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<?xml version="1.0"?>
<!DOCTYPE archimedes SYSTEM "../dtd/archimedes.dtd" >
<archimedes>
      <info>
        <author>Baliani, Giovanni Baptista</author>
        <title>De Motu Naturali Gravium Solidorum et Liquidorum</title>
        <date>1646</date>  
        <place>Genf</place>
        <translator/>
         <lang>la</lang>
         <cvs_file>balia_demot_064_la_1646.xml</cvs_file>
         <cvs_version/>
         <locator>064.xml</locator>

</info>


<text><front/><body><pb xlink:href="064/01/001.jpg"/><chap><p type="main">

<s>DE MOTV <lb/>NATVRALI <lb/>GRAVIVM SOLIDORVM <lb/>ET LIQUIDORVM <lb/>IO: BAPTISTAE BALIANI <lb/>PATRITII ENVENSIS. </s></p><p type="main">

<s>GENVAE</s></p><p type="main">

<s>Ex Typographia IO: Mari&aelig; Farroni 1646 <lb/>Superiorum Permi&longs;&longs;u.</s></p><pb xlink:href="064/01/002.jpg"/><pb xlink:href="064/01/003.jpg"/><p type="main">

<s>DE MOTV<lb/>GRAVIVM<lb/>SOLIDORVM<lb/>LIBER PRIMVS.<lb/></s></p><p type="main">

<s>Mihi quoque, sicut &amp; <lb/>caeteris hominibus, inest <lb/>sciendi cupiditas, nec gra&shy;<lb/>ve fuit, usque a primis <lb/>annis, &amp; aliorum scripta <lb/>percurrere, &amp; naturales <lb/>effectus observare, qui fa&shy;<lb/>cile mihi persuaserim, ex hisce fontibus, tum <lb/>scientiam, tum sapientiam in animum de&shy;<lb/>rivare, si tandem ex effectibus diligentius<pb xlink:href="064/01/004.jpg"/>perspectis, non modo ad inde consequentes, <lb/>sed etiam ad causas, usque ad primam de&shy;<lb/>veniat intellectus. </s>

<s>Statui igitur apud me ip&shy;<lb/>sum non acquiescere soli relationi pluri&shy;<lb/>morum, etiam doctiorum; potuisse siquidem <lb/>contingere existimavi, ut aliqua laterent, <lb/>etiam in plurimis oculatissimos, vel non ple&shy;<lb/>ne ab eis explicarentur; &amp; ratus sum non <lb/>inutilem laborem futurum, si ex accuratiori <lb/>naturae rerum investigatione, &amp; ex affection&shy;<lb/>um inde resultantium deductione, circa <lb/>quod omnis demonstrativa scientia versatur, <lb/>aut scitis adderem aliqua, aut doctioribus <lb/>acuerem desiderium addendi plura: hinc fa&shy;<lb/>ctum est, ut excitata mens ex praecognitis le&shy;<lb/>gendo, ad ea, quae se offerebant, secun&shy;<lb/>dum privatas, aut publicas occupationes per&shy;<lb/>vestiganda, converteretur studiosus. </s>

<s>Inter <lb/>alia dum anno millesimo sexcentesimo un&shy;<lb/>decimo, per paucos menses, ex patriae legis <lb/>praescripto, Praefectum Arcis Savonae agerem, <lb/>ex militaribus observationibus quae occurre&shy;<lb/>bant, illud maxime depraehendi, ferreos, <lb/>&amp; lapideos tormentorum bellicorum glo&shy;<lb/>bos, &amp; sic corpora gravia, seu eiusdem, seu<pb xlink:href="064/01/005.jpg"/>diversae speciei, in inaequali satis Mole, &amp; <lb/>gravitate, per idem spatium, aequali tem&shy;<lb/>pore, &amp; motu, naturaliter descendere, idque <lb/>ita uniformiter, ut repetitis experimentis mihi <lb/>plane constiterit, duos ex praedictis globis, <lb/>vel ferreos ambos, vel alterum lapideum <lb/>alterum plumbeum, eodem plane mo&shy;<lb/>mento temporis dimissos sibi, per spatium <lb/>quinquaginta pedum, etiam si unus es&shy;<lb/>set librae unius tantum, alter quinquagin&shy;<lb/>ta, in indivisibili temporis momento, subje&shy;<lb/>ctum solum ferire, ut unus tantum ambo&shy;<lb/>rum ictus sensu perciperetur. </s>

<s>Repetebam <lb/>animo sapientum esse pronunciatum, gravia <lb/>moveri naturali motu, secundum gravitatum <lb/>proportionem; Processi ulterius, &amp; pericu&shy;<lb/>lum feci, num forte iuxta eorum sententiam <lb/>contingeret, si corpora dimissa, eiusdem fere <lb/>essent molis, sed longe diversi ponderis, pu&shy;<lb/>ta unum plumbeum, cereum alterum; &amp; ex&shy;<lb/>pertus sum in cereo aliquam longiorem mo&shy;<lb/>ram in descensu, attamen longe infra propor&shy;<lb/>tionem gravitatum, globus quippe ille ce&shy;<lb/>reus, in data distantia quinquaginta pedum <lb/>descensus, uno circiter pede distabat a solo,<pb xlink:href="064/01/006.jpg"/>quando plumbeus tangebat subjectum pla&shy;<lb/>num, objecto aere intermedio ni fallor, sen&shy;<lb/>sibiliter resistente, &amp; impediente motum. <lb/></s>

<s>Institi adhuc, &amp; globos in gravitate, &amp; in <lb/>materia inaequales appendi funiculis aequali&shy;<lb/>bus, &amp; agitatos animadverti moveri tempo&shy;<lb/>re aequali, &amp; hoc servare adeo fideliter, ut <lb/>globus plumbeus duarum unciarum, alter <lb/>librarum duarum, ferreus librarum 34. &amp; la&shy;<lb/>pideus quadraginta circiter, nec non, &amp; la&shy;<lb/>pis informis, quorum funiculi comprehen&shy;<lb/>sis ipsorum semidiametris aequales essent, <lb/>uno, &amp; eodem temporis spatio moverentur, <lb/>&amp; vibrationes easdem numero darent hinc <lb/>inde, sive motus unius globi fieret per aequa&shy;<lb/>le spatium, sive per inaequale, ita ut qui <lb/>maiori impetu jactabatur, &amp; sic majus spa&shy;<lb/>tium percurrebat, illud tanto velocius per&shy;<lb/>transiret. </s>

<s>In quibus peragendis illud praeter <lb/>expectationem sese mihi obtulit, quod quo&shy;<lb/>tiescunque globi penderent ex funiculis inae&shy;<lb/>qualibus, ita inaequali motu ferebantur, ut <lb/>longitudines funiculorum, durationibus mo&shy;<lb/>tuum, in duplicata ratione responderent.<lb/></s></p><p type="main">

<s>Porro cum ex praemissis satis superque li&shy;<lb/><pb xlink:href="064/01/007.jpg"/>queret, in naturali motu gravium, pro&shy;<lb/>portionem gravitatum communiter credi&shy;<lb/>tam, non servari; in eam descendi sen&shy;<lb/>tentiam, ut arbitrater fortasse, gravitatem <lb/>se habere ut agens, materiam vero, seu <lb/>mavis materiale corpus, ut passum, &amp; <lb/>proinde gravia moveri juxta proportionem <lb/>gravitatis ad materiam, &amp; ubi sine impedi&shy;<lb/>mento naturaliter perpendiculari motu fe&shy;<lb/>rantur, moveri aequaliter, quia ubi plus est <lb/>gravitatis, plus pariter sit materiae, seu ma&shy;<lb/>terialis quantitatis; si vero accedat aliquid <lb/>resistentiae, regulari motum secundum ex&shy;<lb/>cessum virtutis agentis supra resistentiam <lb/>passi, seu impedientia motum; qui exces&shy;<lb/>sus momentum noncupabitur, &amp; quod com&shy;<lb/>muniter gravitati attributum fuit, momen&shy;<lb/>to attribui debere, nimirum ut sit momen&shy;<lb/>tum ad momentum, ut velocitas ad velo&shy;<lb/>citatem; Et hinc fieri posse, ut cognosca&shy;<lb/>mus qua mensura, seu proportione corpora <lb/>gravia naturali motu ferantur super subje&shy;<lb/>ctis planis, si super eis quomodolibet in&shy;<lb/>clinatis, ipsorum gravium momenta ubique <lb/>innotescant, quae maiora, aut minora viden&shy;<lb/><pb xlink:href="064/01/008.jpg"/>tur censenda, secundum quod magis, aut <lb/>minus super plano quiescunt, &amp; sic secun&shy;<lb/>dum maiorem, aut minorem inclinationem <lb/>plani resistentis; quod demum tali propor&shy;<lb/>tione facile fieri mihi existimandum vide&shy;<lb/>tur, juxta quam reciproce momentis pro&shy;<lb/>portionantur lineae dictorum planorum, si <lb/>ambae ductae sint ab eodem puncto ad idem <lb/>planum orizontale; de quo Simon Stevi&shy;<lb/>nus l. p. de Statica prop. 19. &amp; acutissime <lb/>Galileus in Mechanica manuscripta, ubi de <lb/>Cochlea, &amp; ego aliquali experientia com&shy;<lb/>pertum habui. </s>

<s>Caeterum si per experien&shy;<lb/>tiam Scientia hominibus efficitur, praedicta <lb/>de quibus saepius repetitis actibus expertus <lb/>fui, ut principia scientiae habenda fore cen&shy;<lb/>sui; in quibus occultae conclusiones delites&shy;<lb/>cant, demonstrationibus duntaxat aperien&shy;<lb/>dae. </s>

<s>Rimari caepi; an deprehenderim alio&shy;<lb/>rum erit judicium. </s>

<s>Subjecta paucula, quae <lb/>presens aliquod otium expedire permisit, <lb/>de motu naturali solidorum gravium, Ami&shy;<lb/>ce lector tibi exhibeo, mox de liquidorum, <lb/>&amp; deinceps alia plura tam parata daturus, <lb/>si haec placuerint. </s>

<s>Placuit sane mihi, vel<pb xlink:href="064/01/009.jpg"/>paucula tibi dare, qui te eius ingenij esse <lb/>confidam, ut non verba, sed res, easque <lb/>non mole, sed pondere censeas, felicior si <lb/>de eorum genere existimaveris, quae non <lb/>mole magna sunt, quod si talia non fue&shy;<lb/>rint, quo minora minus defatigabunt, sui <lb/>exilitate, auctoris partus proprios omnino <lb/>esse probatura. </s>

<s>Idioma latinum elegi ut <lb/>communius. </s>

<s>Praemisi aliqua naturalia prin&shy;<lb/>cipia, sine quibus naturales conclusiones <lb/>aliunde duci posse non video. </s>

<s>Quae ex prae&shy;<lb/>dictis experimentis innotuerunt, supposi&shy;<lb/>tiones appellare, &amp; a reliquis petitionibus <lb/>secernere libuit. </s>

<s>Petitiones illas, quibus quid <lb/>fieri petimus, constructioni deservientes, <lb/>tanquam factu, &amp; cognitu faciles, &amp; pro&shy;<lb/>inde supervacaneas, prudens praetermisi; <lb/>ratus siquidem nil inde incredulitatis, aut <lb/>difficultatis derivaturum. </s>

<s>Septimum po&shy;<lb/>stulatum ea ratione segregavi, quod il&shy;<lb/>lud aliquo pacto a 22. prop. pendeat, &amp; <lb/>quod in illo etiamsi veritas non deficiat, <lb/>evidentiam tamen ut in caeteris non agno&shy;<lb/>scens, certis dubia quo quo pacto permisce&shy;<lb/>re noluerim; ut proinde plura eorum, quae<pb xlink:href="064/01/010.jpg"/>ex illo deducta sunt, &amp; diversa Methodo &amp; <lb/>attingendo potius, quam demonstrando <lb/>subjunxerim. </s>

<s>Si quae demum minus pro&shy;<lb/>bata, seu explicata, aut quo quo pacto im&shy;<lb/>perfecta reperies, velim te tribuere cuidam <lb/>naturali meae propensioni, ad nova potius, <lb/>qualiacumque ea sint, invenienda, quam <lb/>inventa perficienda. </s>

<s>Vale.</s></p><pb xlink:href="064/01/011.jpg"/><p type="main">

<s>De mandato Reuerendi&longs;&longs;imi Patris Magi&longs;tri <lb/>lu&longs;tiniani Vagnoni Inqui&longs;itoris Generelis <lb/>Genu&aelig;, &amp;c.</s></p><p type="main">

<s>Rudi ego infra&longs;criptus Sancti Officij Con&longs;ultor <lb/>De Motu Grauium Illu&longs;tri&longs;&longs;imi D. Ioannis <lb/>Baptiste Baliani Libros sex.</s>

<s>In quibus nilre&shy; <lb/>peri S. Catholica fidei, bonis moribus, &longs;acri&longs;&shy; <lb/>ue decretis di&longs;&longs;onum; &longs;ed dignam ubique typis, <lb/>&amp; publica luce doctrinam, &longs;i prefato Reue&shy; <lb/>rendi&longs;&longs;imo Patri ita videbitur.</s>

<s>In quorum fi&shy; <lb/>dem, &amp;c.</s></p><p type="main">

<s>Ex Conuentu Sancti&longs;&longs;ime Annunciat&aelig; Veteris <lb/>Genue 27. Nouembris 1646.</s></p><p type="main">

<s>Magi&longs;t. Fr. Angelicus Riccobonus Aug.</s></p><p type="main">

<s>IMPRIMATVR.</s></p><p type="main">

<s>F. Iu&longs;tinianus Vagnonus a Calli S. T. M. <lb/>Inqui&longs;itor Generalis Genu&aelig; &amp;c.</s></p><pb xlink:href="064/01/012.jpg"/><pb xlink:href="064/01/013.jpg"/><subchap1 type="definition"><p type="head">

<s>DEFINITIONES</s></p><subchap2 type="definition"><p type="main">

<s>Pendulus dicimus pondus filo <lb/>appensum.</s></p></subchap2><subchap2 type="definition"><p type="main">

<s>Pendula dicuntur aequalia, <lb/>seu aequipendula, sive inae&shy;<lb/>qualia, quae, &amp; longiora, <lb/>aut breviora, quatenus <lb/>fila, e quibus dependent, sunt <lb/>aequalia, longiora, aut breviora.</s></p></subchap2><subchap2 type="definition"><p type="main">

<s>Vibrationes pendulorum sunt eorum motus hinc <lb/>inde </s></p></subchap2><subchap2 type="definition"><p type="main">

<s>Vibrationes aequales dicimus, quae fiunt per spa&shy;<lb/>tia aequalia, &amp; e contra inaequales.</s></p></subchap2><subchap2 type="definition"><p type="main">

<s>Vibrationes aeque celeres si fiant per spatia aequa&shy;<lb/>lia tempore aequali.</s></p></subchap2><pb xlink:href="064/01/014.jpg"/><subchap2 type="definition"><p type="main">

<s>Vibrationis diuturnitatem dicimus ipsius Dura&shy;<lb/>tionem, tempus nimirum, quo ipsa vibratio <lb/>perficitur.</s></p></subchap2><subchap2 type="definition"><p type="main">

<s>Vibrationes &aelig;quediuturne, sunt, quae fiunt tem&shy;<lb/>pore aequali, etiamsi per spatia inaequalia, <lb/>inde diuturnior est, quae longiori perficitur <lb/>tempore.</s></p></subchap2><subchap2 type="definition"><p type="main">

<s>Vibrationes integras dicimus eas, quae se exten&shy;<lb/>dunt per integrum semicirculum, se hinc in&shy;<lb/>de moventes per circuli quadrantem.</s></p></subchap2><subchap2 type="definition"><p type="main">

<s>Vibrationis portio est pars arcus, quem ipsa vi&shy;<lb/>bratio disignant.</s></p></subchap2><subchap2 type="definition"><p type="main">

<s>Vibrationum similes portiones sunt arcus ipsa&shy;<lb/>rum intercepti inter binas lineas ductas a <lb/>centro, a quo concipiuntur pendula pendere.</s></p></subchap2><subchap2 type="definition"><p type="main">

<s>Vibrationis portionem priorem decimus eam mi&shy;<lb/>nimam portionem, a qua integra vibratio <lb/>initium habet.</s></p></subchap2><subchap2 type="definition"><p type="main">

<s>Momentum est excessus virtutis moventis supra <lb/>motus impedimenta.</s></p></subchap2></subchap1><pb xlink:href="064/01/015.jpg"/><subchap1 type="supposition"><p type="head">

<s>SUPPOSITIONES</s></p><subchap2 type="supposition"><p type="main">

<s>PRIMA. </s>

<s>Solidorum aequipendu&shy;<lb/>lorum cujuscumque gravitatis vibra&shy;<lb/>tiones aequales sunt aequediu&shy;<lb/>turnae.</s></p></subchap2><subchap2 type="supposition"><p type="main">

<s>2 Equipendulorum eorundem vibrationes <lb/>sunt aequediuturnae, etiamsi inaequales.</s></p></subchap2><subchap2 type="supposition"><p type="main">

<s>3 Pendulorum inaequalium longitudines sunt <lb/>in duplicata ratione diuturnitatum vi&shy;<lb/>brationum, seu ut quadrata vibratio&shy;<lb/>num.</s></p></subchap2><subchap2 type="supposition"><p type="main">

<s>4 Momentum gravis super plano inclinato <lb/>est ad ipsius gravitatem, ut perpendi&shy;<pb xlink:href="064/01/016.jpg"/>cularis ad inclinatam, si ab eodem <lb/>puncto ducta sint ad idem planum <lb/>orizontale dicta perpendicularis, &amp; di&shy;<lb/>ctum planum inclinatum, &amp; proinde <lb/>tali casu proportio gravitatis ad mo&shy;<lb/>mentum est reciproca proportioni li&shy;<lb/>nearum super quibus grave movetur.</s></p></subchap2></subchap1><pb xlink:href="064/01/017.jpg"/><subchap1 type="postulate"><p type="head">

<s>PETITIONES, SEU POSTULATA</s></p><subchap2 type="postulate"><p type="main">

<s>Pr. </s>

<s>Pendulorum inaequalium portiones similes vi&shy;<lb/>brationum sunt inter se quoad diuturni&shy;<lb/>tatem, ut vibrationes integrae.<figure id="id.064.01.017.1.jpg" xlink:href="064/01/017/1.jpg"/></s></p></subchap2><subchap2 type="postulate"><p type="main">

<s>Sint pendula AB, AC; dependentia a puncto A, <lb/>&amp; eleventur ad libellam orizontis puncti A, <lb/>in E, D, describentia arcus BD, CE, inte&shy;<lb/>grarum vibrationum, &amp; in arcubus BD, <lb/>CE sumantur portiones similes EF, DG, seu <lb/>HI, KL ductis EA, FA, seu HA, IA. </s>

<s>Peto <lb/>mihi concedi, esse pendulorum diuturnitates in <lb/>arcubus EC, DB, ut in portionibus EF, DG, <lb/>nec non HI, KL, &amp; ita deinceps.</s></p></subchap2><subchap2 type="postulate"><p type="main">

<s>2. Ut est momentum ad momentum solidi <lb/>gravis, ita velocitas ad velocitatem.</s></p></subchap2><subchap2 type="postulate"><p type="main">

<s>Huiusmodi passio communiter attribui solet gra&shy;<lb/>vitati simpliciter, quod eum nimis clare expe&shy;<lb/>rientijs supra expositis nullo pacto congruere <lb/>possit, momentis attribuenda esse visa est, ut <lb/>in praefatione explicatum fuit.</s></p></subchap2><pb xlink:href="064/01/018.jpg"/><subchap2 type="postulate"><p type="main">

<s>3. Portiones minimae peripheriae Circuli con&shy;<lb/>cipiende sunt, ac si essent lineae rectae.</s></p></subchap2><subchap2 type="postulate"><p type="main">

<s>Quaecumque arcus portio est circularis, atta&shy;<lb/>men si est minima portio, tam parum aber&shy;<lb/>rat a linea recta, ut non modo quo ad <lb/>sensum, sed quoad quascunque physicas passio&shy;<lb/>nes, perinde esse videatur, ac si esset linea re&shy;<lb/>cta, idcirco ut petitionem admittendam cen&shy;<lb/>seo, quemadmodum in mechanicis admittitur&shy; <lb/>illa, quod perpendiculares sunt parallelae, etiamsi <lb/>in centro concurrant universi, quatenus eis&shy;<lb/>dem sunt passionibus physicis subjectae, ac si <lb/>vere essent parallelae.</s></p></subchap2><subchap2 type="postulate"><p type="main">

<s>4. Data recta linea, possimus concipere cir&shy;<lb/>culum talis magnitudinis, cujus portio pe&shy;<lb/>ripheriae aequalis quo ad sensum datae lineae, <lb/>concipienda sit, ac si esset linea recta.</s></p></subchap2><subchap2 type="postulate"><p type="main">

<s>Haec petitio videtur concedenda, quia si conci&shy;<lb/>piamus circulum, eiusque portionem mini&shy;<lb/>mam, ut in praecedenti, si fiat ut huiusmodi <lb/>portio ad datam lineam, ita circulus ad alium, <lb/>portio huius, datae lineae aequalis erit, &amp; simi&shy;<lb/>lis omnino praedicta minimae portioni, &amp; proin&shy;<lb/>de pariter concipienda ut linea recta.</s></p></subchap2><pb xlink:href="064/01/019.jpg"/><subchap2 type="postulate"><p type="main">

<s>5. Solida perpendicula libero motu aeque <lb/>velociter feruntur, &amp; in tali proportione, <lb/>ac si essent pendula, &amp; moverentur in <lb/>priori portione vibrationum.</s></p></subchap2><subchap2 type="postulate"><p type="main">

<s>Quoniam prior portio non differt sensibiliter a re&shy;<lb/>cta, ut in tertia petitione ijsdem physicis passio&shy;<lb/>nibus subjicitur, &amp; exinde motibus aequalibus.</s></p></subchap2><subchap2 type="postulate"><p type="main">

<s>6. Solida naturaliter mota super plano incli&shy;<lb/>nato aeque velociter moventur ac si essent <lb/>pendula, &amp; moverentur in tali portione vi&shy;<lb/>brationum, quae quoad sensum esset aequa&shy;<lb/>lis, &amp; paralella lineae dicti plani super qua <lb/>dicta solida moverentur.</s></p></subchap2><subchap2 type="postulate"><p type="main">

<s>Non differt a praecedente, nisi quod in illa mo&shy;<lb/>tus est perpendicularis, in hac inclinatus, in <lb/>reliquis est par ratio.</s></p></subchap2></subchap1><subchap1 type="enunciation"><p type="head">

<s>PRONUNCIATA</s></p><subchap2 type="enunciation"><p type="main">

<s>P. </s>

<s>Quae sunt aequidiuturna tertio, sunt aequi&shy;<lb/>diuturna inter se.</s></p></subchap2><subchap2 type="enunciation"><p type="main">

<s>2. Quadrata datorum temporum, sunt etiam <lb/>quadrata aliorum datis aequalium.</s></p></subchap2><subchap2 type="enunciation"><p type="main">

<s>3. Gravia eadem super planis aequalibus &amp; <lb/>pariter inclinatis, pariter moventur.</s></p></subchap2></subchap1><pb xlink:href="064/01/020.jpg"/><subchap1 n="1" type="proposition"><p type="head">

<s>PROPOSITIO PRIMA.</s></p><subchap2 n="1" type="statement"><p type="main">

<s>Solidi penduli naturaliter moti vibratio&shy;<lb/>nes quantumvis semper minores, sunt <lb/>aequidiuturnae.<figure id="id.064.01.020.1.jpg" xlink:href="064/01/020/1.jpg"/></s></p></subchap2><subchap2 n="2" type="proof"><p type="main">

<s>Sit solidum A pendulum debite applicatum filo <lb/>BA, quod ab altera parte elevatum naturaliter, <lb/>postea faciat hinc inde vibrationes semper mi&shy;<lb/>nores, ita ut prior vibratio sit V.G. per spatium <lb/>CD maius, posterior vero per spatium EF minus.</s></p><p type="main">

<s>Dico quod dicta vibrationes erunt aequidiuturnae, <lb/>ita ut vibratio per spatium CD sit eiusdem du&shy;<lb/>rationis, ac vibratio per spatium EF.</s></p><p type="main">

<s>Sit aliud solidum G aequipendulum solido A, de&shy;<lb/>bite applicatum filo HG, quod elevetur ab una <lb/>parte eodem tempore minus quam solidum A <lb/>ita ut sint minores vibrationes solidi G, quam, <lb/>solidi A, ut sit motus penduli G in initio per <lb/>spatium IK aequale spatio EF.</s></p><p type="main">

<s>Quoniam spatia EF, &amp; IK, sunt aequalia ex sup&shy;<lb/>positione, sunt etiam vibrationes EF, &amp; IK, <lb/>aequidiuturnae,<arrow.to.target n="marg1"/>,sed IK, &amp; CD sunt pariter <lb/>aequidiuturnae<arrow.to.target n="marg2"/>, ergo EF, &amp; CD sunt etiam <lb/>aequidiuturnae<arrow.to.target n="marg3"/>. </s>





<s>Quod fuit probandum.</s></p><p type="margin">

<s><margin.target id="marg1"></margin.target>Per primam suppositionem.</s></p><p type="margin">

<s><margin.target id="marg2"></margin.target>Per secundam suppositionem.</s></p><p type="margin">

<s><margin.target id="marg3"></margin.target>Per pr. pron.</s></p></subchap2></subchap1><subchap1 n="2" type="proposition"><p type="head">

<s>PROPOSITIO II. PROB. PRIMUM</s></p><pb xlink:href="064/01/021.jpg"/><subchap2 n="2" type="statement"><p type="main">

<s>Pendula constituere, quorum diuturnita&shy;<lb/>tes vibrationum sint in data ratione.<figure id="id.064.01.021.1.jpg" xlink:href="064/01/021/1.jpg"/></s></p></subchap2><subchap2 n="3" type="proof"><p type="main">

<s>Data sit proportio diuturnitatum vibratio&shy;<lb/>num, quam volumus esse inter solida A,B; <lb/>&amp; sit ea, quae est inter C, &amp; D; quae est continuo <lb/>eadem,<arrow.to.target n="marg4"/>,</s></p><p type="margin">

<s><margin.target id="marg4"></margin.target>Per pr. huius.</s></p><p type="main">

<s>Venanda est longitudo filorum, quibus applicata <lb/>dicta solida producant vibrationes quaesitas.</s></p><p type="main">

<s>Fiat L tertia proportionalis ad C, &amp; D,<arrow.to.target n="marg5"/> &amp; fila <lb/>IA, KB fiant inter se ut C ad L,<arrow.to.target n="marg6"/> &amp; erunt <lb/>fila quaesita.</s></p><p type="margin">

<s><margin.target id="marg5"></margin.target>Per 11 sexti.</s></p><p type="margin">

<s><margin.target id="marg6"></margin.target>Per 12 sexti.</s></p><p type="main">

<s>Quoniam ita est IA ad KB ut C ad L per constr. <lb/>erunt C, &amp; D diuturnitates vibrorum pendu&shy;<lb/>lorum AB.<arrow.to.target n="marg7"/> Quod etc</s></p><p type="margin">

<s><margin.target id="marg7"></margin.target>Per 3 Supp.</s></p></subchap2></subchap1><pb xlink:href="064/01/022.jpg"/><subchap1 n="3" type="proposition"><p type="head">

<s>PROPOSITIO TERTIA</s></p><subchap2 n="3" type="statement"><p type="main">

<s>Lineae descensus gravium, dum naturali motu <lb/>perpendiculariter feruntur, sunt in dupli&shy;<lb/>cata ratione diuturnitatum.<figure id="id.064.01.022.1.jpg" xlink:href="064/01/022/1.jpg"/></s></p></subchap2><subchap2 n="4" type="proof"><p type="main">

<s>Sint LN, KM linea descensus gravium L, K, <lb/>&amp; sint PO ipsorum diuturnitates.</s></p><p type="main">

<s>Dico LN, KM esse in duplicata ratione ipsarum P, O.</s></p><p type="main">

<s>Sint pendula AH, AI, dependentia a puncto A, &amp; <lb/>eleventur ad libellam ipsius A usque ad E, B, <lb/>quae in elevatione producant arcus HB, IE, &amp; <lb/>sint talis longitudinis, ut ducta ACF, secet ar&shy;<lb/>cus BC, &amp; EF, tam parvae curvitatis ut pro <lb/>rectis habeantur, puta portionis minimae, &amp; <lb/>proinde aequales quo ad sensum rectis KM, LN,<arrow.to.target n="marg8"/> <lb/>&amp; fiat V tertia proportionalis ad O, P,<arrow.to.target n="marg9"/><lb/></s></p><p type="margin">

