranititur, atque ab eo expellitur. potentia verò mouens vectem e&longs;t in malleo, dum &longs;uperius latus cunei A B, percutit. alter huic auer&longs;us vectis e&longs;t latus A C, cuius fultura e&longs;t C, cadem cum priori, onus propul&longs;atum D, potentia cum altero communis e&longs;t in latere A B, à malleo validè percu&longs;&longs;o. cunei igitur virtus partim ex vectibus, partim ex percu&longs;&longs;ione con&longs;tat.

QVÆSTIO XVIII.

De Trochlea.

257

Hvius quæ&longs;tionis &longs;en&longs;us, ac verba optimè intelligentur ex &longs;equen­tibus. Trochlea, vt patet ex &longs;uperioribus Ari&longs;t. e&longs;t orbiculus in periphæria &longs;triatus, vna cum toto loculumento, cui in&longs;eritur: cuius imaginem ad 8. quæ&longs;t. exhibui. Apud Architectores verò trochlea con&longs;tat &longs;altem ex duobus prædictis loculamentis, in quibus &longs;unt orbiculi; & vnus orbiculus e&longs;t &longs;upernè collocatus, alter verò infernè, vt pa­tebit in &longs;equenti figuratione: quod in&longs;trumentum nunc vulgò dicitur Taglia, à nonnullis dicitur etiam Rechamo. Auxilio huius in&longs;trumenti machinato­res parua vi attollunt ingentia pondera. communiter autem con&longs;tat ex plu­

ribus orbiculis, qui partim &longs;uperiori loculamento, partim infetiori inditi &longs;unt, per quos orbiculos cer­ta lege circumductus e&longs;t ductarius funis, qui deinde in &longs;ui po&longs;trema parte à potentia tractus omnes illos orbiculos, per quos tran&longs;it circumuoluens inferius loculamentum, cui appen&longs;um e&longs;t pondus, vnà cum ponderc attollit. figuram &longs;implicis trochleæ, con­&longs;tantis &longs;cilicet ex duobus tantum orbiculis, facilita­tis cau&longs;a exhibebo, in hac enim melius apparebit, qua ratione trochlea ad vectem reducatur. vnde, & Ari&longs;t. &longs;en&longs;um, quamuis ob&longs;curi&longs;&longs;imum, ac proinde problematis &longs;olutionem optimè percipere licebit. Sit igitur orbiculus &longs;uperior A, qui in pegmate I K­L D, voluatur circa axem G, &longs;itque; pegma i&longs;tud &longs;upe­rius fixum, & immobile à clauo H, pendens. Infe­rior orbiculus B, in loculamento O P Q R, circa axem B, conuoluatur: &longs;itque funis ductarius circa hos orbiculos hoc modo circumductus. primo ca­put funis religetur clauo D, in &longs;uperiori pegmate infixo, hinc demi&longs;&longs;us &longs;ubtus inferiorem rotulam per ip&longs;ius &longs;triam de&longs;cendat per puncta L S, a&longs;cendatque po&longs;tea per M E N, ad &longs;uperiorem rotulam, &longs;upra quam a&longs;cendat per punctum T, de&longs;cendatque; ad V, & inde demittatur ad potentiam F. am &longs;i quepiam po­tentia in F, traxerit funem F V, deor&longs;um, interim partes T, N, E, M, &longs;ur&longs;um attrahentur, & locula­mentum inferius &longs;imul cum appen&longs;o pondere eleua­bitur, manente tamen interim fune prope D, vbi clauo D, e&longs;t religatus, & immobilis. &longs;ed vbinam hic vectis? con&longs;idera diametrum M L, inferioris orbiculi, hæc enim ea e&longs;t, quæ vectem gerit. huius enim extrema L M, à fune tanguntur, & ab eius medio B, onus pender, & grauitat; & quia funis in M, &longs;ur&longs;um trahitur, &longs;ecumque; ex parte illa &longs;ur&longs;um eieuat diametrum L M, erit potentia mouens, & eleuans in M. pondus verò intra vectem ad B, medium vectis; quare fulcimentum erit in reliquo extremo L, vbi funis &longs;u&longs;tinet loculamentum, & vbi diameter, &longs;eu vectis innititur. quare diameter hæc e&longs;t vectis &longs;ecundi generis expo&longs;iti. aduerte præterea vectem hunc e&longs;&longs;e mobilem, &longs;imul cum fulcimento, quia dum ex parte M, &longs;ur&longs;um tollitur &longs;imul cum toto orbiculo, ac loculamento, &longs;ub­&longs;equitur etiam alterum extremum L, quod fune fulcitur, & in ip&longs;o fune &longs;ur­&longs;um ver&longs;us D, a&longs;cendit; & hoc modo inferius tignum cum onere tandem ad­&longs;uperius tignum &longs;ublatum erit. hinc verum dixi&longs;&longs;e Ari&longs;t. con&longs;tat, trochleam &longs;cilicet idem e&longs;&longs;e, ac vectem. quod tamen de &longs;olo inferiori orbiculo intelli­gi debet, &longs;uperior enim rotula quamuis vectis fiat, non tamen vires vllas potentiæ tribuit, cum eius hypomoclion &longs;it in medio, quemadmodum &longs;upra ad 8. quæ&longs;t. expo&longs;ui. Inferior igitur ille e&longs;t, qui mouenti maximo e&longs;t adiu­mento. quod &longs;i &longs;cire aueas quantum iuuet, re&longs;pondeo ip&longs;um vires potentiæ duplicare; adeo vt &longs;i quatuor. v. g. homines erant nece&longs;&longs;arij ad pondus tol­lendum, auxilio huius &longs;implicis trochleæ duo tantum &longs;ufficiant. quod &longs;i ad­dantur duo alij orbiculi, vnus &longs;uperior, alter inferior, rur&longs;us vires duplica­buntur, eritque; vnus tantum homo nece&longs;&longs;arius. quod &longs;i plures aliæ rotulæ tam &longs;upernè, quàm infernè addantur, vt&longs;olet in maioribus trochleis, quas ve­teres Poly&longs;pa&longs;tos, ide&longs;t multum trahentes dixerunt, augebuntur vires in in­finitum. quod dixi de virium duplicatione con&longs;tat ex 6. & 7. propo&longs;itione Archimedis de Aequip. quia enim in vecte no&longs;tro L M, dupla e&longs;t proportio inter L M, & L B, eadem etiam proportio erit inter pondus, & potentiam, quare pondus C, duplum erit potentiæ in M, hoc e&longs;t à minore potentia &longs;ibi &longs;ubdupla &longs;u&longs;tinebitur: & à quauis adhuc quantumcunque maiore eleuabitur.

Qui plura de trochlea de&longs;iderat, adeat Guidi Vbaldi, Mechanica, cuius auxilio fateor me verum &longs;en&longs;um harum Mechanicarum Ari&longs;t. & præ&longs;ertim huius loci enuclea&longs;&longs;e. quæ &longs;i cum Piccolominei expo&longs;itione contuleris, vide­bis eum nequaquam cognoui&longs;&longs;e, vbi nam vectis in trochlea lateret, eumque tam &longs;uperiorem, quàm inferiorem rotulam æquè vectem facere; in quo etiam Io. Bapti&longs;ta Benedictus pariter erra&longs;&longs;e videtur in &longs;uis &longs;peculationibus, cum inferiores tantummodo vice vectium fungantur, vt probatum e&longs;t.

Atque ex his &longs;atis mihi videtur textus, ac &longs;en&longs;us Ari&longs;t. illu&longs;trari.

QVÆSTIO XVIIII.

De Securi.

258

Pattim ex &longs;e, partim ex dictis in 17. quæ&longs;t. &longs;atis clara e&longs;t. placet au­tem his, quæ de cuneo, & &longs;ecuri dicta &longs;unt, nonnulla ex Guido Vbal­do loco corollarij adijcere, videlicet. Ad huiu&longs;modi facultatis in­&longs;trumentum ca quoque omnia commodè referri po&longs;&longs;unt, quæ percu&longs;­&longs;ione, &longs;iue impul&longs;u incidunt, diuidunt, perforant, huiu&longs;modique; alia obeunt munera; vt en&longs;es, gladij, mucrones, &longs;ecures, terebræ, & &longs;imilia: &longs;erra quoque ad hoc reducitur, dentes enim percutiunt, cuneique; in&longs;tar exi&longs;tunt.

Additio de veteri Securi, & Bipenne.

Libet etiam huic tractationi de &longs;ecuri nonnulla addere, quæ olim oc­ca&longs;ione ex Proclo accepta in tenebris diu delite&longs;centia in lucem re­&longs;tituimus, &longs;unt autem hæc. Primò, antiquæ &longs;ecuris, necnon bipen­nis figuram re&longs;tituam. Secundò, o&longs;tendam angulum &longs;ecuris, qui curuilineus e&longs;t, æqualem e&longs;&longs;e angulo trianguli æquilateri, qui rectilineus e&longs;t. Proclus igitur in comm. 23. primi Euclidis, &longs;ic ait: o&longs;ten&longs;um fuit ab anti­quis, &longs;cilicet Geometris, quod angulus figuræ illius, quæ &longs;ecuri &longs;imilis e&longs;t, æqualis e&longs;t angulo rectilineo, quippe qui duabus tertijs anguli recti æqualis e&longs;t. hanc anguli &longs;ecuris affectionem, cum nec ille, nec alij, quod &longs;ciam de­mon&longs;trent, ego paulò po&longs;t demon&longs;trabo. deinde &longs;ubdit; fit autem huiu&longs;mo­di &longs;ecuralis figura, quæ pelecoides vocatur duobus circulis per centra &longs;e mutuò &longs;ecantibus. hæc Proclus. Ex his autem po&longs;tremis verbis de&longs;criptio­nem antiquæ &longs;ecuris, &longs;ic puto eruendam. Ducatur primo recta A C, quæ

erit in&longs;tar manubrij &longs;ecuris. de­inde ex centro C, interuallo. v. g. C B, de&longs;cribatur circulus B F; &longs;i­militer eodem interuallo B D, ex centro D, de&longs;cribatur circulus B E; tandem ex B, centro, atque eodem interuallo ducatur alius circulus D E F C, qui priores duos &longs;ecabit in punctis E F. con&longs;ideremus iam, reliquis circulorum partibus ommi&longs;&longs;is, curuilineam figuram B E F, quam e&longs;&longs;e veteris &longs;ecuris formam ex &longs;ententia Proclinon e&longs;t dubitandum, cum cir­cis &longs;e mutuò per centra &longs;ecantibus con&longs;tituatur, vt vult ip&longs;e, & præterea habeat angulos E F, tantos, quantos ip&longs;e tradit, vt mox patebit; linea au­tem A B C, &longs;ecuris manubrium refert.

Quod autem tam angulus E, quàm angulus F, &longs;int æquales duabus tertijs vnius angulirecti, &longs;iue quod idem e&longs;t angulo trianguli æquilateri, manife­ftum erithoc modo. De&longs;cribatur iterum &longs;ecuralis figura prædicto mode, itque ea A B C. ducantur præterea ad &longs;ingulos angulos tres rectæ A B, B C, C A, quæ con&longs;tituunt trianguium æquilaterum A B C, tria enim ip&longs;ius late­

ra &longs;ubtendunt tres arcus æquales A B, B C, C A, &longs;unt enim tres &longs;extantes æqualium circulorum, t facilè colligi pote&longs;t ex 15. 4. ex quo etiam &longs;e­quitur tres ilias circulorum portiones, quas re­ctè cum &longs;uis arcubus con&longs;tituunt e&longs;&longs;e inuicem æquales, & limiles portiones nimirum A B E, B C D, C A F. hinc pr&ecedil;terea &longs;equitur angulos ip­&longs;arum e&longs;&longs;e inuicem æquales, angulos, v.g. A B E, C B D, mixtos e&longs;&longs;e æquales, quod facilè e&longs;t per imaginatiam &longs;uperpo&longs;itio­nem demon&longs;trare. cum igitur prædicti duo anguli &longs;int æquales, &longs;itque intet eos medius alius angulus E B C, qui pariter mixtus e&longs;t, &longs;i ip&longs;e addatur tanl angulo C B D, quàm angulo A B E, inuicem æqualibus, erunt duo anguli A B C, rectilineus, & E B D, curuilineus æquales. ille autem e&longs;t angulus æquilateri, qui æqualis e&longs;t duabus tertijs vnius recti ex corollario 32. primi. hic verò e&longs;t angulus &longs;ecuris. e&longs;t igitur angulus &longs;ecuris æqualis duabus ter­tijs vnius recti, vt ait Proclus, quod demon&longs;trandum erat. quod etiam ma­nife &longs;tum &longs;ignum e&longs;t &longs;ecuris figuram a me re&longs;titutam e&longs;&longs;e illam veterem, de qua idem Proclus loquitur.

Re&longs;tat, vt de antiquæ bipennis etiam figura di&longs;&longs;eramus; quæ nihil aliud erat, quàm duplex &longs;ecuris, &longs;iue &longs;ecuris anceps, qualis e&longs;t præ&longs;ens figura, vt

propterea etiam &longs;æpius bipennis ip­&longs;a &longs;ecuris appelletur. dicitur enim bipennis, qua&longs;i binis pinnis, quæ &longs;e­cures erant, con&longs;tet, vt & Græcis dixteros dicebatur. te&longs;te etiam No­nio, illud bipenne e&longs;t, quod vtrinque acutum e&longs;t. collegi autem vtcunque hanc bipennis figuram ex Simmiæ peruetufti poetæ græci epigrammate, quod Simmiæ &longs;ecuris appellattur. quod epigramma carminibus loco linearum con&longs;tat, quæ in &longs;ecuris formam con­&longs;tituta &longs;unt.

Sciendum namque e&longs;t Simmiam, poeticam hanc &longs;ecurim concinna&longs;&longs;e in gratiam Epei illius, qui equum Troianum ligneum fuerat architectatus, vt e&longs;t apud Virg. Et ip&longs;e doli fabricator Epeus. qui cum &longs;oluendi voti cau&longs;a vellet &longs;ecurim, &longs;iue bipennem, qua in equi Durij molitione v&longs;us fuerat, Mi­neruæ Deæ, quod &longs;ibi in eo opere faciendo auxilio fui&longs;&longs;et, dedicare, eamque; vt Ari&longs;t. in libello de admirandis audit. num. 104. narrat, in templo græ­cæ Mineruæ quod erat in Gargaria Italiæ Regione propè Metapontum, &longs;u&longs;pendere, a præfato Simmia quæ&longs;iuit, vt epigrammate aliquo dedicatio­nem hanc &longs;uam complecteretur. qui vt illi morem gereret ingenio&longs;æ illius bipennis dedicationem, vt melius imitaretur, &longs;ecuri hac carminum com­plexus e&longs;t. quæ dedicatio, &longs;iue epigramma, quod adhuc extat, deinceps &longs;e­curis Simmiæ vocitata e&longs;t; ex qua figura bipennis illius, equi Durij fabrica­tricis nobis adhuc magna cum voluptate innotuit. Porrò gratum, atque ad ea, quæ diximus intelligenda vtile Lectori fore arbitrati &longs;umus, ip&longs;am Sim­miæ bipennem ex operibus Theocriti, quibus addi &longs;olet, huc referre; quam P. Ricardus E&longs;ius de no&longs;tra Societate linguæ græcæ periti&longs;&longs;imus, in hunc modum tran&longs;tulit. hoc autem ordine legenda e&longs;t: lectio à manubrio incipiat, deinde legatur carmen; forti&longs;&longs;imæ Deæ, quod &longs;ub&longs;e­quatur; dedit Epeus, & &longs;ic in orbem lectio, v&longs;que ad me­dium circumducatur. hæc &longs;unt, quæ præ&longs;ertim in gratiam eorum, qui &longs;uaui&longs;&longs;imo an­tiquitatis &longs;tudio tenentur, la­tere nolui.

Simmiæ Rhodij Bipennis.

QVÆSTIO XX.

De Statera.

259

Antequam ad textus explicationem accedamus, con&longs;ultius e&longs;&longs;e iu­dico veteris &longs;tateræ figuram, atque de&longs;criptionem præmittere, quàm ex hoc Ari&longs;t. loco, magna mihi licuit cum delectatione col­ligere: quod etiam antiquitatis &longs;tudio&longs;is pergratum fore non du­bito: atque hinc etiam ineptas, atque ad&longs;cititias textus huius figuras tanquam adulterinas reijcere; inque; earum locum veras re&longs;tituere licebit. erat igitur

&longs;tatera, quantum ex Ari&longs;t. conijcio primum ha&longs;ta oblonga, qualis e&longs;t in præ&longs;enti figura A B, ex cuius altero extremo B, pendebat appendicu­lum, quod propriè æquipondium dicitur: ex altera verò extremitate A, lanx vna pendebat; in qua carnes, aliæuè merces ponderabantur: in me­dia denique ha&longs;ta paribus interuallis plures trutinæ, ex quibus &longs;ingulis modo hac, modo illa, prout pondus emptoris po&longs;tulabat &longs;u&longs;pendebatur, atque in­terim tantum mercis lanci imponebatur, donec æquipondio præpondera­ret in æquilibrio. &longs;ingulæ autem trutinæ ad aliquod determinatum pondus trutinandum, erant con&longs;titutæ, v. g. vna ad &longs;ex libras, altera ad octo, &c. quam diui&longs;ionem, ac fabricam &longs;tateræ non e&longs;t difficilè exhibere, cum ex Ar­chimede propo&longs;. 6. & 7. de æquip. eadem &longs;it proportio inter pondus mer­cis, & pondus æquipondij, quæ e&longs;t permutatim inter di&longs;tantias vtrinque ab a&longs;&longs;umpta trutina, quæ in trutinando hypomoclij vicem gerit: nam &longs;tatera reducitur ad vectem; pondus erit æquipondium; & merces in lance erit po­tentia mouens: &longs;unt autem in tota &longs;tateræ ha&longs;ta trutinæ plures, hoc enim modo tota fit vniformis quoad pondus. æquipondium præterea debet ha­bere tantum pondus, quantum e&longs;t in nuda lance, vt &longs;ic tota &longs;tatera &longs;it per &longs;e &longs;ola æquilibrabilis: & præterea debet habere pondus &longs;tatum, a c legitimum, v. g. vnius libræ, aut duarum, aut trium, prout magis trutinandæ merci ido­neum erit, & hoc erit proprium æquipondij pondus. vt autem ex &longs;ingulis trutinis &longs;ingula pondera ponderentur. &longs;ingulis nota aliqua &longs;culpenda e&longs;t, vt facilè mercatores merces ponderent, quod hac ratione fieri pote&longs;t. pona­mus æquipondium e&longs;&longs;e 12. librarum. dico, quod trutina C, dabit in lance pondus mercis 12. librarum, &longs;i ex ea fiat æquilibrium, e&longs;t enim vt A C, ad C B, ita permutatim æquipondium 12. ad mercem; &longs;ed A C, ip&longs;i C B, e&longs;t æqualis, ergò etiam æquipondium 12. erit merci æquale, hoc e&longs;t vtrunque erit, 12. librarum.

Similiter &longs;i &longs;ieret a quilibrium ex trutina D, e&longs;&longs;et vt A D, 3. ad B D, 9. ita 12. ad 36. tandem trutina E, æquilibrante, e&longs;&longs;et vt A E, 9. ad E B, 3. ita 12. ad 4. Si igitur trutina C, notetur 12. numero, trutina D, num. 36. tru­tina E, num. 4. & idem de cæteris: &longs;tatim facilè erit quodlibet pondus per huiu&longs;modi &longs;tateram exhibere. Vnde videas contrario ab illis modo in no­&longs;tris &longs;tateris æquipondium totam ha&longs;tam percurrere; in illis verò manentè æquipondio trutinam quodammodo per ha&longs;tam moueri.

His præmi&longs;&longs;is ad textus paraphra&longs;im veniamus.

Cur &longs;tatera, qua carnes ponderantur, paruo appendiculo magna truti­nat onera, cum alioquin tota &longs;tatera nihil aliud &longs;it, quàm dimidiata libra, vbi enim onus mercis imponitur vna lanx pendet, quam vnicam &longs;tatera ha­bet; in altera autem parte, vbi libra habet alteram lancem, &longs;tatera nullam habet, &longs;ed &longs;ola &longs;ine lance e&longs;t. Cau&longs;a igitur e&longs;t, quia &longs;tatera &longs;imul, & libra e&longs;t, & vectis. libra e&longs;t, quia &longs;partorum, &longs;iue trutinarum quælibet fit veluti cen­trum libræ, inque; altera parte e&longs;t lanx; in altera verò loco lancis ip&longs;um æqui­pondium, quod libræ incumbit, fungiturque; vice alterius lancis, cui &longs;it onus impo&longs;itum; manife&longs;tum enim e&longs;t, quod æquipondium &longs;tateræ tantumdem trahit oneris, quantum e&longs;t illud, quod in altera lance e&longs;t. eapropter &longs;tatera quodammodo tot libras in &longs;e continet, quot trutinas: quarum vna quæque cum &longs;it intra appendiculum, & lancem, apta e&longs;t e&longs;&longs;e medium, &longs;eu centrum &longs;tateræ, atque adeo etiam libræ; quæ vnam quidem lancem habeat ex vna parte, ex altera verò pro lance æquipondium. &longs;tatera verò dicitur, quate­nus ex vna parte habet non lancem, &longs;ed perpendiculum. &longs;ed hoc nihil e&longs;t aliud quàm e&longs;&longs;e plures in vna libras; Cur autem &longs;parta, quæ lanci, &longs;iue ap­pen&longs;o oneri proximiora &longs;unt, maiora &longs;ubleuent onera, cau&longs;a e&longs;t vectis natu­ra, quæ &longs;tateræ ine&longs;t. e&longs;t enim &longs;tatera vectis, quamuis quodammodo inuer­fus, e&longs;t enim ip&longs;ius fulcimentum trutina ip&longs;a &longs;upernè collocata, pondus ve­rò leuandum e&longs;t ip&longs;a merx, potentia verò appendiculum. quantò autem pro­ductior fuerit pars vectis à fulcimento ad potentiam, tanto facilius poten­tia mouet, vt in præ&longs;entia accidit. mouet autem v&longs;que ad æquilibrium; hocque; modo pars illa productior &longs;tateræ, quæ vergit ad æquipondium, facit, vt onus &longs;tateræ impo&longs;itum facilè trutinetur.

QVÆSTIO XXI.

De Dentiforcipe.

260

Cvr Medici facilius dentes extrahunt dentiforcipis onere adiecto, quàm &longs;i &longs;ola manu vtantur? fortè, quia ex manu facilius dens ela­bitur propter &longs;ui ip&longs;ius lubricitatem, quàm ex forcipe. Vel etiam, quia digiti propter carnis mollitiem cedentem nequeunt dentem &longs;miter circumplecti; &longs;errum verò, cum vndique durum æque &longs;it, nec ce­dens, melius dentem comprçhendit. Aut tandem, quia forceps hæc duos in &longs;e continet contrarios vectes; quorum, vnum tantum e&longs;t hypomoclion,

corum &longs;cilicet connexio; Virtute igitur vectis arctius dentem per&longs;tringunt, atque adeò obtinent, atque hinc etiam facilius commouent. &longs;it dentiforcip is figura, ex­po&longs;ita, cuius alterum extremum, vbi &longs;unt A, B, e&longs;t illud, quod binis &longs;emicirculis concurrentibus dentem arctè con&longs;tringit, & commouet. Vectis vnus e&longs;t A G D, alter B G C, communis fultura e&longs;t G, vbi e&longs;t ip&longs;orum decu&longs;&longs;ata connexio; dens loco ponderis e&longs;t; vtroque igitur C, & D, tanquam manubrijs vectium dentem Medici compræhendentes ip­&longs;um facilè commouent: quando autem commotus fuerit, facilius manu, quàm in&longs;trumento extrahitur.

QVÆSTIO XXII.

De Instrumento Nucifrago.