<s><margin.target id="marg8"></margin.target>Per 3 pet.</s></p><p type="margin">

<s><margin.target id="marg9"></margin.target>Per 11 sexti.</s></p><p type="main">

<s>Quoniam O, P sunt diuturnitates KM, LN ex <lb/>constr., sunt itidem diuturnitates BC, EF, <arrow.to.target n="marg10"/> &amp; <lb/>quia diuturnitates vibrorum AH, AI sunt <lb/>etiam ut O ad P <arrow.to.target n="marg11"/> AH AI sunt ut O, ad V<arrow.to.target n="marg12"/> <lb/>&amp; pariter BC, &amp; EF sunt ut O ad V<arrow.to.target n="marg13"/> Ergo <lb/>KM, LN eis aequales per constr. sunt etiam ut <lb/>O ad V, &amp; proinde in duplicata ratione O, P, <lb/>temporum seu diuturnitatum earumdem. </s>

<s>Quod, etc.</s></p><p type="margin">

<s><margin.target id="marg10"></margin.target>Per 5 pet.</s></p><p type="margin">

<s><margin.target id="marg11"></margin.target>Per p. pet.</s></p><p type="margin">

<s><margin.target id="marg12"></margin.target>Per 3 supp.</s></p><p type="margin">

<s><margin.target id="marg13"></margin.target>Per p. pet.</s></p></subchap2></subchap1><pb xlink:href="064/01/023.jpg"/><subchap1 n="4" type="proposition"><p type="head">

<s>PROPOSITIO QUARTA. PROB. II.</s></p><subchap2 n="4" type="statement"><p type="main">

<s>Data diuturnitate gravis descendentis a data <lb/>altitudine, constituere altitudinem, a qua <lb/>idem grave cadat in data alia diuturnitate.<figure id="id.064.01.023.1.jpg" xlink:href="064/01/023/1.jpg"/></s></p></subchap2><subchap2 n="5" type="proof"><p type="main">

<s>Sit A diuturnitas gravis B, dum cadit in C, &amp; <lb/>data sit diuturnitas quaecumque D.</s></p><p type="main">

<s>Constituenda est alia altitudo, a qua grave de&shy;<lb/>scendat iuxta diuturnitatem D.</s></p><p type="main">

<s>Fiat I, tertia proportionalis ad AD,<arrow.to.target n="marg14"/> &amp; ut I ad A <lb/>fiat altitudo GH ad altitudinem datam BC,<arrow.to.target n="marg15"/> <lb/>Dico GH esse altitudinem quaesitam.</s></p><p type="margin">

<s><margin.target id="marg14"></margin.target>Per 11. sexti.</s></p><p type="margin">

<s><margin.target id="marg15"></margin.target>Per 12. sexti.</s></p><p type="main">

<s>Quoniam BC, &amp; GH sunt in duplicata ratione <lb/>datarum diuturnitatum A, D, per constructio&shy;<lb/>nem; per ipsas gravia B, &amp; G cadent in diu&shy;<lb/>turnitatibus A, &amp; D datis<arrow.to.target n="marg16"/>, unde reperta est <lb/>altitudo GH quaesita. </s>

<s>Quod fuit faciendum.</s></p><p type="margin">

<s><margin.target id="marg16"></margin.target>Per 3. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/024.jpg"/><subchap1 n="5" type="proposition"><p type="head">

<s>PROPOSITIO V. PROB. III.</s></p><subchap2 n="5" type="statement"><p type="main">

<s>Data altitudine, a qua descendat grave in no&shy;<lb/>ta diuturnitate; perquirere quanta sit diutur&shy;<lb/>nitas, qua descendat ab alia altitudine data.<figure id="id.064.01.024.1.jpg" xlink:href="064/01/024/1.jpg"/></s></p></subchap2><subchap2 n="6" type="proof"><p type="main">

<s>Sit A altitudo per quam descendat grave diutur&shy;<lb/>nitate B nota, &amp; data sit alia altitudo C.</s></p><p type="main">

<s>Oportet reperire quanta sit diuturnitas, qua idem <lb/>grave descendat per C.</s></p><p type="main">

<s>Fiat ut A ad C ita B ad G,<arrow.to.target n="marg17"/> inter quas media, <lb/>proportionalis F<arrow.to.target n="marg18"/> est diuturnitas quaesita.</s></p><p type="margin">

<s><margin.target id="marg17"></margin.target>Per 12. sexti.</s></p><p type="margin">

<s><margin.target id="marg18"></margin.target>Per 13. sexti.</s></p><p type="main">

<s>Quoniam A, &amp; C sunt in duplicata ratione diu&shy;<lb/>turnitatum B, &amp; F per constructionem, per <lb/>ipsas gravia descendent in diuturnitatibus B, <lb/>F,<arrow.to.target n="marg19"/> unde F est diuturnitas ipsius C quaesita.</s></p><p type="margin">

<s><margin.target id="marg19"></margin.target>Per 3. huius.</s></p><p type="main">

<s>Quod faciendum fuit.</s></p></subchap2></subchap1><pb xlink:href="064/01/025.jpg"/><subchap1 n="6" type="proposition"><p type="head">

<s>PROPOSITIO VI.</s></p><subchap2 n="6" type="statement"><p type="main">

<s>Gravia naturali motu descendunt semper velo&shy;<lb/>cius ea ratione, ut temporibus aequalibus de&shy;<lb/>scendant per spatia semper maiora, iuxta <lb/>proportionem quam habent impares nu&shy;<lb/>meri ab unitate inter se.<figure id="id.064.01.025.1.jpg" xlink:href="064/01/025/1.jpg"/></s></p></subchap2><subchap2 n="7" type="proof"><p type="main">

<s>Sit grave A quod descendat per lineam ABC, <lb/>&amp; tempus quo descendit ab A in B sit aequale <lb/>tempori, quo descendit a B in C, &amp; a C in D.</s></p><p type="main">

<s>Dico quod lineae AB, BC, CD sunt inter se ut 1.<lb/>3.5.&amp; sic deinceps.</s></p><p type="main">

<s>Sit G linea mensurans tempus, quo A descendit <lb/>in B, &amp; H, quo de&shy;<lb/>scendit a B in C, &amp; I, quo descendit a C in D, quae tempora sunt ex suppositione <lb/>aequalia, &amp; sit K latus quadrati ipsius G, &amp; L <lb/>quadrati GH, &amp; N quadrati totius GHI.</s></p><p type="main">

<s>Quoniam quadrata K, L, N sunt ut AB, AC, A<lb/>D<arrow.to.target n="marg20"/>, quae quadrata sunt ut 1, 4, 9, sunt itidem <lb/>AB, AC, AD, ut 1. 4. 9. &amp; dividendo AB, <lb/>BC, CD, ut 1. 3. 5. &amp; sic deinceps. </s>

<s>Quod <lb/>probandum fuit.</s></p><p type="margin">

<s><margin.target id="marg20"></margin.target>Per 3. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/026.jpg"/><subchap1 n="7" type="proposition"><p type="head">

<s>PROPOSITIO VII.</s></p><subchap2 n="7" type="statement"><p type="main">

<s>Lineae descensus gravium super plano incli&shy;<lb/>nato motorum, sunt in duplicata ratione <lb/>diuturnitatum.<figure id="id.064.01.026.1.jpg" xlink:href="064/01/026/1.jpg"/></s></p></subchap2><subchap2 n="8" type="proof"><p type="main">

<s>Sint AB, CD plana pariter inclinata, super <lb/>quibus moveantur gravia A, C, &amp; sint EF <lb/>ipsorum diuturnitates.</s></p><p type="main">

<s>Dico AB, CD, esse in duplicata ratione ipsarum E, F.</s></p><p type="main">

<s>Secetur AB bifariam in G, &amp; erecta GH, per&shy;<lb/>pendiculari longissima, fiant pendula HI, HK, <lb/>quae sint inter se ut AB, CD, &amp; eleventur in <lb/>L, M, describentia arcus LI, KM, secantes <lb/>GH in N, O, &amp; ab N hinc inde secentur ar&shy;<lb/>cus NP, NQ aequales quo ad sensum rectis <lb/>GA, GB, &amp; ductis PH, QH, secetur pariter <lb/>arcus LI, in R, S, &amp; intelligantur arcus PQ, <lb/>RS, tam parvae curvitatis, ob maximam lon&shy;<lb/>gitudinem pendulorum HI, HK, ut pro re&shy;<lb/>ctis habeantur, puta portionis minimae, &amp; pro&shy;<lb/>inde aequales rectis AB, CD.<arrow.to.target n="marg21"/></s></p><p type="margin">

<s><margin.target id="marg21"></margin.target>Per 3. pet.</s></p><p type="main">

<s>Quoniam EF sunt diuturnitates AB, CD per<pb xlink:href="064/01/027.jpg"/>construct, sunt etiam diuturnitates portionum <lb/>PQ, RS<arrow.to.target n="marg22"/>, &amp; pariter vibrationum pendulo&shy;<lb/>rum HK, HI<arrow.to.target n="marg23"/> sunt autem diuturnitates <lb/>praedictae E, F, in subduplicata ratione pendu&shy;<lb/>lorum HK, HI<arrow.to.target n="marg24"/> unde pariter portionum PQ, <lb/>RS, &amp; proinde plenorum AB, CD, Quod, etc.</s></p><p type="margin">

<s><margin.target id="marg22"></margin.target>Per 6. pet.</s></p><p type="margin">

<s><margin.target id="marg23"></margin.target>Per pr. pet.</s></p><p type="margin">

<s><margin.target id="marg24"></margin.target>Per 3. supp.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium</s></p><p type="main">

<s>Hinc patet esse longitudines planorum per quae <lb/>gravia feruntur ut quadrata temporum, &amp; <lb/>tempora ut radices longitudinum planorum.</s></p></subchap2></subchap1><pb xlink:href="064/01/028.jpg"/><subchap1 n="8" type="proposition"><p type="head">

<s>PROPOSITIO VIII. PROB. IV.</s></p><subchap2 n="8" type="statement"><p type="main">

<s>Dato plano inclinato, super quo per spatium <lb/>datum grave moveatur in nota diuturni&shy;<lb/>tate, determinare in eodem plano spatium <lb/>per quod dictum grave moveatur in qua&shy;<lb/>vis alia diuturnitate data.<figure id="id.064.01.028.1.jpg" xlink:href="064/01/028/1.jpg"/></s></p></subchap2><subchap2 n="9" type="proof"><p type="main">

<s>Sit A diuturnitas gravis B, dum descendit in <lb/>C super plano inclinato BC, &amp; data diu&shy;<lb/>turnitas D.</s></p><p type="main">

<s>Praescribendum est aliud spatium in eodem pla&shy;<lb/>no BC, per quod idem grave pertranseat in <lb/>diuturnitate D.</s></p><p type="main">

<s>Fiat H tertia proportionalis ad A &amp; D, &amp; ut <lb/>H ad A fiat BG ad BC, Dico BG esse spa&shy;<lb/>tium quaesitum.</s></p><p type="main">

<s>Quoniam BC, &amp; BG sunt in duplicata ratione <lb/>datorum temporum A, D per constructionem, <lb/>per ipsa cadet grave B diuturnitatibus A, D <lb/>datis<arrow.to.target n="marg25"/>, ergo reperta est BG quaesita. </s>

<s>Quod <lb/>faciendum erat.</s></p><p type="margin">

<s><margin.target id="marg25"></margin.target>Per 6. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/029.jpg"/><subchap1 n="9" type="proposition"><p type="head">

<s>PROPOSITIO IX. PROB. V.</s></p><subchap2 n="9" type="statement"><p type="main">

<s>Dato plano inclinato, super quo per spatium <lb/>datum grave moveatur nota diuturnitate; <lb/>&amp; dato alio spatio quocumque; reperire <lb/>diuturnitatem, qua grave per ipsum de&shy;<lb/>scendat.<figure id="id.064.01.029.1.jpg" xlink:href="064/01/029/1.jpg"/></s></p></subchap2><subchap2 n="10" type="proof"><p type="main">

<s>Sit Nota diuturnitas gravis B, dum descendit <lb/>in C super plano inclinato BC, &amp; dato alio <lb/>spatio BG.</s></p><p type="main">

<s>Quaerendum quanta sit diuturnitas gravis in BG.</s></p><p type="main">

<s>Intelligatur BC diuturnitas ipsius BC, &amp; fiat <lb/>BH, media inter BC, &amp; BG, quae erit diu&shy;<lb/>turnitas quaesita.</s></p><p type="main">

<s>Quoniam BC, &amp; BG sunt in duplicata ratio&shy;<lb/>ne diuturnitatum BC, &amp; BH, per constructio&shy;<lb/>nem; per ipsa cadunt gravia diuturnitatibus <lb/>BC, BH,<arrow.to.target n="marg26"/> unde BH est diuturnitas per spa&shy;<lb/>tium BG quaesita. </s>

<s>Quod, etc.</s></p><p type="margin">

<s><margin.target id="marg26"></margin.target>Per 7. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/030.jpg"/><subchap1 n="10" type="proposition"><p type="head">

<s>PROPOSITIO X.</s></p><subchap2 n="10" type="statement"><p type="main">

<s>Gravia descendunt super planis inclinatis per <lb/>spatia semper maiora, iuxta rationem, quam <lb/>habent impares numeri successive inter se. <figure id="id.064.01.030.1.jpg" xlink:href="064/01/030/1.jpg"/></s></p></subchap2><subchap2 n="11" type="proof"><p type="main">

<s>Sit grave A, quod descendat super plano ABC <lb/>inclinato, &amp; tempus quo descendit ab A in <lb/>B sit aequale tempori, quo descendit a B in C, <lb/>&amp; a C in D.</s></p><p type="main">

<s>Dico quod lineae AB, BC, CD sunt inter se ut <lb/>1. 3. 5. &amp;. sic deinceps.</s></p><p type="main">

<s>Sit E numerus mensurans tempus, quo A descen&shy;<lb/>dit in B, &amp; F quo descendit a B in C, &amp; G <lb/>quo descendit a C in D, quae tempora sunt ex <lb/>suppositione aequalia, &amp; sit H quadratum ip&shy;<lb/>sius E, &amp; I quadratum EF, &amp; K quadra&shy;<lb/>tum totius EFG.</s></p><p type="main">

<s>Quoniam quadrata HIK sunt ut AB, AC, AD<arrow.to.target n="marg27"/>, <lb/>quae quadrata sunt ut 1. 4. 9. sunt pariter <lb/>AB, AC, AD, ut 1. 4. 9. &amp; dividendo AB, <lb/>BC, CD, sunt ut 1. 3. 5. &amp; sic deinceps. <lb/></s>

<s>Quod probandum erat.</s></p><p type="margin">

<s><margin.target id="marg27"></margin.target>Per 7. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/031.jpg"/><subchap1 n="11" type="proposition"><p type="head">

<s>PROPOSITIO XI.</s></p><subchap2 n="11" type="statement"><p type="main">

<s>Si Duo gravia descendant alterum super li&shy;<lb/>nea perpendiculari, alterum vero super <lb/>inclinata; proportio velocitatum est reci&shy;<lb/>proca proportioni linearum.<figure id="id.064.01.031.1.jpg" xlink:href="064/01/031/1.jpg"/></s></p></subchap2><subchap2 n="12" type="proof"><p type="main">

<s>Sit ABC planum normaliter erectum super <lb/>lineam orizontalem BC, cuius latus AB sit <lb/>perpendiculare, &amp; AC, inclinatum.</s></p><p type="main">

<s>Dico quod proportio velocitatum solidorum gra&shy;<lb/>vium motorum secundum lineam AB perpen&shy;<lb/>dicularem, &amp; AC inclinatum, est ut propor&shy;<lb/>tio longitudinis inclinatae AC ad longitudinem <lb/>perpendicularis AB; videlicet ita est longitudo <lb/>AB ad longitudinem AC, ut velocitas super <lb/>AC ad velocitatem in AB.</s></p><p type="main">

<s>Quoniam est ut AC ad AB, ita momentum in <lb/>AB, ad momentum in AC<arrow.to.target n="marg28"/>; &amp; ut momentum <lb/>in AB ad momentum in AC, ita velocitas in <lb/>AB ad velocitatem in AC<arrow.to.target n="marg29"/>; ergo est etiam <lb/>ut AC ad AB, ita velocitas in AB ad veloci&shy;<lb/>tatem in AC. </s>

<s>Quod fuit probandum.</s></p><p type="margin">

<s><margin.target id="marg28"></margin.target>Per 4. supp.</s></p><p type="margin">

<s><margin.target id="marg29"></margin.target>Per 2. pet.</s></p></subchap2></subchap1><pb xlink:href="064/01/032.jpg"/><subchap1 n="12" type="proposition"><p type="head">

<s>PROPOSITIO XII.</s></p><subchap2 n="12" type="statement"><p type="main">

<s>Gravia descendunt super plana diverse in&shy;<lb/>clinata tali proportione, ut si velocitas ad <lb/>velocitatem reciproca longitudinibus pla&shy;<lb/>norum ductorum ab eodem puncto, ad <lb/>idem planum orizontale.<figure id="id.064.01.032.1.jpg" xlink:href="064/01/032/1.jpg"/></s></p></subchap2><subchap2 n="13" type="proof"><p type="main">

<s>Sint F, D plana inclinata ducta ad idem pla&shy;<lb/>num orizontale.</s></p><p type="main">

<s>Dico esse ut planum D ad planum F, ita veloci&shy;<lb/>tatem gravis ducti super F, ad velocitatem <lb/>eiusdem ducti super D.</s></p><p type="main">

<s>Ducatur perpendicularis E, &amp; sint B, A, C ve&shy;<lb/>locitates gravium latorum super perpendicu&shy;<lb/>lari, &amp; super planis F, D.</s></p><p type="main">

<s>Quoniam est A ad B, ut E ad F, item, &amp; B ad <lb/>C, ut D, ad E<arrow.to.target n="marg30"/>, erit A ad C ut D ad F<arrow.to.target n="marg31"/>, sci&shy;<lb/>licet velocitas gravis super F ad velocitatem <lb/>gravis super D, ut lon&shy;<lb/>gitudo plani D ad longitudinem plani F. </s>

<s>Quod fuit probandum.</s></p><p type="margin">

<s><margin.target id="marg30"></margin.target>Per 11. huius.</s></p><p type="margin">

<s><margin.target id="marg31"></margin.target>Per 13. Quinti.</s></p></subchap2></subchap1><pb xlink:href="064/01/033.jpg"/><subchap1 n="13" type="proposition"><p type="head">

<s>PROPOSITIO XIII. PROB. VI.</s></p><subchap2 n="13" type="statement"><p type="main">

<s>Reperire inclinationem plani, super quo <lb/>grave moveatur tali velocitate quae cum <lb/>alia super diversa inclinatione sit in ra&shy;<lb/>tione data.<figure id="id.064.01.033.1.jpg" xlink:href="064/01/033/1.jpg"/></s></p></subchap2><subchap2 n="14" type="proof"><p type="main">

<s>Moveatur grave A super recta AB, seu <lb/>perpendiculari, seu inclinata, &amp; data sit <lb/>proportio C ad D.</s></p><p type="main">

<s>Oportet reperire aliud planum inclinatum, ita <lb/>ut velocitas gravis moti super AB ad velo&shy;<lb/>citatem alterius moti super illo reperiendo, <lb/>sit ut D ad C.</s></p><p type="main">

<s>Producatur BA; &amp; fiat ut C ad D ita BA, ad <lb/>AE; &amp; centro A, intervallo AE describatur <lb/>circulus, secans BF in F; ni secet, problema <lb/>insolubile est; si secat, ducatur AF, quam di&shy;<lb/>co esse planum quaesitum.</s></p><p type="main">

<s>Quoniam ut C ad D, ita AB ad AE, seu AF <lb/>per constructionem, erit C velocitas super AF, <lb/>&amp; D super AB<arrow.to.target n="marg32"/>, unde velocitates super ip&shy;<lb/>sis sunt in ratione data. </s>

<s>Quod faciendum fuit.</s></p><p type="margin">

<s><margin.target id="marg32"></margin.target>Per 12. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/034.jpg"/><subchap1 n="14" type="proposition"><p type="head">

<s>PROPOSITIO XIV. PROB. VII.</s></p><subchap2 n="14" type="statement"><p type="main">

<s>Data linea perpendiculari, per quam grave <lb/>descendat, cui annectatur linea, seu pla&shy;<lb/>num declinans; in declinante reperire <lb/>punctum, quo grave perveniat eo tempo&shy;<lb/>re, quo pertransiverit perpendicularem.<figure id="id.064.01.034.1.jpg" xlink:href="064/01/034/1.jpg"/></s></p></subchap2><subchap2 n="15" type="proof"><p type="main">

<s>Sit triangulum ABC orthogonaliter erectum <lb/>super plano orizontali BC, cuius latus AB <lb/>intelligatur linea perpendicularis, per quam <lb/>grave descendat, &amp; latus AC planum incli&shy;<lb/>natum.</s></p><p type="main">

<s>Oportet in plano AC reperire punctum quo gra&shy;<lb/>ve perveniat eodem tempore, quo in B.</s></p><p type="main">

<s>Fiat ut AC ad AB, ita AB ad tertiam AD<arrow.to.target n="marg33"/>, <lb/>&amp; D erit punctum quaesitum.</s></p><p type="margin">

<s><margin.target id="marg33"></margin.target>Per 11. Sexti.</s></p><p type="main">

<s>Quoniam velocitas super AD ad velocitatem in <lb/>AB est ut AB ad AC<arrow.to.target n="marg34"/>, &amp; proinde ut AD <lb/>ad AB per const, quae velocitates eadem con&shy;<lb/>tinuo duplicata proportione augentur<arrow.to.target n="marg35"/>, gra&shy;<lb/>via in eis moventur tempore aequali, quia quo&shy;<lb/>tiscunque spatia sunt ut velocitates, aequali <lb/>peraguntur tempore, quod, etc.</s></p><p type="margin">

<s><margin.target id="marg34"></margin.target>Per 11. huius.</s></p><p type="margin">

<s><margin.target id="marg35"></margin.target>Per 3. &amp; 7. huius.</s></p></subchap2><pb xlink:href="064/01/035.jpg"/><subchap2 type="corollary"><p type="head">

<s>Corollarium 1.</s></p><p type="main">

<s>Hinc est quod in D, &amp; B velocitates sunt ut AD, <lb/>AB, &amp; ita in quibuslibet punctis respondenti&shy;<lb/>bus paralellis ad DB cum in AD, &amp; AB ve&shy;<lb/>locitates semper eadem ratione augeantur.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium 2.</s></p><p type="main">

<s>Hinc est etiam quod si esset AE aequalis AB, &amp; <lb/>AF media inter AD, AE, tempus AD, &amp; <lb/>proinde AB ad tempus AE, esset ut AD ad <lb/>AF<arrow.to.target n="marg36"/>.</s></p><p type="margin">

<s><margin.target id="marg36"></margin.target>Per 7. huius.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium 3.</s></p><p type="main">

<s>Si AE est quadrupla AD, AF erit dupla AD, <lb/>unde tempus AE erit duplum tempori AB.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium 4.</s></p><p type="main">

<s>Si AC esset quadrupla AD, grave moveretur <lb/>temporibus aequalibus per AB, AD, DC.</s></p></subchap2></subchap1><pb xlink:href="064/01/036.jpg"/><subchap1 n="15" type="proposition"><p type="head">

<s>PROPOSITIO XV.</s></p><subchap2 n="15" type="statement"><p type="main">

<s>Si duo gravia descendunt alterum quidem <lb/>perpendiculariter, alterum vero super pla&shy;<lb/>no declinante, perveniunt ad idem pla&shy;<lb/>num Orizontale tali ratione, ut sit eadem <lb/>proportio inter diuturnitates eorum, quae <lb/>inter perpendicularem, &amp; declinantem.<figure id="id.064.01.036.1.jpg" xlink:href="064/01/036/1.jpg"/></s></p></subchap2><subchap2 n="16" type="proof"><p type="main">

<s>Sit linea AB perpendiculariter erecta super <lb/>plano Orizontali BC, &amp; AC planum declinans.</s></p><p type="main">

<s>Dico quod diuturnitates gravium descendentium <lb/>per AB, &amp; per AC, sunt ut AB ad AC.</s></p><p type="main">

<s>Fiat AD tertia proportionalis ad AC, &amp; AB<arrow.to.target n="marg37"/>,</s></p><p type="margin">

<s><margin.target id="marg37"></margin.target>Per 11. Sexti.</s></p><p type="main">

<s>Quoniam est ut AD ad AC ita quadratum tem&shy;<lb/>poris AD ad quadratum temporis AC<arrow.to.target n="marg38"/>, &amp; <lb/>tempora AD, &amp; AB sunt aequalia<arrow.to.target n="marg39"/>, &amp; proin&shy;<lb/>de eorum quadrata<arrow.to.target n="marg40"/>, ergo ut AD, ad AC <lb/>ita quadratum temporis AB ad quadratum <lb/>temporis AC, sed ut AD ad AC ita quadra&shy;<lb/>tum AB ad quadratum AC<arrow.to.target n="marg41"/>, ergo ut quadratum temporis AB ad quadratum temporis A<lb/>C, ita quadratum AB ad quadratum AC<arrow.to.target n="marg42"/>, <lb/>sed quia latera sunt inter se ut eorum qua&shy;<lb/>drata<arrow.to.target n="marg43"/>, est ut AB ad AC ita tempus AB ad <lb/>tempus AC. </s>

<s>Quod, etc.</s></p><p type="margin">

<s><margin.target id="marg38"></margin.target>Per cor. 7. huius.</s></p><p type="margin">

<s><margin.target id="marg39"></margin.target>Per 14. huius.</s></p><p type="margin">

<s><margin.target id="marg40"></margin.target>Per 2. pron.</s></p><p type="margin">

<s><margin.target id="marg41"></margin.target>Per 19. Sexti.</s></p><p type="margin">

<s><margin.target id="marg42"></margin.target>Per 11. Quinti.</s></p><p type="margin">

<s><margin.target id="marg43"></margin.target>Per 22. Sexti.</s></p></subchap2></subchap1><pb xlink:href="064/01/037.jpg"/><subchap1 n="16" type="proposition"><p type="head">

<s>PROPOSITIO XVI. PROBL. VIII.</s></p><subchap2 n="16" type="statement"><p type="main">

<s>Data linea perpendiculari, &amp; plano decli&shy;<lb/>nante; reperire in perpendiculari produ&shy;<lb/>cta punctum, quo perveniat grave eo tem&shy;<lb/>pore, quo pertransit planum inclinatum.<figure id="id.064.01.037.1.jpg" xlink:href="064/01/037/1.jpg"/></s></p></subchap2><subchap2 n="17" type="proof"><p type="main">

<s>Data sit perpendicularis AB, cui connexum <lb/>planum inclinatum AD.</s></p><p type="main">

<s>Oportet in AB producta reperire punctum, quo <lb/>perveniat grave eo tempore, quo pervenit in <lb/>puncto D.</s></p><p type="main">

<s>In puncto D perpendicularis erigatur ad AD, &amp; <lb/>protrahatur usquequo coeat cum AB produ&shy;<lb/>cta in E, &amp; E est punctum quaesitum.</s></p><p type="main">

<s>Quoniam triangula, ADE, AEC sint aequian&shy;<lb/>gula, cum anguli ADE, AEC sint aequales, <lb/>nempe recti, &amp; BAD communis<arrow.to.target n="marg44"/>, sunt etiam <lb/>similia<arrow.to.target n="marg45"/>, ergo ut AC ad AE, ita AE ad AD<arrow.to.target n="marg46"/>, <lb/>unde tempora per AD, &amp; AE sunt aequalia<arrow.to.target n="marg47"/>.</s></p><p type="margin">

<s><margin.target id="marg44"></margin.target>Per 32. prim.</s></p><p type="margin">

<s><margin.target id="marg45"></margin.target>Per 4. sexti.</s></p><p type="margin">

<s><margin.target id="marg46"></margin.target>Per 4. sexti.</s></p><p type="margin">

<s><margin.target id="marg47"></margin.target>Per 14 huius.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium</s></p><p type="main">

<s>Hinc est quod super plano AC erit AD men&shy;<lb/>sura diuturnitatis motus peracti super AE.</s></p></subchap2></subchap1><pb xlink:href="064/01/038.jpg"/><subchap1 n="17" type="proposition"><p type="head">

<s>PROPOSITIO XVII. PROBL. IX.</s></p><subchap2 n="17" type="statement"><p type="main">

<s>Dato plano declinante, super quo grave de&shy;<lb/>scendat, &amp; dato alio plano minus declinan&shy;<lb/>te, in hoc reperire punctum, quo perveniat <lb/>mobile eo tempore, quo pertransit dictum <lb/>planum magis declinans.<figure id="id.064.01.038.1.jpg" xlink:href="064/01/038/1.jpg"/></s></p></subchap2><subchap2 n="18" type="proof"><p type="main">

<s>Sint plana AB, AC quorum AC minus in&shy;<lb/>clinatum.</s></p><p type="main">

<s>Oportet in AC reperire punctum, quo grave per&shy;<lb/>veniat, quando pervenit in B.</s></p><p type="main">

<s>Fiat ut AC ad AB ita AB ad AD, &amp; dico D <lb/>esse punctum quaesitum.</s></p><p type="main">

<s>Quoniam ut AC ad AD ita est quadratum AC <lb/>ad quadratum AB<arrow.to.target n="marg48"/>, &amp; ut AC ad AD ita <lb/>quadratum temporis AC ad quadratum tem&shy;<lb/>poris AD<arrow.to.target n="marg49"/> ergo ut quadratum AC ad qua&shy;<lb/>dratum AB, ita quadratum temporis AC ad <lb/>quadratum temporis AD Vnde AC ad AB<lb/>ut tempus AC ad tempus AD<arrow.to.target n="marg50"/>, sed ut AC <lb/>ad AB, ita tempus AC ad tempus AB<arrow.to.target n="marg51"/>, ergo <lb/>tempora AB, AD, sunt aequalia. </s>

<s>Quod, etc.</s></p><p type="margin">

<s><margin.target id="marg48"></margin.target>Per 19. sexti.</s></p><p type="margin">

<s><margin.target id="marg49"></margin.target>Per cot. 7. huius.</s></p><p type="margin">

<s><margin.target id="marg50"></margin.target>Per 22. sexti.</s></p><p type="margin">

<s><margin.target id="marg51"></margin.target>Per 15. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/039.jpg"/><subchap1 n="18" type="proposition"><p type="head">

<s>PROPOSITIO XVIII. PROBL. X.</s></p><subchap2 n="18" type="statement"><p type="main">

<s>Datis planis declinantibus ortis ab eodem <lb/>puncto, reperire in magis declinante pun&shy;<lb/>ctum quo grave perveniat eo tempore, quo <lb/>pertransit planum minus declinans.<figure id="id.064.01.039.1.jpg" xlink:href="064/01/039/1.jpg"/></s></p></subchap2><subchap2 n="19" type="proof"><p type="main">

<s>Datum sit planum minus declinans AC, &amp; <lb/>magis AD, terminantia super plano ori&shy;<lb/>zontali BD.</s></p><p type="main">

<s>Oportet in AD producta reperire punctum, quo <lb/>perveniat grave eo tempore, quo pertransivit <lb/>planum minus declinans AC.</s></p><p type="main">

<s>Fiat ut AD ad AC ita AC ad dictam AD pro&shy;<lb/>ductam in E, quod est punctum quaesitum.</s></p><p type="main">

<s>Quoniam ut AE ad AD ita est quadratum AC <lb/>ad quadratum AD<arrow.to.target n="marg52"/>, sed AE ad AD est ut <lb/>quadratum tempo&shy;<lb/>ris AE, ad quadratum temporis AD<arrow.to.target n="marg53"/>, ergo ut quadra&shy;<lb/>tum AC ad quadratum AD, ita quadratum temporis AE ad qua&shy;<lb/>dratum temporis AD<arrow.to.target n="marg54"/>, unde AC ad AD ut <lb/>tempus AE ad tempus AD<arrow.to.target n="marg55"/>, sed AC ad AD <lb/>est ut tempus AC ad tempus AD<arrow.to.target n="marg56"/>, ergo tem&shy;<lb/>pora AE, AC sunt aequalia. </s>

<s>Quod, etc.</s></p><p type="margin">

<s><margin.target id="marg52"></margin.target>Per 19. sexti.</s></p><p type="margin">

<s><margin.target id="marg53"></margin.target>Per cor. 7. huius.</s></p><p type="margin">

<s><margin.target id="marg54"></margin.target>Per 11. Quinti.</s></p><p type="margin">

<s><margin.target id="marg55"></margin.target>Per 22. sexti.</s></p><p type="margin">

<s><margin.target id="marg56"></margin.target>Per 15. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/040.jpg"/><subchap1 n="19" type="proposition"><p type="head">

<s>PROPOSITIO XIX. PROBL. XI.</s></p><subchap2 n="19" type="statement"><p type="main">

<s>Dato motus naturali gravis quomodocumque <lb/>ad punctum datum, reperire seu in perpen&shy;<lb/>diculari, seu in plano quomodolibet incli&shy;<lb/>nato punctum, a quo digressum, perveniat <lb/>ad idem punctum quo prius, tempore aequali.<figure id="id.064.01.040.1.jpg" xlink:href="064/01/040/1.jpg"/></s></p></subchap2><subchap2 n="20" type="proof"><p type="main">

<s>Sit AB linea quomodocumque aut perpendicu&shy;<lb/>laris, seu planum inclinatum; super qua <lb/>grave descendat in B, &amp; data sit quaecunque <lb/>linea BC, aut perpendicularis, aut quomodo&shy;<lb/>libet inclinata, quae cum AB, coeat in B.</s></p><p type="main">

<s>Oportet in BC reperire punctum, a quo grave digres&shy;<lb/>sum perveniat in B tempore quo pervenit ab A in idem B.</s></p><p type="main">

<s>Ducatur AC orizontalis, &amp; fiat BD tertia pro&shy;<lb/>portionalis ad CB AB<arrow.to.target n="marg57"/>, &amp; D est punctum <lb/>quaesitum. </s>

<s>Quod ut probetur.</s></p><p type="margin">

<s><margin.target id="marg57"></margin.target>Per 11. Sexti.</s></p><p type="main">

<s>Fiat iterum rectae AC paralella, &amp; aequalis BE, &amp; <lb/>ducta EA, secetur recta BF parallela ipsi AD.</s></p><p type="main">

<s>Quoniam AF, BD sunt pariter inclinatae, &amp; <lb/>aequales<arrow.to.target n="marg58"/>, gravia per ipsas aequali tempore mo&shy;<lb/>ventur<arrow.to.target n="marg59"/>, sed per AF, grave movetur tempo&shy;<lb/>re quo per AB<arrow.to.target n="marg60"/>, ergo per BD movetur pari&shy;<lb/>ter tempore quo per AB<arrow.to.target n="marg61"/>, quod, etc.</s></p><p type="margin">

<s><margin.target id="marg58"></margin.target>Per 33. Primi.</s></p><p type="margin">

<s><margin.target id="marg59"></margin.target>Per 3. pronun.</s></p><p type="margin">

<s><margin.target id="marg60"></margin.target>Per 17 huius.</s></p><p type="margin">

<s><margin.target id="marg61"></margin.target>Per 1. pron.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium</s></p><p type="main">

<s>Hinc est quod super plano CB, DB est mensura <lb/>diuturnitatis motus in AB.</s></p></subchap2></subchap1><pb xlink:href="064/01/041.jpg"/><subchap1 n="20" type="proposition"><p type="head">

<s>PROPOSITIO XX. PROBL. XII.</s></p><subchap2 n="20" type="statement"><p type="main">

<s>Datis duobus planis diverse inclinatis lon&shy;<lb/>gitudinis notae; &amp; nota diuturnitate gra&shy;<lb/>vis moti super uno, reperire diuturnita&shy;<lb/>tem si moveatur super alio.<figure id="id.064.01.041.1.jpg" xlink:href="064/01/041/1.jpg"/></s></p></subchap2><subchap2 n="21" type="proof"><p type="main">

<s>Sint plana AB, CD inclinata, &amp; sit data diu&shy;<lb/>turnitas E plani AB.</s></p><p type="main">

<s>Oportet reperire diuturnitatem plani CD.</s></p><p type="main">

<s>Fiat AF, paralella, &amp; aequalis datae CD, in qua <lb/>reperiatur punctum G quo perveniat grave, <lb/>tempore quo in B<arrow.to.target n="marg62"/>, unde E est etiam diuturnitas <lb/>spatij AG, quo dato, &amp; spatio AF perquiratur <lb/>eias diuturnitas, quae sit H<arrow.to.target n="marg63"/>, &amp; dico H esse <lb/>diuturnitatem quae grave descendit in CD.</s></p><p type="margin">

<s><margin.target id="marg62"></margin.target>Per 17. huius.</s></p><p type="margin">

<s><margin.target id="marg63"></margin.target>Per 9. huius.</s></p><p type="main">

<s>Quoniam E, H sunt diuturnitates gravium de&shy;<lb/>scendentium in AG, seu AB, &amp; AF, per con&shy;<lb/>structionem, &amp; AF est aequalis, &amp; paralella <lb/>datae CD per constructionem, sunt etiam E, H <lb/>diuturnitates ipsarum AB, &amp; CD<arrow.to.target n="marg64"/>, unde <lb/>reperta est diuturnitas ipsius CD. </s>

<s>Quod, etc.</s></p><p type="margin">

<s><margin.target id="marg64"></margin.target>Per 3. pron.</s></p></subchap2></subchap1><pb xlink:href="064/01/042.jpg"/><subchap1 n="21" type="proposition"><p type="head">

<s>PROPOSITIO XXI. PROBL. XIII.</s></p><subchap2 n="21" type="statement"><p type="main">

<s>Datis duabus diuturnitatibus, quarum prior <lb/>sit gravis moti super plano dato longitu&shy;<lb/>dinis notae, &amp; dato alio plano diversimo&shy;<lb/>de declinante; reperiendum est in eo pun&shy;<lb/>ctum, quo grave perveniat in secunda <lb/>diuturnitate data.<figure id="id.064.01.042.1.jpg" xlink:href="064/01/042/1.jpg"/></s></p></subchap2><subchap2 n="22" type="proof"><p type="main">

<s>Dato plano declinante AB, super quo grave <lb/>A moveatur diuturnitate C, &amp; dato alio <lb/>plano D declinationis quae sit dissimilis decli&shy;<lb/>nationi datae AB; data itidem diuturnitate E.</s></p><p type="main">

<s>Oportet reperire in D punctum quo grave per&shy;<lb/>veniat in diuturnitate E.</s></p><p type="main">

<s>Ducatur AF parallela ipsi D, in eaque reperia&shy;<lb/>tur punctum F, quo grave perveniat tempore quo <lb/>in B<arrow.to.target n="marg65"/>, &amp; praescribatur in eadem spatium AG per <lb/>quod moveatur in diuturnitate E<arrow.to.target n="marg66"/>, &amp; fiat DH <lb/>aequalis ipsi AG, &amp; dico H esse punctum quaesitum.</s></p><p type="margin">

<s><margin.target id="marg65"></margin.target>Per 17. huius.</s></p><p type="margin">

<s><margin.target id="marg66"></margin.target>Per 8. huius.</s></p><p type="main">

<s>Quoniam diuturnitates in AB, AF sunt aequales <lb/>per constructionem, &amp; C, E sunt diuturnita&shy;<lb/>tes super planis AF, AG per constructionem, <lb/>sunt etiam diuturnitates super AB, AG, &amp; <lb/>proinde super DH ipsi AG aequali, &amp; para<lb/>lellae, quod, etc.</s></p></subchap2></subchap1><pb xlink:href="064/01/043.jpg"/><subchap1 n="22" type="proposition"><p type="head">

<s>PROPOSITIO XXII.</s></p><subchap2 n="22" type="statement"><p type="main">

<s>Data perpendiculari seu plano quomodoli&shy;<lb/>bet inclinato diuturnitatis notae, &amp; assi&shy;<lb/>gnata ubivis quaecunque eius portione, re&shy;<lb/>perire eius diuturnitatem.<figure id="id.064.01.043.1.jpg" xlink:href="064/01/043/1.jpg"/></s></p></subchap2><subchap2 n="23" type="proof"><p type="main">

<s>Data linea AB perpendiculari aut inclina&shy;<lb/>ta, cuius, diuturnitas sit CD, dataque qua&shy;<lb/>cunque eius portione EF.</s></p><p type="main">

<s>Quaerenda eius diuturnitas.</s></p><p type="main">

<s>Fiat CG diuturnitas AE, &amp; CH diuturnitas <lb/>AF<arrow.to.target n="marg67"/>, GH est diuturnitas quaesita.</s></p><p type="margin">

<s><margin.target id="marg67"></margin.target>Per 5. aut 9. huius.</s></p><p type="main">

<s>Quoniam CH est diuturnitas AF per constr. ab <lb/>ea ablata CG diuturnitate AE per const. resi&shy;<lb/>duum GH est diuturnitas portionis EF quod, <lb/>etc.</s></p></subchap2></subchap1><pb xlink:href="064/01/044.jpg"/><subchap1 n="23" type="proposition"><p type="head">

<s>PROPOSITIO XXIII.</s></p><subchap2 n="23" type="statement"><p type="main">

<s>Duo gravia descendentia super planis diversa <lb/>ratione declinantibus, perveniunt ad idem <lb/>planum orizontale ea ratione, ut sit eadem <lb/>proportio inter diuturnitates, quae inter <lb/>dicta plana si ab eodem puncto ad idem <lb/>planum orizontale producta sint.<figure id="id.064.01.044.1.jpg" xlink:href="064/01/044/1.jpg"/></s></p></subchap2><subchap2 n="24" type="proof"><p type="main">

<s>Datis planis AB, AC declinantibus, ductis <lb/>ab eodem puncto A ad planum orizontale BC. <lb/> </s>

<s>Dico quod diuturnitates gravium descendentium <lb/>per AB, AC sint ut AB ad AC.</s></p><p type="main">

<s>Fiat ut AC ad AB ita AB ad AD, ita ut grave <lb/>perveniat in D eodem tempore quo pervenit in B<arrow.to.target n="marg68"/>.</s></p><p type="margin">

<s><margin.target id="marg68"></margin.target>Per 17. huius.</s></p><p type="main">

<s>Quoniam est ut AD ad AC, ita quadratum tem&shy;<lb/>poris AD ad quadratum temporis AC<arrow.to.target n="marg69"/>, &amp; <lb/>tempora AD, AB sunt aequalia<arrow.to.target n="marg70"/>, &amp; proinde <lb/>eorum quadrata; ergo ut AD ad AC ita qua&shy;<lb/>dratum temporis AB, ad quadratum tempo&shy;<lb/>ris AC<arrow.to.target n="marg71"/>, sed ut AD ad AC, ita quadra&shy;<lb/>tum AB ad quadratum AC<arrow.to.target n="marg72"/>, ergo ut quadra&shy;<lb/>tum temporis AB ad quadratum temporis AC, <lb/>ita quadratum AB ad quadratum AC, ergo <lb/>ut tempus AB ad tempus AC, ita AB ad AC<arrow.to.target n="marg73"/>. </s>

<s>Quod fuit probandum.</s></p><p type="margin">

<s><margin.target id="marg69"></margin.target>Per Cor. 7. huius.</s></p><p type="margin">

<s><margin.target id="marg70"></margin.target>Per const.</s></p><p type="margin">

<s><margin.target id="marg71"></margin.target>Per 2. pronun.</s></p><p type="margin">

<s><margin.target id="marg72"></margin.target>Per 10. sexti.</s></p><p type="margin">

<s><margin.target id="marg73"></margin.target>Per 22. sexti.</s></p></subchap2></subchap1><pb xlink:href="064/01/045.jpg"/><subchap1 n="24" type="proposition"><p type="head">

<s>PROPOSITIO XXIV</s></p><subchap2 n="24" type="statement"><p type="main">

<s>Datis planis, &amp; perpendiculari ad eadem li&shy;<lb/>nea orizontali egressis, quae coeant infra in <lb/>eodem puncto, gravia super ipsis mota <lb/>procedunt ea ratione, ut sit eadem propor&shy;<lb/>tion inter diuturnitates, quae inter longitu&shy;<lb/>dines planorum, &amp; dictam perpendicularem.<figure id="id.064.01.045.1.jpg" xlink:href="064/01/045/1.jpg"/></s></p></subchap2><subchap2 n="25" type="proof"><p type="main">

<s>Data sit linea orizontalis AB, in qua ini&shy;<lb/>tium sumant plana declinantia AC, DC, <lb/>nec non perpendicularis BC coeuntia in puncto C.</s></p><p type="main">

<s>Dico quod diuturnitates gravium super ipsis mo&shy;<lb/>torum, sunt ut AC, DC, BC.</s></p><p type="main">

<s>Ducatur CE paralella ipsi AB, &amp; a puncto A du&shy;<lb/>cantur paralellae ipsis CB, CD, &amp; sint AE, AF.</s></p><p type="main">

<s>Quoniam diuturnitates super planis AF, AC, <lb/>sunt ut AF, AC<arrow.to.target n="marg74"/>, &amp; super planis eisdem, &amp; <lb/>perpendiculari AE, sunt ut AF, seu AC ad <lb/>AE<arrow.to.target n="marg75"/>, &amp; AE, AF sunt paralellae ipsis CD, <lb/>CB, &amp; eisdem aequales,<arrow.to.target n="marg76"/>, sequitur quod etiam <lb/>super AC, DC, BC diuturnitates sunt iuxta <lb/>proportiones longitudinum<arrow.to.target n="marg77"/>, Quod probandum fuit.</s></p><p type="margin">

<s><margin.target id="marg74"></margin.target>Per 23. huius.</s></p><p type="margin">

<s><margin.target id="marg75"></margin.target>Per 15. huius.</s></p><p type="margin">

<s><margin.target id="marg76"></margin.target>Per 33. prim.</s></p><p type="margin">

<s><margin.target id="marg77"></margin.target>Per 3. pron.</s></p></subchap2></subchap1><pb xlink:href="064/01/046.jpg"/><subchap1 n="25" type="proposition"><p type="head">

<s>PROPOSITIO XXV.</s></p><subchap2 n="25" type="statement"><p type="main">

<s>In circulo Orthogonaliter erecto, si a sum&shy;<lb/>mitate ad puncta peripheriae ducantur pla&shy;<lb/>na, quo tempore grave perpendiculariter <lb/>inde pervenit ad planum orizontale; si de&shy;<lb/>scendat per dicta plana, eodem perveniet <lb/>respective ad quodlibet dictorum puncto&shy;<lb/>rum peripheriae.<figure id="id.064.01.046.1.jpg" xlink:href="064/01/046/1.jpg"/></s></p></subchap2><subchap2 n="26" type="proof"><p type="main">

<s>Sit circulus cuius centrum B, &amp; diameter AC <lb/>erectus super plano orizontali GC, &amp; in eo <lb/>ducta sint plana declinantia a puncto A ad <lb/>puncta peripheriae DEF, &amp; descendant gravia <lb/>super dicta plana, &amp; perpendiculariter.</s></p><p type="main">

<s>Dico quod eodem tempore pervenient ad, D, E, F, C.</s></p><p type="main">

<s>Ducantur DC, EC, FC.</s></p><p type="main">

<s>Quoniam puncta praedicta sunt ea, in quae cadunt <lb/>perpendicularia ducta a puncto C in AD, AE, <lb/>AF<arrow.to.target n="marg78"/>, eo perveniunt gravia eodem tempore <lb/>quo in C<arrow.to.target n="marg79"/>. </s>

<s>Quod probandum fuit.</s></p><p type="margin">

<s><margin.target id="marg78"></margin.target>Per 30. Tertij.</s></p><p type="margin">

<s><margin.target id="marg79"></margin.target>Per 16. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/047.jpg"/><subchap1 n="26" type="proposition"><p type="head">

<s>PROPOSITIO XXVI.</s></p><subchap2 n="26" type="statement"><p type="main">

<s>Sit in circulo erecto, a puncto inferiori ducan&shy;<lb/>tur plana ad puncta peripheriae, &amp; a dictis <lb/>punctis descendant gravia super dicta pla&shy;<lb/>na eodem tempore quo a puncto supremo <lb/>descendit aliud grave perpendiculariter; <lb/>pervenient omnia eodem instanti ad di&shy;<lb/>ctum punctum inferius.<figure id="id.064.01.047.1.jpg" xlink:href="064/01/047/1.jpg"/></s></p></subchap2><subchap2 n="27" type="proof"><p type="main">

<s>Sit circulus cuius diameter ABC erectus super <lb/>plano orizontali, quod tangat in C, &amp; a C <lb/>ducantur plana CD, CE, &amp; a punctis, E, D <lb/>gravia descendant super dicta plana, nec non, <lb/>&amp; a puncto supremo A perpendiculariter.</s></p><p type="main">

<s>Dico quod eodem tempore perveniunt in C.<lb/></s></p><p type="main">

<s>A puncto A ducantur AF, AG paralellae ipsis <lb/>CE, CD, &amp; ducantur AF, FC.</s></p><p type="main">

<s>Quoniam in triangulis AEC, AFC anguli al&shy;<lb/>terni FAC, ACE sint aequales,<arrow.to.target n="marg80"/>, &amp; anguli<lb/> <pb xlink:href="064/01/048.jpg"/>AFC, AEC sunt etiam aequales puta re&shy;<lb/>cti<arrow.to.target n="marg81"/>, &amp; basis AC communis, Triangula sunt <lb/>aequalia<arrow.to.target n="marg82"/>, &amp; proinde AF est aequalis CE, quod <lb/>idem probabitur de reliquis, ergo cum AF, <lb/>CE, &amp; reliquae sint paralellae, &amp; aequales, gra&shy;<lb/>via per CE, CD pervenient in C eodem tem&shy;<lb/>pore, quo digressa ab A perveniunt ad puncta <lb/>FG, sed haec eodem tempore quo perpendicula&shy;<lb/>riter pervenit in C<arrow.to.target n="marg83"/>, ergo etiam ea quae per <lb/>CE, CD. </s>

<s>Quod, etc.</s></p><p type="margin">

<s><margin.target id="marg80"></margin.target>Per 29. primi.</s></p><p type="margin">

<s><margin.target id="marg81"></margin.target>Per 30. Tertij.</s></p><p type="margin">

<s><margin.target id="marg82"></margin.target>Per 16. primi.</s></p><p type="margin">

<s><margin.target id="marg83"></margin.target>Per 25. huius.</s></p><pb xlink:href="064/01/049.jpg"/><p type="main">

<s>POSTULATUM VII</s></p><p type="main">

<s>Ductis planis inclinatis, &amp; linea perpen&shy;<lb/>diculari inter binas paralellas orizon&shy;<lb/>tales, Gravia super illis mota ubi perveni&shy;<lb/>unt ad paralellam inferiorem habent aequa&shy;<lb/>les velocitatis gradus; &amp; proinde si ab in&shy;<lb/>de infra sortiantur parem inclinationem, <lb/>aequevelociter moventur.</s></p><p type="main">

<s>Videtur probabile. </s>

<s>Primo quia si diuturni&shy;<lb/>tates sunt longitudinibus proportionales, ut <lb/>propositione 15. huius probatum fuit, credibile <lb/>est motus in fine esse aequales.</s></p><p type="main">

<s>Secundo. </s>

<s>Argumento ducto ab experientia pen&shy;<lb/>dulorum, quae quantumvis longiora, aut brevio&shy;<lb/>ra, &amp; proinde circa finem magis, aut minus in&shy;<lb/>clinata, pariter ascendunt, si pariter descendant.</s></p><p type="main">

<s>Tertio. </s>

<s>Quia videmus aquam per siphones rectos, <lb/>sive obliquos, seu inclinatos ductam, pariter <lb/>ascendere, si pariter descendat. </s>

<s>Ceterum fa&shy;<lb/>teor minorem evidentiam hoc postulatum caete&shy;<lb/>ris praemissis prae se ferre, quae fuit causa quod <lb/>illud, ut in praefatione, segregaverim, &amp; se&shy;<lb/>quentia, alia methodo, tangendo fere tantum&shy;<lb/>modo exposuerim, &amp; a pluribus alijs proposi&shy;<lb/>tionibus, quae hinc deduci facile possent, data <lb/>opera abstinuerim.</s></p></subchap2></subchap1><pb xlink:href="064/01/050.jpg"/><subchap1 n="27" type="proposition"><p type="head">

<s>PROPOSITIO XXVII. PROBL. XIV.</s></p><subchap2 n="27" type="statement"><p type="main">

<s>Dato gravi moto perpendiculariter per spa&shy;<lb/>tium datum diuturnitate data, quod per&shy;<lb/>ficiat motum super plano inclinato per <lb/>spatium itidem datum; perquirere in ipso <lb/>diuturnitatem.<figure id="id.064.01.050.1.jpg" xlink:href="064/01/050/1.jpg"/></s></p></subchap2><subchap2 n="28" type="proof"><p type="main">

<s>Moveatur grave A perpendiculariter per <lb/>spatium AB diuturnitate C, &amp; perseve&shy;<lb/>ret in motu super spatio BD in plano incli&shy;<lb/>nato BD.</s></p><p type="main">

<s>Venanda est diuturnitas eius in ipso BD.</s></p><p type="main">

<s>Producatur DB donec concurrat cum AE orizon&shy;<lb/>taliter ducta ab A in E, &amp; fiat ut AB ad EB, <lb/>ita diuturnitas C ad diuturnitatem G, quae <lb/>idcirco erit diuturnitas ipsius EB<arrow.to.target n="marg84"/>, &amp; sit H <lb/>quadratum diuturnitatis G, &amp; fiat ut EB <lb/>ad ED, ita quadratum H ad aliud quod sit I a <lb/>cuius latere K, quod est diuturnitas ipsius <lb/>ED, ablata KL aequali G, erit LM reli&shy;<lb/>quum diuturnitas BD quaesita.</s></p><p type="margin">

<s><margin.target id="marg84"></margin.target>* Est quarta tertij.</s></p><pb xlink:href="064/01/051.jpg"/><p type="main">

<s>Quoniam notum est triangulum AEB, cum no&shy;<lb/>tus sit angulus AEB aequalis alterno EDF <lb/>inclinationis notae, &amp; EAB rectus ex constru&shy;<lb/>ctione, &amp; notum latus AB ex hypotesi, notum <lb/>erit etiam latus EB, &amp; quia diuturnitas in <lb/>plano BD est eadem ac si motus antecedens <lb/>esset per EB<arrow.to.target n="marg85"/>, EB &amp; ED sunt in duplicata <lb/>ratione diuturnitatum G, K ex con&shy;<lb/>structio&shy;<lb/>ne; unde a K deducta KL aequali G ex constructione, remanet LM diuturnitas BD. </s>

<s>Quod, etc.</s></p><p type="margin">

<s><margin.target id="marg85"></margin.target>Per 22 huius.</s></p><p type="main">

<s>Inde sequitur quod summa diuturnitatum C, &amp; <lb/>LM, est diuturnitas totius ABD.**</s></p><p type="main">

<s>Eadem operatione pariter reperietur diuturni&shy;<lb/>tas BD si BD sit perpendicularis, &amp; AB <lb/>inclinata.</s></p><p type="main">

<s>Item si ambo sint plana inclinata.</s></p><p type="main">

<s>Ducta AD facile reperietur diuturnitas in ipsa <lb/>si fiat ut ED ad AD, ita K ad aliud per <lb/>21. huius.</s></p><pb xlink:href="064/01/052.jpg"/><p type="main">

<s>Ducto alio plano puta DN, reperietur eius <lb/>diuturnitas.<figure id="id.064.01.052.1.jpg" xlink:href="064/01/052/1.jpg"/></s></p><p type="main">

<s>Si fiat ut ED ad OD ita diuturnitas ipsius <lb/>ED puta L ad diuturnitatem OD, quae sit <lb/>P, deinde ut OD ad ON ita quadratum <lb/>diuturnitatis P ad aliud quadratum, cuius <lb/>Radix erit diuturnitas ipsius DN.</s></p><p type="main">

<s>Ex his patet quod si addantur plura plana ea&shy;<lb/>dem ratione reperientur eius diuturnitates.</s></p><pb xlink:href="064/01/053.jpg"/><figure id="id.064.01.053.1.jpg" xlink:href="064/01/053/1.jpg"/><p type="main">

<s>Ex his itidem patet quod si in circulo dentur <lb/>plura, plana v.g. FA, AC, CB, &amp; data sit <lb/>diuturnitas super diametro orizonti perpen&shy;<lb/>diculari, dabitur diuturnitas cuiusvis dicto&shy;<lb/>rum FA, AC, CT, &amp; omnium simul.7*</s></p><p type="main">

<s>In super ex his facile cognosces esse breviorem, <lb/>diuturnitatem per AC, CB, simul, quam per <lb/>AB;8* nam ducta AE perpendiculari ad BC <lb/>productam in D ad orizontalem AD, diutur&shy;<lb/>nitas motus in AC, super DB mensuratur per <lb/>EC<arrow.to.target n="marg86"/>, ergo addita CB, quae est eiusdem diutur&shy;<lb/>nitatis, fuerit ne motus per AC an per DC<arrow.to.target n="marg87"/>, <lb/>tota EB erit mensura diuturnitatis in ACB, <lb/>sed AB mensurat diuturnitatem ipsius AB <lb/>respectu eiusdem DB<arrow.to.target n="marg88"/>, quae est maior quam <lb/>EB<arrow.to.target n="marg89"/>, maior ergo est diuturnitas in AB quam <lb/>in ACB.</s></p><p type="margin">