261

Tempore Ari&longs;t. vt colligitur ex hac quæ&longs;tione, ad frangendas nu­ces peculiare in&longs;trumentum ligneum adhibeant, quod erat in&longs;tar forcipis, ita tamen concinnatum, vt non ad &longs;cindendum, nec ad extrahendum, &longs;ed ad frangendum per compre&longs;&longs;ionem e&longs;&longs;et aptum. cuius hanc qualemcum que figuram in&longs;pice. cuius latus inferius A D, fortè licui fulcimento in plano horizontis, fixum hærebat: alterum verò A C, manu tractabatur, vt &longs;ic expeditæ nucium plurima quantitas breui po&longs;&longs;et confringi. Credibile e&longs;t nucifragam hanc ad capita F E, habui&longs;&longs;e aliquod impedimentum, ne omninò con&longs;tringeretur, vt nuces frangerentur quidem, non autem comminuerentur. Cur igitur nuces ab&longs;que ictu facilè confringun­tur hi&longs;ce in&longs;trumentis, quæ ad eum fiunt v&longs;um? contrarium namque accidere deberet, vtentes enim prædictis in&longs;trumentis, omnibus illis viribus de&longs;ti­tuuntur, quas motio, ac violentia percu&longs;&longs;ionis afferre &longs;olent. præterea cur ligneo vtuntur, ac proinde leui? non ne aptius e&longs;&longs;et durum, atque pondero­&longs;um veluti ferreum?

His re&longs;pondendum e&longs;t, nucifragum i&longs;tud in&longs;trumentum reduci ad binos vectes, quemadmodum etiam dentiforcipem. nuxigitur hoc modo duplici vecte comprimitur. vecte autem facilè onera quælibet obuiantia diuelluntur. qui duo vectes vnicum habent hypomoclion ip&longs;am &longs;cilicet connexionem

A. vectes &longs;unt binæ in&longs;trumenti ha&longs;tæ, F A D, E A C. dilatando igitur extrema C D, deducun­tur etiam alia extrema F, E, & impo&longs;ita nuce in hiatu K, quæuis potentia con&longs;tringendo C, D, con&longs;tringet &longs;imul F, E, ip&longs;amque; nucem confrin­get. quod igitur cum percu&longs;&longs;ione feci&longs;&longs;et pon­dus mallei, id valentiori vectium virtute efficiunt F A D, E A C. quanto au­tem locus nucis K, propinquior fuerit hypomoclio A, tanto celerius confringitur, quia partes vectium A C, A D, tunc à centro A, productiores fiunt, ide&longs;t multò maiores fiunt, quàm &longs;int di&longs;tantiæ inter nucem, & cen­trum A, quod maximè poten­tiam iuuat.

Ex quibus præ&longs;enti quæ&longs;tioni &longs;atisfactum videtur.

QVÆSTIO XXIII.

De Rhombo.

262

Rhombus ex definitione 23. primi Elem. e&longs;t figura æquilatera qui­

dem, &longs;ed non æquiangula, habet enim binos oppo&longs;itos angulos acutos, & alies binos oppo&longs;itos obtu&longs;os, talis e&longs;t præ­&longs;ens figura A B D C. In præ&longs;enti porrò quæ&longs;tione &longs;upponitur punctum A, quod e&longs;t vnum extremum in rhombo moueri &longs;uper latus A B, ver&longs;us B, & &longs;i­militer interim æqua velocitate moueri alterum extremum B, &longs;uper idem latus A B_{2} ver&longs;us A, & in­terim dum hæc duo puncta hoc modo &longs;ibi obuiam procedunt, moueri latus totum A B, eadem ve­locitate, ver&longs;us latus C D, ita vt &longs;emper ip&longs;i C D, æquidi&longs;ter, de&longs;cendatque; per latera A C, B D, quo­u&longs;que ip&longs;i C D, congruat.

Horum igitur trium motuum quemadmodum æquæ &longs;unt celeritates, ita etiam &longs;patia, quibus peraguntur, nam puncta duo mouentur in latere A B, ip&longs;um verò A B, mouetur in lateribus A C, & B D, quæ cum priori A B, &longs;unt æqualia.

Aduertendum præterea, quod hac ratione duo puncta A, & B, duabus la­tionibus mouebuntur, &longs;i quidem proprio motu mouentur in ip&longs;o latere A B, & quia latus A B, per quod ip&longs;a incedunt eodem tempore mouetur ver&longs;us C D, &longs;equitur, quod etiam ip&longs;a hoc eodem motu ferantur. erit igitur ip&longs;o­rum motus ex his duobus mixtus; & quidem ip&longs;ius A, latio erit per longio­rem diametrum A D; ip&longs;ius verò B, per breuiorem B C. Quare cum pun­ctum A, peruenerit ad D, etiam punctum B, eadem c&ecedil;leritate acce&longs;&longs;erit ad C. maius autem e&longs;t &longs;patium A D, quod confecit A, quam &longs;patium B C, con­fectum a C. Quærit igitur primò, cur cùm A, & B, mota fmt æquali celeri­rate in vtra que latione, vnum tamen maiorem lineam, quàm alterum per­tran&longs;iuit? Quærit &longs;ecundò, cur punctum B, confecit lineam B C, quæ mi­nor e&longs;t quam ip&longs;um latus A C, quod in &longs;uo motu conficit latus A B, quando ad D C, acce&longs;&longs;it. & tamen B, duplici fertur latione; A B, verò vnica; vtrun­que autem in æquali velocitate? Quod autem punctus A, motu illo de&longs;eri­bat lineam A D, punctus verò B. lineam B C, manife&longs;tum erit hoc modo. &longs;it v. g. punctum A, motu proprio delatum, v&longs;que ad punctum E, medium late­ris A B, erit interim totum latus A B, tran&longs;latum vbi e&longs;t F G, hoc e&longs;t, ad &longs;ui itineris dimidium, quia horum motus ponuntur æquales: hoc autem motu ip&longs;um punctum A, erit nece&longs;&longs;ariò in K, hoc e&longs;t in linea A D, vt dicebamus. Similiter in fine vtriu&longs;que motus, A, erit in B, proprio motu, &longs;ed lieno in D, extremo &longs;cilicet lineæ A D. &longs;imili ratione o&longs;tendi pote&longs;t de ip&longs;o B, qui cum æqua velocitate moueatur, ac punctum A, quando A eri E; B. pariter illi occurret in E, proprio motu: &longs;ed alieno à latere B A, pron ente erit in K, vbi etiam ob alterum motum erit A: erit igitur B, in linea B C, vt vo­lebamus. à quo po&longs;tea di&longs;cedens ver&longs;us C, motu pariter compo&longs;ito &longs;i&longs;titur tandem in C, extremo lineæ pariter B C. eodem ergo tempore duo rhombi extrema puncta æquè velocia, &longs;ecundum vtramque lationem mota, interual­la nequaquam æqualia confecerunt, &longs;ed A, maius, nimirum A D; B, verò minus nimirum B C.

Ex quibus etiam &longs;ecundæ quæ&longs;tionis explicatio, & dubitandi ratio pate­bit: nam cum in rhombo duo &longs;int obtu&longs;i anguli B, & C, & duo acuti A, & D, punctus ille, qui ab obtu&longs;o angulo B, recedit, fertur duabus lationibus inui­cem ferè contrarijs, propria enim tendit &longs;ur&longs;um ad A, aliena verò deor&longs;um trahitur ver&longs;us D; cau&longs;a huius contrarietatis &longs;unt lineæ D B, B A, obtu&longs;um angulum continentes, quæ à prædicto angulo in contrarias partes &longs;eparan­tur: per has autem lineas fiunt prædicti motus, vnde ip&longs;i quoque contrarij &longs;int nece&longs;&longs;e e&longs;t: & propterea &longs;e mutuò impediunt: atque hinc nece&longs;&longs;e e&longs;t pun­ctum B, motu compofito hinc inhibito minus interuallum B C, pertran&longs;ire. At verò punctum A, quia ab acuto angulo de&longs;cendit, vtraque latione fertur deor&longs;um, quæ lationes &longs;e mutuò iuuant, faciuntque; vt A, maius, quamuis eo­dem tempore, & eadem celeritate peragret &longs;patium A D. nam punctum A, &longs;ua &longs;pontè de&longs;cendit per latus A B, & ab ip&longs;o latere A B, quod fertur ad C D, pariter deor&longs;um vehitur. nihil igitur mirum fit, &longs;i A, maius interuallum A D, quam B C, percurrat. cau&longs;a verò huius motuum concordiæ e&longs;t angulus acu­tus A, ob quem latera rhombi magis inuicem approximantur, redduntque longiorem A D, quàm B C: è contrariò autem, quo obtu&longs;iores &longs;unt anguli B, C, minorem faciunt ip&longs;am B C, latera enim &longs;emper magis ad rectam li­neam accedunt; donec tandem omni angulo euane&longs;cente in directum con­&longs;tituantur; quo ca&longs;u congruerent cum linea A D, rhombusque; ip&longs;e amplius nullus e&longs;&longs;et.

Ex his igitur &longs;equitur, quod punctum A, ab angulo A, acuto di&longs;cedens, duobus feratur motibus &longs;imilibus ad eandem partem tendentibus, & quò acutiores &longs;unt anguli, eò magis tendent ad eandem partem; & melius &longs;e mutuò inuabunt. B, autem vice ver&longs;a, quoniam quanto obtu&longs;ior e&longs;t angulus B, tanto magis latera illius diuaricantur; duæ etiam motiones, quibus B, progreditur in diuer&longs;a partes tendent; fiunt enim per illa latera; & tanto etiam magis &longs;ibi contrariæ erunt; magisque; &longs;ibi mutuò impedimento erunt. & propterea punctum B, minus interuallum, quale e&longs;t B C, percurret, quan­do A, maius A D, percurrit.

Ad &longs;ecundam verò quæ&longs;tionis partem, re&longs;pondeo con&longs;iderandum e&longs;&longs;e latus B A, moueri vnico motu ad D C, quare à nullo impedi­tur, vnde nihil mirum videri debet, quòd ip&longs;um vnica latione maius conficiat &longs;pacium quàm B, quod quamuis duplici pellatur motu, vnus tamen ab altero inhibetur.

QVÆSTIO XXIIII.

De duobus circulis.

263

Vnde e&longs;t, quod &longs;i duo circuli, vnus altero maior, cirea idem cen­trum po&longs;iti, volutentur, ita vt etiam centrum feratur, eo &longs;cilicet modo, quo plau&longs;trorum rotæ &longs;olent, &longs;ecundum æqualem lineam conuoluuntur, &longs;iue æquale &longs;patium conficiunt: &longs;i verò &longs;eor&longs;um &longs;eparati quilibet eodem modo volutetur, non æquale &longs;patium pertran&longs;ibunt, &longs;ed maior maiorem lineam, quàm minor; idque; ea proportione, quam inui­cem eorum circunferentiæ obtinent, cum in hac veluti rotæ conuolutione, circunferentia tota &longs;ucce&longs;&longs;iuè decur&longs;o &longs;patio adaptetur, ita vt tanta &longs;it de­cur&longs;a linea, quanta e&longs;t rotæ circunferentia? Quin etiam eodem exi&longs;tente vtriu&longs;que centro, aliquando confectum &longs;patium ab vtroque tantum e&longs;t, quan­tum minor circulus &longs;olus, &longs;ecundum &longs;uam periphæriam reuolutus perfeci&longs;­&longs;et; quandoque; verò quantum maior &longs;olus ab&longs;olui&longs;&longs;et. Quod autem maior &longs;olus in &longs;ua reuolutione maiorem lineam de&longs;cribat, manife&longs;tum e&longs;t hinc, quia &longs;en&longs;u patet maiorem circunferentiam in maiori circulo &longs;ubtendere angulum, qui fit à diametris in centro; minorem verò circunferentiam &longs;ubtendere eundem angulum in minori orbe, vt etiam in 8. quæ&longs;t. dictum e&longs;t: eandem igitur, vt proximè dixi habebunt etiam proportionem illæ lineæ, quæ à &longs;ingulis &longs;eor&longs;um orbibus reuolutis de&longs;ignabuntur. Quod præterea &longs;e­cundum æqualem conuoluuntur, quando circa idem po&longs;iti fuerint centrum, manife&longs;tum e&longs;t, ita tamen, vt aliquando ambæ æquales &longs;int ei, &longs;ecundum quam &longs;olus maior conuolueretur; aliquando verò &longs;ecundum quam minor.

&longs;it enim circulus maior quidem vbi D F C, minor verò vbi E G B, vtrique autem centrum A, linea, &longs;ecundum quam quadrans F C, maioris per &longs;e rotaretur, &longs;it F L. linea verò, &longs;ecun­dum quam quadrans G B, minoris &longs;e­iuncti à maiori, volutaretur &longs;it G K, quæ æqualis e&longs;t dicto quadranti G B, &longs;icut etiam F I, æqualis e&longs;t quadran­ti F C. &longs;i quis igitur impellat mino­rem orbem mouens &longs;imul commune centrum A, cui maior e&longs;t circumpo­&longs;itus, donec diameter A B, perpendicularis &longs;it lineæ G K, in puncto K. tunc pariter diameter maioris A C, erit perpendicularis lineæ F L, in puncto L. G K, autem, & F L, nece&longs;&longs;ariò erunt æquales per 34. primi, æquales igitur lineas hoc modo peragrarunt inæquales circunferentiæ, &longs;iue quadrantes G B, F C. &longs;i autem quadrantes hoc præ&longs;tant, manife&longs;tum e&longs;t, quod & toti ambitus idem efficiunt, quare quando tota periphæria G B E G, fuerit re­uoluta etiam tota F C D F, &longs;uum orbem completum habebit. &longs;imiliter &longs;i ma­iorem quis mouerit, cui minor &longs;it annexus eodem exi&longs;tente centro, &longs;imul ac diameter A C, erit perpendicularis ad F I, in puncto I, erit etiam A B, per­pendicularis ip&longs;i G M, in M; &longs;unt autem G M, & F I, æquales, quare quan­do F C, quadrans maioris pertran&longs;iuerit rectam F C, etiam C B, quadrans minoris tran&longs;actam habebit illi parem G M. hoc autem accidit nulla inter­cedente mora in vllo ip&longs;orum: quando enim mouetur maior, nihil ce&longs;&longs;at minor: & quando minor agitur, maior nunquam quie&longs;cit. quod &longs;i hoc acci­dit quartæ parti circulorum, idem, & totis accidit periphærijs. vbi in&longs;uper illud etiam mirum, centrum nimirum ip&longs;orum eadem celeritate motum, ac vnica &longs;emper exi&longs;tenti latione, modo maius, modo minus &longs;patium per­ficere; idem verò eadem velocitate latum, æquale &longs;emper deberet interual­lum tran&longs;ilire. & tamen in præ&longs;entia vtrouis modo moueas eadem pernici­tate, modò maius, modò minus &longs;patium pertran&longs;ibit.

Huius quæ&longs;tionis enodandæ cau&longs;a, &longs;upponendum primò e&longs;t, quod eadem, &longs;eu æqualis potentia, hanc quidem magnitudinem tardius, illam verò citius mouere pote&longs;t. &longs;i enim fuerit quippiam, quod à &longs;eip&longs;o moueri minimè ap­tum &longs;it; & aliud, quod à &longs;e ip&longs;o moueri aptum &longs;it; qui hoc &longs;imul cum illo coniunctum mouerit, tardius mouebit, quàm &longs;i ip&longs;um &longs;olum moueret. & &longs;i quid moueatur, quod aptum &longs;it ex &longs;e moueri, verumtamen in eo motu nihil ex &longs;e moueatur, perinde e&longs;t, ac &longs;i minimè aptum &longs;it ad motum, & proinde tardius mouebitur; nec fieri poterit, vt plu&longs;quam mouens moueatur, cum nihil innata motione vtatur. Si quis igitur minorem circulum, quem mo­do B, appello, mouerit &longs;upra &longs;uam circunferentiam, cui annexus &longs;it maior, quem modo appello A, &longs;ic quidem maior mouebitur, non autem ex &longs;e, &longs;ed &longs;olum quatenus à minori feretur, vnde tantum pertran&longs;ibit de recta F L, quantum à minori fuerit impul&longs;us; tantum autem e&longs;t impul&longs;us, quantum minor e&longs;t motus; quare æqualem cum illo viam confecit. &longs;i igitur minor fe­cit pedalem G K, maior confecit etiam pedalem F L, quia maior nihil de proprio motu addidit, &longs;ed &longs;olum motione minoris e&longs;t tran&longs;latus. &longs;imiliter &longs;i quis rotet maiorem &longs;upra &longs;uam circunferentiam annexo minori, tantum minor mouebitur, quantum à maiori deportabitur, quia nihil ex &longs;e impel­litur. Verum &longs;i &longs;eor&longs;um ambo ex &longs;e &longs;ecundum &longs;uos ambitus moueantur, &longs;iue citò, &longs;iue tardè, eadem etiam velocitate perficiant integram &longs;uæ periphæ­riæ volutationem, maior maius, minor verò minus conficiet &longs;patium.

Sed fortè augebitur difficultas con&longs;ideranti, quod prædicti circuli &longs;unz circa idem centrum, & circa illud mouentur. moueri autem circulum cir­ca &longs;uum centrum, e&longs;t moueri &longs;ecundum &longs;uum naturalem motum, ad quem circuli ex &longs;e &longs;unt apti. &longs;i verò vnus moueretur circa &longs;uum centrum, alter ve­rò non, vt quando alter alteri non e&longs;t circa idem centrum compactus, & ab altero mouetur, vbi manife&longs;tè apparet, quod fertur omninò ab illo, & in il­la latione non circumuertitur circ proprium centrum, quare tunc minimè mirum e&longs;t, &longs;i neque plus, neque minus &longs;patium conficiat, quàm ab altero de­portetur, cui quoquo modo adiacet, aut appen&longs;us e&longs;t extra illius centrum.

Huic obiectioni re&longs;pondendum e&longs;t, quod quamuis prædicti orbes &longs;int con­centrici, nihilominus non mouentur ambo &longs;uamet motione, &longs;ed ille, qui ab alio fertur mouetur &longs;ecundum motionem illam, tanquam &longs;i nullam ad eam haberet aptitudinem; quamuis enim po&longs;lit moueri circa centrum illud A, propria natura, in præ&longs;enti tamen ca&longs;u minimè vtitur illa aptitudine; & propterea motus debet moueri, quantum mouens, nec plus, nec minus.

Quòd autem &longs;pectat ad id, quod initio dicebatur de eodem centro, & de mouente eadem velocitate, & de æquali ab inæqualibus orbibus pertran&longs;i­ta linea, &longs;ubeft huic dubitationi paralogi&longs;mus: quamuis enim &longs;it idem am­borum centrum, e&longs;t tamen vnius centrum per &longs;e in motione, alteri verò per accidens, veluti per accidens e&longs;t eundem virum e&longs;&longs;e mu&longs;icum, & album. ille enim circulus, qui mouet alterum, obtinet illud centrum per &longs;e, & ex natu­ra &longs;ua; alter verò, qui mouetur, habet illud idem per accidens, quia non vtitur illo tanquam centro. non igitur circa idem &longs;impliciter centrum fit horum motus, &longs;ed alio modo vnus, alio modo alter, vnde & reliquis dubi­tationibus facilè &longs;atisfiet.

QVÆSTIO XXV.

De Lecto

264

Cvr lectulorum &longs;pondas faciunt &longs;ecundum duplam proportionem, hoc e&longs;t longiorem &longs;pondam duplo longiorem, quàm &longs;it altera: il­lam enim &longs;ex pedum, vel paulò plus, hanc verò trium? præterea cur re&longs;tes, quibus culcitræ &longs;u&longs;tinentur non extendunt per diame­trum, &longs;ed per tran&longs;uer&longs;um?

Ad primum re&longs;pondetur ideò facere &longs;pondas in dup la ratione, vt &longs;int hu­mano corpori proportionatæ, &longs;ic enim lecti longitudinem habebunt qua­tuor cubitorum, latitudinem verò duorum, in tali enim &longs;patio commo­dè cubamus.

Ad &longs;ecundum verò dicendum extendi illos funes non per diametrum, &longs;ed ex oppo&longs;ito, quia hoc modo ligna ip&longs;ius lecti minus di&longs;trahuntur: facilè enim ex natura &longs;ua ligna hæc ab inuicem &longs;ecundum longum &longs;eparantur; ar­ctius autem ductis funibus per tran&longs;uer&longs;um, quàm per diametrum inuicem con&longs;tringuntur: præterea, quia &longs;ic etiam funes minus laborant, cum &longs;int eo­rum ductus breuiores; & quia debent &longs;u&longs;tinere onus ftragulorum, atque cul­cìtrarum, &longs;ic certè ex hoc onere minus laborabunt &longs;i tran&longs;uer&longs;im, quàm &longs;i diametraliter &longs;ubtendantur.

Tertia demum ratio e&longs;t, quia hac ratione minus re&longs;tium ab&longs;umitur, quæ

vt benè intelligatur, de&longs;eriba­tur lectuli figura A F G K, & bifariam diuidatur latus F G, in B. & quia tota F G, dupla e&longs;t ip&longs;ius A F, erit dimidium F B, æquale ip&longs;i A F. & propte­rea tot erunt foramina, quibus funes immittuntur in F B, quot in A F. extendunt autem funem hoc modo incipiunt ab A, & ducunt ad B, po&longs;tea per C, re­nertuntur ad D; hinc flectunt per H, v&longs;que ad E, & per G, angulum iterum de&longs;cendunt ad M, à quo recta tendunt in F, hinc per 2. deducunt ad 3. à quo foramine, per foramen 4. reflexum faciunt ad 5. à quo iterum per B, de&longs;cen­dunt ad angulum K, ibique; alterum funis extremum de&longs;init: hocque; modo duo anguli A, & K, re&longs;tis habent capita, & re&longs;tes exten&longs;æ &longs;unt non diametrali­ter, &longs;ed tran&longs;uer&longs;im.

Notandum autem, quod re&longs;tes æquales &longs;unt cum &longs;uis curuaturis. v. g. re­&longs;tis A B, cum &longs;ua curuatura B C, æqualis e&longs;t re&longs;ti C D, vnà cum eius curua­tura D H, & aliæ eodem modo &longs;e habent, quia eadem demon&longs;tratio omni­bus accommodari pote&longs;t: quia enim figura A B G M, parallelogrammum e&longs;t, æqualia enim &longs;unt latera B G, A M, & quot foramina &longs;unt in vno, tot etiam &longs;unt in altero, eaque; inuicem æquidi&longs;tant, &longs;equitur omnes re&longs;tes e&longs;&longs;e parallelas, & æquales, per 33, primi. ex qua etiam &longs;cquitur prædictas cu­ruaturas, B C, D H, E G, e&longs;&longs;e æquales. quare manife&longs;tum e&longs;t in dimidio le­ctulo tot e&longs;&longs;e re&longs;tes æquales re&longs;ti A B, quot &longs;unt foramina in dimidio latere B G, vel in dimidio F B, hoc e&longs;t e&longs;&longs;e quatuor. porrò oportet quantitatem harum omnium re&longs;tium per&longs;crutari, vt eam cum quantitate re&longs;tium diame­traliter exten&longs;arum conferamus, quod geometricè hoc modo a&longs;&longs;eque mur: triangulum enim B G K, rectangulum e&longs;t, ergò per 47. primi, quadrata la­terum B G, G K, æqualia &longs;unt quadrato lineæ B K: latus B G, e&longs;t trium pe­dum, quemadmodum etiam latus G K quadratus autem numerus ternarij e&longs;t 9. ergo duo quadrati numeri 9. &longs;iue 18. æquales &longs;unt quadrato lineæ B K, ergò linea B K, e&longs;t radix quadrata numeri 18. quæ radix non pote&longs;t exactè in numeris repræ&longs;entari, e&longs;t enim, vt aiunt, radix &longs;urda. verumtamen per radicum extractionem, atque approximationem ea poni pote&longs;t e&longs;&longs;e 41/4. ide&longs;t quatuor pedum cum vna quarta. cum igitur in toto lecto &longs;int huiu&longs;modi octo re&longs;tes, erit omnium &longs;umma pedum 34. ferè. &longs;i autem &longs;eeundum diame­trum extendantur re&longs;tes, vti factum e&longs;t in lectulo A B C D, neutiquam re­&longs;tes omnes &longs;imul &longs;uperiori quantitati adæquabuntur, &longs;ed illam longè &longs;upe­

rabunt. Sit igitur lectus A B­C D, in quo diametraliter du­ctæ &longs;int re&longs;tes B D, E H, & re­liquæ, vt in figura. harû quan­titas &longs;i per 47. primi, & per ra­dicis quadratæ extractionem inueniatur, erit &longs;umma earum pedum quadraginta cum dimi­dio; quæ quantitas præcedenti maior e&longs;t &longs;ex pedibus cum di­midio.

Atque hic e&longs;t &longs;en&longs;us Ari&longs;t. quamuis tex. ip&longs;ius propter nimiam tam in græ­cis, quàm in latinis codicibus corruptionem, totus re&longs;titui nequiuerit.

QVÆSTIO XXVI.

De ligno humeris gestato.

265

Cvr difficilius e&longs;t longa ligna ab extremo &longs;uper humeros ferre, quàm &longs;ecundum medium, cùm tamen vtroque modo &longs;it &longs;emper idem pon­dus? An quia dum fertur lignum &longs;uper humeros ab altero extre­mo, alterum extremum vibratur, & agitatur, quæ agitario ip&longs;ius lationem impedit? An quia licet nihil inflectatur ob agitationem, neque ma­gnam habeat longitudinem, difficilius tamen ab extremo fertur, quoniam facilius ex medio eleuatur, quàm ab extremo, & quia latio e&longs;t qua&longs;i quæ­dam continua eleuatio, propterea etiam difficilius &longs;ic portatur? cau&longs;a au­tem cur facilius ex medio eleuetur e&longs;t, quia hoc modo totum lignum fit ve­ctis, cuius hypomoclion e&longs;t in medio, vbi is, qui eleuat, tenet aut fert: ex­trema autem &longs;ibi mutuò æqueponderant, ita vt ab&longs;que vllo alio auxilio, â tan­ta vi, quantum e&longs;t totum ligni pondus &longs;u&longs;tineatur; quod &longs;i ab extremo ele­uetur non &longs;ufficit amplius prædicta vis, &longs;ed opus erit maiori, quia non &longs;o­lum oportebit illud eleuare, &longs;ed præterea etiam illud in æquihbrio con&longs;ti­tuere, & con&longs;eruare. pondus enim totius ligni vergit ferè ad alteram ligni medietatem, quæ ab hypomoclio productior cuadit, quapropter ad onus i&longs;tud æquilibrandum, opus e&longs;t alia potentia in altero extremo. &longs;it lignum

A B, &longs;u&longs;pen&longs;um ex medio C. hoc modo lignum ponderi­bus libratum &longs;uis manet in æquilibrio, pote&longs;tque à &longs;ola potentia illud eleuante etiam deferri: quia A, & B, extrema &longs;e mutuò &longs;u&longs;ti­
nent. quod &longs;i non ex medio eleuaretur, &longs;ed ab extremo, vt in &longs;ecunda figura, eleuans potentia ex C, æqualis oportet, vt &longs;it præcedenti; &longs;ed præterea opus e&longs;t alia vi, quæ in B, æquiponderet alteri extremo A, quod magis grauitat, quo ab C, longius fuerit; & hoc modo in æquilibrio con&longs;titutum, & con&longs;eruatum poterit non &longs;olum eleuari, &longs;ed etiam circumferri.

QVÆSTIO XXVII.

De Gestatis &longs;uper humerum.

266

Cvr &longs;i valdè procerum &longs;uerit idem pondus difficilius &longs;uper humeros ge&longs;tatur, etiam &longs;i ex medio illud feratur, quàm &longs;i breuius &longs;it? quod enim dudum dictum e&longs;t cau&longs;a non e&longs;t, &longs;ed vibratio, & &longs;uccu&longs;&longs;atio ligni nunc e&longs;t: quando enim ab humero productius fuerit, magis vibrantur extrema, quam ob rem contingit portantem difficilius ge&longs;tare. vibrationis autem cau&longs;a e&longs;t, quoniam ab eadem vi moueute magis extrema huc illuc transferuntur, quanto procerius fuerit lignum, quia tunc maior fit di&longs;tantià à centro, &longs;eu hypomoclio, quod modo e&longs;t humerus ip&longs;e. &longs;it vt in prima præcedentis quæ&longs;tionis figura, humerus vbi A. di&longs;tantiæ autem ab ip&longs;o centro &longs;unt A B, A C, quod autem maior di&longs;tantia; faciliorem reddat motum o&longs;ten&longs;um e&longs;t initio huius operis.

QVÆSTIO XXVIII.

De Tollenone.

267

In&longs;trumentum i&longs;tud, quod græca voce Leonicus interpres Celonia vo­cat, latinis dicitur Tolleno, à tollendo; quod etiam manife&longs;tum e&longs;t ex Fe&longs;to, qui ait, Tolleno e&longs;t genus machinæ, quo hauritur aqua in al­teram partem prægrauante pondere; quæ tollenonis de&longs;criptio om­ninò machinæ præ&longs;entis quæ&longs;tionis competit. Hi&longs;pani Telonam fortè a tol­lenone nuncupant. E&longs;t autem tolleno in&longs;trumentum hauriendæ è puteo aquæ idoneum, quo ru&longs;tici pa&longs;&longs;im vtuntur: idque; iuxta puteos &longs;tabile, ac firmum con&longs;truunt, quale à figura &longs;equenti refertur. vbi puteus F, tolleno con&longs;tat

erecto tigno D C, & tran&longs;­uer&longs;a ha&longs;ta A C B, vnà cum fune B E, & hydria E. ap­ponitur præterea onus &longs;a­tis graue ad partem A, quale e&longs;t G. ha&longs;ta porrò A B, ve­luti vectis circa punctum C, tanquam hypomoclion, &longs;usque; deque; agitur, à poten­tia funem B E, trahente. &longs;ed iam textus exponatur.

Cur iuxta puteos tolle­nones faciunt eo, quo vi­&longs;untur modo, ligno enim tran&longs;uer&longs;o A B, adiungunt onus plumbi G, cum alio­quin vas ip&longs;um E, & vacuum, & plenum pondus habeat: cur inquam, vt fa­cilius moueant tollenonem, tollenonis oneri onus addunt G? An quoniam cùm opus hauriendi diuidatur in duo, in intingendi nimirum, & &longs;ur&longs;um tra­hendi tempora: accidit quidem ab&longs;que plumbi onere facilius intingere, quia tunc vas e&longs;t vacuum: at verò &longs;ur&longs;um vas deinde plenum trahere, laborio­&longs;ius erit. &longs;i verò addatur onus G, tunc quidem paulò difficilius intingemus, &longs;ed tamen vas plenum po&longs;tea multò facilius, quod opus, & labor e&longs;t, &longs;ur&longs;um educemus: operæpretium igitur e&longs;t, onus illud plumbi, aut lapidis adiun­gere in extremo A, quia &longs;ic pondus illud tanquam quædam potentia vecte A B, vtens &longs;ur&longs;um hydriam plenam rapiet, hacque; ratione nos labore leua­bit, totumque; hauriendi opus demi&longs;&longs;ione, atque eleuatione con&longs;tans, alleuabit,

QVÆSTIO XXVIIII.

De onere phalanga gestato.

268

Cvr quando &longs;uper ligno, aut huiu&longs;modi quopiam duo portauerint homines æquale pondus, non &longs;imiliter grauantur, ni&longs;i quando pon­dus in medio eorum fuerit; &longs;ed magis ille premitur, cui onus vici­nius fuerit? An quia lignum illud vectis efficitur, cuius hypomo­clion e&longs;t vbi pondus ge&longs;tatum &longs;u&longs;penditur; ge&longs;tantium autem oneri proxi­mior gerit vicem illius, quod vecte mouetur, remotior verò e&longs;t potentia vecte mouens. quanto igitur plus di&longs;tat ab hypomoclio, &longs;eu ge&longs;tato ponde­re, tanto facilius mouet, hoc e&longs;t, alterum magis deor&longs;um premit, contra­nitente nimirum ge&longs;tato onere tanquam hypomoclio. &longs;i autem in medio fue­rit pondus, nihilo magis alter ge&longs;tantium fit id, quod vecte mouetur, quàm alter; neque magis mouet: &longs;ed eodem modo alter alteri fit pondus.

Cæterum &longs;ciendum huiu&longs;modi lignum, quo tran&longs;uer&longs;o onera deportantur dici à latinis phalangam, vnde etiam verbum phalangare deducitur, quod huiu&longs;modi ge&longs;tationem &longs;ignificat; e&longs;tque; Vitruuio v&longs;itatum, & Afranio, qui ait, capream vnam &longs;emilaceram quaterni &longs;imul phalangabant.

QVÆSTIO XXX.

De &longs;urgente à &longs;eßione.

269

Cvm &longs;edemus, præcipuè &longs;i commodè &longs;edeamus, &longs;olemus duos angu­los rectos facere, vnum quidem, quem facit thorax cum femore; alterum quem facit femur cum crure, vt in figura thorax &longs;it A B,

femur B C, crus C D, anguli duo recti &longs;unt B, & C. Quærit igitur, cur quando &longs;urgere volumus angu­los ho&longs;ce rectos in acutos commutamus, nam crus re­trahimus &longs;ub femur ad acutum angulum, v. g. ad po&longs;itio­nem C F. fitque; acutus angulus B C F. &longs;imiliter thoracem femori aptamus ad acutum angulum E B C, alioquin &longs;ur­gere non valemus? An quia id, quod æquale e&longs;t, quietis vbique e&longs;t cau&longs;a, rectus autem angulus e&longs;t angulus æquali­tatis, atque &longs;tationis? quæcunque enim angulis rectis con­&longs;tant, vt quadratum, vt cubus, quieti, ac &longs;tationi &longs;unt idonea, vt propterea Pytagorei dicerent terram e&longs;&longs;e cubicam, propten ip­&longs;ius immobilitatem. e&longs;t autem angulus rectus, angulus æqualitatis, quia omnes anguli recti &longs;unt inuicem æquales, vel quia linea illa, quæ angulum rectum facit e&longs;t perpendicularis alteri lineæ, cui incumbit, æqualiterque; in vtramque partem inclinata e&longs;t: quapropter fit, vt quæcunque con&longs;tituta &longs;int &longs;uper &longs;uperficiem terræ ad angulos rectos non cadant, &longs;ed racta maneant. pariter quæcunque ad angulos rectos pauimento incumbunt, non &longs;olum, quia cum illo faciant angulos rectos, &longs;ed etiam, quia &longs;imul faciunt cum &longs;uperficie terræ perpendiculum. An quia qui &longs;urgit fit rectus; rectus autem manens, oporter, vt &longs;it &longs;uperficiei terræ perpendicularis. debet igitur e&longs;&longs;e &longs;ecundum eandem rectitudinem, ide&longs;t caput &longs;upra thoracem, thorax verò &longs;upra femo­ra, femora verò &longs;upra crura in eadem rectitudine, quæ horizonti perpendi­culariter in&longs;i&longs;tat: quando autem &longs;edemus thorax, & crura, non &longs;unt in ea­dem linea horizonti perpendiculariter erecta, quapropter nece&longs;&longs;e e&longs;t pedes retrahere, caput autem reclinare, vt &longs;ic in eadem recta linea horizonti per­pendiculariter con&longs;tituantur, hocque; modo a&longs;&longs;urgere erit po&longs;&longs;ibile.

270

Reliquæ quæ&longs;tiones ad Phy&longs;icum &longs;pectant. In 33. aperit propriam &longs;en­tentiam de motu proiectorum.

In 35. & vltima de vortice quamuis vide atur mathematicam &longs;apere, e&longs;t tamen phy&longs;ica. Eius autem re&longs;olutiones tres ab Ari&longs;t. allatas, fal&longs;as e&longs;&longs;e &longs;u&longs;picor; experientia enim docet, quod &longs;i quippiam ponatur &longs;upra rotam figuli, id non ad centrum, &longs;ed extra rotam proijcitur. &longs;ed cau&longs;a e&longs;t, quia in vortice aqua ip &longs;a &longs;piratim circumcurrens tandem in centrum, vbi demer­gitur de&longs;cendit; nece&longs;&longs;e igitur e&longs;t, vt etiam ea, quæ in ip&longs;a &longs;unt, &longs;imul cum illa ad centrum per plures conuolutiones deducantur. Cæterum &longs;i quis ve­lit Mechanicam facultatem &longs;eriò aggredi, nequaquam paucis his ab Ari&longs;t. traditis, eisque; leui brachio pertractatis, contentus &longs;it: verùm Archimedem de Aquæponderantibus, Commandinum, ac Lucam Valerium de centro grauitatis &longs;olidorum, ac tandem Guidi Vbaldi Mechanica adeat, vbi hu­ius &longs;cientiæ admiranda plurima, eaque; firmi&longs;&longs;imè demon&longs;trata reperiet.

IN LIBELLVM DE MVNDOAD ALEXANDRVM.

Cvm plures libellum hunc Ari&longs;t. attribuant, cogor loca ip&longs;ius ma­thematica ex in&longs;tituto exponere.

271

In 2. cap. recen&longs;et Planetarum ordinem, iuxta antiqui&longs;&longs;imorum A&longs;tronomorum traditiones, qui ob paucas, easque; imperfectas ob­&longs;eruationes muita ignorarunt, atque in multis, & præcipuè in ordine Plane­tarum &longs;tatuendo, fal&longs;i &longs;unt: A&longs;tronomi enim po&longs;teriores, & maximè Ptolæ­meus, vnà cum recentioribus no&longs;tri &longs;eculi alium ordinem exactioribus ob­&longs;eruationibus, atque demon&longs;trationibus a&longs;trucntes vetu&longs;ti&longs;&longs;imorum illorum errores patefecerunt. E&longs;t autem verus ordo, vt Luna &longs;it omnium terris pro­xima, deinde Mercurius, tùm Venus, po&longs;tea Sol, Mars, Iupiter, Saturnusque; à terris alti&longs;&longs;imus, quos omnes &longs;tellarum affixarum &longs;phæra, quæ etiam fir­mamentum dicitur, complectitur. non me latet huius no&longs;tri &longs;eculi di­ligenti&longs;&longs;imos a&longs;tronomos nouam mundani &longs;y&longs;tematis hy­pothe&longs;im inducere; &longs;ed ea prædicto Planctarum ordini parum, aut nihil repugnat.

Deæstu Maris.

272

In 3. cap. (Aiunt etiam multos æstus vndarumqué &longs;ublationes fiatis quibu&longs;­dam temporibus cum Luna circumag:) Perpaucis maris fluxum, & reflu­xum attingit, qui quia ex motu præcipuè Lunæ pender, non videtur alienum hoc loco eum fu&longs;ius explicare, atque nonnullis difficultatibus occurrere, quibus recentiores nonnulli nimis implicautur. Ae&longs;tus maris e&longs;t quædam maris ebullitio, ob quam vt &longs;olet in ebullientibus aquis, mare intume&longs;cit: fiunt autem in toto mundo duobus tantum in locis ex hoc æ&longs;tu tumores duo, quorum vnus &longs;emper directè Lunæ &longs;ubiacet, alter verò in auer&longs;a terræ parte, &longs;iue huic antipoda, & diametraliter oppo&longs;ita.

Ex his Marium tumoribus fit vt aquœ, quæ naturæ &longs;ua decliuiora petunt, qua&longs;i exundantes ad littora flaant. atque hic aquarum cur&longs;us fluxus maris appellatur. decre&longs;cente deinde maris æ&longs;tu, & tumore ex rece&longs;&longs; Lunæ, aquæ iterum ad medium mare refluunt: atque hic maris refluxus dicitur. Cum au­tem in toto die &longs;int 24. horæ & &longs;emper &longs;int &longs;imul in mundo duo æ&longs;tus, & tu­mores, fit vt &longs;int pariter &longs;emper in mundo duo fluxus, qui tumores illos co­mitantur; necnon duo refluxus, qui eo&longs;dem &longs;ub&longs;equantur; hinc fit vt vni­cuique illorum &longs;ex heræ conueniant, &longs;ex fluxui, &longs;ex refluxui, qui &longs;ub Luna fiunt; &longs;ex verò fluxui, & &longs;ex tandem refluxui Lunæ auer&longs;is, quæ totam Lunæ circa mundum periodum 25. horarum expleant. Cau&longs;am autem cur mare hoc modo &longs;tatis horis, paulò tamen &longs;erius ob Lunæ tardiorem ortum &longs;emper cre&longs;cat, & decre&longs;cat antiqui omnes in Lunam retulerunt, vt primus omnium Ari&longs;t. hoc loco, deinde Strabo, Pomponius Mela, Plinius, Solinus, & alij plures idem &longs;en&longs;erunt. Lunam &longs;cilicet eam habere vim in mare, vt pars il­la, quæ Lunæ &longs;irbiacet, &longs;iue quam Luna radijs ferit, æftuet, & turgeat; non aliter pars maris huic antipoda, & auer&longs;a, quamuis tota terræ moles inter

ip&longs;am, & Lunam interpona­tur, æ&longs;tuat, fluxumque, ac re­fluxum quamuis priori mi­norem, efficit. quæ omnia melius in figura cernentur; vbi infra Lunam vides tumo­rem A, ex quo fluxus deriua­tur. & in parte huic auer&longs;a tumorem B, ex quo alter flu­xus deriuatur. & quia in alijs duobus mundi lateribus non fiunt huin&longs;modi tumores, imò mare ob refrigerationem &longs;ub&longs;idet, ibi fiunt duo reflu­xus C, & D, ita vt &longs;emper &longs;int in mari præ&longs;ertim Oceano quatuor prædicti effectus, qui &longs;imul, vt ait hic Ari&longs;t. & ex­perientia te&longs;tatur, &longs;imul cum Luna circa mundum circumaguntur. hoe e&longs;t &longs;i Luna, quæ modo e&longs;t in &longs;uperiori parte meridionali, venerit ad locum E, occidentalem, eam fluxus A, &longs;uble quitur, vergitque; tumorem &longs;uum ad occi­dentem E, vnde, & fluxus B, promouebitur ad orientem, ita vt punctum F, orientalem a&longs;piciat.

Alij præterea duo refluxus eadem proportione promoti erunt, vbi prius erant fluxus: quæ con&longs;equentia ad Lunam perpetua, manife&longs;tum e&longs;t, fignum, ho&longs;ce fluxus, acrefluxus non aliunde quàm à Luna manare. quod adhuc ma­nife&longs;tius erit, &longs;i con&longs;ideremus, quod quanto tardius quotidie Luna oritur, tanto etiam maris æ&longs;tus tardius incipit. Porrò vt appareat hanc e&longs;&longs;e vete­rum &longs;ententiam libet hic attexere quædam ex lib. 3. Strabonis, quæ ip&longs;e ex Po&longs;&longs;idonio acceperat. &longs;ic. Oceani verò motum ait, &longs;cilicet Po&longs;&longs;idonius, &longs;y­deris &longs;ubire circuitum, quendam quidem diurnum, quendam men&longs;truum, quendam annuum, vt Lunæ etiam contingit. quo etiam tempore i&longs;ta &longs;uper horizontem a&longs;cenderit, mare terram a&longs;cendere incipit, &longs;en&longs;u te&longs;te, quou&longs;que ad cœnedium Luna con&longs;cenderit. Vbi verò declinare &longs;ydus ip&longs;um cœ­perit, &longs;en&longs;im rur&longs;us à terr pelagus ad medium mare reuertitur, donec ad occidentis painctum Luna de&longs;cenderit. deinde tanto eadem incon&longs;tantia tempote inanct, quanto Luna ad iplumoccafum conumgitur, & adhuc tan­to magis, quanto &longs;ub terram mota, &longs;ignnm ab horizonte di&longs;tet. po&longs;tea rur­&longs;us mare a&longs;cendere, quou&longs;que &longs;ub teliurem in medio cœli &longs;it Luna, deinde mare à littore regredi quoad iterum Luna in orientem procedat, ac &longs;upra horizontem eleuetur, con&longs;i&longs;ere verò v&longs;que quo fignum &longs;upra terram eleue­tur, & rur&longs;us terras mare a&longs;cendere. Hanc diurnam e&longs;&longs;e circuitionem a&longs;&longs;e­rit Po&longs;&longs;idonius, men&longs;truam verò, &c. vbi pergit explicare, qua ratione, ma­ria etiam alijs motibus men&longs;trno. &longs;cilicet, & annuo cieantur, iuxta Lunæ periodos men&longs;truam, & annuam. Eadem omninò habet Plinius, & alij ve­teres omnes, quos tu con&longs;ulere poteris vnde mirum videri debeat, cur re­centiores plurimi, neque veterum auctoritate, neque ratione, aut experientia nixi, hanc maris affectionem, à Luna effici negarint.

Verum ip&longs;i duabus poti&longs;&longs;imum rationibus id negant.

Prima e&longs;t, quod vario admodum tempore, & modo in diuer&longs;is fiant ma­ribus, & in nonnullis nihil horum æ&longs;tuum appareat.

Huic re&longs;pondendum e&longs;t, id ex varia marium di&longs;pofitione, tum eriam va­rio fitu, quo Lunam a&longs;piciunt prouenire. hoc modo videmus vario tempo­re, & modo, in toto orbe effici dies, ac noctes, æ&longs;tatem, & hyemem; & ta­men certum e&longs;t Solem i&longs;ta omnia efficere. Sed melius etiam huic dubita­tioni occurremus certa quadam, atque omninò explorata experientia ex ar­te Nautica de&longs;umpta. libri enim nautici ab&longs;que vlla dubitatione Luuæ hæc cmnia verè a&longs;cribunt, dum qua&longs;dam regulas tradunt, eastamen pro varijs maribus varias, quibus per ætatem Lunæ, & &longs;itum ip&longs;ius &longs;upra horizonteni illius maris certò certius horam fluxus; & refluxus, imò eorum etiam ma­gnitudinem præuo&longs;cunt, ac prædicunt. huiu&longs;modi librum vidiego Parmæ, manu &longs;criptum, auctore Augu&longs;tino Cæ&longs;areo, quem ille olim Sereni&longs;s. Duci Octauio dono dederat. quod &longs;i hi æ&longs;tus à Luna minimè penderent, nulla ra­tione regulæ illæ effici potui&longs;&longs;ent, quibus per ætatem ipfius, ac &longs;itum &longs;upra horizontem eos prædicere tuto valerent.

Secunda verò ratio, quæ maximè eos torquet e&longs;t quanam ratione à Luna effici po&longs;&longs;it &longs;ecundus refluxus B, primò oppo&longs;itus, cum tota terræ moles in­teriecta ob&longs;tare videatur.

Verum huic difficultati optimè ex opticis &longs;atisfacere po&longs;&longs;umus, fi dixe­rimus, æ&longs;tum illum effici quidem à Luna, & Sole, &longs;ed tamen per lumen ex &longs;yderibus ad partem illam auer&longs;am reflexum; quod vt melius explicetur, & confirmetur. Illud primò &longs;ciendum non &longs;olam Lunam, verumetiam Solem adæ&longs;tum maris ciendum concurrere, quamuis primas in hoc Lunæ conce­dat; experientia enim con&longs;tat maiorem fieri fluxum, quando Sol, & Luna &longs;imul &longs;unt coniuncta, vt in nouilunio accidit, quia lumina, & eorum virtu­tes vnitæ fortius eandem maris partem directis radijs percellunt. &longs;imiliter maior fit, quando luminaria &longs;unt oppo&longs;ita, vt in plenilunio contingit, quia tunc radij vnius directi, a&longs;&longs;ociantur cum reflexis alterius radijs, hocque; mo­do duplicati ea&longs;dem terræ partes, & directè, & reflexè feriunt, vt melius in &longs;equenti figura patebit.

Secundò præmittendum e&longs;t, lumen Solis, & Lunæ reflecti ex den&longs;is, ac per­politis corporibns, vti &longs;unt omnia &longs;ydera.