<s><margin.target id="marg86"></margin.target>Per 7. post.</s></p><p type="margin">

<s><margin.target id="marg87"></margin.target>** Est pars secunda quartae tertij.</s></p><p type="margin">

<s><margin.target id="marg88"></margin.target>*** Est Tertia tertij.</s></p><p type="margin">

<s><margin.target id="marg89"></margin.target>**** Est corol. quartae tertij.</s></p><p type="main">

<s>Eadem prorsus ratione probabitur citius grave <lb/>descendere per FA, AC, CB, simul, quam per <lb/>planum ductum ab F in B.9*</s></p><p type="main">

<s>In figura propositionis 27. si facto H quadrato <lb/>diuturnitatis G, fiat ML aequalis C, cui ad&shy;<pb xlink:href="064/01/054.jpg"/>dita LK aequali G, fiat I quadratum MK, <lb/>&amp; ut H ad I, ita EB ad ED; MK erit <lb/>diuturnitas ED, &amp; ML diuturnitas BD <lb/>aequalis C. diuturnitas ipsius AB, unde diu&shy;<lb/>turnitates in AB, &amp; in BD aequales erunt.10*</s></p><p type="main">

<s>Et si BD esset fere Orizontalis, BE fieret longis&shy;<lb/>sima, &amp; quia EB ad ED est ut G ad tertiam <lb/>proportionalem ad G, &amp; MK, haec tertia exce&shy;<lb/>deret ipsam G fere duplo ipsius ML, seu C, ob <lb/>magnam diferentiam inter G, &amp; C, ob quam <lb/>G esset fere aequalis ipsi MK, unde itidem E<lb/>D excederet EB fere duplo ipsius AB, &amp; quo <lb/>BD esset magis orizontalis, eo BD propinquior <lb/>esset duplo AB.11*</s></p><p type="main">

<s>Ceterum ex hisce plura alia postmodum deduci <lb/>facile poterunt, haec vero in praesentia pauca <lb/>sufficere mihi visa sunt.</s></p></subchap2></subchap1></chap><pb xlink:href="064/01/055.jpg"/><chap><p type="main">

<s>DE MOTV <lb/>GRAVIVM <lb/>SOLIDORVM <lb/>LIBER SECVNDUVS <lb/> VBI DE IMPETV.</s></p><p type="main">

<s>LIBELLVM edidi octo ab <lb/>bine annis anno &longs;iquidem <lb/>1638 de motu &longs;olidorum, mox de liquidis editurus, quibus nimirum &longs;olida &longs;oli&shy; <lb/>dius &longs;truerent fundamen&shy; <lb/>tum.</s>

<s>Hucu&longs;que di&longs;tuli, exi&shy; <lb/>&longs;timans hos itidem duos libros de &longs;olidis prae&shy; <lb/>mittendos; faciliorem &longs;iquidem vi&longs;i &longs;unt &longs;ter&shy; <lb/>nere viam ad illorum demon&longs;trationem cla&shy; <lb/>riorem.</s>

<s>Quod eo libentius feci, quoniam &longs;e&shy; <lb/>ptimum po&longs;tulatum, quod inter principia, <lb/>connumerandum non videbatur, tanquam <lb/>minus euidens, decima huius propo&longs;itione <lb/>demon&longs;trare contigit; ex quo inde deducta, <pb xlink:href="064/01/056.jpg"/>&longs;eu potius leuiter tacta, libro &longs;equenti re&shy; <lb/>petere, &amp; clarius explica re coactus mihi vi&shy; <lb/>&longs;us &longs;um.</s>

<s>Qu&aelig; nihilomimus, citius perfici po&shy; <lb/>tui&longs;&longs;ent, ni pluribus litigijs, alijque negotijs <lb/>proprijs, &amp; alienis, tum muneribus publicis <lb/>di&longs;tractus, litterarum &longs;tndia dimittere &longs;&aelig;pius <lb/>mihi opus fui&longs;&longs;et.</s>

<s>Non ignoro litteris auide <lb/>deditos nu&longs;quam ijs obrui negotijs, quin horas <lb/>furtiuas quotidie reperiant, quibus di&longs;cipli&shy; <lb/>narum &longs;tudijs vacent: verum &longs;atis con&longs;tat in&shy; <lb/>tellectum libentius elaborare in nouis per di&shy; <lb/>&longs;cendis, &longs;eu aliorum partus ingeniorum in&shy; <lb/>quiras, &longs;eu (quod delectabilius longe e&longs;t) <lb/>noua proprio marte reperias, quam in iam <lb/>repertis po&longs;tmodum expoliendis, in quo ni&shy; <lb/>mirum labor ingens, nulla animi voluptas. <lb/></s>

<s>Ex quo mirandum non e&longs;t &longs;iquid otij occupa&shy; <lb/>tiones permi&longs;&longs;erunt, meum ad noua potius pro&shy; <lb/>pen&longs;um ingenium, ea &longs;&aelig;pius intermi&longs;i&longs;&longs;e, que <lb/>ad opus perficiendum nece&longs;&longs;ario requireban&shy; <lb/>tur: quod cau&longs;a fuit non modo proca&longs;tinatio&shy; <lb/>nis, &longs;ed cur opus prodeat impolitum, po&longs;tre&shy; <lb/>ma vide licet lima deficiente; vnde, &longs;i ani&shy; <lb/>mo meo morem gerere volui&longs;&longs;em, ad huc &longs;ub <lb/>tenebris latitaret.</s>

<s>Qualecunque &longs;it, tibi nunc <lb/>exhibere libuit, &amp; priorem librum iterum edi, <lb/>allique alligari ad eorundem captum nece&longs;&longs;arium, <lb/>tu illud accipias, &amp; excu&longs;es, &amp; corrigas velim.</s></p></chap><pb xlink:href="064/01/057.jpg"/><chap type="bk"><subchap1 type="definition"><p type="head">

<s>DEFINITIONES</s></p><subchap2 type="definition"><p type="main">

<s>1. Motus dicitur aequabilis, si mobile fera&shy;<lb/>tur per spatia, quae inter se sint ut <lb/>tempora, quibus conficiuntur.</s></p></subchap2><subchap2 type="definition"><p type="main">

<s>2. Impetus est vis, quia  mobile est aptum progre&shy;<lb/>di absque actione gravitatis, aut cuiusvis al&shy;<lb/>terius rei.</s></p></subchap2></subchap1><subchap1 type="postulate"><p type="head">

<s>Petitio</s></p><subchap2 type="postulate"><p type="main">

<s>Impetus sunt ut spatia, quae eius virtute aequis <lb/>temporibus permeantur.</s></p></subchap2></subchap1><subchap1 type="postulate"><p type="head">

<s>Axiomata</s></p><subchap2 type="axiom"><p type="main">

<s>1. Pares causae producunt pares effectus.</s></p></subchap2><subchap2 type="axiom"><p type="main">

<s>2. In effectu procedente a duabus causis, ablata eius <lb/>portione proveniente ab una, reliquum erit <lb/>portio proveniens ab altera.</s></p></subchap2></subchap1><pb xlink:href="064/01/058.jpg"/><subchap1 n="1" type="proposition"><p type="head">

<s>PROPOSITIO PRIMA.</s></p><subchap2 n="1" type="statement"><p type="main">

<s>Grave in motu naturali, sive perpendiculari, <lb/>sive inclinato, fertur sine ope gravitatis, <lb/>aequali tempore, per duplum spathuius praece&shy;<lb/>dentis.</s></p></subchap2><subchap2 n="1" type="proof"><p type="main"><figure id="id.064.01.058.1.jpg" xlink:href="064/01/058/1.jpg"/>

<s>Dato gravi A naturaliter la&shy;<lb/>to ab A ad B tempore ab, <lb/>cuius aequale sit tempus bc, &amp; <lb/>spatium BC, sit duplum spathuius AB. <lb/></s>

<s>Dico quod tempore bc fertur grave <lb/>sine ope gravitatis per spatium <lb/>aequale ipsi BC.</s></p><p type="main">

<s>Producatur AB, sumaturque portio <lb/>BD aequalis, &amp; DE dupla lineae AB, &amp; pro&shy;<lb/>inde aequalis ipsi BC.</s></p><p type="main">

<s>Quoniam ope gravitatis A tempore ab fertur <lb/>in B per constructionem, tempore bc eadem <lb/>ope prodibit in D per  spatium BD aequale A<lb/>B<arrow.to.target n="marg90"/>, at prodit in E<arrow.to.target n="marg91"/>, ergo fertur per DE du&shy;<lb/>plum  ipsius AB sine ope gravitatis, cui cum <lb/>sit aequalis BC per constructionem, constat, <lb/>quod sine ope gravitatis tempore bc fertur per <lb/>spatium aequale BC, quod etc.</s></p><p type="margin">

<s><margin.target id="marg90"></margin.target>Per axioma primum.</s></p><p type="margin">

<s><margin.target id="marg91"></margin.target>Per 3. primi huius.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium Primum</s></p><p type="main">

<s>Hinc sequitur quod si spatium AB sectum esset <lb/>in quatuor partes aequales, grave perficeret<pb xlink:href="064/01/059.jpg"/>primam tempore aequali illi quo conficit tres <lb/>reliquas, quia in fine primae acquisivit virtu&shy;<lb/>tem, seu impetum, quo perficeret duas partes, <lb/>tertiam verum conficit eadem virtute qua per&shy;<lb/>ficit primam. </s>

<s>Quod pari ratione sequitur si <lb/>AE producatur, &amp; in ea sumantur tres par&shy;<lb/>tes aequales ipsi AE, quae tres conficientur tem&shy;<lb/>pore ei aequali quo perficitur AE.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium II</s></p><p type="main">

<s>Impetus autem non sumpsit initium  in B, sed <lb/>prius, attamen cum mobile est in B ille impe&shy;<lb/>tus qui simul cum gravitate tempore ab duxit <lb/>mobile ab A in B non est sufficiens tempore bc <lb/>aequali ab ducere illud ultra D per dictum pri&shy;<lb/>mum Axioma,  unde impetus ducens grave a <lb/>D in E eodem tempore bd necessario est is qui <lb/>est acquisitus per motum AB in puncto B.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium III</s></p><p type="main">

<s>Quoniam impetus de nouo acquisitus  non <lb/>operatur seorsim ab impetu qui simul cum <lb/>gravitate duxit mobile ab A in B, sed eo&shy;<lb/>dem prorsus tempore ducitur mobile non modo <lb/>ab impetu de novo acquisito in B, sed etiam, &amp; <lb/>gravitate, &amp; ab impetu qui continuo produ&shy;<pb xlink:href="064/01/060.jpg"/><figure id="id.064.01.060.1.jpg" xlink:href="064/01/060/1.jpg"/>citur respondens illi qui duxit mobile ab A in <lb/>B, idcirco ipsum mobile a B in E fertur perpe&shy;<lb/>tuo velocius,  unde  motus est  velocior in E quem <lb/>fuerit in quolibet puncto superiori, &amp; pro&shy;<lb/>inde in E sortitum est impetum maiorem quam <lb/>habuerit prius, aptum ducere illud aequali tem&shy;<lb/>pore per spatium duplum ipsius AE.</s></p></subchap2></subchap1><pb xlink:href="064/01/061.jpg"/><subchap1 n="2" type="proposition"><p type="head">

<s>PROPOSITIO II. PROBL. I.</s></p><subchap2 n="2" type="statement"><p type="main">

<s><figure id="id.064.01.061.1.jpg" xlink:href="064/01/061/1.jpg"/>Dato spatio per quod grave naturali&shy;<lb/>ter ducatur virtute impetus solius sine <lb/>ope gravitatis, in dato tempore: repe&shy;<lb/>rire eius portionem per quam duca&shy;<lb/>tur eadem virtute in quavis portione <lb/>dicti temporis.</s></p></subchap2><subchap2 n="2" type="proof"><p type="main">

<s>Ducatur grave A per spatium  AE <lb/>tempore ae, nec non per spatium <lb/>aequale EB duplum AE virtute impetus <lb/>acquisiti in E sine ope gravitatis tempore e<lb/>h aequale ipsi ae<arrow.to.target n="marg92"/> cuius temporis eh data sit <lb/>portio quaelibet, &amp; sit primo portio immedia&shy;<lb/>ta tempori ae, &amp; sit eg.</s></p><p type="margin">

<s><margin.target id="marg92"></margin.target>Per pr. huius.</s></p><p type="main">

<s>Oportet reperire portionem spathuius EB, per quod <lb/>grave A ducatur, virtute impetus solius acqui&shy;<lb/>siti in E, sine ope gravitatis, in dicta portione <lb/>temporis eg.</s></p><p type="main">

<s>Concipiantur tempora ae, eh, eg tanquam lineae <lb/>rectae metientes tempora ae, eh, eg, &amp; fiat <lb/>ac tempus aequale tempori eg, &amp; ut ae <lb/>ad ac, fiat AE ad AD<arrow.to.target n="marg93"/> ad quas fiat tertia <lb/>AC<arrow.to.target n="marg94"/>, ex quo AE, AC sunt in duplicata ratio&shy;<lb/>ne temporunn ae, ac,<arrow.to.target n="marg95"/>. Fiat ut ae ad ag ita <lb/>AE ad AF<arrow.to.target n="marg96"/>, quibus tertia AG<arrow.to.target n="marg97"/>, ex quo AG, <lb/>AE sunt in duplicata ratione temporum ag, ae<arrow.to.target n="marg98"/>.</s></p><p type="margin">

<s><margin.target id="marg93"></margin.target>Per 12. sexti.</s></p><p type="margin">

<s><margin.target id="marg94"></margin.target>Per 11. sexti.</s></p><p type="margin">

<s><margin.target id="marg95"></margin.target>Per 10. def. quinti.</s></p><p type="margin">

<s><margin.target id="marg96"></margin.target>Per 12. sexti.</s></p><p type="margin">

<s><margin.target id="marg97"></margin.target>Per 11. sexti.</s></p><p type="margin">

<s><margin.target id="marg98"></margin.target>Per 10 def. 5.</s></p><p type="main">

<s><pb xlink:href="064/01/062.jpg"/>Fiat EH aequalis AC, et ab AG abla&shy;<lb/>ta AH, residuo HG fiat aequalis EI.</s></p><p type="main">

<s>Dico EI esse portionem quaesitam.</s></p><p type="main">

<s>Quoniam AE est casus gravis A tempore ae per <lb/>supp. &amp; AE, AC sunt in dupl. ratione tem&shy;<lb/>porum ae, ac per constr. </s>

<s>AC est casus gravis <lb/>tempore ac<arrow.to.target n="marg99"/>, &amp; proinde EH aequalis AC est <lb/>casus tempore eg aequali ipsi ab si grave du&shy;<lb/>ceretur per EH eadem prorsus virtute qua <lb/>ductum fuit per AC<arrow.to.target n="marg100"/>.</s></p><p type="margin">

<s><margin.target id="marg99"></margin.target>Per 3. pr. huius.</s></p><p type="margin">

<s><margin.target id="marg100"></margin.target>Per axioma primum.</s></p><p type="main">

<s>Item quia AG, AE sunt in duplicata ratione tem&shy;<lb/>porum ag, ae per constr., AG est casus tempo&shy;<lb/>re ag<arrow.to.target n="marg101"/>, &amp; proinde residuum EG est casus re&shy;<lb/>sidui eg<arrow.to.target n="marg102"/>, dum tamen   motus proveniat tam <lb/>e gravitate quam a quolibet impetu superaddi&shy;<lb/>to, at EH probatum est esse casum itidem, eg <lb/>dum tamen grave ducatur ea solum virtute <lb/>qua ductum fuit per AC<arrow.to.target n="marg103"/>, ig, residuum HG <lb/>est spatium quod perficitur eodem tempore eg, <lb/>a solo impetu acquisito in E<arrow.to.target n="marg104"/>, quod est aequa&shy;<lb/>le EI per constr., unde EI est spatium quaesitum.</s></p><p type="margin">

<s><margin.target id="marg101"></margin.target>Per 3. primi huius.</s></p><p type="margin">

<s><margin.target id="marg102"></margin.target>Per 19. Quinti.</s></p><p type="margin">

<s><margin.target id="marg103"></margin.target>Per axioma primum.</s></p><p type="margin">

<s><margin.target id="marg104"></margin.target>Per axioma secundum.</s></p><p type="main">

<s>Sit deinde portio temporis eb disiuncta ab ae, puta <lb/>gK, &amp; sit rursus reperienda portio spathuius EB <lb/>per quod grave A ducatur vi solius impetus <lb/>in E acquisiti in dicta portione temporis gk: <lb/>reperto prius spatio EC respondenti tempori eg <lb/>immediato ipsi ae modo quo supra dictum <lb/>fuit; fiat ac tempus aequale tempori gK, &amp; ut<pb xlink:href="064/01/063.jpg"/><figure id="id.064.01.063.1.jpg" xlink:href="064/01/063/1.jpg"/> ag ad ac fiat AG ad AD, ad quas tertia A<lb/>C; AG, AC erunt in duplicata ratione tem&shy;<lb/>porum ag, ac. </s>

<s>Item fiat ut ag ad aK ita AG <lb/>ad AL, quibus tertia AK: AK, AH erunt in <lb/>duplicata ratione temporum aK, ag; fiat GM <lb/>aequalis AC, &amp; ab AK auferatur AM, &amp; <lb/>residuo MK fiat aequale 1N, &amp; eodem ratio&shy;<lb/>cinio demonstrabitur IN esse spatium quae&shy;<lb/>situm. </s>

<s>Reperta est igitur portio quaesita, <lb/>quod etc.</s></p></subchap2></subchap1><pb xlink:href="064/01/064.jpg"/><subchap1 n="3" type="proposition"><p type="head">

<s>PROPOSITIO TERTIA.</s></p><subchap2 n="3" type="statement"><p type="main">

<s>In motu naturali gravium, spatia quae conficiun&shy;<lb/>tur virtute impetus sine ope gravitatis sunt <lb/>inter se ut tempora quibus conficiuntur.<figure id="id.064.01.064.1.jpg" xlink:href="064/01/064/1.jpg"/></s></p></subchap2><subchap2 n="3" type="proof"><p type="main">

<s>Descendat grave A in E tempore ae, &amp; tem&shy;<lb/>pore eh aequali ae, ex solo impetu, sine ope <lb/>gravitatis, per spatium aequale EB, duplo ipsius <lb/>AE,<arrow.to.target n="marg105"/> &amp; secetur EI portio dicti spathuius EB <lb/>quae sit aequalis spatio per quod duci debeat gra&shy;<lb/>ve A tempore eg portione dicti temporis eh so&shy;<lb/>la vi impetus acquisiti in E<arrow.to.target n="marg106"/>.</s></p><p type="margin">

<s><margin.target id="marg105"></margin.target>Per pr. huius.</s></p><p type="margin">

<s><margin.target id="marg106"></margin.target>Per 2. huius.</s></p><p type="main">

<s>Dico spatium EI ad spatium EB esse ut <lb/>tempus eg ad tempus eh.</s></p><p type="main">

<s>Percipiantur tempora ae, eh, eg tanquam rectae me&shy;<lb/>tientes tempora ae, eh, eg, &amp; reperiantur ut in <lb/>praecedenti puncta C, H, G, e, &amp; describantur <lb/>quadrata ab, ad, bd, supra ae, ag, eg<arrow.to.target n="marg107"/>.</s></p><p type="margin">

<s><margin.target id="marg107"></margin.target>Per 46. primi.</s></p><pb xlink:href="064/01/065.jpg"/><p type="main">

<s>Quoniam AG, AE sunt in duplicata ratione <lb/>ad ag, ae per constr., &amp; quadrata ad, ab <lb/>sunt pariter in duplicata ratione ad ag, ae,<arrow.to.target n="marg108"/> <lb/>erunt AG, AE ut quadrata ad, ab,<arrow.to.target n="marg109"/> &amp; di&shy;<lb/>videndo ut EG ad AE ita ad minus ab, hoc est <lb/>gnomon edf, ad ab.<arrow.to.target n="marg110"/> Pari ratione probabimus <lb/>ut AE ad EH esse quadrata ab, ad bd, &amp; <lb/>proinde EG ad EH est ut gnomon edf ad <lb/>quadratum bd<arrow.to.target n="marg111"/> unde HG, ad EG, ut com&shy;<lb/>plementa gb, bf ad gnomonem edf,<arrow.to.target n="marg112"/> at EG <lb/>ad AE sunt ut gnomon  edf ad quadratum ab, <lb/>ut probatum est supra, ergo HG, seu EI <lb/>ipsi <lb/>aequalis per constr. ad AE est ut dicta comple&shy;<lb/>menta gb, bf, ad quadratum ab,<arrow.to.target n="marg113"/> bisk seu <lb/>ut gb ad ab,<emph type="sup"/>1<emph.end type="sup"/> seu ut eg ad ae,m seu eh, ei <lb/>aequale per constr. </s>

<s>Quod, etc.</s></p><p type="margin">

<s><margin.target id="marg108"></margin.target>Per 20. sexti.</s></p><p type="margin">

<s><margin.target id="marg109"></margin.target>Per 11. Quinti.</s></p><p type="margin">

<s><margin.target id="marg110"></margin.target>Per 17. Quinti.</s></p><p type="margin">

<s><margin.target id="marg111"></margin.target>Per 22. Quinti.</s></p><p type="margin">

<s><margin.target id="marg112"></margin.target>Per 19. Quinti.</s></p><p type="margin">

<s><margin.target id="marg113"></margin.target>Per 22. Quinti.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium Primum</s></p><p type="main">

<s>Si portio temporis eh non sit immediata tempori <lb/>ae sed ab ea seiuncta, puta in schemate propo&shy;<lb/>sitionis secundae gK, reperto in EB spatio IN<pb xlink:href="064/01/066.jpg"/><figure id="id.064.01.066.1.jpg" xlink:href="064/01/066/1.jpg"/> ipsi gk, respondenten, eodem ratiocinio quo supra <lb/>probabitur spatium EB ad eius portionem IN <lb/>esse ut tempus eh ad eius portionem gK, quan&shy;<lb/>doquidem qua ratione EI respondet tempori eg, <lb/>eadem EN respondet tempori eK, &amp; proinde <lb/>reliquum IN respondet reliquo gK.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium II</s></p><p type="main">

<s>Motus ab impetu proveniens est aequabilis.</s></p></subchap2></subchap1><pb xlink:href="064/01/067.jpg"/><subchap1 n="4" type="proposition"><p type="head">

<s>PROPOSITIO IV.</s></p><subchap2 n="4" type="statement"><p type="main">

<s>In motu naturali impetus successive acquisi&shy;<lb/>ti sunt ut tempora transacta.</s></p></subchap2><figure id="id.064.01.067.1.jpg" xlink:href="064/01/067/1.jpg"/><subchap2 n="4" type="proof"><p type="main">

<s>Dato gravi moto naturali motu per AC, tem&shy;<lb/>pore ac, &amp; per AB, tempore ab.</s></p><p type="main">

<s>Dico impetum seu velocitatem in B ad impetum <lb/>in C esse ut ab ad ac. </s>

<s>Concipiantur tempora ab, ac tanquam lineae re&shy;<lb/>ctae metientes tempora ab, ac. </s>

<s>Fiat BD dupla ipsius AB mensura impetus in B <lb/>tempore ab, &amp; CE dupla ipsius AC mensura <lb/>impetus in C tempore ac<arrow.to.target n="marg114"/>, &amp; BF media inter <lb/>BD, CE<arrow.to.target n="marg115"/>.</s></p><p type="margin">

<s><margin.target id="marg114"></margin.target>k Per 25. Quinti.</s></p><p type="margin">

<s><margin.target id="marg115"></margin.target>l Per 22. Quinti &amp; 43. pr.</s></p><p type="main">

<s>Quoniam AB, AC sunt in duplicata ratione <lb/>temporum ab, ac<arrow.to.target n="marg116"/>, BD, CE sunt pariter in <lb/>duplicata ratione eorundem temporum ab, ac<arrow.to.target n="marg117"/>, <lb/>sed BD, CE sunt etiam in duplicitata ratione <lb/>spatiorum BD, BF per constructionem, ergo BD, BF <lb/>sunt ut tempora ab, ac<arrow.to.target n="marg118"/>. Sed BD mensura <lb/>impetus in B tempore ab, est spatium per <lb/>quod percurrit mobile virtute solius impetus <lb/>acquisiti in B tempore ab per constructionem, erit igitur<pb xlink:href="064/01/068.jpg"/>BF spatium per quod percurret idem mobile <lb/>eadem virtute impetus acquisiti in B tempore <lb/>ac<arrow.to.target n="marg119"/>, at CE est spatium quod percurrit mobile <lb/>eodem tempore ac per constr. </s>

<s>Igitur eodem tem&shy;<lb/>pore ac mobile in C perficit spatium CE, &amp; in <lb/>B perficit spatium BF; sed impetus sunt ut spa&shy;<lb/>tia quae aequali tempore transiguuntur<emph type="sup"/>g<emph.end type="sup"/><arrow.to.target n="marg120"/>. Ergo <lb/>impetus in C, &amp; B sunt ut CE ad BF spatia, <lb/>quae probatum est esse ut tempora ac, ab, unde <lb/>impetus in C &amp; B sunt ut tempora ac, ab<arrow.to.target n="marg121"/>, <lb/>quod etc.</s></p><p type="margin">

<s><margin.target id="marg116"></margin.target>m Per 36. primi.</s></p><p type="margin">

<s><margin.target id="marg117"></margin.target>n Per 2. huius.</s></p><p type="margin">

<s><margin.target id="marg118"></margin.target>o Per primam defin.</s></p><p type="margin">

<s><margin.target id="marg119"></margin.target>Per primam huius.</s></p><p type="margin">

<s><margin.target id="marg120"></margin.target>Per 13 Sexti.</s></p><p type="margin">

<s><margin.target id="marg121"></margin.target>Per tertiam pr. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/069.jpg"/><subchap1 n="5" type="proposition"><p type="head">

<s>PROPOSITIO V.</s></p><subchap2 n="5" type="statement"><p type="main">

<s>In motu naturali gravium impetus successive <lb/>acquisiti sunt in subduplicata ratione spa&shy;<lb/>tiorum transactorum.</s></p></subchap2><figure id="id.064.01.069.1.jpg" xlink:href="064/01/069/1.jpg"/><subchap2 n="5" type="proof"><p type="main">

<s>Iisdem positis.</s></p><p type="main">

<s>Dico impetus, seu velocitates in B, &amp; in C <lb/>esse in subduplicata ratione spatiorum <lb/>AB, &amp; AC.</s></p><p type="main">

<s>Quoniam impetus in B, &amp; C sunt ut tempora ab, <lb/>ac transacta<arrow.to.target n="marg122"/>.</s></p><p type="margin">

<s><margin.target id="marg122"></margin.target>Per 11. Quinti.</s></p><p type="main">

<s>Sed tempora ab, ac sunt in subduplicata ra&shy;<lb/>tione spatiorum AB, AC<arrow.to.target n="marg123"/>. </s>

<s>Pariter impetus <lb/>in B, &amp; in C sunt in subduplicata ratione <lb/>spatiorum AB, AC, quod etc.</s></p><p type="margin">

<s><margin.target id="marg123"></margin.target>Per 11 Quinti.</s></p></subchap2></subchap1><pb xlink:href="064/01/070.jpg"/><subchap1 n="6" type="proposition"><p type="head">

<s>PROPOSITIO VI.</s></p><subchap2 n="6" type="statement"><p type="main"><figure id="id.064.01.070.1.jpg" xlink:href="064/01/070/1.jpg"/>

<s>Datis in perpendiculari quibuslibet pun&shy;<lb/>ctis reperire impetus singulorum in&shy;<lb/>ter se.</s></p></subchap2><subchap2 n="6" type="proof"><p type="main">

<s>Data linea perpendiculari AB, &amp; <lb/>in ea punctis C, D,</s></p><p type="main">

<s>Venandi impetus in C, D dum grave ab <lb/>A dimissum fertur per AB.</s></p><p type="main">

<s>Sit E media inter AC, AD, item fiat AF media <lb/>inter AC, AB.</s></p><p type="main">

<s>Dico impetus in C, D, B esse ut AC, AE, AF.</s></p><p type="main">

<s>Quoniam AE est media inter AC, AD per con&shy;<lb/>structionem, AD, AC sunt in duplicata ratio&shy;<lb/>ne rectarum AE, AC<arrow.to.target n="marg124"/>.</s></p><p type="margin">

<s><margin.target id="marg124"></margin.target>Per 3. huius.</s></p><p type="main">

<s>Ergo AC, AE metiuntur impetus in C &amp; D<arrow.to.target n="marg125"/>.</s></p><p type="margin">