Tertiò, ex opticis a&longs;&longs;umendum, &longs;i corpora plurima &longs;phærica lumen re­flectentia fuerinuin circulari ambitu con&longs;tituta, quemadmodum &longs;unt &longs;tellæ affixæ in ambitu firmamenti collocatæ, reflectere plurimum lumen ad vnum, & idem punctum, quod &longs;it inter lumen, & ambitum illum; quod a&longs;&longs;umptum manife&longs;tum e&longs;t ex Iride, vbi ex plurimis &longs;phæricis guttulis lumen Solis re­flectitur ad oculum; quamuis geometricè, & quidem facilè à Per&longs;pectiuo demon&longs;trari po&longs;&longs;it.

Quartò, ex opticis, dato corpore lumino&longs;o, & &longs;phærico reflectente, & puncto quouis, ad quod po&longs;&longs;it reflecti lumen, pote&longs;t inueniri in &longs;phæra refle­ctente punctum reflexionis.

Quintò, quanto radij perpendiculariores incidunt, tanto maiorem vim habere.

Sit ergò Sol, & Luna &longs;imul, vt in figura &longs;itque; octauæ &longs;phæræ portio A B C, cum innumeris in ea affixis &longs;yderibus. e&longs;&longs;e autem totum cœlum &longs;tellis penè infinitis, ac con&longs;tipatis refertum &longs;en&longs;ui palam fit, adhibito nouo illo, ac mi­rabili Tele&longs;copij inuento.

Iam, vt patet ex 39.5. Alhazeni, ex &longs;ingulis &longs;tellis Solis, ac Lunæ lumen reflecti pote&longs;t (ni&longs;i quid ob&longs;tet) ad partem terræ D, luminaribus auer&longs;am, vt quarto loco &longs;uppo&longs;ui. & præterea ex &longs;tellis circa B, po&longs;itis radij Solis re­percuti po&longs;&longs;unt ad eandem terræ partem D, perpendiculares, qui præ cæte­ris maximam vim obtinent. quemadmodum lineæ in figura reflexæ vtcunque o&longs;tendunt, ideò a&longs;&longs;erendum e&longs;t eos, æ&longs;tum D, excitare præcipuè po&longs;&longs;e, neque terræ quantitas Solis luci obe&longs;t, cum con&longs;tet vmbram terræ parum &longs;upra Lunæ cœlum produci. pote&longs;t tamen Lunæ e&longs;&longs;e impedimento quoad hos ra­dios perpendiculares; &longs;ed tamen alios minus perpendiculares, &longs;eu parum obliquos nullo modo impedire pote&longs;t, quo minus ad D, re&longs;iliant. qui quam­uis &longs;int minus quàm perpendiculares efficaces, obtinent tamen non modi­cam vim. Ex &longs;tellis igitur circa A, & C, reflecti pote&longs;t ex quarto fundamen­to lumen vtriu&longs;que luminaris ad D, quod &longs;atis e&longs;t efficax, cùm ferè perpendi­

culariter terræ D, incidat. quamuis autem ex &longs;tellis F, E, lumen aliquod ad D, tran&longs;mittatur, tamen cum obliquè admodum illi accidat, nihil penè ef­ficere valet. Verumenimuerò qui&longs;piam in hunc modum obijciet: hac ra­tione deberet fieri etiam æ&longs;tus in terræ lateribus H, I, quando quidem etiam illuc lumen ex quarto fundamento reflecti pote&longs;t.

Cui &longs;ic re&longs;pondendum, po&longs;&longs;e quidem aliquod lumen illuc re&longs;ilire, &longs;ed ta­men exiguum admodum, & proinde nullius penè roboris, quod experientia de&longs;umpta ex illuminatione Lunæ comprobari pote&longs;t; videmus enim, quod quanto Luna magis Soli opponitur, & proinde &longs;uam illuminationem magis ver&longs;us terram obuertit, vt in plenilunio, tanto maiorem eam vim habere æ&longs;tus excitandi. multo verò minorem, quando e&longs;t in a&longs;pectu Solis quadrato, quia dimidiam tantum &longs;ui illuminationem nobis reflectit. Idem proportio­naliter de &longs;tellis dicendum, quæ enim luminari maximè opponuntur, vt quæ &longs;unt circa B, illæ totam illuminationem terræ o&longs;tendunt, vnde, & efficacio­res &longs;unt. cæteræ, quo magis ab illis di&longs;tant minus de &longs;ua illuminatione ter­ræ, &longs;eu mari obuertunt, & proinde minus efficiunt. vnde fit, vt quamuis non­nulli radij etiam perpendiculares ad terræ latera H, I, referri po&longs;&longs;int, tamen quia pauciores &longs;unt, quàm alibi, propterea nullam ibi æ&longs;tus prouocandi vim obtinent. &longs;ydera porrò illa, quæ &longs;upra Solem exi&longs;tunt, etiam &longs;i ip&longs;orum illu­minatio tota ad terras vergat, tamen in lateribus terræ prædictis nihil ef­ficiunt, quia in illa vel obliquè admodum radij incidunt, vel ea tantummo­do tangunt. Verum illuminatione &longs;ua ea&longs;dem maris partes, quæ &longs;unt ad G, vnà cum Sole, ac Luna percellunt.

Ex quibus apparet duas tantum orbis terræ partes totis, ac plenis a&longs;tro­rum luminibus impeti, in quibus &longs;cilicet duo opoo&longs;iti æ&longs;tus ebulliunt.

Idem po&longs;&longs;umus hoc modo confirmare, quia cum totum firmamentum &longs;it innumeris penè &longs;yderibus &longs;tipatum, loco concaui, ac &longs;phæriçi &longs;peculi ha­beri pote&longs;t, & proinde illius in&longs;tar amborum luminarium lumen reflectere; qua ratione patet omnem ferè ad partes prædictas D, emitti reflexionem.

His rationibus manife&longs;tum e&longs;&longs;e patet prædictum æ&longs;tus tumorem lumina­ribus auer&longs;um, atque antipodum ex prædicta reflexione exurgere.

Po&longs;&longs;et etiam qui&longs;piam &longs;ic opponere, &longs;i illuc prædicta luminum reflexio pertineret, non &longs;olum illam aquarum ebullitionem efficeret, verum etiam lucem aliquam eòdem afferret, quod tamen &longs;en&longs;u minimè apparet. cui &longs;ic re&longs;pondendum videtur, nece&longs;&longs;arium non e&longs;&longs;e, vt reflexio illa, quæ hoc modo mare afficit tanta &longs;it, vt etiam illud luce &longs;olito maiori afficiat; quod expe­rientia con&longs;tat in alijs c&ecedil;li influxibus: quàm &longs;æpè enim Luna nubilo&longs;o etiam tempore, fluxum, ac re&longs;luxum priorem parit, cum tamen nullam tunc lu­cem nobis afferat? quamuis enim lumen &longs;tellarum &longs;uperficiem maris non attingat, attingit tamen &longs;uperficiem vaporum, exhalationum, ac nubium, quæ terram in &longs;phæræ modum ambiunt, ac parum à terra circumquaque at­tolluntur: quem exhalationum ambitum deinde luminarium virtus facilè penetrare pote&longs;t. Nullum præterea lumen apparet, quia lumen reflexum præ&longs;ertim ex conuexis corporibus, vt &longs;unt &longs;tellæ, valde debile e&longs;t, quia con­uexum illud reflectendo non vnit, &longs;ed di&longs;gregat, contra quam facit concauum.

Tandem quærere quis po&longs;&longs;et, cur æ&longs;tus hic &longs;ecundus minor &longs;it priori. Cui re&longs;pondendum, quia ille à directis radijs, hic verò à reflexis progignitur: radios autem reflexos debiliores e&longs;&longs;e directis optici docent, atque experien­tia confirmat.

Porrò quando luminaria &longs;unt oppo&longs;ita, vt &longs;i Luna e&longs;&longs;et in B, Sol verò in K, tunc maximus fit vterque fluxus, quia radij directi vtriu&longs;que vniuntur cum ra­dijs reflexis alterius; ita vt vterque æ&longs;tus fiat, & per radium reflexum, & per directum &longs;imul, v. g. æ&longs;tus, qui Lunæ &longs;ubiacet fit per radium Lunæ directum, & quia Sol e&longs;t in oppo&longs;itione cum Luna, &longs;it vt ip&longs;ius radij reflectantur, & vniantur cum directis Lunæ ad eundem tumorem excitandum. &longs;imiliter in­fra Solem directè alius fit à directis ip&longs;ius radijs; & quia Luna ei opponitur lumen eius ad v&longs;que &longs;ydera pertinens reuertitur, vnaque; cum directa Solis lu­ce ad eundem efficiendum concurrit.

Exi&longs;tentibus demum lumidaribus circa quadratum a&longs;pectum, vt &longs;i Luna e&longs;&longs;et in F, Sole exi&longs;tente in K. exiguus, ac penè nullus fit fluxus, quia eorum vires non &longs;unt vnitæ, cùm radij nec incidentes, nec reflexi vniantur imò vi­res corum &longs;eparatæ inaria in contrarias partes di&longs;trahunt, vnde fit, vt neu­tro alteri concedente, apud neutrum victoria con&longs;tet.

Atque hæc e&longs;t mea de æ&longs;tu maris per reflexionem &longs;ententia. quam iamdiu inuentam, atque auditoribus meis &longs;æpius explicatam, reperi tandem non &longs;ine gaudio fui&longs;&longs;e etiam &longs;ubtili&longs;&longs;imi Scoti opinionem, quam ip&longs;e breuiter in pri­mum &longs;ent. de creatione mundi tantummodo &longs;ine vlla expo&longs;itione, atque con­firmatione proponit. in eadem pror&longs;us &longs;ententia e&longs;t Rogerius Bachon inter Opticos probati&longs;&longs;imus, cap. 5. de Speculis Mathematicis.

Aliorum demum opinationes, &longs;iue Angelo cuidam, &longs;iue virtuti totam terram peruadenti hunc æ&longs;tum a&longs;cribentium, non e&longs;t meum refellere, cum non phy&longs;icum, &longs;ed mathematicum agere in&longs;tituerim.

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Cap. 7. (Quod Imagunculas animatas e&longs;&longs;e, &c.) huiu&longs;modi imagines, & &longs;tatuas, quæ &longs;pontè mouebantur Græci appellarunt Automata, ide&longs;t &longs;pon­tanea, cuiu&longs;modi &longs;unt automata Heronis, Alexandrini, quæ adhuc extant.

IN LIBELLVMDe admirandis auditionibus.

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Nvmero 82. Quæ de illa in&longs;ula extra Herculis columnas &longs;ita narrat, eam putant recentiores Geographi, & quidem meritò nouo orbi conuenire.

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Numero 100. Quæ de I&longs;tro, &longs;iue Dannubio tradit, eum &longs;cilicet e&longs;&longs;e bifidum, alteroque; ramo in Pontum, altero verò in Mediterraneum ex­onerari: &longs;unt contra omnes recentiores Geographos; apparet tamen eam fui&longs;&longs;e veterum nonnullorum opinionem, quos &longs;equutus Ari&longs;t. deceptus e&longs;t, à quibus etiam multò po&longs;t fal&longs;i &longs;unt Diodorus, Pomponius, & Solinus, qui I&longs;trum I&longs;triæ Prouincìæ fluuium faciunt, quem ex I&longs;tro Germaniæ veluti ra­mum contra omnem veritatem deriuant. Verùm hoc illis-condonandum præ&longs;ertim antiquioribus, cum tunc temporis Geographia parum e&longs;&longs;et exculta.

Primus Strabo hanc fal&longs;itatem libro 1. redarguit, & po&longs;t ip&longs;um Plinius I&longs;trum i&longs;tum fabulo&longs;um appellat.

IN LIBELLVMDe lineis in&longs;ecabilibus, &longs;iue indiuiduis.

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Di&longs;putat libellus hic &longs;anè acuti&longs;&longs;imus, Vtrum quantitas con&longs;tet ex indiui&longs;ibilibus, quam qu&ecedil;&longs;tionem recentiores agitant in Phy&longs;icis tractatione de Quantitate; atque hinc nonnulla &longs;umunt argumen­ta: plura &longs;umpturi ni&longs;i operis ob&longs;curitas, & mathematicarum, ignoratio hactenus ob&longs;titi&longs;&longs;et.

Sciendum igitur primo loco, nos po&longs;&longs;e duo indiui&longs;ibilium genera in quan­titate concipere. primum eorum, quæ verè indiuidua &longs;unt, nullasque; habent partes, &longs;iue nullo modo &longs;unt quanta; cuiu&longs;inodi e&longs;t punctum mathematicum.

Alterum quorumdam indiui&longs;ibilium quidem, &longs;ed tamen quantorum cu­iu&longs;modi e&longs;&longs;ent, quædam adeò minimæ lineæ, quæ omnem effugiant diui&longs;io­nem: ex quibus antiqui opinabantur lineas totales, ac diniduas componi. atque de hec &longs;ecundo indiuiduorum, quantorum genere videtur opu&longs;culum i&longs;tud di&longs;&longs;erere. & quia partim rationibus phy&longs;icis, partim geometricis vti­ nec omninò phy&longs;icus nec omninò mathematicus e&longs;t. Ego igitur, quæ mathematica &longs;unt, exi &longs;tituto exponere aggrediar.

A lintigentiam igitur huius operis nece&longs;&longs;arium e&longs;t noui&longs;&longs;e, quæ nam &longs;int quantitates commen&longs;urabiles, & quæ in commen&longs;urabiles. quæ prima, & &longs;ecunda definitione 10. Elem. explicantur; egoque; eas primo Priorum oc­ca&longs;ione a&longs;ymetriæ diametri cum co&longs;ta &longs;atis expo&longs;ui: vtrumuis locum vide­ris præ&longs;enti nece&longs;&longs;itati con&longs;ultum erit.

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Primus locus Mathematicus e&longs;t hic (Po&longs;tremò ex ijs, quæ tradunt Mathe­maticis imbuti di&longs;ciplinis, quiuis lineam aliquam in&longs;ecabilem e&longs;&longs;e concedet. nam &longs;i, vt aiunt, illæ commen&longs;urabiles &longs;unt lineæ, quæ eadem men&longs;ura dimetiri queunt, & nihil impedit, quin omnes commen&longs;urabiles reip&longs;a dimetiantur, extabit profe­ctò longitudo aliqua, qua omnes commen&longs;urabuntur; quæ nece&longs;&longs;ario erit indiuidua, nam &longs;i dicatur e&longs;&longs;e diuidua, huius quoque men&longs;uræ partes, men&longs;aram aliquam com­munem habebunt, partes enim toti commen&longs;urabiles &longs;unt ita, vt portio partis il­lius, quæ dimidium totius fuerat, efficiatur dupla alterius; quoniam autem hoc fieri nequit, atoma debet e&longs;&longs;e men&longs;ura hæc communis.

Eodem modo, & quæ &longs;imul ab ip&longs;a men&longs;ura commen&longs;uratæ, tanquam omnes ex ea men&longs;ura compo&longs;itæ &longs;unt lineæ, veluti ex atomis conflantur.

Affert rationem quandam ex Mathematicis, qua nonnulli probabant ex­tare lineas atomas, ex quibus cæteræ lineæ tanquam partibus con&longs;tarent: ac proinde negabant lineas e&longs;&longs;e in infinitum diuiduas, &longs;eu quamlibet lineam &longs;ecari po&longs;&longs;e, &longs;ed a&longs;&longs;erebant diuidendo, tandem ad indiuiduas deueniendum e&longs;&longs;e.

Præmi&longs;&longs;a igitur, vt monui commen&longs;urabilium, & incommen&longs;urabilium linearum cognitione in hunc modum, & textum Ari&longs;tot. & rationem ip&longs;o­rum exponam.

Mathematici o&longs;tendunt extare lineas commen&longs;urabiles, quæ &longs;cilicet ea­dem communi men&longs;ura men&longs;urantur: at nihil impedit quin omnes commen­&longs;urabiles re ip&longs;a men&longs;urentur, debet ergò extare vna aliqua longitudo, qua omnes commen&longs;urabiles dimetiamur. hanc autem uece&longs;&longs;e e&longs;t e&longs;&longs;e atomam, nam &longs;i diuidua &longs;tatuatur, poterit &longs;emper &longs;ecari, & &longs;ub&longs;ecari bifariam, qua­re cum partes huiu&longs;modi &longs;int toti commen&longs;urabiles, &longs;equetur aliam exi&longs;tere men&longs;uram, qua omnes hæ partes, & proinde tota linea commen&longs;urentur. Verùm hoc fieri nequit, nam hoc pacto non e&longs;&longs;et vna tantum longitudo om­nium commen&longs;urabilium linearum communis men&longs;ura, verùm plures, & plures in infinitum, quod e&longs;t contra Mathematicorum placita. dicendum, itaque, communem illam omnium men&longs;uram e&longs;&longs;e omnis diui&longs;ionis exper­tem; & propterea etiam lineas omnes commen&longs;urabiles ex atomis lineis componi, quæ nimirum prædictæ communi men&longs;uræ æquales &longs;int. atque hæc e&longs;t illarum prima argumentatio.

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Secundus locus (Idem etiam contingit in figuris planis, quæ à lineis rationa­libus procreantur: nam omnes huiu&longs;modi figuræ erunt etiam inuicem commen&longs;ura­biles, quare enadem ratione, qua in lineis proximè v&longs;i &longs;umus, &longs;equetur earum com­munem men&longs;uram e&longs;&longs;e pariter indiuiduam.

Sciendum e&longs;t omnes lineas commen&longs;urabiles longitudine, e&longs;&longs;e etiam com­men&longs;urabiles (vt aiunt Geometræ) potentia, ide&longs;t &longs;ecundum quadrata ea­rum, &longs;iue dicas quadrata quoque earum e&longs;&longs;e commen&longs;urabilia, v. g. linea dua­

rum vnciarum, & linea trium vnciarum &longs;unt commen&longs;urabiles longitudine, & potentia, quia potentia lineæ duarum vnciarum, &longs;iue quadratum, e&longs;t quatuor vnciarum &longs;uperficia­lium: & quadratum lineæ trium vnciarum, e&longs;t nouem vnciarum quadratarum, vt patet in figuris, quorum quadratorum communis men&longs;ura e&longs;t vncia vna quadrata. atque hanc illi nullo modo diuidi po&longs;&longs;e contendebant.

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Tertius locus (Præterea &longs;i quis communem &longs;tatam, ac determinatam men&longs;u­ram &longs;aciat diuiduam, non erit amplius in rerum natura linea vlla rationalis, aut irrationalis, re&longs;pectu expo&longs;itæ, ac determinatæ lineæ; neque aliarum vlla erit, de quibus modo dictum e&longs;t, veluti quam Apotomen vocant ex duobus nominibus. Ve­rùm neque &longs;ecundum &longs;e aliquam definitam naturam habebunt, &longs;ed collatæ &longs;ibi ip&longs;is tam rationales, quàm irrationales erunt omnes.

Hæc e&longs;t alia eorumdem ratio ad idem comprobandum: quam, vt benè percipiamus, nonnulla prius ex definitionibus 10. Elem. &longs;unt explicanda: vt quæ nam &longs;int lineæ rationales, quæ irrationales, quæ ex binis nomini­bus, quæ Apotomæ.

Propo&longs;ita igitur linea quapiam, v. g. trium palmorum qualis e&longs;t linea A, po&longs;&longs;unt inueniri quamplurimæ lineæ, quarum aliæ &longs;int illi longitudine com­

men&longs;urabiles, &longs;iue quæ cum expo&longs;ita A, ha­beant communem men&longs;uram. v. g. linea B, quinque palmorum e&longs;t commen&longs;urabilis lineæ A, quia vtramque communis men&longs;ura vnius palmi metitur: aliæ verò &longs;int eidem A, lon­gitudine incommen&longs;urabiles, qualis e&longs;&longs;et diameter C D, quadrati lineæ A, quæ e&longs;t cum latere A, incommen&longs;urabilis ex vltima 10.

Cæterum lineam primò expo&longs;itam, vt e&longs;t in præ­&longs;entia A, quod e&longs;&longs;et notæ quantitatis, Græci appella­runt Ph/thg, ide&longs;t rationalem, quemadmodum Latini eam appellant.

Linearum autem longitudine incommen&longs;urabilium cum expo&longs;ita rationali A, aliæ &longs;unt, quæ tamen &longs;unt commen&longs;urabiles eidem potentia, ide&longs;t con&longs;tituunt quadrata, quæ &longs;unt commen&longs;urabilia quadrato ra­tionali A, vt linea C D, cum &longs;it diameter quadrati li­neæ A, quadratum exhibet, quod e&longs;t duplum quadrati lineæ A, ex 47. primi, quadratum autem lineæ A, e&longs;t nouem, igitur quadratum eius duplum erit octodecim, quadratum &longs;cilicet lineæ C D. octodecim autem, & nouem &longs;unt commen&longs;urabilia communi vnitatis men&longs;ura, huiu&longs;modi lineæ dicuntur com­men&longs;urabiles poteutia tantum, potentia. n. lineæ dicuntur quadratum illius.

Quæ igitur rationali propo&longs;itæ &longs;unt commen&longs;urabiles aliquo modo, &longs;iue longitudine, & potentia (quæcunque enim commen&longs;urabilis e&longs;t longitudine, e&longs;t etiam potentia) &longs;iue potentia &longs;olùm, rationales ip&longs;æ quoque dicuntur.

Aliæ verò (quarum permultæ in decimo reperiun­tur) quæ nec longitudine, nec potentia illi &longs;unt commen&longs;urabiles, irrationales appellantur, qua­lis e&longs;&longs;et media proportionalis E F, inter duas A, & C D, in præ&longs;enti figura ex 11. 10.

Sciendum præterea ex 37. 10. & &longs;equentibus, quod ex duabus lineis rationalibus re&longs;pectu rationalis expo&longs;itæ. v. g. A, com­men&longs;urabilibus inuicem tantum potentia, componitur linea, quæ cum ea­

dem expo&longs;ita e&longs;t irrationalis, vocaturque; ex duobus nominibus, &longs;iue Binomium, vt &longs;i ex latere A, & diametro C D, componatur li­nea A C D, erit irrationalis cum rationali A, diceturque; binomium. Amplius ex 74. 10. & &longs;equentibus, &longs;i prædictum minus nomen, &longs;iue minor linea A, detrahatur ex maiori nomine C D, vt re­linquatur B D linea, erit ip&longs;a reliqua B D, irrationalis, quam po&longs;tea appel­lant Apotomen, &longs;iue latinè Re&longs;iduum.

Po&longs;tremò, & hoc non ignorandum ex 43. 10. lineam, &longs;iue binomium A C D, non po&longs;&longs;e diuidi in alio puncto, præter C, in duas lineas, quæ &longs;int rationales expo&longs;itæ, & potentia tantum inuicem commen&longs;rabiles.

His præmi&longs;&longs;is textum, ac rationem illorum explicabo in hunc modum.

Si quis faciat diuiduam lineam illam, quæ e&longs;t communis men&longs;ura omnium commen&longs;urabilium, &longs;equetur hoc ab&longs;urdum contra demon&longs;trationes 10. quod nulla erit amplius linea rationalis, nec irrationalis, quia &longs;i communis men&longs;ura diuidatur, tolletur ea de rerum natura; vnde non erit amplius in­ter lineas &longs;ymetria vlla, quare neque vllæ erunt rationales, e&longs;&longs;e enim ratio­nale oritur ex commen&longs;urabilitate. quare neque extabit illa rationalis expo­&longs;ita, ad quam cæteræ relatæ dicuntur rationales, vel irrationales: quapro­pter etiam irrationales nullæ erunt, neque vlla alia erit ex prædictis, veluti nec irrationalis illa, quam vocant Apotomen ex Binomio, &longs;iue ex duobus nominibus, de qua Euclides propo&longs;. 74. 10. & &longs;equentibus pertractat.

Notandum in ver&longs;u illo (Apotomen ex duobus nominibus compo&longs;itam) vni­ca voce illa (Compo&longs;itam) addita ab Interprete Iatino, quæ non extat in tex. græco, magnum Ari&longs;toteli imponi erratum, cum hac ratione dicat apoto­men ex duobus nominibus e&longs;&longs;e compo&longs;itam, quod fal&longs;i&longs;&longs;imum e&longs;t. Apotome enim, vt &longs;upra dictum e&longs;t, ne dum ex duobus nominibus con&longs;tat, verum ip­&longs;a e&longs;t re&longs;iduum lineæ maioris, &longs;i minor ab ip&longs;a detrahatur. Verumenimuero vox illa (Compo&longs;itam) in nullo codice reperitur, quare pro arbitrio, atque ex Geometriæ in&longs;citia addita, tolli debet, ne tantæ in&longs;citiæ Ari&longs;t. ip&longs;e re­darguatur. hæc in hunc locum &longs;ufficiant.

280

Quartus locus (Quod verò de commen&longs;urabilibus lineis po&longs;iremò dicunt, om­nes vua quadam, & eadem men&longs;ura oportere men&longs;urari, fal&longs;um t&longs;i admodum, & nequaquam Mathematicorum &longs;uppo&longs;itionibus concrdat. non enim ita &longs;upponunt Geometræ, neque vtile ip&longs;is i&longs;tud foret, imò potius aduer&longs;aretur, lineas omnes com­men&longs;urabiles e&longs;&longs;e, & omnium commen&longs;urabilium linearam communem men&longs;uraexi&longs;timare. quamobrem ridiculum e&longs;t eos, qui dicunt &longs;e demonstrare ex Geometra­rum decretis, & ex quibus Mathematici docent in contentio&longs;am pariter, ac falla-em diuertere argumentationem, præ&longs;ertim tam inualidam. nam multis modis im­hecillis e&longs;t eiu&longs;modi ratio, & quouis modo licet euitare, ne aut inu&longs;itata dicere, aut argui videamur.

Refellit hoc loco &longs;uperiores rationes in tribus locis præmi&longs;&longs;is allatas, quibus nonnulli probabant quantitatem ex indiuiduis con&longs;tare, & proinde concedenda e&longs;&longs;e quædam Quanta, omninò atoma; &longs;ic igitur inquit. Quod verò de commen&longs;urabilibus lineis dicunt, omues videlicet vnica quadam, eademque; determinata men&longs;ura men&longs;urari oportere, fal&longs;um omninò e&longs;t, & contra mathematicorum dogmata, non enim Geometræ hoc a&longs;&longs;erunt, cùm ip&longs;orum demon&longs;trationibus a duer&longs;etur; &longs;ed tantum dicunt omnes lineas, quæ ad inuicem &longs;unt commen&longs;urabiles, commen&longs;urari, vna eademque; men&longs;ura,

&longs;ed non tamen vnica, ide&longs;t non vnica, ac determi­nata. po&longs;&longs;unt enim e&longs;&longs;e plures eædemque; men&longs;uræ communes plurium quantitatum commen&longs;ura­bilium, vt præ&longs;entium trium linearum 4. 6. 8. communis men&longs;ura e&longs;t linea 2. binarius enim tres numeros 4.6. & 8. men&longs;urat. & &longs;i linea 2. bifariam &longs;ecetur, erit dimidium eius linea 1. quæ pariter erit communis men&longs;ura trium prædictarum li­nearum, cûm vnitas &longs;it omnium numerorum communis men&longs;u 3. benè ve­rum e&longs;t, quod Geometræ, quando &longs;impliciter loquuntur de huiu&longs;modi com­muni men&longs;ura, intelligunt de ea, quæ inter omnes e&longs;t maxima: vt in prædi­ctis tribus lineis maxima earum communis men&longs;ura e&longs;t linea 2. Atque hec&longs;i­bi volunt Geometræ, ex quibus totus hic textus intelligi pote&longs;t.

281

Quintus locus (Ob rectæ verò lineæ motum in &longs;emicirculum, quam nece&longs;&longs;e e&longs;t in rectum ita diuidere, vt infinitæ circunferentiæ, & interualla totidem inuenian­ur) Interpres latinus &longs;ic vertit (Ob rectæ verò lineæ motum in &longs;emicirculum diuiduas non credere, &c.) vbi verba illa (Diuiduas non credere) pro arbittio, ac &longs;ine ratione, imò contra rationem addidit: tum quia in Græco textu non extant, tum quia &longs;en&longs;us totius &longs;ententiæ is e&longs;t, vt potius debui&longs;&longs;et affirmati­uè dicere (Diuiduas credere) nam Ari&longs;toteles videtur &longs;ic argumentari, quan­

do recta linea A B, vt in appo&longs;ita figura mo­uetur intrando in &longs;emicirculum C A D B, ita vt primò &longs;it in &longs;itu A B, &longs;ecundò in E F, tertiò in G H, & &longs;imiliter in alijs omnibus &longs;emicir­culi locis, nece&longs;&longs;ariò accidit, vt infitæ pri­ph&ecedil;riæ, quales sunt A B, E A B F, G E A B F H, cadant inter infinitas partes lineæ ingredien­tis, vt &longs;unt A B, E F, G H, atque tom tota recta ingrediens, quàm totus &longs;emicirculus, diuidatur in partes infinitas, ita vt nulla pars lineæ rectæ, neque vlla &longs;emicirculi &longs;uper&longs;it, quæ &longs;e &longs;e mutuò non diuidantur, ergò nihil tam in linea, quàm in &longs;emicirculo remanet, quod non &longs;ecetur: tota igitur linea recta, & periphæria illa diuidua e&longs;t, quam ob rem nullo modo con&longs;tare pote&longs;t ex indiuiduis, ex quibus manife&longs;tum e&longs;t perpe­ram additamentum illud factum e&longs;&longs;e, & &longs;imul ratio, & textus Ari&longs;t. adem opera patefacta &longs;unt.

282

Sextus locus (Rur&longs;us quoque facilè per&longs;uaderi pote&longs;t ex mota durura circulo) rum æqualium, nam qui&longs;quis borum moueatur, oportet per maiorem &longs;emicirculum moueri, & quæcunque alia buiu&longs;modi constituta &longs;unt de lineis, fieri non po&longs;&longs;e, vt talis vllus motus peragatur, quin prius omnibus, & &longs;ingulis interictis occurrat. Atque bæc Mathematicorum &longs;cita, multò magis ab omnibus conce&longs;&longs;a &longs;unt, quàm illorum dicta.

Hæc e&longs;t alia ratio, qua probat totam circuli periphæriam e&longs;&longs;e diuiduam.

&longs;int enim duo circuli æquales primum in eo­dem loco, vocenturque; A, & B, deinde circu­lus B, moueatur, & di&longs;cedat à circulo A, ma­nente; &longs;tatim namque pars egre&longs;&longs;a E F G, erit maior &longs;emicirculo, & &longs;emper fiet maior, ac maior. atque in tali motu omnes partes egre­dientis circuli &longs;ecantur ab omnibus partibus circuli manentis. vnde patet nihil e&longs;&longs;e in eo­rum periphærijs, quod non diuidatur. nul­lum igitur in eis e&longs;t indiuiduum. falluntur igitur aduer&longs;arij.

283

Septimus locus (Quamuis autem ex confutatis nuper rationibs appareat, ne­que probabile, neque nece&longs;&longs;arium e&longs;&longs;e lineas vllas indiuiduas extare, tamen ex ijs etiam, quæ deinceps &longs;abiungam, multò magis per&longs;picuum uadet. & primò quidem per ea, quæ Mathematici demon&longs;trant, at que addi&longs;cenda proponunt, quæ mutare non decet, ni&longs;t probabiliores rationes habeamus. Nam neque lineæ, neque rectæ li­neæ definitio cum in&longs;ecabili linea con&longs;entit, vt quæ ne inter duo puncta exten&longs;a &longs;it, nec medium vllam babeat.

Idem, &longs;ed paulò mutatis verbis po&longs;tea repetit, quæ fortè ab aliquo per errorem addita &longs;unt. Verumenimuerò maximè con&longs;iderandum e&longs;t, quan­tum hoc loco Ari&longs;t. Mathematicis demon&longs;trationibus tribuat: quod dixe­rim propter recentiores quo&longs;dam, qui eò audaciæ deuenerunt, vt Euclidis firmi&longs;&longs;imas, atque Ari&longs;tot. te&longs;timonio, veterumque; Philo&longs;ophorum omnium comprobatas, negare non verentur Demon&longs;trationes.

Cæterùm Ari&longs;t. iterum opinionem a&longs;&longs;erentium lineas in&longs;ecabiles hoc mo­do confutat: nam &longs;i inquit, lineam illam, quam vocant in&longs;ecabilem, e&longs;t non &longs;olum linea, &longs;ed etiam linea recta, illi conueniret rectæ lineæ definitio, &longs;ed nullo modo pote&longs;t ci conuenire, ergò tollendæ &longs;unt de rerum natura huiu&longs;­modi lineæ. Porrò definitio lineæ e&longs;t, vt &longs;it longitudo latitudinis expers, & &longs;i recta &longs;it ex æquo &longs;ua interiacet puncta extrema, ergò ip&longs;a linea media erit inter duo indiuidua extrema puncta; at verò linea, quam ip&longs;i volunt e&longs;&longs;e indiuiduum quoddam, qua ratione medium erit inter alia duo indiuidua? ip&longs;i enim videntur velle i&longs;tam linem non habere medium vllum, &longs;i enim con­cederent habere medium, iam po&longs;&longs;e in medio &longs;ecari, quod ipfi nequaquam concederent: patet igitur definitionem lineæ minimè illi conuenire, & pro­pterea neque e&longs;&longs;e inter lineas enumerandam.

284

Octauus locus (Deinde omns lineæ commen&longs;urabiles erunt: nam omnes ab in­diuiduis lineis dimetientur, æqué; longitude, quæqué; potena &longs;nt commen&longs;urabi­les. indiu duæ autem lineæ &longs;ibi ip&longs;is comen&longs;urabiles &longs;unt longitudine, cuminter &longs;e &longs;iat æquales; quare poemia quoque, quod &longs;i hoc e&longs;t, diuiduum erit quadratum.

Pergit adhuc nouis rationibus aduer&longs;arios refellere, dicens, &longs;i extarent huiu&longs;modi indiuiduæ lineæ, &longs;equeretur omnes omninò lineas e&longs;&longs;e commen­&longs;urabiles, quod e&longs;t contra demon&longs;trata in 10. Elem. quia cum omnes lineæ con&longs;tent per ip&longs;os ex lineis atomis, i&longs;tæ atomæ e&longs;&longs;ent omnium linearum com­munes men&longs;uræ, vnde & illæ, quæ dicuntur potentia tantum commen&longs;ura­biles, vt &longs;upra explicaui, erunt etiam commen&longs;urabiles longitudine. indiui­duæ verò ip&longs;æ, cum &longs;int inuicem æquales, erunt ip&longs;æ quoque commen&longs;urabi­les longitudine, quare & potentia, omnes enim longitudine commen&longs;ura­biles, &longs;unt etiam potentia commen&longs;urabiles, ex 9. 10. vnde &longs;equitur qua­drata earum omnia e&longs;&longs;e quoque commen&longs;urabilia: atque hinc con&longs;equitur, in­quit, ea e&longs;&longs;e quoque diuidua (quam con&longs;ecutionem probat infra num. 290.) vnde &longs;equeretur ip&longs;am quoque lineam latus quadrati po&longs;&longs;e diuidi, non igitur ponenda erat indiuidua.

285

Nonus Iocus, cuius latinam interpretationem, cum admodum e&longs;&longs;et de­prauata ex græco textu, in hunc modum correxi (Præterea cùm circa maio­rem lstitudinem facit applicata, æquale ei, quod ab indiuidua, & pedali copulatis circa bipedalem, minorem faciet latitudinem, quàm &longs;it indiuidua: erit minus, quod circa induiduam) ide&longs;t cùm minor linea applicata cum maiore, latitudinem

faciat. v. g. linea minor A B, applicata cum ma­iori B C, vt in figura, ita vt contineant figuram A B C D. Minor A B, facit latitudinem figuræ, maior verò B C, facit longitudinem. Iam cum aduer&longs;arij velint extare huiu&longs;modi lineas ato­mas, con&longs;tituatur figura &longs;ub vna ex illis, quæ &longs;it v. g. A B, & altera maiori, quæ &longs;it pedalis, v. g. B C, vt in præcedenti figura, &longs;umatur deinde linea bi­
pedalis E F, cui per 45. primi ap­plicetur &longs;patium E F G H, æquale &longs;patio &longs;uperiori A B C D, nece&longs;&longs;a­riò latitudo E H, huius &longs;ecundæ fi­guræ minor erit quàm latitudo il­lius, hoc e&longs;t minor, quàm &longs;it indinidua A B, quod e&longs;t ab&longs;urdum. vel dicere oportet &longs;patium eirca indiuiduam A B, e&longs;&longs;e minus quàm i&longs;tud po&longs;terius, quod e&longs;t contra con&longs;tructionem, & propterea pariter inconueniens, non igitur huiu&longs;modi lineæ &longs;unt ponendæ.

286

Decimus locus (Cum ex tribus datis lineis triangulus componatur, ex tribus quoque indiuiduis lineis componi poterit. in omni autem æquilatero perpendicularis in mediam ba&longs;im mcidit, quare, & in medium indiuiduæ.

Ex 22. primi Elem. ex tribus datis lineis, quarum quælibet duæ &longs;int, re­liqua maiores pote&longs;t con&longs;titui triangulum: poterit igitur ex tribus indiui­

duis con&longs;titui triangulum, illudque; æquilaterum, cum omnes in­diuiduæ lineæ &longs;int æquales. &longs;it igitur ex eis triangulum A B C, &longs;i igitur ab angulo A, ducatur perpendicularis A D, ad ba&longs;im B C, eam bifriam &longs;ecabit ex &longs;cholio 26. primi, erit igitur li­nea B C, &longs;ecabilis, contra quam aduer&longs;arij opinantur.

287

Vndecimus locus (Si quadratum ex quatuor indiuiduis con&longs;ttuatur diameom protracta, & perpendiculari ducta, quadrati ce&longs;ta potentia perpendicularem, diame-trumqué mediam æquat: quare non erit minima. neque duplum erit &longs;patium à diame­tro con&longs;urgens illius, quod ab indiuidua procreatur: nans æquali ablato, reliquum erit minus indiutdua, nam &longs;i æqualis, diameter quadruplum de&longs;criberet, &c.)

ide&longs;t &longs;i per 46 primi quadratum. v.g. A B C D, ex qua­tuor in&longs;ecabilibus componatur, cuius diametro B C, perpendicularis A E, in&longs;i&longs;tat, erit per 47. primi qua­dratum lineæ A B, æquale quadratis linearum A E, E B, quare tam E B, quàm A E, minores erunt ip&longs;a A B; quare ip&longs;a non erit minima cum &longs;it indiuidua, quod e&longs;t ab&longs;urdum. Præterea ex &longs;cholio 47. primi, quadratum C B F G, diametri C B, duplum e&longs;t quadrati A B C D, ergò diameter C B, maior quàm A B. Auferatur igitur ab ip&longs;a, C B, æqua­lis ip&longs;i A B, quæ igitur reliqua erit, vel erit æqualis ip&longs;i A B, vel minor. non æqualis, quia tunc diameter dupla e&longs;&longs;et lateris A B, & quadratum diametri quadruplum foret quadrati lateris A B. ex &longs;cholio 4. &longs;ecundi, quod ab&longs;ur­dum e&longs;t, repugnat enim 47. primi. nec minor, quia hoc modo exi&longs;teret linea quædam minor minima, &longs;cilicet atoma, quod pariter e&longs;t inconueniens.

288

Duodecimus locus (Amplius &longs;i quæuis linea præter in&longs;ectilem in partes diuidi pote&longs;t, tùm æquales, tùm inæquales, &longs;eindatur linea in tria fru&longs;ta, quæ non con­&longs;tet ex tribus atomis, &longs;ed vniuer&longs;aliter ex imparibus numero atomis, &longs;ic diui&longs;a erit linea indiuidua. &longs;imiliter autem &longs;i in duo diuidatur linea, quæ ex imparibus con&longs;tat)hoc e&longs;t detur linea quæpiam ab aduer&longs;ario ex lineis ndiuiduis numerò im­paribus, con&longs;tans. v. g. ex quinque; hæc diuidi pote&longs;t in tres æquas partes per 10.6. Si igitur diuidatur in tria æqualia, nece&longs;&longs;ariò tres ex atomis illam integrantibus erunt di&longs;&longs;ectæ, nam tertia quælibet pars continebit indiui­duam vnam cum duabus tertijs alterius partibus. idem accidet fi bifariam per 10. primi, &longs;ecetur quæuis ex imparibus numero atomis conflata.

289

Decimustertius locus (Quod &longs;i bifariam quidem non omnis linea finditur, &longs;ed quæ &longs;olum ex paribus conflata &longs;it. &longs;i iam in duas partes diui&longs;a, in quæcunque diuidi pote&longs;t diuideretur, &longs;ic quoque in&longs;ectilis linea diuideretur, quando ex paribus compo­&longs;ita, per inæqualia &longs;cinderetur) ide&longs;t, quod &longs;i dixerit aduer&longs;arius, non omnem neam bifariam diuidi po&longs;&longs;e, &longs;ed eam &longs;olùm, quæ ex numero paribus atomis con&longs;titerit: ea igitur diuidatur primo bifariam. deinde iterum diuidatur quomodocunque, ide&longs;t & bifariam, & non bifariam, nam hoc etiam pacto indiuidua diuidetur, quod e&longs;t inconueniens.

290

Decimusquartus locus (Amplius non e&longs;&longs;et cuiu&longs;uis lineæ quadratum: babe­ret enim longitudinem, & latitudinem; atque idcircò diui&longs;ibile erit, cumilla quidealiquid, bæc autem aliquid aliud; quod &longs;i quadratum diuiduum e&longs;t, & linea, vnde procreatur, diuidua erit) po&longs;&longs;e &longs;uper quamuis datam lineam quadratum de­&longs;cribi patet ex 46. primi, quadratum igitur de&longs;criptum ab indiuidua, cum &longs;it &longs;uperficies, latitudinem, ac longitudinem habebit, quæ diuer&longs;æ &longs;unt di­men&longs;iones. poterit ergò &longs;ecundum vtramque diuidi; ex qua diui&longs;ione nece&longs;­&longs;ariò latera ip&longs;ius, hoc e&longs;t lineæ, quas indiuiduas illi ponunt diuidentur, quod e&longs;t inconueniens, non igitur indiniduæ erunt.

291

Decimusquintus locus (Adbuc etiam, vt linea &longs;ic, & &longs;uper&longs;icies, & corpus crit impartibile: vno quippe indiiduo exi&longs;tente, cætera quoque con&longs;equntur, quianum per aliud diuiditur, at corpus indiuiduum non e&longs;t, cum in &longs;e latitudinem, & profunditatem contineat: quare nec linea pote&longs;t e&longs;&longs;e atoma. corpus &longs;iquidem in &longs;u­per&longs;icies, &longs;uperficies verò in lineas &longs;oluitur) hoc e&longs;t: præterea, quemadmodum linea per aduer&longs;arium extat indiuidua, &longs;ic & fuperficies ab eadem linea de­&longs;cripta erit atoma, & corpus ab hac &longs;uperficie de&longs;criptum erit impartibile. Sciendum enim, quod ex motu puncti de&longs;cribitur linea: ex motu lineæ de­&longs;cribitur &longs;uperficies: ex motu tandem &longs;uperficiei corpus ortum habet, vt &longs;o­let in horum definitionibus explicari.

Si igitur horum vnum nempè linea &longs;it atoma, & reliqua, quæ ab ip&longs;a ma­nant erunt indiui&longs;a, quia corpus diuiditur per &longs;uperficiem, & &longs;uperficies per lineam, ide&longs;t ad diui&longs;ionem corporis nece&longs;&longs;e e&longs;t diuidi &longs;uperficiem, & ad &longs;uperficiei diui&longs;ionem diuidi lineam, quæ ip&longs;am terminat. At cum omne corpus latitudinem, & profunditatem habeat, nullum poterit extare cor­pus, quod diuidi nequeat; quare neque illud, quod ab atoma linea oriretur. Quare nec linea illa corporis procreatrix erit indiuidua; corpus &longs;iquidem in &longs;uperficies, & &longs;uperficies in lineas quodammodo re&longs;oluitur: & ex diui­&longs;ione &longs;olidi &longs;uperficies &longs;ecari debet, & demum &longs;uperficiei, &longs;ectionem lineæ &longs;ectio &longs;ub&longs;equitur. Tollendæ igitur &longs;unt de rerum natura lineæ atomæ.

292

Decimus&longs;extus locus (Quin etiam orbis circunferentia rectam lineam pluri­bus tanget punctis, punctus enim contactus, quiqué e&longs;t in circulo, quiqué e&longs;t in recta, &longs;e &longs;e mutuò tangunt. quod &longs;i hoc fieri nequit, neque punctus punctum tangere valet: quod &longs;i &longs;e tangere nequeunt, neque linea punctis con&longs;tare pote&longs;t, nam neque punctum tangere nece&longs;&longs;arium e&longs;t.

In 2. 3. & corollario eius demon&longs;tratur circuli peripheriam tangere re­ctam lineam in vnico puncto. iam &longs;i linea con&longs;taret ex punctis indiuiduis tanquam partibus, po&longs;&longs;et circulus tangere rectam lineam in duobus punctis.

Sit circulus, cuius centrum A, tangens lineam rectam B C, con&longs;tantem ex punctis, quorum vnus &longs;it in extremo D, lineæ B D, alterum verò in E, principio lineæ E C, circulus A, tangere poterit in F, termino communi vtriu&longs;que lineæ, hocque modo tanget vtrunque punctum D, & E, quod e&longs;t impo&longs;&longs;ibile per 2. 3. &longs;equitur igitur neque illa duo puncta D, E, &longs;e mutuò tan­gere, & eadem ratione nulla alia puncta eiu&longs;dem lineæ, ex quibus manife&longs;tum e&longs;t, impo&longs;&longs;ibile e&longs;&longs;e, lineam ex huiu&longs;modi punctis con&longs;tare po&longs;&longs;e.

Reliqua huius opu&longs;culi, quamuis Mathematica alicui videri po&longs;&longs;int, non tamen &longs;unt, non enim linearibus indigent demon&longs;trationi­bus, neque ex Geometriæ principijs procedunt. ad Phy&longs;i­cum igitur pertinebunt, cuius e&longs;t di&longs;putare, num indiuidua exi&longs;tant, & quomodo in quanti­tate, idque; rationibus aliunde, quàm ex Geometria deductis.

In Librum de Propriet. Elementorum.

Libellum de cau&longs;is proprietatum Elementorum, quamuis nonnulla mathematica loca contineat, tamen, quia certò con&longs;tat ex ijs, quæ in eo de Secta Arabum, de Sclauis, de Dalmatis, qui multis po&longs;t Ari&longs;totelem &longs;æculis floruerunt, auctorem alium e&longs;&longs;e ab Ari&longs;to­tele con&longs;ultò & meritò omi&longs;i.

In Librum de Cau&longs;is.

Alterum de cau&longs;is libellum pariter prætermi&longs;i, cum is vocibus Arabi­cam barbariem redolentibus &longs;cateat: phra&longs;is præterca, & qu&ecedil;dam de Deo dicta, planè indicant authorem non e&longs;&longs;e Ari&longs;tctelem; &longs;ed potius Arabem quempiam.

EX LIBRO NONODE HIST. ANIMALIVM

Araneorum industriæ.