<s><margin.target id="marg125"></margin.target>Per pet. huius.</s></p><p type="main">

<s>Item quoniam AF est media inter AC, AB per <lb/>constructionem, AF, AC sunt in subduplicata <lb/>ratione rectarum AB, AC, igitur AC, AF <lb/>metiuntur impetus in C &amp; B, quod etc.</s></p></subchap2></subchap1><pb xlink:href="064/01/071.jpg"/><subchap1 n="7" type="proposition"><p type="head">

<s>PROPOSITIO VII.</s></p><subchap2 n="7" type="statement"><p type="main">

<s>In quolibet puncto motus reperire spatium, <lb/>per quod mobile sit aptum duci sine ope <lb/>gravitatis in dato tempore.</s></p></subchap2><subchap2 n="7" type="proof"><figure id="id.064.01.071.1.jpg" xlink:href="064/01/071/1.jpg"/><p type="main">

<s>Ducatur grave tempore ab a puncto B per <lb/>spatium aequale rectae BD sine ope gravi&shy;<lb/>tatis ut in praecedenti.</s></p><p type="main">

<s>Oportet reperire in alio puncto ipsius motus, puta <lb/>C, spatium aequale ei, per quod ducetur sine ope <lb/>gravitatis eodem  tempore ab.</s></p><p type="main">

<s>Sit ac tempus, per quod ducitur grave  naturali&shy;<lb/>ter motum ab A in C, &amp; fiat CE dupla ad AC, &amp; <lb/>secetur CE in F ea ratione, ut partes CF, FE <lb/>sint partibus ab, bc proportionales<arrow.to.target n="marg126"/>.</s></p><p type="margin">

<s><margin.target id="marg126"></margin.target>Per 11. Quinti.</s></p><p type="main">

<s>Dico CF spatium aequari illi, per quod ducetur&shy;<lb/>grave digressum a C tempore ab.</s></p><p type="main">

<s>Qunoniam CF ad FE est ut ab ad bc per constructionem, <lb/>erit ut CE ad CF ita ac ad ab<arrow.to.target n="marg127"/>, &amp; permutando <lb/>ut CE ad ac, ita CF ad ab<arrow.to.target n="marg128"/> at spatium aequa&shy;<lb/>le CE perficitur tempore ac<arrow.to.target n="marg129"/> motu aequabili<arrow.to.target n="marg130"/>.</s></p><p type="margin">

<s><margin.target id="marg127"></margin.target>Per 4. huius.</s></p><p type="margin">

<s><margin.target id="marg128"></margin.target>Per 3. pr. huius.</s></p><p type="margin">

<s><margin.target id="marg129"></margin.target>Per 10. def. Quinti.</s></p><p type="margin">

<s><margin.target id="marg130"></margin.target>Per 5. huius.</s></p><p type="main">

<s>Ergo spatium aequale CF conficitur tempore ab, quod etc.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium</s></p><p type="main">

<s>Huic sequitur quod eodem tempore, puta ab, <lb/>grave ducitur per BD, &amp; per CF.</s></p></subchap2></subchap1><pb xlink:href="064/01/072.jpg"/><subchap1 n="8" type="proposition"><p type="head">

<s>PROPOSITIO VIII.</s></p><subchap2 n="8" type="statement"><p type="main">

<s>Si lineae perpendicularis, &amp; inclinata ab eo&shy;<lb/>dem puncto digressae, per quas idem grave <lb/>naturaliter ducatur, secentur a recta norma&shy;<lb/>lis ad inclinatam; impetus in punctis sectionis, <lb/>sunt ut portiones linearum intra sectiones.</s></p></subchap2><figure id="id.064.01.072.1.jpg" xlink:href="064/01/072/1.jpg"/><subchap2 n="8" type="proof"><p type="main">

<s>Sint rectae AB perpendicularis, &amp; AC quomo&shy;<lb/>documque; inclinata per quas grave naturaliter <lb/>ducatur, sectae a BD normali ad AC declinantem.</s></p><p type="main">

<s>Dico impetum in B ad impetum in D esse ut AB <lb/>ad AD.</s></p><p type="main">

<s>Fiat BE dupla AB mensura impetus in B, &amp; DF <lb/>dupla AD mensura impetus in D<arrow.to.target n="marg131"/>.</s></p><p type="margin">

<s><margin.target id="marg131"></margin.target>Per 10. sexti.</s></p><p type="main">

<s>Quoniam grave ducitur per AB AD eodem <lb/>tempore<arrow.to.target n="marg132"/>. Ducitur etiam sine ope gravitatis eo&shy;<lb/>dem tempore per spatia aequalia ipsis BE, DF<arrow.to.target n="marg133"/> <lb/>&amp; proinde BE, DF sunt ut impetus in B &amp; D<arrow.to.target n="marg134"/>.</s></p><p type="margin">

<s><margin.target id="marg132"></margin.target>Per 18. Quinti.</s></p><p type="margin">

<s><margin.target id="marg133"></margin.target>Per 16. Quinti.</s></p><p type="margin">

<s><margin.target id="marg134"></margin.target>Per pr. huius.</s></p><p type="main">

<s>At BE, DF sunt ut AB, AD per constr. quip&shy;<lb/>pe earum duplae. </s>

<s>Igitur AB, AD sun t ut im&shy;<lb/>petus in B &amp; D<arrow.to.target n="marg135"/> quod, etc.</s></p><p type="margin">

<s><margin.target id="marg135"></margin.target>Per cor. 3. huius.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium</s></p><p type="main">

<s>Impetus sive velocitas in B ad impetum in D <lb/>est ut AC ad AB.</s></p></subchap2></subchap1><pb xlink:href="064/01/073.jpg"/><subchap1 n="9" type="proposition"><p type="head">

<s>PROPOSITIO IX.</s></p><subchap2 n="9" type="statement"><p type="main">

<s>Ductis a puncto superno perpendiculari, &amp; <lb/>inclinata ad planum Orizontale, &amp; a pun&shy;<lb/>cto inferno perpendicularis ducta normali <lb/>ad inclinatam, impetus inclinatae in pun&shy;<lb/>ctis, in quibus secat normalem, &amp; orizon&shy;<lb/>talem, sunt ut perpendicularis, &amp; inclinata.</s></p></subchap2><figure id="id.064.01.073.1.jpg" xlink:href="064/01/073/1.jpg"/><subchap2 n="9" type="proof"><p type="main">

<s>Sint rectae AB AC ductae a puncto A ad orizon&shy;<lb/>talem CB &amp; a B ducatur normalis BD ad <lb/>AC.</s></p><p type="main">

<s>Dico impetum in D ad impetum in C esse ut AB <lb/>ad AC.</s></p><p type="main">

<s>Quoniam AC AD sunt in duplicata ratione im&shy;<lb/>petus C ad impetum D<arrow.to.target n="marg136"/>.</s></p><p type="margin">

<s><margin.target id="marg136"></margin.target>Per pr. huius.</s></p><p type="main">

<s>Sunt itidem in duplicata ratione AC ad AB<arrow.to.target n="marg137"/>.</s></p><p type="margin">

<s><margin.target id="marg137"></margin.target>Per 14. pr. huius.</s></p><p type="main">

<s>Igitur impetus in C ad impetum in D sunt ut AC <lb/>AB<arrow.to.target n="marg138"/> quod, etc.</s></p><p type="margin">

<s><margin.target id="marg138"></margin.target>Per pr. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/074.jpg"/><subchap1 n="10" type="proposition"><p type="head">

<s>PROPOSITIO X.</s></p><subchap2 n="10" type="statement"><p type="main">

<s>Ductis a puncto superno per pendiculari, &amp; <lb/>inclinata in punctis in quibus secant lineam <lb/>orizontalem sortiuntur impetus aequales.</s></p></subchap2><figure id="id.064.01.074.1.jpg" xlink:href="064/01/074/1.jpg"/><subchap2 n="10" type="proof"><p type="main">

<s>A puncto A superno ducatur AB perpendi&shy;<lb/>cularis, &amp; AC declinans ad BC Orizon&shy;<lb/>talem.</s></p><p type="main">

<s>Dico, quod in B, &amp; C sunt impetus aequales.</s></p><p type="main">

<s>Quoniam impetus in C ad impetum in D est ut <lb/>AC ad AB<arrow.to.target n="marg139"/>.</s></p><p type="margin">

<s><margin.target id="marg139"></margin.target>Per pet. huius.</s></p><p type="main">

<s>Item impetus in B ad impetum in D est pariter <lb/>ut AC ad AB<arrow.to.target n="marg140"/>.</s></p><p type="margin">

<s><margin.target id="marg140"></margin.target>Per 11. Quinti.</s></p><p type="main">

<s>Igitur impetus in C, &amp; B sunt aequales<arrow.to.target n="marg141"/>. </s>

<s>Quod <lb/>etc.</s></p><p type="margin">

<s><margin.target id="marg141"></margin.target>Per 5. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/075.jpg"/><subchap1 n="11" type="proposition"><p type="head">

<s>PROPOSITIO XI. PROBL. IV.</s></p><subchap2 n="11" type="statement"><p type="main">

<s>Datis pluribus lineis &aelig;qualibus ab eodem <lb/>puncto superno descendentibus, etiam si <lb/>una sit perpendicularis, reperire impetus <lb/>in fine ipsarum inter se.</s></p></subchap2><figure id="id.064.01.075.1.jpg" xlink:href="064/01/075/1.jpg"/><subchap2 n="11" type="proof"><p type="main">

<s>Datis aequalibus AB, AC, AD, inclinatis, <lb/>&amp; AE perpendiculari oportet venari im&shy;<lb/>petus inter se in B, C, D, E.</s></p><p type="main">

<s>Ducantur BF, CG, DH normales ad AE,<arrow.to.target n="marg142"/> &amp; <lb/>proinde orizontales, &amp; fiat AI media inter <lb/>AF, AG, &amp; fiat AK media inter AF, AH, <lb/>item fiat AL media inter AF, AE.</s></p><p type="margin">

<s><margin.target id="marg142"></margin.target>Per 10. definit. quinti.</s></p><p type="main">

<s>Dico impetus in B, C, D, E esse inter se ut AF, <lb/>AI, AK, AL.</s></p><p type="main">

<s>Quoniam impetus in B, &amp; F sunt aequales nec <lb/>non in CL, &amp; in DH<arrow.to.target n="marg143"/>, &amp; impetus in F, G, <lb/>H, E sunt ut AF, AI, AK, AL<arrow.to.target n="marg144"/>,</s></p><p type="margin">

<s><margin.target id="marg143"></margin.target>Per 16. Quinti.</s></p><p type="margin">

<s><margin.target id="marg144"></margin.target>Per 9. huius.</s></p><p type="main">

<s>Igitur impetus in B, C, D, E, sunt ut AF, AI, <lb/>AK, AL, Quod etc.</s></p></subchap2></subchap1><pb xlink:href="064/01/076.jpg"/><subchap1 n="12" type="proposition"><p type="head">

<s>PROPOSITIO XII</s></p><subchap2 n="12" type="statement"><p type="main">

<s>Ductis pluribus lineis diversi mode inclinatis, &amp; <lb/>etiam perpendiculari, quae ab eadem li&shy;<lb/>nea Orizontali terminentur in idem pun&shy;<lb/>ctum inferius; ibi sortiuntur impetus aequales.<figure id="id.064.01.076.1.jpg" xlink:href="064/01/076/1.jpg"/></s></p></subchap2><subchap2 n="12" type="proof"><p type="main">

<s>Sint lineae BD CD diversimode inclinatae, &amp; AD <lb/>perpendicularis, ductae a linea Orizontali AC <lb/>ad punctum inferius D. </s>

<s>Dico gravia a punctis <lb/>A B C digressa, &amp; in eis lata, in D sortiri im&shy;<lb/>petus aequales.</s></p><p type="main">

<s>Fiat DEF parallela ad AC<arrow.to.target n="marg145"/>, &amp; proinde ori&shy;<lb/>zontalis, ad quam dimittantur perpendicula&shy;<lb/>res BE CF<arrow.to.target n="marg146"/>.</s></p><p type="margin">

<s><margin.target id="marg145"></margin.target>Per cor. 8. huius.</s></p><p type="margin">

<s><margin.target id="marg146"></margin.target>Per 11. Quinti.</s></p><p type="main">

<s>Quoniam gravia ducta per AD, BE, CF in DEF <lb/>habent impetus aequales, quia omnia paria<arrow.to.target n="marg147"/>, <lb/>&amp; gravia ducta per BD, BE in DE habent im&shy;<lb/>petus aequales, item per CD, CF in DF habent <lb/>impetus aequales<arrow.to.target n="marg148"/> sequitur quod etiam ducta <lb/>per AD, BD, CD sortita sunt in D impetus <lb/>aequales. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg147"></margin.target>Per 12. sexti.</s></p><p type="margin">

<s><margin.target id="marg148"></margin.target>Per 10. huius.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium</s></p><p type="main">

<s>Hinc sequitur, quod si ABC non sit linea, sed planum <lb/>Orizontale, item loco puncti D sint plura puncta, <lb/>dummodo in plano Orizontali; gravia in punctis <lb/>D habebunt impetus aequales.</s></p></subchap2></subchap1><pb xlink:href="064/01/077.jpg"/><subchap1 n="13" type="proposition"><p type="head">

<s>PROPOSITIO XIII. PROBL. V.</s></p><subchap2 n="13" type="statement"><p type="main">

<s>Datis gravibus descendentibus per perpendi&shy;<lb/>cularem, &amp; declinantem reperire rationes im&shy;<lb/>petus in punctis datis.<figure id="id.064.01.077.1.jpg" xlink:href="064/01/077/1.jpg"/></s></p></subchap2><subchap2 n="13" type="proof"><p type="main">

<s>Descendat grave per AC per pendicularem , <lb/>&amp; AB declinantem, &amp; dentur puncta B, C.</s></p><p type="main">

<s>Reperire proportionem impe&shy;<lb/>tus in B ad impetum in C.</s></p><p type="main">

<s>Ducatur BD normalis ad AC<arrow.to.target n="marg149"/>, &amp; fiat AE <lb/>media inter AC, AD<arrow.to.target n="marg150"/>, Dico impetum in C ad <lb/>impetum in B esse ut AE ad AD.</s></p><p type="margin">

<s><margin.target id="marg149"></margin.target>Per 6. huius.</s></p><p type="margin">

<s><margin.target id="marg150"></margin.target>Per 31. primi.</s></p><p type="main">

<s>Quoniam impetus in C ad impetum in D est ut <lb/>AE ad AD<arrow.to.target n="marg151"/>, &amp; impetus in D &amp; B sunt aequa&shy;<lb/>les<arrow.to.target n="marg152"/>, ergo impetus in C ad impetum in B est <lb/>ut AE ad AD, Quod etc.<figure id="id.064.01.077.2.jpg" xlink:href="064/01/077/2.jpg"/></s></p><p type="margin">

<s><margin.target id="marg151"></margin.target>Per 13. primi.</s></p><p type="margin">

<s><margin.target id="marg152"></margin.target>Per axioma primum.</s></p></subchap2><pb xlink:href="064/01/078.jpg" pagenum="78"/><subchap2 type="corollary"><p type="head">

<s>Corollarium</s></p><p type="main">

<s>Eodem pacto reperies impetus in planis ut&shy;<lb/>cumque declinantibus ductis perpendicula&shy;<lb/>ribus ad AC.</s></p></subchap2></subchap1></chap><pb xlink:href="064/01/079.jpg"/><chap type="bk"><p type="main">

<s>DE MOTV<lb/>GRAVIVM<lb/>SOLIDORVM<lb/>LIBER TERTIVS.<lb/>VBI DE MOTV SVPER<lb/>PLVRIBVS PLANIS<lb/>DIVERSIMODE INCLINATIS.</s></p><subchap1 type="preface"><subchap2 type="preface"><p type="main">

<s>Ex libro secundo praecedenti con&shy;<lb/>stat, mobile dum movetur fieri ap&shy;<lb/>tum ex se moveri, quatenus post <lb/>priorem  motum ei tribuitur, &amp; im&shy;<lb/>primitur quaedam virtus, seu vis, a qua fit <lb/>aptum duci, sine alicuius ope, ea velocitate qua <lb/>movebatur, dum illa virtus imprimebatur, &amp; <lb/>proinde motu aequabili; quae virtus dicitur Im&shy;<lb/>petus, differens solum fortasse a velocitate, quia <lb/>impetus sit velocitas in actu primo, ita ut ali&shy;<lb/>quo pacto impetus sit causa velocitatis; conve&shy;<lb/>niunt tamen, quatenus velocitates sunt ut spa&shy;<lb/>tia quae mobilia aequali tempore permeant, <lb/>impetus vero ut spatia quae virtute ipsius im&shy;<pb xlink:href="064/01/080.jpg"/>petus sunt apta, &amp; in potentia proxima per&shy;<lb/>meare, &amp; de facto permeant ni impedimen&shy;<lb/>tum aliquod obijciatur, secus enim effectus <lb/>causae non responderet. </s>

<s>Porro ex impe&shy;<lb/>tu provenit quod missilia quaelibet, a mo&shy;<lb/>tore velociter ducta, deficiente motoris actio&shy;<lb/>ne, nihilominus a solo impetu ferantur, quod <lb/>in proiectis quotidie experimur. </s>

<s>De quibus <lb/>locus postularet ut aliquid agerem, ni via <lb/>quam eorum motu conficiunt, me adhuc late&shy;<lb/>ret; quamvis non ignorem viris oculatissimis <lb/>visam esse parabolicam. </s>

<s>Cum illis igitur sup&shy;<lb/>pono proiecta a motore seiuncta, motu du&shy;<lb/>plici moveri, nimirum ab impetu, aequabili <lb/>motu, eadem prorsus directe via qua a motore <lb/>novissime ducta fuerant, &amp; itidem a gravitate <lb/>deorsum, &amp; proinde motu mixto secundum <lb/>quamdam lineam curvam mihi ignotam, <lb/>quamhoc argumento ducti parabolicam ar&shy;<lb/>bitrantur.<figure id="id.064.01.080.1.jpg" xlink:href="064/01/080/1.jpg"/></s></p><p type="main">

<s>Prohuiusciatur missile A versus D motu violento <lb/>quo virtute impetus temporibus aequalibus <lb/>conficiat aequalia spatia AB, BC, CD, &amp; in<pb xlink:href="064/01/081.jpg"/>priori tempore, vi gravitatis descendat per <lb/>spatium aequale AE, quod sit BF, motu mix&shy;<lb/>to describet curvam  AF; ducatur mox ab <lb/>impetu eodem quo prius tramite, ab F ver&shy;<lb/>sus G, unde si moveretur eo simplici motu <lb/>violento, in tantundem temporis adiret ip&shy;<lb/>sum G, at quoniam urget etiam gravitas, <lb/>ducitur in H, ita ut GH sit triplum ipsius <lb/>AE, &amp; proinde CH ad BF sit in duplicata <lb/>ratione AC ad AB, describens motu mixto <lb/>curvam FH, &amp; demum eadem ratione du&shy;<lb/>citur in I. </s>

<s>Probant puncta AF HI esse in&shy; <lb/>parabola, per 20 primi A poll. quoniam <lb/>quadrata rectarum AC, AB ordinatim ap&shy;<lb/>plicatarum, seu eis aequalium, sunt ut CH, BF <lb/>ab eis ex diametro praecisae, seu ut eis aequa&shy;<lb/>les. </s>

<s>At vero mihi quidem, contra id quod sup&shy;<lb/>ponitur, apparet proiectum descendere mi&shy;<lb/>nori celeritate, quam si a sola ducatur grav&shy;<lb/>itate, &amp; libere dimissum, celerius solum <lb/>attingere, quam orizontaliter latum. </s>

<s>Insu&shy;<lb/>per si aequis temporibus proiectum conficit <lb/>curvas AF, FH, HI, successive longiores <lb/>motus est successive velocior, quippe maius <lb/>spatium aequo tempore permeat, unde si vis pro&shy;<lb/>huiuscientis provenit a maiori velocitate, ictus <lb/>eo est validior, quo missile longius a prohuius&shy;<lb/>ciente distat; contra id quod quotidie experi&shy;<pb xlink:href="064/01/082.jpg"/>mur, nec sit tardior ab aeris resistentia, quam <lb/>gravia deorsum mota persentirent, unde <lb/>quo graviora, celerius descenderent; quod <lb/>experientiae repugnat. </s>

<s>Sed quia adducere <lb/>inconveniens non est solvere argumentum, <lb/>eius fallaciam pro viribus detegere conabor. <lb/></s>

<s>Dum supponitur ab impetu duci perpetuo <lb/>mobile iuxta orizontalem AD, ego equi&shy;<lb/>dem verum esse censeo, ubi mobile unico so&shy;<lb/>lum violento motu ducatur; sed quia fertur <lb/>motu mixto, ab impetu nimirum, &amp; a gravi&shy;<lb/>tate secundum curvam AFH, quemadmodum <lb/>proiectum, a funda circumlatum, sibi dimis&shy;<lb/>sum fertur per tangentem curvae a funda <lb/>descriptae, ita pariter censendum est, quo&shy;<lb/>tiescumque orizontaliter latum pervenit <lb/>in H, non amplius dirigi secundum rectam <lb/>orizontalem HL, sed secundurn contingen&shy;<lb/>tem ipsam curvam FH, fuerit ne ea para&shy;<lb/>bola nec ne, quae contingens sit HK; unde <lb/>proiectum ab H digressum, motu violento, <lb/>remota gravitate, tenderet non in L, sed in <lb/>K; &amp; proinde motu mixto tanto inferius <lb/>puncto L, quanta est recta LK, puta in M, de&shy;<lb/>scribens curvam non HI, sed HM; at M non est <lb/>in parabola, ut facile demonstrari posset ex ea&shy;<lb/>dem 20. primi Apollon. cum DM maior quam DI, <lb/>&amp; BF non sint in duplicata ratione ordina&shy;<pb xlink:href="064/01/083.jpg"/>tim aplicatarum AD, AB. </s>

<s>Ex quo satis con&shy;<lb/>stare existimo proiectum suo moto parabo&shy;<lb/>lam non describere, quod probandum pro&shy;<lb/>posueram. </s>

<s>De quibus proiectis aliquid in&shy; <lb/>sequentibus addam fortasse ubi occasio <lb/>tulerit. </s>

<s>Reliquum est quod hoc tertio <lb/>libro repetam ea quae in calce libri prio&shy;<lb/>ris dicta fuere, sed parum accurate, quippe <lb/>pendentia ab eo septimo postulato, non satis <lb/>tunc fidem merente, in praesentia vero deci&shy;<lb/>ma secundi huius, ut alibi dixi, ni fallor de&shy;<lb/>monstratum. </s>

<s>Interim ibi in notis marginali&shy;<lb/>bus adnotari volui quem locum in hoc ter&shy;<lb/>tio libro sortiantur.</s></p></subchap2></subchap1><pb xlink:href="064/01/084.jpg"/><subchap1 type="postulate"><p type="head">

<s>PETITIONES</s></p><p type="main">

<s>PRIMA</s></p><p type="main">

<s>Peripheria circuli concipiatur tanquam <lb/>constans plurimis, seu mavis infinitis <lb/>lineis rectis.</s></p><p type="main">

<s>SECUNDA</s></p><p type="main">

<s>Mobile naturaliter motum caeteris pari&shy;<lb/>bus, quo longius distat a puncto quie&shy;<lb/>tis sortitur maiorem impetum, &amp; velocius <lb/>movetur.</s></p></subchap1><pb xlink:href="064/01/085.jpg"/><subchap1 n="1" type="proposition"><p type="head">

<s>PROPOSITIO PRIMA.</s></p><subchap2 n="1" type="statement"><p type="main">

<s>Si grave perpendiculariter ductum perse&shy;<lb/>veret in motu super plano declinante; pro&shy;<lb/>dibit eadem velocitate, ac si motus praece&shy;<lb/>dens fuisset cum eadem declinatione, ini&shy;<lb/>tio ducto ab eodem plano Orizontali.<figure id="id.064.01.085.1.jpg" xlink:href="064/01/085/1.jpg"/></s></p></subchap2><subchap2 n="1" type="proof"><p type="main">

<s>Ducatur grave perpendiculariter per AB, &amp; <lb/>perseveret in motu super BE declinante.</s></p><p type="main">

<s>Dico, quod fertur per BE eadem velocitate ac si <lb/>cepisset moveri in D; quod sit ad libellam ipsius A.</s></p><p type="main">

<s>Quoniam in B sortitum est eumdem impetum <lb/>ductum per AB, ac si latum fuisset per DB<arrow.to.target n="marg153"/>.</s></p><p type="margin">

<s><margin.target id="marg153"></margin.target>Per 12. secundi huius.</s></p><p type="main">

<s>Ergo per BE ducitur ab eadem virtute seu vi, <lb/>ac si motus initiuum fuisset in D, quippe ubique <lb/>ducitur a gravitate, &amp; ab impetu in B, &amp; pro&shy;<lb/>inde fertur eadem velocitate. </s>

<s>Quod etc.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium primum.</s></p><p type="main">

<s>Si initium motus fuisset per lineam declinantem, <lb/>&amp; demum per perpendicularem, seu declinantem <lb/>diversa inclinatione, idem probabitur eadem ratione.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium II.</s></p><p type="main">

<s>Hinc sequitur, quod impetus in E est idem si <lb/>motus fuerit per ABE, ac si fuisset per DE.</s></p></subchap2></subchap1><pb xlink:href="064/01/086.jpg"/><subchap1 n="2" type="proposition"><p type="head">

<s>PROPOSITIO II.</s></p><subchap2 n="2" type="statement"><p type="main">

<s>Grave ductum perpendiculariter per spatium <lb/>datum diuturnitate data, perseveret in <lb/>motu super plano inclinato; perquirere in <lb/>eo motum in data diuturnitate.<figure id="id.064.01.086.1.jpg" xlink:href="064/01/086/1.jpg"/></s></p></subchap2><subchap2 n="2" type="proof"><p type="main">

<s>Ducatur grave A perpendiculariter per AB <lb/>diuturnitate quae sit AB, &amp; perseveret <lb/>in motu super BD plano inclinationis notae.</s></p><p type="main">

<s>Venandus ibi motus in dicta diuturnitate AB.</s></p><p type="main">

<s>Producatur BD in C donec concurrat cum AC <lb/>orizontaliter ducta ab A ad C. </s>

<s>Erit BC diu&shy;<lb/>turnitas ipsius BC<arrow.to.target n="marg154"/>.</s></p><p type="margin">

<s><margin.target id="marg154"></margin.target>Per 15. primi huius.</s></p><p type="main">

<s>Fiat BE aequalis AB, &amp; CD tertia ad CB, CE<arrow.to.target n="marg155"/>.</s></p><p type="margin">

<s><margin.target id="marg155"></margin.target>Per 11. sexti.</s></p><p type="main">

<s>Dico BD esse quaesitum, nempe spatium transa&shy;<lb/>ctum diuturnitate AB.</s></p><p type="main">

<s>Quoniam CE est diuturnitas CD<arrow.to.target n="marg156"/>, &amp; CB est diu&shy;<lb/>turnitas motus per eundem CB ut supra pro&shy;<lb/>batum fuit.</s></p><p type="margin">

<s><margin.target id="marg156"></margin.target>Per 7. pr. huius.</s></p><p type="main">

<s>Erit BE diuturnitas BD stante motu praecedenti <lb/>per BC<arrow.to.target n="marg157"/>.</s></p><p type="margin">

<s><margin.target id="marg157"></margin.target>Per 19. quinti.</s></p><p type="main">

<s>Et pariter si fuerit per AB, BE est diuturni&shy;<lb/>tas motus per BD<arrow.to.target n="marg158"/>.</s></p><p type="margin">

<s><margin.target id="marg158"></margin.target>Per pr. huius.</s></p><pb xlink:href="064/01/087.jpg"/><p type="main">

<s>At AB est aequalis ipsi BE per constructionem.</s></p><p type="main">

<s>Ergo motus per BD fit diuturnitate AB. </s>

<s>Quod <lb/>etc.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium I.</s></p><p type="main">

<s>Hinc sequitur, quod in quolibet puncto infra <lb/>B est par impetus, fuerit ne motus per C<lb/>D aut per ABD, cum fuerit par impetus in B<arrow.to.target n="marg159"/>.</s></p><p type="margin">

<s><margin.target id="marg159"></margin.target>Per 12. secundi huius.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium II.</s></p><p type="main">

<s>Quotiescunque CE est media inter CB, CD, <lb/>etiamsi motus praecedens fuerit per AB; <lb/>BE est diuturnitas motus per BD.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium III.</s></p><p type="main">

<s>Idem sequitur etiamsi AB noni esset perpendicu&shy;<lb/>laris, nam probatur eodem pacto.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium IV.</s></p><p type="main">