293

Cap. 39. (Aranei &longs;tatim cum editi &longs;unt, fila mittunt, non ab intrin&longs;eco tanquam excrementum, vt Democritus ait, &longs;ed ab extrin&longs;eco de &longs;uo cor­pore, veluti cortice; aut more eorum animalium, quæ &longs;uos villos iacu­lantur, vt hystricis) Cum olim in hunc locum incidi&longs;&longs;em, ince&longs;&longs;ic animum meum illa cupido, vt &longs;cilicet certò &longs;cirem, numiure, an iniuria Ari&longs;t. Democritum hoc loco reijceret, Araneum fila ab intrin&longs;eco emitte­re a&longs;&longs;erentem: quapropter ad magi&longs;tram rerum experientiam confugi, ac­cepto manu bacillo Araneum quendam ex ijs, qui circulares telas, quas nonnulli, & quidem aptè labyrinthos appellant, ingenio vtique mathematico contexunt, lic adij, vt Araneus pro arbittio &longs;uper bacillum liberè inambu­laret, dum ip&longs;e interim curio&longs;ius illum ob&longs;eruarem, quanam videlicet ex parte filum foras ederet; cum ecce tibi Araneus experienti mihi vltrò fa­uens &longs;e &longs;e ex baculo demi&longs;it, ita tamen, vt ex filo &longs;uo in aere &longs;u&longs;pen&longs;us re­maneret. cum primum ob&longs;eruo ip&longs;um inuer&longs;um, hoc e&longs;t capite deor&longs;um, & ventre &longs;ur&longs;um pendere. vt autem acutius cernerem, eum opacæ cuidam rei oppo&longs;ui, ne præ nimia luce tenui&longs;&longs;imum aranei filum aciem oculorum effu­geret; quo facto in temperata luce illa, clari&longs;&longs;imè videbam filum ex &longs;ece&longs;&longs;u aranei prodire. Araneumque; vno pede filum illud retinere, ne amplius exi­ret, longiusque; fieret, quàm &longs;uo con&longs;ilio par e&longs;&longs;et. coegi deinde ip&longs;um a&longs;cen­dere, & de&longs;cendere &longs;æpius, donec certò certius, mihi con&longs;titi&longs;&longs;et filum illud non ab extrin&longs;eco, vt hoc loco Ari&longs;t. affirmat, &longs;ed ab intrin&longs;eco quippe ex &longs;ece&longs;&longs;u prodire, ac proinde veri&longs;&longs;imam e&longs;&longs;e quamuis ab Ari&longs;t. reiectam De­mocriti &longs;ententiam. cum Ari&longs;t. pariter errauit Vly&longs;&longs;es Aldobrandus in &longs;uo de in&longs;ectis pulcherrimo, atque docti&longs;&longs;imo Opere.

Verumenimuerò opportunè accidit, vt huius dubitationis &longs;olutio, aliam mihi alterius quæ&longs;tionis, iam olim &longs;ummis votis expetitam afferret expli­cationem. ea e&longs;t huiu&longs;modi. &longs;æpius fueram expertus, Araneos quo&longs;dam e&longs;­&longs;e, qui ex vno loco ad alium omninò &longs;ibi inacce&longs;&longs;ibilem, tran&longs;eant, &longs;iue quod idem e&longs;t, ex eo loco, ad illum fila deducant, vt ex vna arbore ad aliam; quamuis inter vtramque aut aquæ, aut den&longs;il&longs;ima &longs;pineta, ac &longs;epes interpo­nantur. quod maximè mane æquitantes experimur, dum nobis fila per vias tran&longs;uer&longs;a, oculis, atque vultui obuiantia adhærent. Qua ratione id Ara­neus perficeret, neminem, quiliteris manda&longs;&longs;et, reperi, ne ip&longs;um quidem. Vly&longs;&longs;em Aldobrandum, qui in hac eruditorum palæ&longs;tra, maiores no&longs;tros omnes videtur &longs;upera&longs;&longs;e. Phy&longs;iologi à me hac de re interrogati, varij va­ria, nec con&longs;entientia refpondebant. Alij aiebant Araneum &longs;e demittere, ac &longs;u&longs;pendere ex vna arbore, & deinde ad aliam à vento perferri, at ego his minimè a&longs;&longs;entiebar, quia m Araneo nullum e&longs;&longs;et naturale in&longs;trumentum, veluti velum, in quod ventus po&longs;&longs;itimpingere. Alij Araneum ex vna arbo­re de&longs;cendere, & po&longs;tea alteram con&longs;cendere, interim emi&longs;&longs;um retro filum raptando, ac deinde &longs;ur&longs;um attrahendo attollere, ac prætendere: &longs;ed ho­rum re&longs;pon&longs;ionum ob plurima impedimenta, quæ tenui&longs;&longs;imum filum &longs;æpius &longs;cidi&longs;&longs;ent, &longs;ubridens refellebam. Alij verò aiebant Araneum qualitate qua­dam præditum e&longs;&longs;e, qua ip&longs;e per aera, non &longs;ecus, ac per aquam pi&longs;ces, & per aerem volucres, ambulare po&longs;&longs;et. Verum opinatio i&longs;ta, ne ri&longs;u quidem digna videbatur. Huius igitur quæ&longs;iti &longs;olutionem, quam omnes ad hanc v&longs;que diem latui&longs;&longs;e putò, quamque; omnibus grati&longs;&longs;imam fore cognoui tibi lo­co auctarij initio promi&longs;&longs;i, nunc per&longs;oluam. accidit ergò, vt dicebam, vt dum Araneus fugæ cupidus ex bacillo in temperatæ lucis loco, nimirum è regione alicuius opaci penderet, vt cernerem ex filo illo, ex quo &longs;u&longs;pende­batur plura alia fila hinc inde alternatim prodire, quemadmodum ex alter­nis arundinum nodis folia ena&longs;ci &longs;olent. quæ fila, innata læuitate, per ae­rem quoquo ver&longs;us ceu natantia diffundebantur. factum e&longs;t autem, vt eo­rum vnum quendam arboris cuiu&longs;dam ramum attingeret, eique; &longs;tatim adhæ­reret; quod illicò Araneus optimè per&longs;en&longs;it, quippe quod filum illud vi&longs;ce­ribus eius ex altero capite affigeretur, atque per filum illud, alijs ommi&longs;&longs;is, &longs;ubitò, vti egregius funambulus accurrit, &longs;ed tamen pedibus &longs;ur&longs;um, dor &longs;o autem deor&longs;um, non &longs;upra filum, &longs;ed infra ad ramum illum &longs;e contulit, &longs;icque; me ho&longs;tem &longs;uum fuga &longs;æpius elu&longs;it. Ex qna repetita &longs;æpius ob&longs;eruatione lu­ce clarius comperi Araneum non &longs;implex filum, &longs;ed ramo&longs;um, ac multiplex emittere, atque aliquando ex &longs;ece&longs;&longs;u etiam ip&longs;o duo &longs;imul eijcere, alterum quo

&longs;u&longs;pendatur, alterum verò, quod &longs;orte hac, atque illac volitans, ali­cui rei occurrat, atque hæreat, per quod po­&longs;teaip&longs;e incedens, ad locum &longs;ibi prius inac­ce&longs;&longs;um, aditum parat. qua inre fures eos per­bellè imitatur, qui &longs;chalas ex funibus con­textas, ac hamis fer­reis munitas, ad fene­&longs;tras proijciunt, vt per cas ibi affixas con&longs;cen­dere queant. quæ om­nia ex appo&longs;ita figura melius percipies, vbi ex &longs;ini&longs;tra arbore pen­det Araneus A, ex filo B A, ex quo tanquam rami alia fila C G, D H, E I, M O, F L, alter­natim prodeunt, ac per aerem hi c in e volitant. Si ergò filum E I, dextræ arbori occurrerit, eique; hæ&longs;erit, vt in figura, illicò Araneus huius rei con­&longs;cius per filum A E I, a&longs;cendit, &longs;eque; ad prius inacce&longs;&longs;am &longs;ibi dextram arbo­rem transfert; atque deinde inter vtramque ducto iam filo vno, pote&longs;t vltrò, citroque; means, &longs;uam etiam circularem, ac labyrinthiacam telam in mu&longs;ca­rum capturam contexere; quales aliquando inter duas arbores admira­ri &longs;olemus.

Quæres fortè, num Araneus filum intus tanquam in glomo, vel fpira con­uolutum contineat? dicam, quod non &longs;ine experientia conijcio, exi&longs;timo Araneum non continere intra &longs;e filum vllum, verum humorem quendam vi&longs;co&longs;um, qui in tenui&longs;&longs;ima fila &longs;it ductilis; quemadmodum videmus acci­dere gummi, quæ di&longs;rupta exhibet lentorem quendam, qui &longs;olo attritu ita digitis hæret, vt amoto &longs;en&longs;im digito, filum tenue, & oblongum valdè de­ducatur, hoc inde conijcio, quia aliquando cum ventrem Araneorum &longs;ecui&longs;­&longs;em nullum intus filum, &longs;ed &longs;olus humor quidam lentus apparuit.

Cùm ex paruulis hi&longs;ce meis ob&longs;eruationibus circa animalculum i&longs;tud vnum tam præclara cognoui&longs;&longs;em, quæ nullus ad hanc v&longs;que diem, quod &longs;ciam ob&longs;erua&longs;&longs;et; animaduerti lati&longs;&longs;imum patere campum ad animalium hi&longs;to­riam ampliandam, &longs;i ij, qui huic pulcherrimæ cognitioni dant operam, non ijs &longs;olum, quæ ab alijs per&longs;cripta &longs;unt contenti e&longs;&longs;ent, verùm etiam certi&longs;­&longs;imis, atque explorati&longs;&longs;imis experientijs ea coniungerent.

Atque hæc de Araneo &longs;atis.

De ince&longs;&longs;u animalium.

294

Cap. 7. (Etenim habentia pedes, quoniam &longs;uper vtrumque oppo&longs;itorum cru­rum vici&longs;&longs;im &longs;tant, pondusqué &longs;ustinent, nece&longs;&longs;e habent altero progredien­te, inflectere alterum; æqualia namque longitudine nata &longs;unt habere op­po&longs;ita membra. & quod ponderi &longs;ub&longs;tat rectum e&longs;&longs;e oportet, vt perpen­diculum ad terram. quando autem progreditur, fit hypotenu&longs;a, valens manentem magnitudinem, & eam, quæ interiacet. quoniam autem æqualia &longs;unt membra, ne­ce&longs;&longs;e e&longs;t inflecti id, quod manet, aut in poplite, aut in conflexione) Vult probare in gre&longs;&longs;u nece&longs;&longs;ariam e&longs;&longs;e aliquam flexionem membrorum. verum prius &longs;ciendum, quod lineam hypotenu&longs;am, quemadmodum etiam Athenæus lib. 10. te&longs;tatur, eam appellant geometræ, quæ in triangulo rectangulo recto angulo &longs;ubtenditur, vnde & denominata e&longs;t hypotenu&longs;a, ide&longs;t &longs;ubten&longs;a, vt

in triangulo A B C, cuius angulus B, rectus &longs;it, recta A C, angulo recto B, &longs;ubten&longs;a, hypotenu&longs;a dicitur. Ari&longs;t. igitur ait, quod antequam animal ambulare in­cipiat, dum &longs;cilicet manet, habet crura, quæ manent recta, &longs;iue perpendicularia horizonti, cum autem in­cipit progredi nece&longs;&longs;e e&longs;t vtrunque crus inclinari ad ho­rizontem. nam primum crus in ingre&longs;lu prolatum fit hypotenu&longs;a, quia &longs;cilicet &longs;ubtendit angulum rectum, quem facit alterum crus adhuc quie&longs;cens, cum hori­zonte; vt in &longs;uperiori triangulo, &longs;i concipiamus crura fui&longs;&longs;e duo latera A B, A D, quæ manente animali, fui&longs;&longs;ent ambo &longs;imul in &longs;itu A B, perpendicula­ria horizonti; incipiens autem animal ambulare, proferat primo crus A D, A D, fiet hypotenu&longs;a trianguli A B C, & quia crus hoc A D, factum hypo­tenu&longs;a æquale e&longs;t alteri manenti A B, nequit totius veræ hypotenufæ A C, officio fungi, quæ æquiualet toti A D, & præterea interiacenti D C, vrea au­
tem hypotenu&longs;a debet e&longs;&longs;e maior, quia opponitun maiori angulo nimirum recto B, quam latus A B, quod angulo acuto C, opponitur per 19. primi, & propterea ni&longs;i alterum &longs;ub&longs;equens crus A B, incli­netur, vt in &longs;ecunda figura, non pote&longs;t hypotenu&longs;a A D, terram attingere, atque hac de cau&longs;a nece&longs;&longs;e e&longs;t, vt initio gre&longs;&longs;us vtrumque crus, quod prius per­pendiculare erat, inclinetur; inclinato igitur crure A B, antror&longs;um tunc prolatum crus A C, terram contingit, &longs;icque; factus e&longs;t primus gre&longs;&longs;us B C.

295

Eodem loco (Signum autem, quod hoc ita &longs;e habet illud est. &longs;i quis enim iuxta parietem per terram ambulet, quæ de&longs;ignatur linea non e&longs;t recta, &longs;ed obtorta, quo­niam minorem quidem flectentis fieri de&longs;criptam nece&longs;&longs;e e&longs;t; &longs;tantis autem, & ere­cti maiorem) Vt probet, quod animal in gradiendo modo attollitur, modo deprimitur, &longs;ignum hoc affert, quia &longs;i quis &longs;ecus parietem per terram am­bulet, linea quam vertex capitis in pariete de&longs;ignat non e&longs;t recta, &longs;eb obtor­ta: quæ linea optimè de&longs;ignatur, &longs;i ambulantis vmbra in pariete apparens &longs;imul, cum ip&longs;o in pariete ambulet; videmus enim vmbram illam modo al­tiorem fieri, modo breuiorem; quod &longs;ignum e&longs;t ambulantem modo incli­nari, quando &longs;cilicet crus alterum profert, &longs;eu crura dilatat; modo erigi, cum crus &longs;ub&longs;equens præce denti coniungit, tune enim incedens fit horizon­ti perpendicularis.

296

Eodem cap. (Quoniam autem fiat ad rectum, vel concidet recto minore effe­cto, vel non progredietur: &longs;i enim altero crure recto progreditur alterum, maius crt cum &longs;it æquale: hoc nanque poterit, & id, quod quie&longs;cit, & ip&longs;am hypotenu­&longs;am, nece&longs;&longs;e igitur e&longs;t, & inflectere id, quod procurrit, & inflexum &longs;imul alterum extendere, membra enim triangulorum æquilaterorum efficiuntur, caputque, fit infe­rius, vbi perpendiculum fuerit, in quo firmatum e&longs;t) Hæc &longs;unt ferè eadem cum ijs, quæ in primo huius capitis loco dicta &longs;unt. proinde ea cum duabus illis triangulorum figuris repetenda &longs;unt, vt breuius quæ nunc re&longs;tant explicen­tur. quoniam igitur animal antequam gradiatur, maximè homo, &longs;tat hori­zonti perpendicularis, nece&longs;&longs;e e&longs;t ad progrediendum, vt fiat aliqua mem­brorum inflexio, &longs;i enim homo &longs;ine vlla &longs;ui corporis flexura inclinet &longs;e ad horizontem, ita vt cum horizonte faciat ex anteriori parte. v. g. angulum recto minorem, &longs;iue acutum, vel concidet, vel non poterit progredi; &longs;i enim alterum crus præmitteretur, altero manente perpendiculari, &longs;icque; progre­deretur qui&longs;piam, &longs;equeretur crus prolatum, quale e&longs;t A D, iu priori trian­gulo, debere fieri maius altero crure A B, manente, quia fieret tota hypo­tenu&longs;a A C, &longs;ie enim terram attingeret; at non pote&longs;t fieri illo maius, quia e&longs;t illi æquale, ergò hac ratione ince&longs;&longs;us fieri nequit. nece&longs;&longs;e igitur refle­ctere vtrumque crus non &longs;olum ad horixontem, &longs;ed etiam circa aliquam cor­poris flexuram, vel nodum, vt circa genu, aut alia. crura enim in gre&longs;&longs;u fiunt latera &longs;uperiora trianguli i&longs;o&longs;celis, vt in &longs;ecunda figura patuit, cuius ba&longs;is e&longs;t pa&longs;&longs;us. & tunc caput ambulantis fit inferius, quàm antequam gradere­

tur; quia tunc ambo crura erant horizonti perpen­dicularia. quando autem caput fuerit in linea per­pendiculari trianguli i&longs;o&longs;celis, tunc erit inferius quàm alibi, vt in pr&ecedil;&longs;enti figura, linea perpendicularis trian­guli huius i&longs;o&longs;celis e&longs;t linea A E, quia ba&longs;i B C, per­pendicularis incidit; quando igitur caput ambulan­tis. v. g. D, fuerit in hac linea, tunc erit inferius quàm in quauis alia gre&longs;&longs;us parte: quia tunc crura A B, A C, &longs;unt maximè diuaricata, & proinde angulus A, & &longs;imul punctum D, maximè demi&longs;&longs;a.

De motu animalium.

297

Cap. 1. (Primum quidem in animalibus: oportet enim &longs;i moueatur aliqua particularum quie&longs;cere ahquam, & propter hoc, & flexus animalibus in&longs;unt: tanquam enim centro vtuntur flex: bus & fit tota pars, in qua e&longs;t flexus & vna, & duæ; & recta, & flexa, quæ permutatur potentia, & actu, propter flexum. cum autem flectitur, & mouetur, hoc quidem &longs;ignum mo-

etur, illud autem manet in flexibus, quemadmodum vtique &longs;i dia­metri, quæ quidem A D, maneat, quæ cutem B, moueatur, & fiat A C, &longs;ed hic quidem videtur, &longs;ecundum omnem modum in­diui&longs;ibile e&longs;&longs;e centrum. etenim moueri, vt aiunt, fingunt in ip&longs;is, non enim mouetur mathematicorum aliquid.

Intendit probare nece&longs;&longs;e e&longs;&longs;e ad motum animalium, vt vna pars quie&longs;cat, dum altera mouetur. propter hoc enim inquit flexus ani­malibus in&longs;unt, vbi in græco pro voce flexus legitur xampth, quod &longs;ignifi­cat nodum, articulum, & denique locum ip&longs;um, vbi fit membri flexura, tan­quam enim centro quodam vtuntur flexibus, ide&longs;t nodis, &longs;eu iuncturæ &longs;unt in motu membrorum in&longs;tar centri. v. g. nodus cubiti fit centrum, cum bra­chij parte, quæ e&longs;t inter humerum, & cubitum manente, reliquum brachij circumducimus; &longs;ic manente genu tanquam centro, crus huc illud agita­mus, & fit tota pars. v. g. totum brachium, in quo e&longs;t cubiti iunctura, & vna tota pars, quando manet rectum; & duæ quando in flexura cubiti brachium infle ctitur; & fit tota hæc longitudo recta prius, po&longs;tea flexa: quæ propter flexuram modo vna e&longs;t actu, &longs;ed duæ potentia. modo duæ in actu, &longs;ed vna in potentia. cum autem flectitur, & mouetur brachium, vnum quidem fignum, &longs;iue punctum, quod e&longs;t extremum partis manentis, manet; alterum verò &longs;i­gnum, &longs;iue punctum, quod e&longs;t extremum partis motæ e&longs;tque; alteri &longs;igno con­tiguum mouetur &longs;imul cum tota parte mota. quemadmodum, &longs;i diametri &longs;uperioris figuræ, pars D A, maneat, pars autem A B, moueatur ad A C, erit huius flexuræ centrum A, quod vt extremum lineæ D A, manentis, ma­net: vt verò extremum motæ A B, mouetur. quamuis in mathematicis hæc quidem duorum centrorum di&longs;tinctio nulla &longs;it, quia centrum mathemati­cum omninò indiuiduum e&longs;t: neque in mathematicis e&longs;t propriè motus, quamuis enim aliquando Mathematici dicant, &longs;i linea, vel &longs;i punctum mo­ueretur, vel moueatur, & &longs;imilia, huiu&longs;modi tamen motus &longs;unt rebus ma­thematicis extrin&longs;eci, nec quatenus hoc modo mouentur con&longs;iderantur: patet igitur, qua ratione Ari&longs;tot. partem manentem in motu nece&longs;&longs;ariam e&longs;&longs;e velit.

298 a

Cap. 5. (Quemadmodum autem &longs;pontanea mouentur paruo motu facto) Spon­tanea i&longs;ta erant machinæ, quæ à &longs;eip&longs;is mouebantur, quas Græci automata dixerunt, cuin&longs;modi &longs;unt Automata Heronis Alexandrini, quæ adhuc extant.

Cap. 8. E&longs;t ibi quoddam triangulum cum elementis more geometrarum depictum, vnde locus ille videri po&longs;&longs;it mathematicus, verumtamen nullo modo geometriæ auxilio indiget.

De generatione animalium.

298.b

Lib. 2. cap. 1. (Sitqué perinde ac admirabilia illa &longs;pontanea) Intelligit ma­chinas illas miro artificio confictas, quæ à &longs;e ip&longs;is intrin&longs;eco prin­cipio mouebantur, quas Græci veteres Automata, ide&longs;t &longs;pontanea, vel &longs;pontina, vt vertit Interpres vocabant, cuiu&longs;modi &longs;unt Auto­mata Heronis Alexandrini, quæ adhuc extant græca, quæque; ab Abbate Gua­&longs;tallen&longs;i in Italicum &longs;unt conuer&longs;a. Automata hodie &longs;unt Horologia, quæ ex multis dentatis rotis Germani con&longs;truunt.

299

Lib. 2. cap. 4. (Nam & triangula figura duobus rectis æquale &longs;emper habet)vide quæ de hac re &longs;crip&longs;i lib. 1. Priorum, &longs;ecto 3. cap. 1.

300

Ibidem (Et diametrum incommen&longs;urabilem e&longs;&longs;e cum co&longs;t a &longs;empiternum e&longs;t: at­tamen cau&longs;a eorum aliqua & demon&longs;tratio e&longs;t.

Quælibro 1. Priorum, &longs;ecto 1. cap. 23. de hac re annotata &longs;unt, abundè huic etiam loco &longs;atisfaciunt.

In Ethica, &longs;eu Moralia ad Nicomachum.

301

Lib. 1. cap. 7. (Faber enim, & Geometra diuer&longs;o modo rectum angulum vtrique con&longs;iderant: ille quatenus &longs;olum ad opus vtile e&longs;t, hic verò cum ve­ritatis &longs;peculator &longs;it, quid, & qualis &longs;it, indagat) Id quod dicit Ari&longs;t. confirmatur ex eo, quod Fabri omnes vtuntur amu&longs;&longs;i, &longs;eu norma,

quæ nihil aliud e&longs;t quàm angulus rectus, quæ vulgò &longs;quadra dicitur, vt eius auxilio angulum ip&longs;um re­ctum in opus conferant, &longs;icque; normæ, aut amu&longs;&longs;is du­ctu &longs;ua ip&longs;i opera ad angulos rectos, ide&longs;t quadrata, conficiunt. Geometra verò con&longs;iderat eundem an­gulum, quatenus fit à linea &longs;uper lineam aliam per­pendiculariter in&longs;i&longs;tente, vt e&longs;t in definit. 10. primi, vt in figura, vbi linea A B, in&longs;i&longs;tens alteri D C, perpendiculariter, ide&longs;t ita vt faciat angulos hinc inde æqualis A B D, A B C, prædictos inquam duos angulos con&longs;iderat e. &longs;e rectos. contemplatur præterea Geometra omnes angulos rectos e&longs;&longs;e inter &longs;e æquales, vt in 12. axiomate primi Elem. ponitur, & &longs;imilia plura alia, quorum con&longs;iderationem Faber omninò negligit.

302

Libro 2. capite 6. (Id quod &longs;ecundum Arithmeticam rationem medium e&longs;t)Arithmetica ratio, fiue proportio ea e&longs;t, cuius termini cre&longs;cunt per æqua­les exce&longs;&longs;us, vt 2. 6. 10. 14. horum enim terminorum exce&longs;&longs;us æquales &longs;unt, cum &longs;int omnes quaternarij. &longs;imiliter inter hos terminos 3. 6. 9. 12. e&longs;t arith­metica analogia, cùm omnes ternario numero &longs;uperent præcedentes, & à &longs;equentibus &longs;uperentur. Porrò apud Mathematicos tria &longs;unt genera pro­portionum, &longs;iue medietatum, Arithmetica quam modo &longs;uppo&longs;ui; Geome­trica, & Harmonica, quas inferius oblata occa&longs;ione opportunius explicabo.

303

Lib. 2. cap. 9. (Vt circuli medium deprehendere non cuiu&longs;libet, &longs;ed &longs;cientis &longs;olummodo e&longs;t) Reperire medium, &longs;iue centrum dati circuli docet Euclides propo&longs;itio­ne prima 3. hoc modo. in datocirculo ducatur vt­cunque recta B C, quæ per 10. primi diuidatur bifa­riam in F, & per F, ducatur perpendicularis A E F D, quæ &longs;ecetur bifariam in E, eritque; punctum E, non &longs;o­lum ip&longs;ius lineæ medium; &longs;ed etiam totius circuli centrum, quemadm odum ibi demon&longs;trat Euclides.

304

Lib. 3. cap. 3. (De æernis autem nemo con&longs;ultat, vt de mundo, aut diametro, & latere, quod nulla inter &longs;e æquabilitate conueniant) Qua ratione diameter, & latus eiu&longs;dem quadrati nulia æquabilitate, ide&longs;t nulla communi men&longs;ura inter &longs;e conueniant, fusè explicatum e&longs;t libro Priorum, &longs;ecto 1. cap. 23.

305

Eodem cap. (Qui enim con&longs;ultat quærere videtur, & re&longs;oluere prædicto modo, quemadmodum de&longs;ignationes) Per de&longs;ignationes Ari&longs;t. intelligere geometri­cas demon&longs;trationes &longs;æpius dictum e&longs;t in logicis textibus, quod pariter ex hoc loco confirmatur. quando autem ait (Re&longs;olutre prædicto modo, quemad­modum de&longs;ignationes) innuit re&longs;olutionem geometricam, de qua abundè di­ctum e&longs;t in explicatione tituli librorum Re&longs;olutoriorum; quam expo&longs;ui, ni­hil aliud e&longs;&longs;e, quam medij inqui&longs;itionem ad id, quod propo&longs;itum fuerit de­

mon&longs;trandum. veram autem, atque germanam fui&longs;&longs;e huiu&longs;modi explicatio­nem, hoc loco Ari&longs;t. ip &longs;e confirmat, cum hanc re&longs;olutionem dicat e&longs;&longs;e &longs;imi­lem con&longs;ultationi, &longs;iue inqui&longs;itioni mediorum ad finem in rebus practicis con&longs;equendum; ip &longs;a verò e&longs;t inqui&longs;itio mediorum ad id, quod in rebus &longs;pe­culatiuis propo&longs;itum e&longs;t, demon&longs;trandum. con&longs;ultatio igitur e&longs;t in rebus practicis, quod in &longs;peculatiuis e&longs;t re&longs;olutio.

306

307

Lib. 5. cap. 3. (Quod en m proportione con&longs;tat, id non tam vnitario numero, quàm numero in vniuer&longs;um proprium e&longs;t) Per vnitarium numerum intelligitur numerus ex vnitatibus ab&longs;tractis con&longs;litus, ide&longs;t, cuius vnitates non &longs;int res phy&longs;icæ, &longs;ed à naturalibus ab&longs;tractæ, qualis con&longs;iderat Arithmeticus: omni tamen numero &longs;iue ab&longs;tracto, &longs;iue non, connenit proportiones &longs;u&longs;cipere, id e&longs;t & numero, & rebus numeratis.

308

Ibidem (Nim proportio æqualitas e&longs;t rationum) Per proportionem hoc lo­co intelligenda e&longs;t illa, quam nunc appellant proportionalitatem, quæ e&longs;t duarum rationum, &longs;eu proportionum &longs;imilitudo, &longs;iue æqualitas, vt manife­&longs;tum e&longs;t ex 4. definit. 5. Elem. v. g. cum &longs;it eadem ratio 9. ad 6. quæ e&longs;t 6. ad 4. propterea hæc rationum &longs;imilitudo, vel æqualitas dicitur ip&longs;a proportio, &longs;eu di&longs;tinctionis gratia Proportionalitas.

309

Ibidem (In quatuorqué minimis reperitur, di&longs;iunctam &longs;anè in quatuor con&longs;istere per&longs;picuum e&longs;t: &longs;ed & continentem nibilominus, vno enim hæc perinde, ae duobus vtitur, bi&longs;que id accipit in bunc modum, qualis primi re&longs;pectus e&longs;t ad &longs;ecundum, talis &longs;ecundi ad tertium; bis enim bic, &longs;ecundum dictum e&longs;t, quare &longs;i &longs;ecundum bis po&longs;itum &longs;it, quatuor erunt ea, quæ con&longs;tant proportione) Quæ hic ab Ari&longs;tot. di­cuntur de&longs;umpta &longs;unt, partim ex definit. 6. 5. partim ex 9. definit. eiu&longs;dem. breuiter autem &longs;ic &longs;e habent. Ad con&longs;tituendam proportionalitatem ne­ce&longs;&longs;arij &longs;unt omninò quatuor termini, quod quidem primum per&longs;picuum e&longs;t in ea proportionalitate, quam Difiunctam vocant, quæ e&longs;t huiu&longs;modi, vt 9. ad 6. ita 3. ad 2. deinde verum e&longs;t etiam in ea, quam continuam dicunt, quæ talis e&longs;t, vt 9. ad 6. ita 6. ad 4. quæ in tribus quidem terminis 9. 6. 4. con&longs;i&longs;tit, &longs;ed tamen, qnia medius 6. vtrumque re&longs;picit extremum, ideò vices duorum gerit, ac proinde e&longs;t, ac &longs;i hoc modo termini di&longs;ponantur 9. 6. 6. 4. vbi 6. bis ponitur, &longs;untque; quatuor huius etiam proportionalitatis termini. hinc Ari&longs;t. textum &longs;atis intelligere poteris.

310

Eodem cap. (Sicut igitur primus terminus &longs;e babebit ad &longs;ecundum, ita tertius ad quartum; igitur etiam alterna vice, &longs;icut primus ad tertium, ita &longs;ecundus ad quartum. quare etiam totum ad totum, quod di&longs;tributio binatim copulat. quæ &longs;i etiam ita compo&longs;ita fuerint, iustè copulat) Accipit Ari&longs;t. illum argumentandi modum, quem Geometræ alternam rationem vocant, quàmque; definit. 12. 5. exponunt, vt eam rebus ip&longs;is accommodet, atque in praxim deducat; e&longs;t autem huiu&longs;modi, &longs;int primum quatuor termini proportionales, ide&longs;t, vt primus ad &longs;ecundum, ita tertius ad quartum. v. g. vt 9. ad 6. ita 3. ad 2. valet con&longs;equentia hæc, ergò etiam alternatim erit, vt primus ad tertium, ita &longs;ecundus ad quartum, v. g. in allato exemplo, ita erit 9. ad 3. vt 6. ad 2. quam &longs;equelam e&longs;&longs;e validam probat deinde Euclides propo&longs;it. 16. 5. hinc aliam deducit con&longs;equentiam, quam Euclides propo&longs;it. 12. 5. demon&longs;trat, dum ait, quare etiam totum ad totum erit. v. g. quia conclu&longs;um e&longs;t ita e&longs;&longs;e 9. ad 3. quemadmodum 6. ad 2. ita etiam erit totum ad totum, ide&longs;t ita etiam erunt antecedentes termini &longs;imul ad con&longs;equentes &longs;imul, v. g. ita erit etiam totum 15. quod e&longs;t totum ex antecedentibus terminis 9. & 6. ad to­tum 5. conflatum ex con&longs;equentibus terminis 3. & 2. In &longs;umma igitur &longs;i fue­rit vt 9. ad 3. ita 6. ad 2. ita etiam erit 15. ad 5. quod verum e&longs;&longs;e apparet in his numeris, cum tam 9. ad 3. quà 6. ad 2. & 15. ad 5. habeant triplam proportionem.

Horum exemplum in rebus practicis &longs;it hoc: &longs;it vt Plato ad Proclum, ita mille aurei ad quingentos aureos, ergò alternatim ita erit Plato ad 1000. aureos, &longs;icuti Proclus ad 500. quare ita etiam totum erit ad totum, &longs;cilicet Plato, & Proclus &longs;imul ad 1000. & 500. &longs;imul, quæ duo tota, di&longs;tributio mo­ralis, ac practica diuidit, & binatim copulat, hoc modo dicens, vt Plato ad Proclum, ita 1000. ad 500, & po&longs;tea, vt Plato ad 1000. ita Proclus ad 500. iuxta vtriu&longs;que merita, & quidem i&longs;ta e&longs;t huiu&longs;modi moralis di&longs;tributio, cum modis argumentandi ab Euclide comprobatis, nitatur.

311

Ibidem (Hanc verò proportionalitatem Mathematici Geometricam vocant: propterea quod in Geometrica euenit, vt eandem totum ad totum rationem habeat, quam habet alterutrum, ad alterutrum) ide&longs;t, hanc duarum Geometricarum rationum &longs;imilitudinem Mathematici proportionalitatem Geometricam appellant, propterea quod in hac duarum rationum geometricarum &longs;imili­tudine accidit, vt &longs;it totum ad totum, quemadmodum etiam partes toto­rum, vt &longs;upra explicatum e&longs;t; quod non accidit in duarum proportionum arithmeticarum &longs;imilitudine; &longs;i enim ponamus has duas rationes arithme­ticas &longs;imiles, vt 10. ad 8. ita 6. ad 4. quæ &longs;unt &longs;imiles, propter &longs;imiles exce&longs;­&longs;us primorum, & &longs;ecundorum terminorum, cum vbique exce&longs;&longs;us &longs;it binarij. non erit tamen totum 16. ad totum 12. in eadem ratione cum diui&longs;is ter­minis, cum ibi &longs;it exce&longs;&longs;us binarij, hic verò quaternarij. hæc videtur e&longs;&longs;e Ari&longs;t. ratio; quam adhuc melius declara&longs;&longs;e libet. Geometrica igitur pro­portionalitas ita dicta e&longs;t, quia quælibet proportio pote&longs;t in materia Geo­metrica, lineis, &longs;uperficiebus, & corporibus continuari in quatuor termi­nis, ita vt proportionalitas, &longs;eu &longs;imilitudo rationum exurgat, quod in nu­meris fieri &longs;emper nequit, cum plures fint proportiones, quæ numeris ex­primi nequeunt, vt &longs;unt eæ, quas irrationales appellant, cuiu&longs;modi e&longs;t inter diametrum, & co&longs;tam eiu&longs;dem quadrati, cuius nec proportio, nec propor­tionalitas in numeris reperiri pote&longs;t, quæ tamen in lineis, &longs;uperficiebus, ac corporibus e&longs;&longs;e po&longs;&longs;unt: e&longs;t enim vt diameter vnius quadrati ad latus eiu&longs;­dem, ita idem latus ad aliam lineam inuentam per 11. 6. vel vt diameter ad co&longs;tam, ita quælibet alia linea ad aliam inuentam, per 12. 6. omnis igitur proportionalitas rebus Geometricis ine&longs;&longs;e pote&longs;t; non autem numeris, in quibus &longs;olum po&longs;&longs;unt e&longs;&longs;e rationes rationales, &longs;eu rerum commen&longs;urabilium; latius igitur patet Geometrica hæc &longs;imilitudo, quàm Arithmetica, cùm Geometrica complectatur tam rationales, quàm irrationales. meritò igi­tur talis proportionalitas appellari debuit à rebus Geometricis, in quibus &longs;emper reperitur, non autem ab Arithmeticis, cum quibus &longs;æpius reperiri nequit. Vide Campanum in explicatione definitionis 3. 5. Elemen.

312

Ibidem (Non e&longs;t autem continens hæc proportio: non enim vnus, & idem ter­minus efficitur, & cui, & quod) ide&longs;t, hæc proportionalitas contracta ad res practicas, non e&longs;t continens, ide&longs;t, quæ con&longs;i&longs;tat in tribus tantum terminis, quorum medius e&longs;t, ad quem refertur primus, & is qui refertur ad ter­tium; &longs;ed e&longs;t di&longs;iuncta, quia con&longs;tat &longs;emper quatuor terminis, quorum duo &longs;unt per&longs;onæ aliquæ, reliqui verò duo &longs;unt res, quæ per&longs;onis debentur, vt &longs;i &longs;int Plato, & Proclus, quibus iuxta meritorum quantitatem debeant diuidi 1500. aurei, debent diuidi aurei in duas partes, quæ habeant eam propor­tionem, quam habet Plato ad Proclum. quod &longs;i Plato duplum m&ecedil;ruit quàm Proclus, erit vt Plato ad Proclum, ita 1000. ad 500.

Ex quibus patet hanc analogiam in rebus agendis non ni&longs;i in quatuor terminis con&longs;i&longs;tere po&longs;&longs;e, & ideo non e&longs;&longs;e continuam, &longs;ed di&longs;iunctam, vt vo­lebat Ari&longs;tot.

313

Lib. 5. cap. 6. (Atque id vet propotione vel numero) ide&longs;t, vel proportio­nalitate Geometrica, vel Arithmetica; quæ autem &longs;it proportionalitas Geometrica, dictum e&longs;t paulò ante in prioribus locis Mathematicis huius quinti libri; quæ verò &longs;it proportionalitas Arithmetica dictum e&longs;t &longs;uperius lib. 2. cap. 6. Verum hæc Arithmetica proportionalitas, meritò ab Ari&longs;tot. hic contradi&longs;tincta e&longs;t à proportionalitate Geometrica: quia Arithmetica hæc analogia attenditur &longs;olum, iuxta eundem exce&longs;&longs;um numerorum, non, autem iuxta proportionem, &longs;eu habitudinem terminorum ad inuicem, quod maximè in Geometrica &longs;pectatur. propterea Mathematici cen&longs;ent eam vo­candam e&longs;&longs;e potius medietatem Arithmeticam, quam proportionalita­tem, cum quibus nunc Ari&longs;t. con&longs;entit.

314

Lib. 6. cap. 5. (Verbi cau&longs;a triangulum tres angulos duobus rectis æquales ha­bere, velnon habere) lib. 1. Priorum, &longs;ecto 3. cap. 1. fusè hanc trianguli affe­ctionem expo&longs;ui.

315

Lib. 6. cap. 8. (Nam illud etiam con&longs;ideratione dignum videtur. quid &longs;it, quod puer fieri Mathematicus pote&longs;t, &longs;apiens autem naturalis non pote&longs;t. An quia illa per ab&longs;tractionem &longs;unt, horum autem principia ab experientia &longs;umuntur) Ex hoc loco manife&longs;tè apparet Ari&longs;t. exi&longs;timare principia Mathematica nullo mo­do nobis per experientiam innote&longs;cere, quod nonnulli negant.

316

Lib. 7. cap. 8. (In actionibus autem principium illud e&longs;t, cuius cau&longs;a res fit, &longs;icut in Mathematicis &longs;uppo&longs;itiones; nam neque illic ratio e&longs;t, quæ doctrinam tra­dat principiorum, neque hic) Suppo&longs;itionum, &longs;iue principiorum Mathemati­corum tria &longs;unt genera, definitiones, po&longs;tulata, axiomata, quæ in ip&longs;o primi Elementorum ve&longs;tibulo proponuntur: &longs;olaque terminorum explicatione ab&longs;que vllo di&longs;cur&longs;u, addi&longs;cuntur.

Ex primo Libro Magnorum Moralium.

317

Cap. 1. (Nec enim lufcitia e&longs;t numerus pariter par) vt &longs;cilicet dicebat Pythagoras. Porrò definit. 8. 7. &longs;ic habetur: Pariter par nume­rus e&longs;t, quem par numerus per numerum parem, ide&longs;t paribus vi­cibus, metitur, cuiu&longs;modi e&longs;t numerus 24. quem numerus 6. me­titur per numerum parem, nimirum per 4. quia &longs;cilicet numerus 6. paribus vicibus, quippe per 4. &longs;iue quater ip&longs;um numerum 24. men&longs;urat, quia to­ties in ip&longs;o adæquatè continetur.

318

Cap. 2. (Ab&longs;urdum enim &longs;it, volenti o&longs;tendere triangulum duobus rectis æqua­les habere angulos, &longs;umere principinm huiu&longs;modi, anima immortalis est) Repete, quæ de hac trianguli proprietate fusè &longs;crip&longs;i lib. 1. Priorum, &longs;ect. 3. cap. 1. quam affectionem debet Geometra demon&longs;trare ex Geometriæ principijs, quemadmodum facit Euclides in 32. primi, non autem ex principijs extrin­&longs;ecis, vt quod anima &longs;it immortalis.

319

Cap. 10. (Vt enim habuerint principia, ita, quæ de principijs ortum ducunt, Per&longs;picuè autem licet hoc in Geometria magis intueri, vbi cum aliqua &longs;ump&longs;eris principia, vt ea habuerint, ita etiam, quæ ip&longs;a con&longs;equuntur velut &longs;i triangulum duobus rectis æquales habet angulos, quadratum quoque quatuor angulis rectis ha-beat nece&longs;&longs;e e&longs;t. & &longs;i tria gulum &longs;ecus, ita etiam, & quadratum commutabitur, ex altera parte enim ei re&longs;pondet. & &longs;i quadratum quatuor angulis rectis æquales, non habuerit angulos ne quidem triangulum duobus rectis habebit æquales) Hanc trianguli affectionem, habere &longs;cilicet, &longs;uos tres angulos æquales duobus re­ctis angulis abundè explicaui libro 1. Priorum, &longs;ecto 3. cap. 1. quam Eucli­des propo&longs;it. 32. primi demon&longs;trauit, ex qua demon&longs;tratione, tanquam ex Geometrico principio &longs;equitur omne quoque quadrangulum habere quatuor angulos æquales quatuor rectis angulis; omne namque quadrangulum e&longs;t po­tentia duo triangula, cum diuidatur ducta ip&longs;ius diametro in duo trìangula. quod &longs;i triangulus proprietatem illam non haberet, neque hæc quadrangulo conueniret. & &longs;i quadrangulum non haberet quatuor angulos æquales qua­tuor rectis angulis, neque triangulum habere po&longs;&longs;et tres angulos æqua­les duobus rectis, cum nihil &longs;it aliud triangulum, quàm dimidiatum qua­drangulum.

320

Cap. 16. (In Geometria &longs;i quidem cum quis dixerit quadrangulŭ quatuor rectis æquales habere, & percunctatur propter quid, occurrit, quia etiam triangulŭ duo­bus rectis æquales habet. in his igitur ex determinato &longs;ibi principio propter quid a&longs;&longs;ump&longs;erunt) Lege, quæ proximè in præcedenti loco expo&longs;ui, ea enim om­nia huc etiam pertinent. hoc &longs;olum addendum ad illorum verborum (Ex de­terminato &longs;ibi principio propter quid a&longs;&longs;ump&longs;erunt) intelligentiam, ide&longs;t ex vna conclu&longs;ione demon&longs;trata, tanquam principio alia demon&longs;trant; quod rectè fieri Ari&longs;t. in primo Po&longs;ter. docet.

321

Cap. 31. (A qui proportionale in quatuor nihilominus perficitur: nam quem­admodum A, ad B, ita C, ad D.) ide&longs;t proportionalitas in quatuor terminis con&longs;i&longs;tit, quemadmodum pluribus &longs;upra lib. 5. cap. 3. Ethycorum explica­tum e&longs;t: quò nunc Lectorem ablego.

Ex primo Libro Moralium Eudemiorum.

322

Cap. 5 (Vt &longs;i duplum multiplicium primum est, non licet multiplex com­muniter prædicatum &longs;eparari, quippe, quod duplo prius e&longs;t) Inter pro­portionum genera vnum e&longs;t, quod dicitur multiplex, quod &longs;ub &longs;e infinitas &longs;pecies continet, vt Duplum, Triplum, Quadruplum, & c. in infinitum. vbi vides, cur Ari&longs;t. dixerit duplum e&longs;&longs;e primum inter multi­plicia, cum verè naturali ordine numerorum ip&longs;i primus debeatur locus. Vides etiam cur non liceat, Multiplex ip&longs;um genus commune prædicatum omnibus &longs;peciebus veluti Idæam &longs;eparari; tunc enim ait, ip&longs;um mul­tiplex ab&longs;tractum e&longs;&longs;et prius ordine ip&longs;o primo multiplici, &longs;ci­licet duplo; & Duplum non e&longs;&longs;et primum inter mul­tiplicia, quæ vtraque &longs;unt ab&longs;urda; non igitur illud tanquam Idæam licet &longs;epa­ratum ponere.

Ex Secundo Moralium Eudem.

323

Cap. 7. (Nam&longs;i habenti trigono duos rectos, nece&longs;&longs;e e&longs;t tetragonum qua­tuor rectis con&longs;tare, manife&longs;tum e&longs;t, quod trigonus duos rectos habens cau&longs;a eius exi&longs;tat. Verùm &longs;i quid in trigono mutaris, nece&longs;&longs;arium e&longs;t, & in tetragono mutes, vt &longs;i tres habuerunt, &longs;ex; & &longs;i quatuor, octo; &longs;in verò non mutes, vt illud, ita hoc quoque habeat nece&longs;&longs;e e&longs;t) Lege prius, quæ &longs;upra lib. 1. Magnor. moral. cap. 10. &longs;crip&longs;i, ex quibus po&longs;tea &longs;ic locum hunc in­terpretaberis, &longs;i triangulum habet tres angulos æquales duobus rectis an­gulis, nece&longs;&longs;e e&longs;t quodcunque quadrilaterum habere &longs;uos quatuor angulos æquales quatuor rectis, quia omne quadrangulum continet duo triangula; & &longs;i natura trianguli fuerit immutata ita, vt habeat tres angulos æquales non duobus, &longs;ed tribus rectis, tunc nece&longs;&longs;e erit tetragonum quoque mutatum e&longs;&longs;e, quia nece&longs;&longs;ariò habebit &longs;uos angulos æquales non quatuor tantum re­ctis, &longs;ed &longs;ex: pariter &longs;i triangulum habeat tres angulos quatuor rectis pa­res, quadrangulum &longs;uos habebit angulos, octo rectis æquiualentes. His igi­tur ex Geometria &longs;atisfactum &longs;it.

324

Cap. 10. (Multa verò opinione concipiunt, quæ penes nos non &longs;unt, vt diame­trum commen&longs;urabilem e&longs;&longs;e) Quæ lib. 1. Priorum, &longs;ecto 3. cap. 23. de a&longs;yme­tria diametri, & co&longs;tæ eiu&longs;dem quadrati allata &longs;unt, &longs;atis huic etiam loco facere po&longs;&longs;unt.

325

Eodem cap. (Quapropter non deremotis apud Indos, nec de circuli quadratu­ra deliberamus: nam illa ad nos non &longs;pectant, hoc verò fieri nequit) Quid &longs;it cir­culi quadratio, & qua ratione eam antiqui inue&longs;tigauerint in Prædicamen­to Relationis, & alibi in Logicis, pluribus explicatum e&longs;t. An verò po&longs;&longs;i­bilis &longs;it circuli quadratura, re&longs;pondendum e&longs;t cum di&longs;tinctione, nam theo­rematicè quidem facta e&longs;t ab Archimede, cum ip&longs;e probauerit circulum, quemuis æqualem e&longs;&longs;e triangulo, cuius vnum latus circa angulum rectum &longs;it citculi &longs;emidiameter, alterum verò circunferentia. Problematicè verò, ide&longs;t, vt opere ip&longs;o efficiamus triangulum illud, nondum à quoquam ritè per­actum e&longs;t: & propterea problema hoc difficile admodum cen&longs;endum e&longs;t, præ&longs;ertim cum tota Geometrarum antiquitas, atque po&longs;teritas in ip&longs;um fru­&longs;tra hucu&longs;que in&longs;udauerit, atque adeò etiam moraliter impo&longs;&longs;ibile exi&longs;timan­dum e&longs;t. quo &longs;en&longs;u locutum e&longs;&longs;e Ari&longs;t. hoc loco crediderim, dum ait, illud fieri non po&longs;&longs;e. ab&longs;olutè tamen a&longs;&longs;erere non debemus e&longs;&longs;e impo&longs;&longs;ibilem, cum nulla id demon&longs;tratione certum &longs;it, imò ego &longs;impliciter, vt aiunt, credo e&longs;­&longs;e po&longs;&longs;ibilem, cum alia theoremata, atque problemata (quale e&longs;t pytagoreum illud celebre, quod 47. locum in primo Elemen. occupat, & pro cuius adin­uentione Pythagoras Mu&longs;is Hecatombas &longs;acri&longs;icauit) olim fuerint diù à multis inca&longs;&longs;um quæ&longs;ita, atque impo&longs;&longs;ibilia habita, quæ po&longs;tea tandem re­perta &longs;unt.