<s>Sequitur etiam, quod si datis AB, &amp; CB, <lb/>fiat AB lineae aequalis BE, &amp; ad CB, CE <lb/>fiat tertia CD; mobile cadens aC, seu ab A, <lb/>movebitur super BD aequali tempore quo per AB.</s></p><p type="main">

<s>Et notandum pr. quod BD semper excedit du&shy;<lb/>plum ipsius AB, quia excedit duplum rectae BE.</s></p><pb xlink:href="064/01/088.jpg"/><p type="main">

<s>Nota secundo quod quo AC est longior, &amp; proinde <lb/>quo BD magis accedit ad orizontalem DE fit <lb/>semper proximior longitudini EB.</s></p><p type="main">

<s>Nota tertio quod si AC sit fere infinita, ex quo <lb/>BD fere Orizontalis, DE insensibiliter differt <lb/>ab EB, &amp; proinde DB erit dupla ipsius AB, <lb/>seu ab eius dupla insensibiliter differens.</s></p><p type="main">

<s>Et quia in BD tali casu gravitas insensibiliter <lb/>agit, quippe cum grave insensibiliter descendat, <lb/>motus erit fere uniformis, &amp; proinde par ve&shy;<lb/>locitas in BED.</s></p><p type="main">

<s>Ex quo, etiam apparet velocitas inquocunque <lb/>puncto descensus, puta in B; nam est talis, ut <lb/>mobile ubi non agat gravitas, sit aptum duci <lb/>per spatium duplum eius, per quod fuerit de&shy;<lb/>scensus, &amp; paulo amplius.</s></p></subchap2></subchap1><pb xlink:href="064/01/089.jpg"/><subchap1 n="3" type="proposition"><p type="head">

<s>PROPOSITIO III</s></p><subchap2 n="3" type="statement"><p type="main">

<s>Ducto gravi super plano inclinato, &amp; in&shy;<lb/>de perpendiculariter; perquirere eius mo&shy;<lb/>tum in pari diuturnitate.</s></p></subchap2><subchap2 n="3" type="proof"><figure id="id.064.01.089.1.jpg" xlink:href="064/01/089/1.jpg"/><p type="main">

<s>Ducatur grave super AB incli&shy;<lb/>niationis notae, diuturnitate AB <lb/>data, &amp; inde perpendiculariter, per <lb/>BD; venari motum perpendicularem <lb/>in diuturnitate AB.</s></p><p type="main">

<s>Producatur DB, donec concurrat cum AC <lb/>orizontaliter ducta in C, et sit BC <lb/>diuturnitas motus per BC<arrow.to.target n="marg160"/>. Fiat <lb/>BE aequalis AB, &amp; CD tertia ad CB, CE<arrow.to.target n="marg161"/>.</s></p><p type="margin">

<s><margin.target id="marg160"></margin.target>Per 15. pr. huius.</s></p><p type="margin">

<s><margin.target id="marg161"></margin.target>Per 11. sexti.</s></p><p type="main">

<s>Dico BD esse quaesitum.</s></p><p type="main">

<s>Quoniam CE est diuturnitas CD<arrow.to.target n="marg162"/>, erit BE <lb/>diuturnitas BD, si motus pr&aelig;cedens fuerit per <lb/>CB; at pariter si per AB<arrow.to.target n="marg163"/>. </s>

<s>Ergo diuturni&shy;<lb/>tate AB aequali BE pervenit in D. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg162"></margin.target>Per 7. pr. huius.</s></p><p type="margin">

<s><margin.target id="marg163"></margin.target>Per pr. huius.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium</s></p><p type="main">

<s>Hinc sequitur ut in praecedenti, quod impetus <lb/>infra B idem est, fuerit ne motus praecedens <lb/>per CD, ac per ABD.</s></p></subchap2></subchap1><pb xlink:href="064/01/090.jpg"/><subchap1 n="4" type="proposition"><p type="head">

<s>PROPOSITIO IV</s></p><subchap2 n="4" type="statement"><p type="main">

<s>Dato gravi moto perpendiculariter per spa&shy;<lb/>tium datum, diuturnitate data, quod per&shy;<lb/>ficiat motum super plano declinante, per <lb/>spatium itidem datum; Perquirenda in ip&shy;<lb/>so diuturnitas.<figure id="id.064.01.090.1.jpg" xlink:href="064/01/090/1.jpg"/></s></p></subchap2><subchap2 n="4" type="proof"><p type="main">

<s>Moveatur grave per AB perpendiculariter <lb/>diuturnitate data, quae sit eadem AB, inde <lb/>super planum inclinatum BD.</s></p><p type="main">

<s>Perquirenda est diuturnitas motus per BD, &amp; per ABD.</s></p><p type="main">

<s>Fiat CE media inter CB, CD, &amp; AF nor&shy;<lb/>malis ad BD productam usquequo concurrat <lb/>cum orizontali AC.</s></p><p type="main">

<s>Dico BE esse diuturnitatem per motus BD, &amp; <lb/>FE esse diuturnitatem motus per ABD.</s></p><p type="main">

<s>Quoniam nota est diuturnitas CB<arrow.to.target n="marg164"/>, &amp; nota est <lb/>EC per constructionem,  nota est etiam BE diu&shy;<lb/>turnitas motus per BD, si motus praecedens fue&shy;<lb/>rit per CB; at idem est si fuerit per AB<arrow.to.target n="marg165"/>.</s></p><p type="margin">

<s><margin.target id="marg164"></margin.target>Per 15. pr. huius.</s></p><p type="margin">

<s><margin.target id="marg165"></margin.target>Per pr. huius.</s></p><p type="main">

<s>Ergo EB est diuturnitas motus per BD; At <lb/>FB est diuturnitas motus per AB<arrow.to.target n="marg166"/>. </s>

<s>Igitur <lb/>FE est diuturnitas motus per ABD. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg166"></margin.target>Per Co. 19. pr. huius.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium</s></p><p type="main">

<s>Idem sequitur eadem ratione, si AB non sit <lb/>perpendicularis.</s></p></subchap2></subchap1><pb xlink:href="064/01/091.jpg"/><subchap1 n="5" type="proposition"><p type="head">

<s>PROPOSITIO V</s></p><subchap2 n="5" type="statement"><p type="main">

<s>Data diuturnitate in plano perpendiculari <lb/>motus gravis, quod perseveret moveri super <lb/>plano declinante; &amp; data super eo diutur&shy;<lb/>nitate, reperire longitudinem.<figure id="id.064.01.091.1.jpg" xlink:href="064/01/091/1.jpg"/></s></p></subchap2><subchap2 n="5" type="proof"><p type="main">

<s>Ducatur grave perpendiculariter per AB diu&shy;<lb/>turnitate C, &amp; demum super plano incli&shy;<lb/>nato BD, &amp; data sit diuturnus E.</s></p><p type="main">

<s>Perquirenda sit longitudo super BD quam grave <lb/>conficiat diuturnitate E.</s></p><p type="main">

<s>Fiat ut C ad E ita AB ad BF<arrow.to.target n="marg167"/>, unde si AB <lb/>concipiatur tanquam diuturnitas motus super <lb/>AB, erit BF diuturnitas motus super BD. <lb/></s>

<s>Producatur FB donec concurrat cum A G ori&shy;<lb/>zontaliter ducta in G. </s>

<s>Et fiat CD tertia pro&shy;<lb/>portionalis ad GB, GF<arrow.to.target n="marg168"/>.</s></p><p type="margin">

<s><margin.target id="marg167"></margin.target>Per 12. sexti.</s></p><p type="margin">

<s><margin.target id="marg168"></margin.target>Per 11. sexti.</s></p><p type="main">

<s>Dico BD esse longitudinem quaesitam.</s></p><p type="main">

<s>Quoniam AB est diuturnitas ipsius AB per sup&shy;<lb/>pos; GB erit diuturnitas ipsius GB<arrow.to.target n="marg169"/>, at GF <lb/>est diuturnitas ipsius GD<arrow.to.target n="marg170"/>, igitur residuum BF <lb/>est diuturnitas BD. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg169"></margin.target>Per 15. primi huius.</s></p><p type="margin">

<s><margin.target id="marg170"></margin.target>Per 3. pr. huius.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium.</s></p><p type="main">

<s>Grave prodibit per AB, BD aequis tempo&shy;<lb/>ribus si diuturnitas E fiat aequalis diu&shy;<lb/>turnitati C.</s></p></subchap2></subchap1><pb xlink:href="064/01/092.jpg"/><subchap1 n="6" type="proposition"><p type="head">

<s>PROPOSITIO VI.</s></p><subchap2 n="6" type="statement"><p type="main">

<s>Moto gravi super pluribus planis diversimo&shy;<lb/>de inclinatis, venari diuturnitates in quo&shy;<lb/>libet eorurn.<figure id="id.064.01.092.1.jpg" xlink:href="064/01/092/1.jpg"/></s></p></subchap2><subchap2 n="6" type="proof"><p type="main">

<s>Ducatur grave per AB diuturnitate data, <lb/>quae sit eadem AB; inde a B in D, &amp; a D <lb/>in H. </s>

<s>Venanda est diuturnitam motus per DH.</s></p><p type="main">

<s>Producatur DB in E donec concurrat cum <lb/>AG orizontaliter ducta. </s>

<s>Item producatur H<lb/>D donec concurrat cum eadem AG. </s>

<s>Fiat <lb/>EC media inter EB, ED<arrow.to.target n="marg171"/>. </s>

<s>Fiat itidem GF <lb/>media inter GD, GH.</s></p><p type="margin">

<s><margin.target id="marg171"></margin.target>Per 13. Sexti.</s></p><p type="main">

<s>Dico DF esse diuturnitate motus per DH.<arrow.to.target n="marg172"/></s></p><p type="margin">

<s><margin.target id="marg172"></margin.target>Per 7. pr. huius.</s></p><p type="main">

<s>Quoniam DF est diuturnitas motus per DH <lb/>etiamsi motus praecedens fuerit per ED<arrow.to.target n="marg173"/>. At <lb/>impetus in D est idem si motus praecedens fue&shy;<lb/>rit per GD, an per ED<arrow.to.target n="marg174"/>. </s>

<s>Ergo etiam si mo&shy;<lb/>tus fuerit per BD, DF est diuturnitas motus <lb/>per DH. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg173"></margin.target>Per cor. 3.2. huius.</s></p><p type="margin">

<s><margin.target id="marg174"></margin.target>Per 12. secundi huius.</s></p></subchap2><pb xlink:href="064/01/093.jpg"/><subchap2 type="corollary"><figure id="id.064.01.093.1.jpg" xlink:href="064/01/093/1.jpg"/><p type="head">

<s>Corollarium I</s></p><p type="main">

<s>Datis pluribus lineis in quadrante circuli <lb/>puta FA, AB, seu FA, AC, CB, inno&shy;<lb/>tescent diuturnitates in quibuslibet earum, &amp; <lb/>etiam in omnibus simul sumptis.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium II.</s></p><p type="main">

<s>Impetus infra D est idem fuerit ne motus prae&shy;<lb/>cedens per GD, an per ED, vero per ABD.</s></p></subchap2></subchap1><pb xlink:href="064/01/094.jpg"/><subchap1 n="7" type="proposition"><p type="head">

<s>PROPOSITIO VII.</s></p><subchap2 n="7" type="statement"><p type="main">

<s>Grave naturaliter motum velocius ad idem <lb/>ducitur punctum duabus lineis, quam una <lb/>tantum.</s></p></subchap2><subchap2 n="7" type="proof"><p type="main">

<s>Progrediatur grave per AB in B.</s></p><p type="main">

<s>Dico quod citius perveniet in B motum per <lb/>A CB.</s></p><p type="main">

<s>Protrahatur BC, puta in D; &amp; ab A in BD de&shy;<lb/>mittatur normalis AE.</s></p><p type="main">

<s>Quoniam grave per BC pariter movetur, ductum per <lb/>A CB, ac per DB<arrow.to.target n="marg175"/>, &amp; per eamdem CB ve&shy;<lb/>locius fertur digressum a D quam ab E<arrow.to.target n="marg176"/>, per <lb/>illam itidem velocius fertur motum per ACB, <lb/>quam per EB, sed per A C aeque velociter fer&shy;<lb/>tur ac per CE,<arrow.to.target n="marg177"/> ergo per totum ACB velocius <lb/>fertur quam per EB; sed aequali tempore fer&shy;<lb/>tur per EB ac per AB<arrow.to.target n="marg178"/>; ergo per ACB ve&shy;<lb/>locius fertur quam per AB. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg175"></margin.target>Per pr. huius.</s></p><p type="margin">

<s><margin.target id="marg176"></margin.target>Per 2. peti.</s></p><p type="margin">

<s><margin.target id="marg177"></margin.target>Per 19. pr. huius.</s></p><p type="margin">

<s><margin.target id="marg178"></margin.target>Per 19. pr. huius.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium.</s></p><p type="main">

<s>Hinc est, quod si motus fuerit per ACB, im&shy;<lb/>petus in B est  maior ac si fuisset per AB <lb/>secundum proportionem AB ad EB.</s></p></subchap2></subchap1><pb xlink:href="064/01/095.jpg"/><subchap1 n="8" type="proposition"><p type="head">

<s>PROPOSITIO VIII</s></p><subchap2 n="8" type="statement"><p type="main">

<s>Grave naturaliter ductum, velocius fertur su&shy;<lb/>per tribus lineis descendentibus, quam su&shy;<lb/>per una tantum.<figure id="id.064.01.095.1.jpg" xlink:href="064/01/095/1.jpg"/></s></p></subchap2><subchap2 n="8" type="proof"><p type="main">

<s>Feratur grave per AB, BC, CD.</s></p><p type="main">

<s>Dico citius duci in D quam per AD.</s></p><p type="main">

<s>Producantur CB, DC ad orizontalem AF in EF.</s></p><p type="main">

<s>Ducantur normales AG, BH, &amp; ducatur AC.</s></p><p type="main">

<s>Quoniam grave pervenit citius in C per ABC, <lb/>quam per AC<arrow.to.target n="marg179"/>. Item citius in D per ACD <lb/>quam per AD<arrow.to.target n="marg180"/>, tanto citius perveniet in D <lb/>per ABCD quam per AD. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg179"></margin.target>Per 7. huius.</s></p><p type="margin">

<s><margin.target id="marg180"></margin.target>Per eamdem.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium. I.</s></p><p type="main">

<s>Eodem pacto facile probabitur quod citius <lb/>perveniet in D, quatenus ducitur pluribus <lb/>inclinationibus.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium. II.</s></p><p type="main">

<s>Impetus in D est maior, si fuerit motus per AB<lb/>CD, quam per AD.</s></p></subchap2></subchap1><pb xlink:href="064/01/096.jpg"/><subchap1 n="9" type="proposition"><p type="head">

<s>PROPOSITIO IX</s></p><subchap2 n="9" type="statement"><p type="main">

<s>In quadrante inferiori circuli grave celerius <lb/>fertur, si moveatur super peripheria, quam <lb/>si una, aut pluribus rectis lineis.<figure id="id.064.01.096.1.jpg" xlink:href="064/01/096/1.jpg"/></s></p></subchap2><subchap2 n="9" type="proof"><p type="main">

<s>Sit ABC quadrans inferius.</s></p><p type="main">

<s>Dico grave B velocius duci si moveatur in <lb/>peripheria, quam  si per BC, aut BDC, aut <lb/>BDEFC.</s></p><p type="main">

<s>Quoniam in peripheria ducitur pluribus inclina&shy;<lb/>tionibus<arrow.to.target n="marg181"/>.</s></p><p type="margin">

<s><margin.target id="marg181"></margin.target>Per primam pet.</s></p><p type="main">

<s>Ergo grave super ipsa motum celerius transigit.<arrow.to.target n="marg182"/> Quod etc.</s></p><p type="margin">

<s><margin.target id="marg182"></margin.target>Per cor. primum 8. huius.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium I.</s></p><p type="main">

<s>Idem sequitur, si digrediatur a quovis puncto <lb/>Peripheriae, puta a D.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium II.</s></p><p type="main">

<s>In  C impetus est maior, si motus fuerit per <lb/>Peripheriam, quam aliter quomodocunque.</s></p></subchap2></subchap1></chap><pb xlink:href="064/01/097.jpg"/><chap type="bk"><p type="main">

<s>DE MOTV<lb/>GRAVIVM<lb/>LIBER QVARTVS.<lb/>ET LIQVIDORVM PRIMVS.</s></p><subchap1 type="preface"><subchap2 type="preface"><p type="main">

<s>Hactenus<arrow.to.target n="note1"/> mihi videor de <lb/>scientia motus naturalis <lb/>gravium solidorum satis <lb/>pro viribus dixisse, dum <lb/>ex quibusdam proprieta&shy;<lb/>tibus sensui notis, plures <lb/>ignotae deductae, &amp; patefa&shy;<lb/>ctae sunt: in hoc enim so&shy;<lb/>lummodo ex Aristotele omnis scientia ver&shy;<lb/>satur: ut in praxi apud Euclidem, &amp; alios, qui <lb/>veras, &amp; simplices scientias tractant, videre <lb/>est: unde nec agit Geometra de natura quan&shy;<lb/>titatis, nec Musicus de natura soni, nec per&shy;<lb/>spectivus de natura luminis, nec mechanicus <lb/>de natura ponderis.</s>

<s>At<arrow.to.target n="note2"/> vero meus intelle&shy;<lb/>ctus non omnino acquiescit, ni causas priores, <lb/>a quibus hi effectus demum proveniunt, si non<pb xlink:href="064/01/098.jpg"/>assequatur, saltem investiget; perquirendo <lb/>quae sit natura mobilium, corporum nimi&shy;<lb/>rum prout mobilia sunt; etiam si hoc non <lb/>ad scientiam de motu, sed ad habitum supe&shy;<lb/>riorem, nimirum sapientiae pertineat; quo <lb/>non effectus, sed rerum naturae, &amp; principia <lb/>nobis innotescunt, ut Aristoteles in Metaphis. <lb/>etiam si in moralibus videatur secus sentire, <lb/>seu quia ex communi potius quam ex propria <lb/>sententia ibi loquutus fuerit, ubi exactam di&shy;<lb/>scussionem locus non postulabat, seu mavis <lb/>culpa transcriptoris; in quo nihilominus plu&shy;<lb/>rimos, &amp; magni nominis habuit sectatores. <lb/></s>

<s>Ut<arrow.to.target n="note3"/> ut sit ego quid tale delibavi, dum in prae&shy;<lb/>fatione priori libro praeposita, causam aperire <lb/>conatus sum, cur duo quaelibet gravia, quan&shy;<lb/>tumvis inaequalia, aequalia spatia conficiant; <lb/>videlicet quia natura gravium talis sit, ut <lb/>utrobique gravitas tali pacto sit materiae con&shy;<lb/>nexa, &amp; ita eam perpetuo sequatur, ut quanta <lb/>sit gravitas, seu eius actio; tantumdem sit pa&shy;<lb/>riter materiae, &amp; proinde resistentiae; ex quo <lb/>demum aequales sequantur effectus: quod ta&shy;<lb/>men ad motuum indaginem supervacaneum <lb/>erat.</s>

<s>Non tamen ex hoc ego me adhuc gra&shy;<lb/>vium naturam omnino assecutum esse pro <lb/>certo habeo. </s>

<s>Non quilibet collimans scopum <lb/>ferit; at quotus quisque propius dirigit, non<pb xlink:href="064/01/099.jpg"/>inutiliter laborasse censendus est. </s>

<s>Ut<arrow.to.target n="note4"/> cumque <lb/>sit, quod tum factum est, hic pariter peragere <lb/>libuit, videlicet naturam motus pro viribus <lb/>investigare, causas nimirum, &amp; principia, a <lb/>quibus hae demum motus passiones proveni&shy;<lb/>ant. </s>

<s>Iam<arrow.to.target n="note5"/> ante plures annos mihi visus sum <lb/>assequi causam accelerationis motus , dum ad <lb/>huc mobile a motore impellitur; quia nimirum <lb/>mobili moto imprimatur impetus, causa mo&shy;<lb/>tus subsequentis; ex quo in secundo tempore <lb/>adsunt duo motores, unde est velocior, &amp; im&shy;<lb/>petus maior; in tertio tempore sunt duo iti&shy;<lb/>dem motores, at alter puta impetus maioris <lb/>virtutis, unde motus adhuc celerior; &amp; ita de&shy;<lb/>inceps.</s>

<s>Non<arrow.to.target n="note6"/> vero ex hoc constabat qua pro&shy;<lb/>portione talis acceleratio fieret. </s>

<s>Interim dum <lb/>pendulorum motus, perquirerem, praeter ex&shy;<lb/>pectationem se se mihi obtulit, eorum longi&shy;<lb/>tudines diuturnitatibus in duplicata respon&shy;<lb/>dere ratione; de quo in prioris libri praefatio&shy;<lb/>ne; ex quo demum, nihil minus cogitanti mi&shy;<lb/>hi, in sexta propositione eiusdem deducere con&shy;<lb/>tigit, motum tali pacto accelerari, ut in secun&shy;<lb/>do tempore sit prioris triplum, in tertio quin&shy;<lb/>tuplum, &amp; deinceps iuxta numerorum impa&shy;<lb/>rium progressionem: quod<arrow.to.target n="note7"/> miram mihi exci&shy;<lb/>tavit cupidinem venandi a qua nam virtute, in <lb/>secundo tempore tanta motus fieret accretio,<pb xlink:href="064/01/100.jpg"/>dum nec videbatur esse impetus primum im&shy;<lb/>pressi maior activitas, quam ipsius motoris a <lb/>quo ortum duxerat; nec quid aliud ibi esse de <lb/>novo productum suspicandum videbatur. </s>

<s>Non <lb/>tamen deterreri potui, quin ulterius progre&shy;<lb/>diens huius adhuc causam consequi sperarem: <lb/>quamvis se mihi dificillimum obtulerit, &amp; <lb/>pluries me esse assecutum perperam existima&shy;<lb/>verim, meque demum fuisse deceptum com&shy;<lb/>pererim. </s>

<s>Contigit<arrow.to.target n="note8"/> interim reperire, quod est <lb/>in Corol. Tertiae Secundi huius, motum or&shy;<lb/>tum ab impetu esse aequabilem; quod a natu&shy;<lb/>ra ipsiusmet mobilis emanere censendum vi&shy;<lb/>sum fuit: ex quo in spem adductus sum ut ip&shy;<lb/>sammet mobilis naturam assequi valerem. <lb/></s>

<s>Pluries<arrow.to.target n="note9"/> cogitaveram esse naturae consentane&shy;<lb/>um, ut ex simplicissimis principhuiuss quam plur&shy;<lb/>imi mirabiles effectus educantur. </s>

<s>Cuius rei, &amp; <lb/>si plura habeam, unicum tantum in praesentia <lb/>aut alterum adducam exemplum. </s>

<s>Perpen&shy;<lb/>das amabo quot qualia, &amp; quanta, ex Solis sub <lb/>Ecliptica circumlatione, in inferioribus gi&shy;<lb/>gnantur; et quot qualia, et quanta hominibus <lb/>deficerent, ni eis necessitas quotidiani cibi <lb/>imposita fuisset: ex<arrow.to.target n="note10"/> quo mihi pariter probabi&shy;<lb/>le visum est, eam fuisse naturam mobilibus tri&shy;<lb/>butam, ut ex eius aliqua simplici immediata <lb/>proprietate emanent caeterae.</s>

<s>Cum igitur ut <pb xlink:href="064/01/101.jpg" pagenum="101"/>mox dictum fuit mobile motum aequabiliter <lb/>demum moveatur sine motore; videtur infe&shy;<lb/>rendum, quod motus motum producat, seu <lb/>potius quod motus perseveret, &amp; se ipsum, <lb/>ut ita dicam, extendat, &amp; continuet; quatenus<arrow.to.target n="note11"/> <lb/>dum semel mobile motum est, sit potens, <lb/>seu in potentia proxima se ipsum eadem ra&shy;<lb/>tione movendi: ex<arrow.to.target n="note12"/> quibus in eam incidi sen&shy;<lb/>tentiam, ut existimem, eam esse fortasse na&shy;<lb/>turam mobilium, ut indiferenter se habeant <lb/>tam ad quietem, quam ad quemlibet motum; <lb/>unde, dummodo motus praecedat, a quacumque <lb/>causa proveniens, seu naturali seu violenta, <lb/>similis postmodum subsequatur, seu idem <lb/>perseveret, eadem velocitate quam in quoli&shy;<lb/>bet instanti sortitum fuerit, donec impedia&shy;<lb/>tur; &amp; hanc motus continuationem ab ipsa&shy;<lb/>met immobilis natura immediate emanantem, <lb/>forsitam esse unicam, &amp; simplicem causam, a <lb/>qua fluant omnes illi effectus, &amp; passiones, <lb/>quae in motu demum tum naturali, tum vio&shy;<lb/>lento a nobis percipiuntur.</s>

<s>Et<arrow.to.target n="note13"/> quamvis huius&shy;<lb/>modi motus continuatio non sit nova entitas <lb/>superaddita, eam nihilominus intellectus con&shy;<lb/>cipere tanquam quid noviter ortum, nimirum <lb/>posito motu, ex eo oriri virtutem, novum pro&shy;<lb/>ducentem motum, ad faciliorem de motu ra&shy;<lb/>tiocinationem non parum deservientem, quam vir&shy;<pb xlink:href="064/01/102.jpg"/>tutem appellamus impetum; qui<arrow.to.target n="note14"/> re vera nil <lb/>aliud sit, nisi naturalis propensio ad motum, <lb/>seu potentia mobili inexistens continuandi mo&shy;<lb/>tum semel adeptum quae potentia dum mo&shy;<lb/>bile quiescit, sit in actu primo, &amp; mediante, <lb/>motu reducatur in secundum, ea ratione qua <lb/>homini discurrenti non additur nova rationa&shy;<lb/>litas; seu<arrow.to.target n="note15"/> novum principium, &amp; nova poten&shy;<lb/>tia ratiocinandi, sed eademmet, quam intrin&shy;<lb/>secus habet, &amp; est in actu primo, reducitur in <lb/>secundum.</s>

<s>Porro<arrow.to.target n="note16"/> quod vere talis fuerit <lb/>natura mobilibus tradita, ut indiferenter se <lb/>habeant ad motum, &amp; quietem, quamvis ex <lb/>dicta uniformis motus continuatione satis pro&shy;<lb/>babile videatur, non ego tamen pro certo af&shy;<lb/>firmare ausim: sumus<arrow.to.target n="note17"/> in physicis, ubi demon&shy;<lb/>strationes rariores: non<arrow.to.target n="note18"/> tamen videri deberet le&shy;<lb/>viter probatum, si ex hoc solummodo prin&shy;<lb/>cipio omnes probarentur sequi passiones, quae <lb/>in motu quolibet percipiuntur absque quo ali&shy;<lb/>quid aliud, vel de novo oriatur, vel ortum de&shy;<lb/>pereat.</s>

<s>Ex<arrow.to.target n="note19"/> eo autem sequitur, quod dum mo&shy;<lb/>bile impellitur motus necessario augetur; un&shy;<lb/>de<arrow.to.target n="note20"/> quo per maius spatium impellitur eo cor&shy;<lb/>pus obsistens validius percutit; ex<arrow.to.target n="note21"/> quo tamen <lb/>motus ipse fit debilior, respondens siquidem <lb/>oppositi resistentiae; quae<arrow.to.target n="note22"/> si augeatur, velocitas <lb/>taliter minuitur, ut tandem deficiat, absque<pb xlink:href="064/01/103.jpg"/>quo aliquid oriri, aut deperire supponatur: ex <lb/>quibus vires percussionis metiri licet, de quo <lb/>alibi.</s>

<s>Inde<arrow.to.target n="note23"/> est quod si manubrio parietem per&shy;<lb/>cutias, illud intra melleum intruditur, quoniam <lb/>melleo minor obijcitur resistentia; facilius <lb/>siquidem is a manubrio permeatur quam murus <lb/>a manubrio. </s>

<s>Si<arrow.to.target n="note24"/> vero mo&shy;bile expellatur, mo&shy;<lb/>veri perseverat, sine cuiusvis ope adiutoris de <lb/>novo orti; cum ex ipsiusmet natura, prout <lb/>mobile est, eiusdem motus continuatio neces&shy;<lb/>sario subsequatur.</s>

<s>Si<arrow.to.target n="note25"/> offendit in via quod mo&shy;<lb/>tum urgeat, aut retundat; augetur velocitas, <lb/>aut minuitur; at<arrow.to.target n="note26"/> quaecumque ea sit inde per&shy;<lb/>severat, quia ea motus natura ut continuetur; <lb/>unde<arrow.to.target n="note27"/> si permeet murum quem feriat, ei proin&shy;<lb/>de resistentem, remissius fertur, quatenus est <lb/>maior muri durities, &amp; proinde resistentia; ex <lb/>quo velocitas magis retunditur; quae tamen si <lb/>non omnino perit, qualis tandem remanet <lb/>talis perseverat; idem quippe continuatur mo&shy;<lb/>tus; quousque<arrow.to.target n="note28"/> tamen resistentia perdurat, <lb/>motus paulatim minuitur, &amp; tandem extin&shy;<lb/>guitur.</s>

<s>Ceterum<arrow.to.target n="note29"/> cum huiusmodi continuatio <lb/>emanet a propria ipsiusmet mobilis natura, <lb/>subsequi necessario debet quemlibet motum, <lb/>etiamsi per brevem fuerit morulam; quod<arrow.to.target n="note30"/> ap&shy;<lb/>paret in pila lignea, malleo ligneo lusorio lon&shy;<lb/>gioris manubrhuius longe propulsa, quamvis a<pb xlink:href="064/01/104.jpg"/>malleo per parvam morulam, &amp; per minimum <lb/>spatium lata fuerit.</s>

<s>Ex<arrow.to.target n="note31"/> quo itidem sequitur, <lb/>quod pila lusoria ad murum illidens, resilit; <lb/>quia pars murum feriens, vi compressa, ictui <lb/>cedens densatur, &amp; ex curva complanatur; &amp; <lb/>si sit talibus praedita viribus, ut deficiente vio&shy;<lb/>lentia propellente, queat ex se in pristinam re&shy;<lb/>duci rotunditatem; pars explanata, quae ite&shy;<lb/>rum incurvatur, retrocedens versus locum cen&shy;<lb/>tri, eo fertur celeri motu; qui quamvis in tali <lb/>reductione brevis fuerit, &amp; proinde per brevem <lb/>morulam, idem continuatur eadem celeritate, <lb/>cum eius naturae competat, motum etiamsi per <lb/>parvum fuerit spatium continuare. </s>

<s>Quod idem <lb/>sequitur si non pila, sed murus ipse caedat pri&shy;<lb/>us, &amp; demum se in pristinum reducat; unde <lb/>si neutrum caedat non fit resilitio. </s>

<s>Si<arrow.to.target n="note32"/> vero <lb/>non perpendiculariter sed oblique murum <lb/>feriat, resilit ea lege, ut angulus reflexionis sit <lb/>angulo incidentiae proxime aequalis; quoniam <lb/>dum impingit, centrum adhuc fertur antrorsum; <lb/>unde pars pressa dum se in rotunditatem iterum <lb/>reducit, pilam dirigit secundum lineam tran&shy;<lb/>seuntem per centrum iam antrorsum latum; <lb/>qui motus etiamsi per breve spatium, postmodum <lb/>continuatur: quoniam vero ex ea centri pro&shy;<lb/>gressione pilae plures successive partes super <lb/>murum vertuntur, is motus itidem continua&shy;<pb xlink:href="064/01/105.jpg"/>tur unde pila ipsa vertiginem acquirit, eo ce&shy;<lb/>leriorem, quo angulus incidentiae plus acuitur; <lb/>qua vertigine adepta, ex eius continuatione, <lb/>ubi pila in planum iterum incidat, non servat <lb/>praedictam regulam in angulo reflexionis, qui <lb/>erit acutior, si pilae motus sit secundum ver&shy;<lb/>tiginis ordinem, si vero contra obtusior.</s>

<s>Quae <lb/>clarius apparent in pila reticulo, aut alio quo&shy;<lb/>libet transversim percussa, in qua maior impri&shy;<lb/>matur vertigo, quae demum eadem continuatur. <lb/></s>

<s>Inde<arrow.to.target n="note33"/> item est quod pila eadem dum lusoria <lb/>palmula percussa, libere demum fertur, velo&shy;<lb/>cius prodit ipsam et palmula movente; expul&shy;<lb/>sa siquidem non modo ab ipsius impellentis <lb/>motu, sed etiam quoniam ipsiusmet pilae pars <lb/>percussa, ob modo dictam compressionem ce&shy;<lb/>dens, &amp; exinde densata, &amp; mox in pristinam <lb/>redacta formam, ducitur versus ipsius pilae cen&shy;<lb/>trum maiori velocitate, quam si a sola impel&shy;<lb/>lentis vi ducta fuisset; quae maior velocitas con&shy;<lb/>tinuatur. </s>

<s>Imo<arrow.to.target n="note34"/> reticulo expulsa, fertur etiam ve&shy;<lb/>locius, a triplici nempe motore ducta, addito <lb/>tertio, nimirum rete, cedente prius, &amp; mox se <lb/>in pristinum reducente.</s>

<s>Hinc<arrow.to.target n="note35"/> est etiam quod <lb/>quandocumque sphaera circumvolvitur, continua&shy;<lb/>tur vertigo: unde<arrow.to.target n="note36"/> contingere potest, ut inde, <lb/>sequatur motus ipsius sphaerae progressivus, ei <lb/>supposito nimirum plano, suo contactu motum<pb xlink:href="064/01/106.jpg"/>partis inferioris impediente, ex quo pars su&shy;<lb/>perior non impedita, &amp; libere mota celerius <lb/>fertur, et quo vergit, vergit item centrum, &amp; <lb/>talis continuatur motus, unde tota sphaera pro&shy;<lb/>dit ulterius, absque quo alius novus motor su&shy;<lb/>peraddatur. Hinc<arrow.to.target n="note37"/> itidem est, quod si sphaeram <lb/>quiescentem ex aliqua sui parte digito com&shy;<lb/>primas contra subiectum planum, ea sortitur <lb/>duplicem motum, progressivum antrorsiim, <lb/>&amp; validiorem in gyrum retrorsum: unde cessan&shy;<lb/>te priori, si circumlatio continuatur, retro&shy;<lb/>cedit, ac si tum ei planum supponeretur, <lb/>absque eo quod aliquid oriatur, aut depereat. <lb/></s>

<s>Quod<arrow.to.target n="note38"/> pariter evenit in trochulo puerorum, <lb/>qui dum digitis in gyrum ducitur, circa pro&shy;<lb/>prium axem circumfertur, eius inferiori pro&shy;<lb/>minenti polo innixus; qui ubi demum ob im&shy;<lb/>petum diminutum declinans subiectum plan&shy;<lb/>um latere tangit, super illud circumvolvi&shy;<lb/>tur, fere ad instar asinariae molae, cuius pro&shy;<lb/>inde axis sua circumversione conum efficit, <lb/>cuius vertex est polus inferior, superior vero <lb/>dum rotatur circulum describit ipsius coni basim, <lb/>contra ordinem vertiginis peripheriae, motu tali, <lb/>qui minus diligenter intuentibus, apparet es&shy;<lb/>se prioris, adhuc perseverantis, inversio; pluri&shy;<lb/>bus mirabile visum, non percipientibus esse<pb xlink:href="064/01/107.jpg"/>naturae congruum, ambos ibi continuari mo&shy;<lb/>tus, priorem quidem peripheriae circum, <lb/>axem trochi, postremum vero poli superioris <lb/>contra prioris ordinem; quod quibuslibet <lb/>motibus, ut dictum fuit, commune est, ex <lb/>ipsius mobilis natura proveniens, absque <lb/>quod aliquid aliud oriatur, aut ortum depereat, <lb/>remanente siquidem solummodo cuiuslibet <lb/>velocitatis semel impressae, naturali continua&shy;<lb/>tione, quam quodlibet mobile, quocumque <lb/>pacto, ubivis a quocumque motore sortitum <lb/> fuerit; ex quo non modo praedictae oriuntur mo&shy;<lb/>tus passiones, sed omnes alias passim obvias <lb/>emanare, facile demonstrabitur.</s>

<s>A<arrow.to.target n="note39"/> nullo au&shy;<lb/>tem experimento praedicta natura mobilium <lb/>tam clare apparere videtur, quam a facilitate, <lb/>qua mobilia quiescentia, a quolibet etiam mi&shy;<lb/>nimo saepius impelluntur motore. </s>

<s>Quod ap&shy;<lb/>paret in cymbula in aqua natante, ponderis <lb/>librarum quinquaginta, &amp; ultra; quam non <lb/>modo duces capillo mulieris, sed si illum ex <lb/>alio capite uspiam alligaveris, suo solum pon&shy;<lb/>dere cymbulam trahit, &amp; ad litus, ut ita dicam, <lb/>appellere coarctat, non obstante aqua renu&shy;<lb/>ente, propriae siquidem divisioni saltem ali&shy;<lb/>qualiter obsistente: quod aliunde non vi&shy;<lb/>detur oriri nisi ex eademmet praedicta mo&shy;<pb xlink:href="064/01/108.jpg"/>bilis natura, indiferenter nimirum se haben&shy;<lb/>tis ad motum, &amp; quietem. </s>

<s>Vi autem ex eadem <lb/>tandem videamus, qua proportione motus ac&shy;<lb/>celeratio fieri debeat, &amp; an experimentis <lb/>respondeat.<figure id="id.064.01.108.1.jpg" xlink:href="064/01/108/1.jpg"/> Ducatur mobile A, ab <lb/>A versus E a quovis motore, seu <lb/>naturaliter a gravitate deorsum, seu <lb/>violenter ab impellente; et spatium AE con&shy;<lb/>cipiatur sectum in portiones aequales in pun&shy;<lb/>ctis B, C, D tali ratione, ut in B mobile <lb/>ductum virtute motus ab A in B acquirat impe&shy;<lb/>tum, ex quo motus item subsequatur; seu quod <lb/>idem est, cuius virtute potentia mobilis eun&shy;<lb/>dem  continuendi motum, reducatur ad actum <lb/>secundum modo superius explicato; si conci&shy;<lb/>piamus in B deficere actionem motoris, idem <lb/>nihilominus eiusdem velocitatis perseverat, &amp; <lb/>continuatur motus; unde per tantundem tem&shy;<lb/>poris fertur per portionem aequalem ipsi AB, <lb/>puta in C. </s>

<s>Ni vero motoris actio deficiat, eius <lb/>virtute fertur itidem mobile per portionem <lb/>aequalem ipsi a AB; unde in secundo tempo&shy;<lb/>re conficit duas spathuius portiones, eidem AB <lb/>aequales; &amp; proinde dum prodit in D, movetur <lb/>motu dupliciter velociori, &amp; sortitur dupli&shy;<lb/>cem impetum, seu huius duplicis motus con&shy;<lb/>tinuationem; ex quo in tertio tempore, ducitur <lb/>per duplum eiusdem portionis AB, at per<pb xlink:href="064/01/109.jpg"/>aequale a motore, ergo conficit tres portiones; <lb/>in quarta quatuor, in decima decem, &amp; ita de<lb/>inceps. </s>

<s>Obhuiuscies<arrow.to.target n="note40"/> primo, in portione AB iam <lb/>adesse impetum; nec mobile recedere ab A <lb/>quin impetus adsit: cum etenim impetus ema&shy;<lb/>net a motu, &amp; sit eius passio, est ab eo insepa&shy;<lb/>rabilis, &amp; proinde ubi est motus, est pariter im&shy;<lb/>petus, quemadmodum ubi est ignis, est pari&shy;<lb/>ter calor: nec causa est prior effectu tempore, <lb/>sed natura; quod non obstat, quin in eo&shy;<lb/>dem instanti in quo est ignis, seu motus, <lb/>sit pariter calor seu impetus.</s>

<s>Responditur<arrow.to.target n="note41"/> conceden&shy;<lb/>dum, quod etiam in eodem instanti in <lb/>quo est motus, fieri possit ut sit pariter im&shy;<lb/>petus, si vice versa mihi concedatur, nil <lb/>esse prius sua causa, &amp; proinde impetum non <lb/>antecedere motum a quo est productus: at <lb/>dum mobile est adhuc in A non movetur, sed <lb/>quiescit: nec potest vere dici quod moveatur, <lb/>quin ab A recedens perveniat in B, unde sicut <lb/>est absurdum  dicere ignem producere calorem, <lb/>quin prius sit productus ipsemet ignis, ita pa&shy;<lb/>riter esset obsurdum asserere, motum produ&shy;<lb/>cere impetum, quin sit productus ipsemet mo&shy;<lb/>tus, &amp; proinde prius quam mobile sit in B. </s>

<s>Nec <lb/>dicas iam motum adesse priusquam perveniat <lb/>in B; nam quocumque primo perventum <lb/>erit, tum in eo puncto intelligo esse B: non<pb xlink:href="064/01/110.jpg"/>enim quaerimus, portio AD sit ne magna <lb/>aut parva, divisibilis an indivisibilis, &amp; ma&shy;<lb/>thematice vel physice; quod ad praesentem spe&shy;<lb/>culationem non est necessarium; sufficit mi&shy;<lb/>hi namque in praesentia, aliquem motum non <lb/>dici adesse ab impetu dependentem, quin ali&shy;<lb/>us a quocumque impetu independenter prae&shy;<lb/>cedat, productus siquidem a solo motore, cu&shy;<lb/>ius virtute, potentia mobilis in actum secun&shy;<lb/>dum reducatur, per quam demum continuetur <lb/>motus ut supra dictum fuit; secus enim causa <lb/>produceret suam causam in eodem genere <lb/>causae; immo idem esset causa sui ipsius, quippe <lb/>causa suae propriae causae. </s>

<s>Obhuiuscies<arrow.to.target n="note42"/> secundo <lb/>motum non augeri iuxta progressionem Arith&shy;<lb/>meticam naturalem, ut hic asseritur, sed secun&shy;<lb/>dum numeros impares, ut in sexta primi <lb/>huius, &amp; ut apud doctiores in praesentia fere <lb/>communiter creditur.</s>

<s>Responditur<arrow.to.target n="note43"/> hanc sextam pro&shy;<lb/>positionem inniti experimentis, sensui dece&shy;<lb/>ptioni obnoxhuiuss, quibus insensibilis error de&shy;<lb/>tegi nequit; quod hic evenit ex eo, quia por&shy;<lb/>tiones temporis aequales ei priori, in qua confi&shy;<lb/>citur prima motus portio independens ab im&shy;<lb/>petu, percipi nequeant, utpote insensibiles, <lb/>prout est insensibilis dicta motus prima por&shy;<lb/>tio; quae si perciperentur, videremus augeri <lb/>motum iuxta naturalem progressionem: At<arrow.to.target n="note44"/><pb xlink:href="064/01/111.jpg"/>in temporibus, &amp; motibus sensibilibus res di&shy;<lb/>verse se habet, ubi cognosci nequit motus <lb/>pars aliqua, nec tempus in quo conficiatur, <lb/>quin iam sint plures temporis peractae portio&shy;<lb/>nes, ei aequales, in qua fuit motus ab impetu non <lb/>adiutus; cui tempori si plures aequales subse&shy;<lb/>quantur, motus in eis, seu motus portiones, <lb/>portionibus temporum, iuxta numerorum im&shy;<lb/>parium progressionem fere respondebunt.<figure id="id.064.01.111.1.jpg" xlink:href="064/01/111/1.jpg"/></s></p><p type="foot">

<s><foot.target id="foot.1"></foot.target>1 Actum est de scientia motus naturalis.</s></p><p type="foot">

<s><foot.target id="foot.2"></foot.target>2 Modo perquirendae causae.</s></p><p type="foot">

<s><foot.target id="foot.3"></foot.target>3 Ut supra respectu gravitatis factum fuit.</s></p><p type="foot">

<s><foot.target id="foot.4"></foot.target>4 Natura igitur motus investiganda.</s></p><p type="foot">

<s><foot.target id="foot.5"></foot.target>5 Iam quaesiveram causam accel.</s></p><p type="foot">

<s><foot.target id="foot.6"></foot.target>6 At non proportionem.</s></p><p type="foot">

<s><foot.target id="foot.7"></foot.target>7 Reperta iuxta progressionem numerorum imparium. Quaesivi causam.</s></p><p type="foot">

<s><foot.target id="foot.8"></foot.target>8 Repertus motus ab impetu aequabilis.</s></p><p type="foot">

<s><foot.target id="foot.9"></foot.target>10 Natura utitur principhuiuss simplicibus.</s></p><p type="foot">

<s><foot.target id="foot.10"></foot.target>11 Unde visum ex simplici mobilis proprietate emanandas caeteras.</s></p><p type="foot">

<s><foot.target id="foot.11"></foot.target>12 Quae sit motum ex se continuari.</s></p><p type="foot">

<s><foot.target id="foot.12"></foot.target>13 Quia mobilia indiferenter se habeant, ad motum &amp; quietem.</s></p><p type="foot">

<s><foot.target id="foot.13"></foot.target>14 Huiusmodi continuationem non est nova entitas.</s></p><p type="foot">

<s><foot.target id="foot.14"></foot.target>15 At ut nova concipitur. Dicitur &amp; impetus.</s></p><p type="foot">

<s><foot.target id="foot.15"></foot.target>16 Huiusmodi indiferentiam esse mobili naturalem.</s></p><p type="foot">

<s><foot.target id="foot.16"></foot.target>17 Probatur per dictam naturalem motus continuationem.</s></p><p type="foot">

<s><foot.target id="foot.17"></foot.target>18 Ex quo caeterae motus passiones.</s></p><p type="foot">

<s><foot.target id="foot.18"></foot.target>19 Absque quo quid oriatur aut pereat.</s></p><p type="foot">

<s><foot.target id="foot.19"></foot.target>20 Unde dum mobile impellitur motus augetur.</s></p><p type="foot">

<s><foot.target id="foot.20"></foot.target>21 Et quo longius, ictus validior.</s></p><p type="foot">

<s><foot.target id="foot.21"></foot.target>22 At motus debilior. Si resistentia maior motus tardior.</s></p><p type="foot">

<s><foot.target id="foot.22"></foot.target>23 Et tandem deficit.</s></p><p type="foot">

<s><foot.target id="foot.23"></foot.target>24 Patet experimento mallei.</s></p><p type="foot">

<s><foot.target id="foot.24"></foot.target>25 Expulsum moveri perseverat.</s></p><p type="foot">

<s><foot.target id="foot.25"></foot.target>26 Si quid urgeat aut retundat, variatur velocitas.</s></p><p type="foot">

<s><foot.target id="foot.26"></foot.target>27 Et talis perseverat.</s></p><p type="foot">

<s><foot.target id="foot.27"></foot.target>28 Si murum permeet remittitur.</s></p><p type="foot">

<s><foot.target id="foot.28"></foot.target>29 Si perseveret, velocitas minuitur.</s></p><p type="foot">

<s><foot.target id="foot.29"></foot.target>30 Idem etiam per morulam.</s></p><p type="foot">

<s><foot.target id="foot.30"></foot.target>31 Ut in ludo mallei.</s></p><p type="foot">

<s><foot.target id="foot.31"></foot.target>32 Unde pilae resilitio.</s></p><p type="foot">

<s><foot.target id="foot.32"></foot.target>33 Si oblique feriat, oblique resilit.</s></p><p type="foot">

<s><foot.target id="foot.33"></foot.target>34 Pila celerior instrumento expellente.</s></p><p type="foot">

<s><foot.target id="foot.34"></foot.target>35 Et eo magis reticulo expulsa.</s></p><p type="foot">

<s><foot.target id="foot.35"></foot.target>36 Vertigo durat.</s></p><p type="foot">

<s><foot.target id="foot.36"></foot.target>37 Unde motus localis.</s></p><p type="foot">

<s><foot.target id="foot.37"></foot.target>38 Pila digito compressa acquirit duplicem motum.</s></p><p type="foot">

<s><foot.target id="foot.38"></foot.target>39 Ex quo trochulum retrocedere videtur.</s></p><p type="foot">

<s><foot.target id="foot.39"></foot.target>40 Motus est a minimo motore.</s></p><p type="foot">

<s><foot.target id="foot.40"></foot.target>41 Objectio prima non dari primam motus portionem sine impetu.</s></p><p type="foot">

<s><foot.target id="foot.41"></foot.target>42 Responditur etiam si adsit impetus prima motus portio est ab eo independens.</s></p><p type="foot">

<s><foot.target id="foot.42"></foot.target>43 Objectio 2. motum non augeri iuxta progressionem naturalem.</s></p><p type="foot">

<s><foot.target id="foot.43"></foot.target>44 Responditur quod motus augetur iuxta progressionem naturalem per tempora insensibilia.</s></p><p type="foot">

<s><foot.target id="foot.44"></foot.target>45 At per sensibilia fere iuxta progressionem numerorum imparium.</s></p><p type="main">

<s>Quod ut planius fiat, Moveatur mobile A ab <lb/>A in B sensibiliter, &amp; tempore sensibili ab, <lb/>cui subsequantur aequalia tempora bc, cd, &amp; <lb/>primum tempus ab intelligatur divisum in por&shy;<lb/>tiones minimas aequales, in quarum priori a<lb/>e, latum fuerit mobile ab A in E independen&shy;<lb/>ter ab impetu, qui in puncto E motui con&shy;<lb/>currere incipiat; has portiones patet esse eo <lb/>plures quo minores; sint decem, &amp; mobile fe&shy;<lb/>ratur temporibus ab, bc, cd, per spatia AB, <lb/>BC, CD; erunt portiones aequales portioni <lb/>AE in AB 55, in BC 155, in CD 255, inter <lb/>se ut 11, 31, 51. Si vero portio temporis ae <lb/>sit adhuc minor, cui aequales sint in ab cen&shy;<lb/>tum, portiones spathuius aequales portioni AE<pb xlink:href="064/01/112.jpg"/><figure id="id.064.01.112.1.jpg" xlink:href="064/01/112/1.jpg"/> erunt in AB 5050, in BC 15050, in CD <lb/>25050, inter se ut 101, 301, 501, fere iuxta <lb/>rationem numerorum imperium 1, 3, 5. Ex <lb/>quibus constat, quod eo portiones spatiorum <lb/>magis accedunt ad rationem numerorum impa&shy;<lb/>rium, quo portio temporis, in qua motus est in&shy;<lb/>dependenter ab impetu, minor est. </s>

<s>Eadem<arrow.to.target n="note45"/> pror&shy;<lb/>sus ratione probabitur, quo est itidem minor, <lb/>spatia propius esse in duplicata ratione tem&shy;<lb/>porum.</s>

<s>Si namque concipiamus impetum incipere <lb/>in b, tempora ab, ac, ad sunt ut 1, 2, 3, spatia <lb/>vero AB, AC, AD, quae in duplicata ratione <lb/>temporum essent ut 1, 4, 9, sunt ut 1, 3, 6, val&shy;<lb/>de ab eis discrepantes: si vero tempora ab, ac, <lb/>ad, intelligantur divisa in portiones, quarum <lb/>ab, contineat decem, erunt temporum in&shy;<lb/>ter se portiones, ut 10, 20, 30, seu ut prius ut <lb/>1, 2, 3, at vero portiones spatiorum, quarum <lb/>prior ut supra sit AE, erunt ut 55, 210, 455 <lb/>seu ut 11, 42, 93; si denique portiones tempo&shy;<lb/>rum sint 100, 200, 300, portiones spatiorum erunt <lb/>5050, 20100, 45150, ut 101, 402, 903, mi&shy;<lb/>nimus, &amp; insensibiliter discrepantes ab 1, 4, 9, &amp; <lb/>proinde fere in duplicata temporum ratione;<pb xlink:href="064/01/113.jpg"/>unde quo plures temporum portiones, spatia <lb/>ad duplicatam rationem magis accedunt. </s>

<s>Ut <lb/>autem datis temporibus, facile spatia peracta <lb/>reperiant, qui parum in arithmeticis progres&shy;<lb/>sionibus versati sunt, duc numerum tempo&shy;<lb/>rum, si sit par, in medietatem, &amp; adde medie&shy; <lb/>tatem, si impar, in portionem maiorem medie&shy;<lb/>tatis, &amp; prodibit summa spatiorum in dato tem&shy;<lb/>pore peractorum. </s>

<s>Dentur 4 tempora, duc in <lb/>2 producto 8 adde medietatem 2, sit 10 sum&shy;<lb/>ma spatiorum. </s>

<s>Dentur tempora 9, duc in 5, <lb/>productum 45 est summa spatiorum. </s>

<s>Auge&shy;<lb/>tur<arrow.to.target n="note46"/> igitur, ni fallor, motus iuxta progressionem <lb/>arithmeticam, non numerorum imparium ab <lb/>unitate huc usque creditam, sed naturalem; at<arrow.to.target n="note47"/> <lb/>nihilominus, cum fere huiusdem effectus subse&shy;<lb/>quantur, ob insensibilem discrepantiam; mi&shy;<lb/>randum non est, creditum fuisse spatia esse in <lb/>duplicata ratione temporum; quandoquidem <lb/>etiam si verum precise fortasse non sit, est <lb/>attamen adeo veritati proximum, ut verita&shy;<lb/>tem in adhibitis experimentis sensus percipe&shy;<lb/>re nequiverit, quamobrem excusandi sunt <lb/>quicunque ita censuerunt. </s>

<s>Ego autem modo <lb/>veritatem delitescentem detexisse spero, cau&shy;<lb/>sam nimirum a qua huiusmodi proportio ema&shy;<lb/>nat aperuisse, &amp; insuper quales errores fue&shy;<lb/>rint in suppositionibus, &amp; experimentis huc<pb xlink:href="064/01/114.jpg"/>usque habitis, quod an re vera consecutus fue&shy;<lb/>rim aliorum sit indicium: neque enim is sum <lb/>qui tantum mihi tribuam, ut rerum arcana <lb/>intimius caeteris rimari mihi videar, cui satis <lb/>superque est inter illos connumerari, quo&shy;<lb/>rum disputationi mundus traditus fuit: nec <lb/>inutiliter me laborasse existimavero, si cre&shy;<lb/>dar vitam silentio non pertransisse. </s>

<s>Caete&shy;<lb/>rum cum ea, quae de solidis dicenda videban&shy;<lb/>tur, iuxta mei vires ingenhuius, pertractata sint, <lb/>superest, ut ad naturalis motus liquidorum <lb/>passiones inquirendas accedam.</s></p><p type="foot">

<s><foot.target id="foot.45"></foot.target>46 Et fere in duplicata ratione temporum.</s></p><p type="foot">

<s><foot.target id="foot.46"></foot.target>47 Augetur motus iuxta progressionem naturalem.</s></p><p type="foot">

<s><foot.target id="foot.47"></foot.target>48 Et apparet esse in duplicata ratione temporum.</s></p></subchap2></subchap1><pb xlink:href="064/01/115.jpg"/><subchap1 type="definition"><p type="head">

<s>DEFINITIONES</s></p><subchap2 type="definition"><p type="main">

<s>Canale est vas oblongum, per quod aqua de&shy;<lb/>currit; quod in praesentia supponitur habere <lb/>latera erecta, &amp; basi perpendicularia, &amp; pa&shy;<lb/>rallela inter se. </s>

<s>Sectio vasis, est parallelogramum quod supponi&shy;<lb/>tur secare canale ad angulos rectos.</s></p></subchap2></subchap1><subchap1 type="postulate"><p type="head">

<s>PETITIONES</s></p><subchap2 type="postulate"><p type="main">

<s>Aqua transiens per eandem sectionem corre&shy;<lb/>spondet tempori.</s></p></subchap2></subchap1><pb xlink:href="064/01/116.jpg"/><subchap1 n="1" type="proposition"><p type="head">

<s>PROPOSITIO PRIMA</s></p><subchap2 n="1" type="statement"><p type="main">

<s>Aqua aequaliter introducta in pluribus cana&shy;<lb/>libus inaequaliter inclinatis correspondet <lb/>diuturnitatibus.<figure id="id.064.01.116.1.jpg" xlink:href="064/01/116/1.jpg"/></s></p></subchap2><subchap2 n="1" type="proof"><p type="main">

<s>Sint Canales AB, CD, in quibus introducatur <lb/>aqua aequalis, &amp; aqua A ducatur in B diu&shy;<lb/>turnitate E, &amp; aqua C perveniat in D diutur&shy;<lb/>nitate F.</s></p><p type="main">

<s>Dico aquam AB ad aquam CD esse ut E ad F.</s></p><p type="main">

<s>Quoniam aqua A B est ea, quae transit per A, diu&shy;<lb/>turnitate E, &amp; aqua CD est ea quae transit <lb/>per C, diuturnitate F per constructionem; sequi&shy;<lb/>tur quod aqua AB est ad aquam CD ut E ad F<arrow.to.target n="marg183"/>.</s></p><p type="margin">

<s><margin.target id="marg183"></margin.target>Per pet. huius.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium.</s></p><p type="main">

<s>Si diuturnitates sint aequales, aquae quantita&shy;<lb/>tes sunt pariter aequales.</s></p></subchap2></subchap1><pb xlink:href="064/01/117.jpg"/><subchap1 n="2" type="proposition"><p type="head">

<s>PROPOSITIO II.</s></p><subchap2 n="2" type="statement"><p type="main">

<s>In pluribus canalibus ductis ad idem planum <lb/>orizontale, aquae quantitates sunt ut canales.</s></p></subchap2><subchap2 n="2" type="proof"><p type="main">