326

Cap. 12. (Si triangulo duo recti, nece&longs;&longs;um e&longs;t hoc con&longs;equi) ide&longs;t, &longs;i triangu­lum habet tres angulos æquales duobus rectis, nece&longs;&longs;e e&longs;t con&longs;equi, vt &longs;upe­rius &longs;epius dixit, quod quadrilaterum habeat quatuor angulos æquales qua­tuor rectis, lib. 1. Magn. moral. cap. 10. &longs;atis de hac re dictum e&longs;t.

Ex Septimo Moralium Eudem.

327

Cap. 12. (luxtaqué diametrum iungit) ide&longs;t diametraliter opponit, quæ e&longs;t omnium maxima oppo&longs;itio, ita vt quæ diametraliter oppo&longs;ita &longs;unt, amplius di&longs;tare nequeant, quia diameter e&longs;t maxima om­nium di&longs;tantia, &longs;iue fit diameter quadrilateræ figuræ, &longs;iue circuli.

Ex Libro 3. Politicorum.

328

Cap. 2. (Ceu harmoniam earumdem rocum aliam e&longs;&longs;e dicimus, & modò Doricam, modò Phrygiam vocitamus) Harmonias Doricam, & Phry­giam veteres Mu&longs;ici, vt Ari&longs;toxenes, Euclides, Ptolæmeus vocant Tonos, & Modos, Dorium &longs;cilicet, & Phrygium. per mu&longs;icum au­tem modum intelligebant quandam vocum con&longs;titutionem, &longs;eu rithmum, quem nos hodie vulgò ariam vocamus, vt doctè explicat Io&longs;ephus Zarlinus in 4. parte In&longs;titut. Mu&longs;icalium, necnon in lib. 6. &longs;upplem. Denominati au­tem fuerunt prædicti, alijque; plures modi à nationibus illis, apud quas ma­ximè in v&longs;u erant, vt Dorius à Dorien&longs;ibus; Phrygius à Phrygijs; Lydius à Lydijs. Porrò præter prædictos modos alij plures à veteribus Mu&longs;icis com­memorantur; variè tamen, alij enim tres, alij &longs;eptem, alij quindecim, vel &longs;eptemdecim etiam connumerarunt; Tres tamen præcipui, & ad quos reli­qui reuocabantur, fuerunt Dorius, Phrygius, & Lydius. quorum hæ fuerunt proprietates. Dorius erat grauis, &longs;euerus, & bellico&longs;us. vnde pri&longs;ci exi&longs;ti­marunt ip&longs;um in hominum animos prudentiam, ca&longs;titatem, atque virtutem inducere. Phrygius verò erat hilaris, lætus, placidus, ac propterea fe&longs;tis, & choreis idoneus. vnde prouerbium illud vetus ortum habuit, à Dorio ad Phrygium, ide&longs;t à rebus alti&longs;&longs;imis, & &longs;erijs ad humiles, & iucundas. Hos ambos &longs;olos Plato, & Ari&longs;t. in Rempublicam admi&longs;erunt. Lydius demum modus erat horribilis, mœ&longs;tus, ac tri&longs;tis, ideoque; lamentationibus, ac la­crymis aptus. Hoc in funeribus mortuos lamentantes vtebantur, ita vt prç­&longs;entibus lacrymas cierent, vitaque; functos lacrymis pro&longs;equerentur.

Recentiores Mu&longs;ici &longs;uos modos vocant Tonos, in quibus vtinam anti­quos imitarentur, illi enim &longs;uis rithmis, modi&longs;uè auditorum animos varijs pro illorum varietate motibus mirè afficiebant: &longs;ed no&longs;tri, rithmos in &longs;uis cantilenis negligunt, nec illis curæ e&longs;t, vt per rithmos hominum affectiones percellant, cum tamen Plato a&longs;&longs;erat Mu&longs;ici officium e&longs;&longs;e rithmos adinueni­re; præterea quod animis ciendis valdè ob&longs;tat, cantilenæ verba, ac &longs;en&longs;um pror&longs;us per &longs;uos, quos vocant, contrapuntos, omninò offu&longs;cant, vt nihil præter magnum quendam vocum &longs;trepitum concordem exaudiatur: quique; rithmis imitari hominum mores deberent, mimicis quibu&longs;dam adinuentis id præ&longs;tare conantur.

Verùm hac de re legantur eruditi&longs;&longs;imi Dialogi de Mu&longs;ica Vincentij Ga­lilæi, cuius præcipuas rationes in fine huius operis, & chronologiæ videre poteris. Cæterum, qui plura de modis tam antiquis, quàm nouis de&longs;iderat, con&longs;ulat Io&longs;ephum Zarlinum in 4. parte In&longs;titutionum Mu&longs;icalium, necnon lib. 6. &longs;upplemen. virum vatia eruditione refertum, deque; Mu&longs;ica in primis optimè meritum.

Ex Quarto Politicorum.

329

Cap. 3. (Eodemqué modo in harmonijs, vt quidam tradunt: nam & in illis po&longs;uerunt duas &longs;pecies, vnam Doricam, alteram Phrygiam: cæteras verò omnes vel ad Doricam, vel ad Phrygiam referri.

Vide proximè in præcedenti loco dicta, quæ omnia ita etiam huic loco quadrant, vt præterea nihil de&longs;ideretur.

Ex Quinto Politicorum.

330.a

Cap. 1. (Quare opus e&longs;t partim arithmetica æquitate vti, partim ea, quæ e&longs;t &longs;ecundum dignitatem.

Arithmeticam medietatem &longs;upra explicaui lib. 2. cap. 6. Ethi­corum. per eam deinde, quæ e&longs;t &longs;ecundum dignitatem, intelligit Geometricam, quam &longs;upra lib. 5. cap. 3. Ethicorum expo&longs;ui. vtimur enim ea, quando opus e&longs;t di&longs;tribuere præmia non omnibus æqualiter, &longs;ed habita ratione meritorum vniu&longs;cuiu&longs;que. quando autem non &longs;ecundum per&longs;ona­rum dignitatem, &longs;ed omnibus æqualiter fit di&longs;tributio, illa dicitur Arithme­tica proportionalitas, quia &longs;eruat eandem vbique differentiam terminorum.

330.b

Cap. 12. & vlt. (In Republica verò Platonis Socrates de mutation bus loqui­tur, nec tamen rectè. illius enim Reip. quæ e&longs;t optima, atque prima, mutatio nulla propria a&longs;&longs;ignatur. inquit enim cau&longs;am e&longs;&longs;e mutationis, quia &longs;ic natura compara­tum &longs;it, vt nihil permaneat, &longs;ed in ambitu quodam temporis, mutationem recipiat. e&longs;&longs;e verò principium borum, inquit, quorŭ &longs;e&longs;quitertia radix quinario iuncta, duas exhibet harmonias. inquiens quando numerus huius diagrammatis efficiatur &longs;oli­dus) Quoad textus interpretationem, nonnulli pro (&longs;e&longs;quitertia radix) ver­tunt (&longs;e&longs;quitertius cubus) &longs;ed qua id ratione ignoro. græcum verbum e&longs;t puqmh\n, quod fundamentum, latus, & radicem &longs;ignificat, non autem cubum. præterea &longs;en&longs;ui radix, non autem cubus quadrare pote&longs;t. Porrò &longs;ciendum Ari&longs;t. locum hunc ex Platonis lib. 8. de Rep. accepi&longs;&longs;e, loco Mathematico ob&longs;curi&longs;&longs;imo, vbi ille de Reip. &longs;eu Gubernation is mutatione, ac duratione pertractat. quì locus adeò &longs;emper ob&longs;curus habitus e&longs;t, vt Cicero ip&longs;e cum rem pœnitus ob&longs;curam &longs;ignificare vellet, dicere &longs;olitus e&longs;&longs;et, numero Plato­nis ob&longs;curius. quam ob cau&longs;am Theon Smyrnæus, qui Mathematica Plato­nis loca commentarijs illu&longs;trauit, hi&longs;ce tenebris lucem nullam afferre au&longs;us e&longs;t, verùm eas di&longs;&longs;imulans cautè declinauit. cùm igitur præ&longs;ens Ari&longs;t. locus &longs;it illius Platonici particula quædam, quid mirum, &longs;i non mmori ob&longs;curita­te, ac difficultate impeditus &longs;it? vnde etiam &longs;i quitor huius explicationem, ab illius explicatione ptendam e&longs;&longs;e. Locum illum Platonis fu&longs;i &longs;imè expli­cat Mar&longs;ilius Ficinus to 2. operum &longs;uorum pag. 1413. vbi pag. 1421. cap. 12. illius commentarij propè finem præ&longs;ens Ari&longs;t. locus ex præmi&longs;&longs;is ab eo bre­uiter, ac dilucidè declaratur. quæ explanatio, quoniam mihi præ cæteris ar­ridet, eam hoc loco, explicatiorem tamen, referam. Illud autem præ&longs;cien­dum e&longs;t, hæc quæ a Socrate lib. 8. de Repub. recen&longs;entur, confingi à Mu&longs;is, tanquam oraculum quoddam ob&longs;curi&longs;&longs;imum effata; quo arcana quædam my&longs;teria de Rerump. durationibus, ac mutationibus continerentur.

Aiebatigitur Socrates, Mu&longs;arum &longs;piritu afflatus, optimam Politiam, op­timis &longs;cilicet legibus, ac moribus con&longs;titutam, &longs;ua natura omninò immu­tabilem, atque adeò diuturnam per &longs;e fore. Verumtamen mutationi obno­xiam e&longs;&longs;e, quoniam &longs;ie natura comparatum e&longs;t, vt cuncta, quæ naturæ fincontinentur, certa quadam annorum, vel &longs;æculorum periodo exacta, mu­tationem &longs;ubire fatali lege, cogantur. tunc autem harum vice&longs;&longs;itudinum principium contingere, fatidicæ Mu&longs;æ &longs;ignificare voluerunt, cùm is anno­rum, vel &longs;æculorum numerus ab illius Reip. exordio elap&longs;us fuerit, qui &longs;it numerus &longs;olidus, & cubus, eius numeri, in quo optima Reipub. con&longs;titutio con&longs;i&longs;tit. hic porrò numerus, in quo Reip. perfectio &longs;tatuitur, e&longs;t Duodena­rius, quem multis in locis, varias ob rationes extulit Plato, præcipuè verò, quoniam in &longs;e ip&longs;o duas continet harmonias, &longs;iue duas proportiones har­monicas, quæ &longs;imul iunctæ, perfecti&longs;&longs;imam omnium conflant harmoniam, quæ Diapa&longs;on dicitur. duæ autem illæ rationes harmonicæ &longs;unt Se&longs;quiter­tia, & Se&longs;quialtera. Se&longs;quitertia reperitur primò inter hos numeros 4. 3. cùm enim ea inter duas voces, aut &longs;onos reperitur, ij edunt harmoniam, &longs;eu con&longs;onantiam illam, quæ Diate&longs;&longs;aron appellatur. &longs;imul autem ijdem ad­diti efficiunt 7. qui numerus propterea in textu dicitur radix Epitrite, &longs;iue Se&longs;quitertia, quoniam vt vidimus componitur ex numeris 4. 3. Se&longs;quitertiam rationem habentibus. Se&longs;quialtera verò ratio reperitur primò inter hos numeros 3. 2. cùm enim duo &longs;oni in earum fuerint ratione &longs;uauem edent con&longs;onantiam, quæ Diapente nominatur; &longs;imul autem ijdem compo&longs;iti Qui­narium efficiunt; cui quinario &longs;e&longs;quitertia radix adiuncta, quæ e&longs;t 7. Duo­denarium componunt: qui propterea duas exhibet harmonias. Præterea hæ duæ harmoniæ &longs;imul copulatæ conflant &longs;uaui&longs;&longs;imam Diapa&longs;on con&longs;onan­tiam, nam iunctæ &longs;imul prædictæ duæ rationes &longs;e&longs;quialtera, & &longs;e&longs;quitertia, eo modo quo tradunt Mu&longs;ici, hoc &longs;cilicet modo 4. 3. 2. oritur inter extre­mos numeros dupla ratio, quæ ip&longs;ius Diapa&longs;on e&longs;t forma. nam ratio 4.ad 3. e&longs;t &longs;e&longs;quitertia; ratio 3. ad 2. e&longs;t &longs;e&longs;quialtera; ratio verò 4. ad 2. quæ ex il­lis componitur, e&longs;t dupla. quòd &longs;i duo &longs;oni duplam hanc rationem nacti fue­rint, con&longs;onantiam Diapa&longs;on &longs;uaui&longs;&longs;mam re&longs;onabunt. Cùm igitur nume­rus 12. harmonias ha&longs;ce complectatur, per eum Mu&longs;æ optimum Reip. ini­tium, ac &longs;tatum &longs;ignificare voluerunt. Vernmenimuerò cum numerus hu­ius diagrammatis, ide&longs;t huiu&longs;cemodi conditionis, qui e&longs;t 12. factus fuerit &longs;olidus, hoc e&longs;t, quando Re&longs;p. benè con&longs;tituta ad eam annorum, vel &longs;æculo­rum periodum peruenerit, qui &longs;it numerus &longs;olidus numeri 12. tunc fatali ordine, mutationem pati incipiet, atque in peius, cùm optimi mutatio &longs;it pe&longs;sima, prolabi. poriò numerus &longs;olidus ip&longs;ius 12. e&longs;t 1728. vti mox expli­cabo. vult igitur Socrates ibi my&longs;ticè &longs;ignificare po&longs;t tot annorum, aut &longs;æ­culorum numerum Remp. omnem quamuis optimam, in deterius prolpp&longs;u­ram, cùm enim ad &longs;ummam perfectionem peruenerit, quæ in numero &longs;oli­do, & cubico &longs;ignificatur, &longs;i vlterius progre&longs;sura &longs;it, nece&longs;&longs;ariò &longs;ummam perfectionem præteribit, ac derelinquet. Quòd autem numerus 1728. &longs;it numerus &longs;olidus, & cubus ip&longs;ius Duodenarij &longs;ic palm fiet, &longs;i tamen prius, ea repetiueris, quæ &longs;upra in primo Po&longs;ter. num. 33. marginali, de numero Quadrato, & Cubo dicta &longs;unt: e&longs;t autem cubus numerus is, qui ex gemina­to ductu alicuius numeri in &longs;e ip&longs;um, producitur. multiplica igitur primò 12. in 12. & producetur numerus 144. qui quadratus, & planus e&longs;t. rur&longs;us duc 12. in hunc 144. produceturque; numerus 1728. quì cubus, ac proinde &longs;olidus e&longs;t, vt loco citato explicauimus. Atque hæc Socratici huius my&longs;terij explicatio &longs;ufficiat.

Ex Octauo Politicorum.

331

Cap. 5. (Mu&longs;icam verò omnes fatemur e&longs;&longs;e ex iucundi&longs;&longs;imis, &longs;iue nuda &longs;it, &longs;iue cum melodia) Quamuis latina interpretatio pro melodia, di­cat, modulatione, Gr&ecedil;cus tamen textus habet meta melwdias, ide&longs;t cum melodia. per Mu&longs;icam nudam, forte Ari&longs;toteles intelligit eam, quæ &longs;olis &longs;onis ab&longs;que oratione con&longs;tat; per melodiam verò intelligit eam, quam Io&longs;ephus Zarlinus in 2. parte &longs;uarum In&longs;titutionum Mu&longs;icalium defi­nit, quæ e&longs;t concentus plurium vocum harmonicus cum rithmo, & oratio­ne, ide&longs;t, qua canitur oratio aliqua &longs;ub aliquo rithmo, aut modo, &longs;iue vt nunc loquimur, con qualche aria.

Ex quibus liquet no&longs;tros contrapuntiftas toto cœlo aberrare, dum &longs;uas cantilenas, ab&longs;que vlla verborum intelligentia, atque ab&longs;que vllo rithmo di&longs;perdunt.

332

Eodem capite propè finem meminit harmoniæ Lydiæ, Mixtæ, Doricæ, Phrygiæ. de quibus &longs;upra 3. lib. Polit. cap. 2. tractaui, earumque; proprieta­tes, quas hic Ari&longs;t. recen&longs;et ibi connumeraui.

333

Ibidem meminit etiam Rithmorum, & Harmonie. Quid Rithmus dictum e&longs;t &longs;uperius lib. 3. Politic. e&longs;&longs;e quem nunc vulgò ariam cantores, ac tibici­nes appellant.

Harmonia e&longs;t plurium vocum ex acuto, & graui concors modulatio.

Verùm de his fu&longs;ius in Problematibus Mu&longs;icis, &longs;ect. 19.

334

Cap. 7 (Con&longs;iderandum vtrum omnibus vtendum &longs;it harmonijs, & rithmis) Vide quæ &longs;upra lib. 3. Politic. cap. 2. annotaui.

In Oeconomicis nihil Mathematicum reperi.

EX PROBLEMATIBVS ARIST.

Ex Sectione Prima.

335

Sectione 1. num. 3. (Quemadmodum tempora, ita &longs;yderum ortus, Orionis Arcturi, Virgiliarum, Caniculæ, qui flatus, imbresqué excitant, qui &longs;ereni­tates, frigora, tepore&longs;uè &longs;olent afferre) Intelligit de ortu co&longs;mico, qui fit, quando a&longs;trum &longs;imul cum Sole oritur: quem ortum abundè in 2. Meter. &longs;umma 2. cap. 2. explicatum inuenies. Vt autem intelligas, quænam &longs;int Orionis, Arcturi, Virgiliarum, & Caniculæ con&longs;tellationes, & in qua cœli parte &longs;int collocatæ, &longs;atius e&longs;t globum aliquem a&longs;tronomicum, in quo a&longs;teri&longs;mi omnes clarè depicti &longs;int, intueri, quàm hoc loco pluribus verbis rem per &longs;e claram, ob&longs;curare. De Orione plura dicta &longs;unt 2. Meter. præ­&longs;ertim quo tempore oriatur. Arcturus verò, &longs;iue Bootes, primæ magnitu­dinis &longs;tella, mane vnà cùm Sole in no&longs;tro climate ex Magini Tabulis, circa 28. diem Septembris oritur. De Virgilijs tamen illud exi&longs;timo aduertendum, quod in Tauri afteri&longs;mo, duæ aliæ partiales con&longs;tellationes continentur; in capite enim ip&longs;ius, &longs;unt illæ, quæ & Hiades, & Atlantides, & Succulæ nuncu­pantur. in dor&longs;o autem &longs;unt illæ, quæ Pleiades, & Virgiliæ &longs;unt appellatæ,

Quæ &longs;eptem dici, &longs;ex tamen e&longs;&longs;e &longs;olent.

Vt cecinit Ouidius, quandoquidem &longs;eptima ferè nunquam apparet. has vul­gus Gallinellam vocat. quod &longs;i eas per Tele&longs;copium in&longs;piciamus, mirum di­ctu, ea&longs;dem plures e&longs;&longs;e, quàm quadraginta &longs;tellas minimas clarè videbimus, vt optimè primus omnium Galilæus ob&longs;eruauit. Porrò con&longs;tellatio Tauri in no&longs;tris regionibus oriri cum Sole, incipit vno circiter &longs;e&longs;quimen&longs;e po&longs;t ver­num æquinoctium. De Canicula &longs;atis dixi in 2. Meteor. &longs;umma 2. cap. 2.

336

Eadem &longs;ect. num. 17. (Cur à Virgiliarum occa&longs;u ad Fauonij v&longs;que flatus, bi poti&longs;&longs;imum pereant, qui morbo longo laborant, & &longs;enes, quam iuuenes potius?)Lege, quæ &longs;crip&longs;i de occa&longs;u &longs;yderum lib. 2. Meteor. &longs;umma 2. cap. 2. dein­de, quæ in &longs;uperiore proximè loco de Virgilijs: quibus hæc pauca addantur. cum intelligat de co&longs;mico Virgiliarum occa&longs;u, qui noctu apparet, incipitque; tunc primum, quando oriente Sole, ip&longs;e occumbunt, nece&longs;&longs;e e&longs;t occa&longs;um hunc incipere po&longs;t autumnale æquinoctium ferè &longs;e&longs;quimen&longs;e in no&longs;tris regio­nibus; cum enim Virgiliæ &longs;int in Tauro, nece&longs;&longs;e e&longs;t occidente Tauro initio dixi, vt Sol &longs;it in oppo&longs;ito &longs;igno, videlicet in Scorpione; in quo a&longs;teri&longs;mo Sol reperitur po&longs;t prædictum æquinoctium vno ferè men&longs;e cum dimidio. de hac re plura Plinius lib. 18. cap. 31.

Ex Sectione 15.

337

Nvm. 1. (Cur linea ab angulo ad angulum ducta, &longs;ola ex omnibus, quæfi­gur as rectiline as bifariam &longs;ecant, diameter vocata e&longs;t? An quod dia­meter, vt nomen ip&longs;um de&longs;ignat, duas in partes figuram æquè dimetien­do diuidit, nibil dimen&longs;æ figuræ defiruens? igitur hæc, quæ per commi&longs;­&longs;uras, hoc est, per angulos figaram diuidit, appellanda e&longs;t diameter, quoniam hæcfiguram non de&longs;tuit, quamuis diuidat. quemadmodum faciunt; qui a&longs;a militaria partiuntur. At cæteræ lineæ, quæ per lineas compo&longs;itam figuram &longs;ecant, eam cor­rumpunt: committitur enim rectilmea figura in argulis, vel &longs;ecundum angulos)Vt rectè problema hoc percipiamus, proponenda e&longs;t figura rectilinea, & vna ex ijs, quæ paralle logramma dicuntur, vt &longs;unt Quadratum, Quadrila­

terum, Rhombus, Rhomboides, cuiu&longs;mo­di e&longs;t præ&longs;ens, aliter verba Ari&longs;t. illi non &longs;emper quadrarent, quia illarum diameter illas &longs;emper bifariam non &longs;e caret. quemad­modum videre e&longs;t in trapezio. & pentagono etiam æquilatero. Quærit igitur, cur ex om­nibus lineis, quæ quadrilaterum A B C D, bifariam diuidunt, quales &longs;unt E F, G H, & D B. &longs;ola D B, quæ ab angulo ad angulum ducta e&longs;t, mœruit appellari diameter. Re&longs;pondet autem, eam fortè appel­lationem hanc præ cæteris inde promerui&longs;&longs;e, quòd, quamuis aliæ omnes æquè parallelogrammum dimetiantur, &longs;ola tamen ip&longs;a D B, ip&longs;um non de­&longs;truit, nec &longs;cindit, cùm ei nouam aliquam diui&longs;ionem non inferat, &longs;ed id per angulos &longs;ecet, vbi prius laterum commi&longs;&longs;uræ erant: reliquæ verò omnes no­uas figuræ &longs;ectiones inferunt, cùm eius latera in punctis E, F, G, H, diuidant, vbi nulla prius erat diui&longs;io; quapropter ip&longs;am quodammodo de&longs;truunt, atque corrumpunt. Aduertè valgatam verfionem latinam hanc (Angulis enim constant, quæ rectis lineis continentur) malè græco textui sugkeiytai gar to\ euqugrammon kata\ tas gwni/as, re&longs;pondere, qui &longs;ic latinè reddendus e&longs;t: com­ponitur enim rectilineum iuxta angulos; quæ interpretatio vera e&longs;t, quia anguli &longs;unt laterum commi&longs;&longs;uræ, vt dictum e&longs;t.

338

Eadem &longs;ect. num. 2. (cur diameter ita e&longs;t appellata? Vtrum quoniam &longs;ola bi­partitò figuram diuidat? An quod &longs;ola figuram &longs;ecat per partes, &lo