<s>Sint canalia AB, AC, ducta ad planum Orizon&shy;<lb/>tale CB.</s></p><p type="main">

<s>Dico aquam AB esse ad aquam AC, ut longitudo <lb/>AB ad longitudinem AC.</s></p><p type="main">

<s>Quoniam diuturnitas AB ad diuturnitatem AC <lb/>est ut AB ad AC<arrow.to.target n="marg184"/>, at ut diuturnitas AB ad <lb/>diuturnitatem AC, ita aqua AB ad aquam <lb/>AC<arrow.to.target n="marg185"/>; ergo ut aqua AB ad aquam <lb/>AC, ita <lb/>longitudo AB ad longitudinem AC<arrow.to.target n="marg186"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg184"></margin.target>Per 15. primi. huius.</s></p><p type="margin">

<s><margin.target id="marg185"></margin.target>Per primam huius.</s></p><p type="margin">

<s><margin.target id="marg186"></margin.target>Per 11. Quinti.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium</s></p><p type="main">

<s>Idem sequitur si alterum canale sit perpendi&shy;<lb/>culare.</s></p></subchap2></subchap1><pb xlink:href="064/01/118.jpg"/><subchap1 n="3" type="proposition"><p type="head">

<s>PROPOSITIO III. PROBL. I.</s></p><subchap2 n="3" type="statement"><p type="main">

<s>In canali declinante, reperire portionem con&shy;<lb/>tinentem aquam, aequalem eius quae est in <lb/>perpendiculari.<figure id="id.064.01.118.1.jpg" xlink:href="064/01/118/1.jpg"/></s></p></subchap2><subchap2 n="3" type="proof"><p type="main">

<s>Sit AC canale inclinatum, &amp; AB perpendicu&shy;<lb/>lare; oportet reperire in AC portionem con&shy;<lb/>tinentem aquam aequalem aquae AB.</s></p><p type="main">

<s>Ducatur BD normalis ad AC.</s></p><p type="main">

<s>Dico AD esse portionem quaesitam.</s></p><p type="main">

<s>Quoniam aqua ab A ducitur in B eodem tempore, <lb/>quo in D<arrow.to.target n="marg187"/>, erit aqua AB aequalis aqua AD<arrow.to.target n="marg188"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg187"></margin.target>Per 16. pr. huius.</s></p><p type="margin">

<s><margin.target id="marg188"></margin.target>Per Co. primae huius.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium.</s></p><p type="main">

<s>Eadem ratione Dato canali AD reperietur <lb/>in AB portio continens aquam aequalem <lb/>AD, erecta a puncto D perpendiculari DB.</s></p></subchap2></subchap1><pb xlink:href="064/01/119.jpg"/><subchap1 n="4" type="proposition"><p type="head">

<s>PROPOSITIO IV. PROBL. II.</s></p><subchap2 n="4" type="statement"><p type="main">

<s>In quibusvis canalibus quomodolibet inclina&shy;<lb/>tis, reperire portiones continentes aquam <lb/>aequalem cuiusvis dicti canalis.<figure id="id.064.01.119.1.jpg" xlink:href="064/01/119/1.jpg"/></s></p></subchap2><subchap2 n="4" type="proof"><p type="main">

<s>A Canalibus AB, AC, AD, etc. sint secandae <lb/>portiones continentes aquam aequalem aquae <lb/>canalis AE.</s></p><p type="main">

<s>Iungantur omnes praedicti canales, retentis incli&shy;<lb/>nationibus, in puncto superiori A; et si AE est <lb/>perpendicularis ad orizontem, circa ipsum <lb/>tanquam diametrum, describatur circulus AE; <lb/>sin minus a puncto E, erigatur ipsi AE perpen&shy;<lb/>dicularis EF, &amp; ab A demittatur perpendicu&shy;<lb/>laris ad orizontem, donec cum EF coeat in <lb/>F, &amp; circa AF describatur circulus secans <lb/>omnes praedictos canales in G, H, I.</s></p><p type="main">

<s>Dico portiones AG, AH, AI continere aquam <lb/>aequalem aquae canalis AE.</s></p><p type="main">

<s>Quoniam in AG, AE, AH, AI diuturnitates sunt <lb/>aequales<arrow.to.target n="marg189"/>, ergo sunt ibidem quantitates aquae <lb/>aequales<arrow.to.target n="marg190"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg189"></margin.target>Per 25. pr. huius.</s></p><p type="margin">

<s><margin.target id="marg190"></margin.target>Per primam huius.</s></p></subchap2><pb xlink:href="064/01/120.jpg"/><subchap2 type="corollary"><p type="head">

<s>Corollarium</s></p><p type="main">

<s>Si describantur quot vis circuli minores, seu <lb/>maiores, cuiuscumque magnitudinis, se invicem <lb/>tangentes in A, secabunt portiones dictorum <lb/>canalium ea ratione, ut sectiones intra quem&shy;<lb/>vis circulum contineant aquam aequalem.</s></p></subchap2></subchap1><pb xlink:href="064/01/121.jpg"/><subchap1 n="5" type="proposition"><p type="head">

<s>PROPOSITIO V.</s></p><subchap2 n="5" type="statement"><p type="main">

<s>In canali secto quomodolibet; aquae quantita&shy;<lb/>tes in eius portionibus correspondent diu&shy;<lb/>turnitatibus.<figure id="id.064.01.121.1.jpg" xlink:href="064/01/121/1.jpg"/></s></p></subchap2><subchap2 n="5" type="proof"><p type="main">

<s><figure id="id.064.01.121.2.jpg" xlink:href="064/01/121/2.jpg"/>Sit canale AC sectum in B quomodolibet, &amp; <lb/>sit DE diuturnitas aquae donec perveniat in <lb/>B, &amp; DF diuturnitas donec perveniat <lb/>in C, &amp; proinde EF diuturnitas aquae <lb/>ductae a B in C.</s></p><p type="main">

<s>Dico aquam AB ad aquam BC esse ut diuturni&shy;<lb/>tas DE ad diuturnitatem EF.</s></p><p type="main">

<s>Quoniam aqua AB est ea, quae transit per A diu&shy;<lb/>turnitate DE, &amp; AC ea quae transit per idem <lb/>A diuturnitate DF per constructionem; aqua <lb/>AB ad aquam AC est ut diuturnitas DE ad <lb/>diuturnitatem DF<arrow.to.target n="marg191"/>; igitur dividendo, aqua <lb/>AB ad aquam BC est ut diuturnitas DE ad <lb/>diuturnitatem EF<arrow.to.target n="marg192"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg191"></margin.target>Per pet. huius.</s></p><p type="margin">

<s><margin.target id="marg192"></margin.target>Per 19. quinti.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium</s></p><p type="main">

<s>Si Diuturnitates DE, EF sint aequales, aqua <lb/>AB aequatur aquae BC.</s></p></subchap2></subchap1><pb xlink:href="064/01/122.jpg"/><subchap1 n="6" type="proposition"><p type="head">

<s>PROPOSITIO VI.</s></p><subchap2 n="6" type="statement"><p type="main">

<s>In canali secto quomodocumque; aqua in <lb/>priori portione ad aquam totius est in sub&shy;<lb/>duplicata ratione longitudinum.<figure id="id.064.01.122.1.jpg" xlink:href="064/01/122/1.jpg"/></s></p></subchap2><subchap2 n="6" type="proof"><p type="main">

<s>Sit canale AC sectum quomodocumque in D. </s>

<s>Dico, quod aqua AD ad aquam AC est in sub&shy;<lb/>duplicata ratione longitudinum AD, AC.</s></p><p type="main">

<s>Quoniam longitudines AD, AC sunt in duplicata <lb/>ratione diuturnitatum<arrow.to.target n="marg193"/>, at diuturnitates sunt <lb/>ut quantitates aquae<arrow.to.target n="marg194"/>, ergo quantitates aquae <lb/>sunt in subduplicata ratione longitudinum<arrow.to.target n="marg195"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg193"></margin.target>Per 3. &amp; 7. primi huius.</s></p><p type="margin">

<s><margin.target id="marg194"></margin.target>Per 5. huius.</s></p><p type="margin">

<s><margin.target id="marg195"></margin.target>Per 11. quinti.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium</s></p><p type="main">

<s>Unde si fiat AE media proportionalis inter <lb/>AD, AC, aqua AD ad aquam AC erit ut <lb/>AD ad AE.</s></p></subchap2></subchap1><pb xlink:href="064/01/123.jpg"/><subchap1 n="7" type="proposition"><p type="head">

<s>PROPOSITIO VII. PROBL. III.</s></p><subchap2 n="7" type="statement"><p type="main">

<s>Dato canali perpendiculari, &amp; alio inclinato <lb/>eiusdem longitudinis; reperire propor&shy;<lb/>tiones aquarum.<figure id="id.064.01.123.1.jpg" xlink:href="064/01/123/1.jpg"/></s></p></subchap2><subchap2 n="7" type="proof"><p type="main">

<s>Sint canalia AC inclinatum, &amp; AB perpen&shy;<lb/>diculare aequalia, &amp; venanda sit proportio <lb/>inter aquas AB, AC.</s></p><p type="main">

<s>Ducatur BD perpendicularis ad AC, &amp; fiat <lb/>AE media proportionalis inter AD, AC.</s></p><p type="main">

<s>Dico esse aquam AB ad aquam AC ut AD ad <lb/>AE.</s></p><p type="main">

<s>Quoniam aqua AD ad aquam AC est ut AD <lb/>ad AE<arrow.to.target n="marg196"/>, sed aqua AD est aequalis aquae AB<arrow.to.target n="marg197"/>, <lb/>ergo aqua AB ad aquam AC est ut AD ad <lb/>AE<arrow.to.target n="marg198"/>: Quod etc.</s></p><p type="margin">

<s><margin.target id="marg196"></margin.target>Per 6. huius.</s></p><p type="margin">

<s><margin.target id="marg197"></margin.target>Per 3. huius.</s></p><p type="margin">

<s><margin.target id="marg198"></margin.target>Per 11. quinti.</s></p></subchap2></subchap1><pb xlink:href="064/01/124.jpg"/><subchap1 n="8" type="proposition"><p type="head">

<s>PROPOSITIO VIII. PROBL. IV.</s></p><subchap2 n="8" type="statement"><p type="main">

<s>Datis canalibus aequalis longitudinis maio&shy;<lb/>ris aut minoris inclinationis; venari pro&shy;<lb/>portiones aquarum.<figure id="id.064.01.124.1.jpg" xlink:href="064/01/124/1.jpg"/></s></p></subchap2><subchap2 n="8" type="proof"><p type="main">

<s>Sit canale AC minus, AF magis inclinatum <lb/>ei aequale; &amp; venandae sint proportiones aqua&shy;<lb/>rum ab eis contentorum.</s></p><p type="main">

<s>Ducatur AB perpendicularis ad orizontem eiu&shy;<lb/>sdem longitudinis, &amp; ductis perpendiculari&shy;<lb/>bus BD, BG, fiat AE media inter AD, AC, <lb/>&amp; AH inter AG, AF, &amp; ut AG ad AH, ita <lb/>AD ad AI.</s></p><p type="main">

<s>Dico aquam AC ad aquam AF esse ut AE ad AI.</s></p><p type="main">

<s>Quoniam ut aqua AC ad aquam AB ita AE ad <lb/>AD; &amp; ut aqua AB ad aquam AF, ita AG <lb/>ad AH,<arrow.to.target n="marg199"/> seu ut AD ad AI per constructio&shy;<lb/>nem; erit aqua AC ad aquam  AF ut AE ad <lb/>AI<arrow.to.target n="marg200"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg199"></margin.target>Per 7. huius.</s></p><p type="margin">

<s><margin.target id="marg200"></margin.target>Per 22. quinti.</s></p></subchap2></subchap1><pb xlink:href="064/01/125.jpg"/><subchap1 n="9" type="proposition"><p type="head">

<s>PROPOSITIO IX.</s></p><subchap2 n="9" type="statement"><p type="main">

<s>In canali secto iuxta proportionem nume&shy;<lb/>rorum imparium, in portionibus ex ea re&shy;<lb/>sultantibus sunt quantitates aquae aequales <lb/>inter se.<figure id="id.064.01.125.1.jpg" xlink:href="064/01/125/1.jpg"/></s></p></subchap2><subchap2 n="9" type="proof"><p type="main">

<s>Sit canale AD sectum in BC, &amp; deinceps, ut <lb/>portiones AB, BC, CD, etc. sint inter se ut <lb/>1, 3, 5, 7.</s></p><p type="main">

<s>Dico quantitates aquae AB, BC, CD, esse <lb/>aequales inter se.</s></p><p type="main">

<s>Quoniam aqua aequali tempore progreditur ab A <lb/>in B, quo a B in C, &amp; deinceps<arrow.to.target n="marg201"/>, erit aqua <lb/>AB aequalis aquae BC<arrow.to.target n="marg202"/>, etc. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg201"></margin.target>Per 10. pr. huius.</s></p><p type="margin">

<s><margin.target id="marg202"></margin.target>Per cor. quintae huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/126.jpg"/><subchap1 n="10" type="proposition"><p type="head">

<s>PROPOSITIO X.</s></p><subchap2 n="10" type="statement"><p type="main">

<s>In quavis priori portione canalis, est aqua <lb/>aequalis portioni sequenti, triplae prioris.<figure id="id.064.01.126.1.jpg" xlink:href="064/01/126/1.jpg"/></s></p></subchap2><subchap2 n="10" type="proof"><p type="main">

<s>Dato canali A C secto in D ita ut AD sit <lb/>1/4 ipsius A C.</s></p><p type="main">

<s>Dico aquam AD aequari aquae DC.</s></p><p type="main">

<s>Quoniam eo tempore, quo A ducitur in D, D du&shy;<lb/>citur in C<arrow.to.target n="marg203"/>, ergo aqua AD est aequalis aquae <lb/>DC<arrow.to.target n="marg204"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg203"></margin.target>Per 9. huius.</s></p><p type="margin">

<s><margin.target id="marg204"></margin.target>Per cor. quintae huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/127.jpg"/><subchap1 n="11" type="proposition"><p type="head">

<s>PROPOSITIO XI.</s></p><subchap2 n="11" type="statement"><p type="main">

<s>In canali declinante, duplo perpendicularis <lb/>ductae ad idem planum orizontale sectum <lb/>a linea ad illud normaliter ducta a puncto <lb/>inferiori dictae perpendicularis, portiones <lb/>continent aequales aquae quantitates.<figure id="id.064.01.127.1.jpg" xlink:href="064/01/127/1.jpg"/></s></p></subchap2><subchap2 n="11" type="proof"><p type="main">

<s>Sit canale AC duplum AB, sectum in D a <lb/>perpendiculari BD.</s></p><p type="main">

<s>Dico aquam AD aequari aquae DC.</s></p><p type="main">

<s>Quoniam AB est media inter AD, AC<arrow.to.target n="marg205"/>, <lb/>&amp; AB est medietas ipsius AC per constructio&shy;<lb/>nem, AD est medietas ipsius AB, &amp; proinde <lb/>quarta pars totius AC; igitur aqua in AD <lb/>aequalis aquae in DC<arrow.to.target n="marg206"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg205"></margin.target>Per ea quae ad 16. pri. huius.</s></p><p type="margin">

<s><margin.target id="marg206"></margin.target>Per 10. huius.</s></p></subchap2></subchap1></chap><pb xlink:href="064/01/128.jpg"/><pb xlink:href="064/01/129.jpg"/><chap type="bk"><p type ="main">

<s>DE MOTV<lb/>GRAVIVM<lb/>LIBER QVINTVS<lb/>ET LIBER LIQVIDORVM SECVNDUVS.<lb/>VBI DE CANALIVM SECTIONIBVS.</s></p><subchap1 type="preface"><subchap2 type="preface"><p type="main">

<s>Etiamsi simus in liqui&shy;<lb/>dis, lubet adhuc aliquid <lb/>de solidis praefari, sum&shy;<lb/>pta occasione a Quest. <lb/>19. Mech. </s>

<s>Arist. ubi cau&shy;<lb/>sam perquirit cur lignum <lb/>facilius scindat qui secu&shy;<lb/>rim extollens percutit, <lb/>quam qui securim impositam, addito pondere prae&shy;<lb/>mat. </s>

<s>Quod perinde est ac si dicas, cur plus scin&shy;<lb/>das leviori securi mota, quam graviori quies&shy;<lb/>cente. </s>

<s>Nimirum Quoniam grave, motionem <lb/>gravitatis magis assumit, motum quam quies&shy;<lb/>cens: pro qua gravitatis motione impetus in&shy;<lb/>telligitur, qui primo delitescens, a gravi dein&shy;<pb xlink:href="064/01/130.jpg"/>de per motum assumitur; scilicet qui erat in <lb/>potentia, in actum per motum reductus, mo&shy;<lb/>tum inde auget, ipsum reddens velociorem, <lb/>suplente impetu vicem ponderis. </s>

<s>Mihi ta&shy;<lb/>men semper visus est Arist. problema non in&shy;<lb/>tegre solvisse, reticuit siquidem cur huiusmo&shy;<lb/>di motio gravitatis, seu impetus sit talis virtu&shy;<lb/>tis, ut efficacius agat quam pondus additum, ex <lb/>quo demum maior scissio subsequatur. </s>

<s>Cuius<arrow.to.target n="note48"/> <lb/>quidem ego causam pro viribus investigare <lb/>mihi proposui, quonam nimirum modo me&shy;<lb/>tiri queat actio percutientis securis, &amp; passio <lb/>ligni resistentis, ut demum percipi possit quan&shy;<lb/>tum sit pondus addendum, ut impetus eius vi&shy;<lb/>ribus respondeat.</s>

<s>Quod<arrow.to.target n="note49"/> ut breviter de more <lb/>discutiatur, respectu actionis securis certum <lb/>est, quod si eius potentia non excedit li&shy;<lb/>gni resistentiam, quamvis sit ei aequalis, nulla <lb/>fiet actio; atqui<arrow.to.target n="note50"/> si securis extollatur, quantum&shy;<lb/>vis minimum, actio subsequetur, quoniam mo&shy;<lb/>vens motum plus agit quam dum prius quiescebat, <lb/>quatenus actio gravitatis adhuc perseverat, &amp; <lb/>insuper additur impetus, unde potentia quae <lb/>prius erat aequalis resistentiae, iam eam  excedit; <lb/>&amp; eius demum continuatur motus, quousque po&shy;<lb/>tentia minuatur, aut augeatur resistentia: Et<arrow.to.target n="note51"/> <lb/>quo magis securis extollitur, validius scindit; <lb/>acquirit namque impetum maiorem, tali ad<pb xlink:href="064/01/131.jpg"/>priorem proportione, ut sint impetus in sub&shy;<lb/>duplicata ratione spatiorum peractorum; ut <lb/>in quinta secundi huius: Unde<arrow.to.target n="note52"/> data minori <lb/>actione, facile metieris maiorem, percipiens <lb/>quantane ea sit, ex qualibet proveniens altitu&shy;<lb/>dine.</s>

<s>Quod<arrow.to.target n="note53"/> item sequitur in quavis percus&shy;<lb/>sione seu a securi, seu a quolibet ad percutien&shy;<lb/>dum idoneo naturaliter moto; trabes siqui&shy;<lb/>dem, seu pali longiores, fortius in terram pan&shy;<lb/>guntur, quo fistuca non modo est ponderosior, <lb/>sed altius effertur, tali ratione, ut altitudines <lb/>in duplicata proportione, percussionum viri&shy;<lb/>bus respondeant. </s>

<s>Si vero securis a motore <lb/>impellatur, validius percutit; quoniam motus <lb/>in initio, est celerior ab impulsu, quam a gra&shy;<lb/>vitate; cuius perseverante actione, maior pro&shy;<lb/>ducitur impetus, unde motus celerior, &amp; ictus <lb/>validior, etiam nulla concurrente gravitate, <lb/>ut si motus non deorsum sed ad latera tendat, <lb/>aut sursum. </s>

<s>Unde<arrow.to.target n="note54"/> quo malleus a pariete re&shy;<lb/>motior in eum fortius impellitur, clavus ma&shy;<lb/>gis figitur, &amp; longe facilius quam si omnibus <lb/>adhibitis viribus, malleum contra clavum com&shy;<lb/>primas.</s>

<s>Unde<arrow.to.target n="note55"/> etiam est, quod mobile vehe&shy;<lb/>mentius impulsum, expulsum demum, in <lb/>quodcumque illidat, validius ferit, &amp; intimius <lb/>intruditur, quod in ictu a funda, arcu, sclopo <lb/>passim videre est. </s>

<s>Huius autem vim impulsus pon&shy;<pb xlink:href="064/01/132.jpg"/>dere proxime metiri licebit, si illud adeo con&shy;<lb/>sentanee aptetur, ut illud extollas, eodem pa&shy;<lb/>cto illi innixus, eademque prorsus directio&shy;<lb/>ne, quemadmodum securim, aut quodvis aliud <lb/>impellere lubeat. </s>

<s>Quod<arrow.to.target n="note56"/> facile continget, dua&shy;<lb/>bus adhibitis trochleis, unius tantum modo <lb/>rotulae, altera superne appensa, inferne altera; <lb/>quibus ductarius circunductus funis, altero <lb/>extremo pondus, sustineat, alterum vero a po&shy;<lb/>tentia trahatur, modo quo mox dictum fuit, <lb/>sit ne ea totum corpus animalis, seu hominis, <lb/>sive eius ambo brachia, aut ipsorum alterum, <lb/>seu tantum digiti, quorum omnium singilla&shy;<lb/>tim vim, seu potentiam, proxime metietur ma&shy;<lb/>ius aut minus pondus, quod ab uno, quoque eo&shy;<lb/>rum, hac ratione in altum ducatur.</s>

<s>Ex qui&shy;<lb/>bus vires percussionis satis aperte apparere ar&shy;<lb/>bitror, nimirum a vi motoris, seu sit gravitas, <lb/>seu impulsus, nec non ab impetu per motum <lb/>acquisito, maiori aut minori, prout motor est <lb/>maioris virtutis. </s>

<s>Quo<arrow.to.target n="note57"/> vero ad ligni resisten&shy;<lb/>tis passionem secundo loco propositam, certum <lb/>est, quod si resistentia est maior, aut aequalis <lb/>activitati securis, nulla fiet actio; si vero sit <lb/>resistentia minoris virtutis, unde vires agen&shy;<lb/>tis securis excedant vires ligni resistentis, ali&shy;<lb/>qua fiet scissio; eo<arrow.to.target n="note58"/> maior, quo minor erit resi&shy;<lb/>stentia, quam non vi duntaxat portionis ligni<pb xlink:href="064/01/133.jpg"/>metiemur, quae securi opponitur; sed partium <lb/>itidem ei a latere cohaerentium, &amp; sic porro <lb/>affixarum, ut ab eis difficulter divelli queat. <lb/></s>

<s>Quantumvis autem huius resistentiae poten&shy;<lb/>tia minus percipiatur, hoc unum est, quod qualis <lb/>qualis sit, velocitati securis contranititur, eam&shy;<lb/>que tali ratione retundit, ut quantum ei tri&shy;<lb/>buitur, tantundem velocitati detrahatur; un&shy;<lb/>de<arrow.to.target n="note59"/> si resistentia addita sit priori decupla, aut <lb/>centupla, velocitas reducitur ad decimam par&shy;<lb/>tem seu centesimam eius quae prius aderat, <lb/>unde spathuius quod securis per aerem peregit dum <lb/>nil obstaret, addita postmodum ligni obvhuius re&shy;<lb/>sistentia, in aequali tempore, decimam pariter <lb/>aut centesimam conficit portionem. </s>

<s>Quandiu<arrow.to.target n="note60"/> <lb/>vero lignum permeat, resistentia success&shy;<lb/>ive augetur; partes quippe ligni ab ipsiusmet <lb/>securis compressione fiunt densiores, praeter <lb/>quam quod saepius, quo ea altius intruditur, <lb/>eo plures sunt partes cohaerentes divellendae. <lb/></s>

<s>Utcunque sit, certum est quod dum impetus inci&shy;<lb/>pit minui, &amp; est successive minor proportio ac&shy;<lb/>tionis securis ad ligni resistentiam, velocitas <lb/>non modo successive minuitur, sed paula&shy;<lb/>tim deficit. </s>

<s>Quod<arrow.to.target n="note61"/> idem sequitur de impetu, <lb/>qui cum velocitate pari passu procedit; unde<lb/><arrow.to.target n="note62"/> quantum velocitati detrahitur, tantundem <lb/>impetus minuitur; qui proinde cessante mo&shy;<pb xlink:href="064/01/134.jpg"/>tu prorsus deperit.</s>

<s>Et<arrow.to.target n="note63"/> quoniam mox adducta <lb/>communia sunt tam motae securi, quam cuili&shy;<lb/>bet mobili, quod nimirum resistentia motum <lb/>retundit, &amp; magis, quo maior proportio resi&shy;<lb/>stentis ad mobilis vires, duae pilae, etiam aequales <lb/>in terram naturaliter cadentes, quae proinde <lb/>in aere aequali feruntur celeritate, etiamsi pon&shy;<lb/>dere inaequales, terram inaequaliter perme&shy;<lb/>ant, resistente nimirum terra magis pilae le&shy;<lb/>viori, quam graviori. </s>

<s>Unde est etiam quod si, <lb/>mobili proiecto, aliud addatur quiescens, &amp; <lb/>proinde resistens, impetus minuitur; &amp; quo<arrow.to.target n="note64"/> <lb/>maius mobile superadditur, tardius fertur, &amp; <lb/>minus, aequo tempore conficit spatium, tali ra&shy;<lb/>tione, ut ratio mobilis compositi, ad anterius <lb/>simplex, spathuiuss aequali peractis tempore, reci&shy;<lb/>proce respondeat: unde<arrow.to.target n="note65"/> si mobile composi&shy;<lb/>tum sit prioris quadruplum, velocitas demum <lb/>subsequens sit praecedentis quadrans, &amp; talis <lb/>demum continuetur.</s>

<s>Ut<arrow.to.target n="note66"/> autem tandem ad <lb/>propositam quaestionem propius accedamus, <lb/>&amp; innotescat quale pondus addi debeat se&shy;<lb/>curi, ut aequa fiat scissio, ac si ea extollatur, <lb/>hoc, ex dictis visum est erui non posse a viribus <lb/>ligni resistentis, utpote pariter se opponentis, <lb/>&amp; contranitentis viribus securis motae levioris, <lb/>&amp; immotae ponderosioris: Igitur tota quaestio <lb/>pendet ab ipsamet vi securis, seu motae, seu<pb xlink:href="064/01/135.jpg"/>quiescentis. </s>

<s>Cum itaque iam visus sit, acti&shy;<lb/>vitatem securis motae a duobus pendere prin&shy;<lb/>ciphuiuss, a vi nimirum impellentis, &amp; imprimen&shy;<lb/>tis motum, quam metiuntur pondera ab eadem <lb/>vi sublata, &amp; itidem a vi impetus, virtute dicti <lb/>motus a securi acquisiti, quam metiuntur <lb/>spatia, quae dum percurruntur, impulsus perse&shy;<lb/>verat eiusdem virtutis; inde sequitur quod <lb/>ratio potentiae, seu momenti, seu virium se&shy;<lb/>curis motae, ad potentiam eiusdem sensibili&shy;<lb/>ter immotae, componitur ex ratione ponderum <lb/>inter se, nimirum eius quod aequipolet vi se&shy;<lb/>curis impulsae, additi ad percutientis securis <lb/>pondus, ad pondus eiusdem quiescentis; nec <lb/>non ex ratione spatiorum peractorum maio&shy;<lb/>ris securis in altum elatae, ad minus, fortasse <lb/>insensibile, eiusdem sensibiliter immotae, adeo <lb/>ut si vires tali pacto mensuratae utriusque se&shy;<lb/>curis motae, &amp; immotae, sint v.g. in ratione de&shy;<lb/>cupla, &amp; spatia peracta sint in centupla, ratio <lb/>porro virium securis motae, ad vires quiescen&shy;<lb/>tis, sit in millecupla; unde si quiescens sit mil&shy;<lb/>lies gravior, aequa fiet scissio. </s>

<s>Nec dicas inter <lb/>spatia motae, &amp; immotae nullam dari propor&shy;<lb/>tionem, quia agitur hic de sensibiliter immo&shy;<lb/>ta, &amp; non praecise, seu mathematice, sed phy&shy;<lb/>sice, nec videtur dari posse casum quin securis <lb/>imposita tantulum moveatur, etiamsi insen&shy;<pb xlink:href="064/01/136.jpg"/>sibiliter; quod eo facilius existimandum vide&shy;<lb/>tur, cum in hypotesi suppositum fuerit, secu&shy;<lb/>ris vires esse viribus resistentiae prorsus aequa&shy;<lb/>les: ex hoc tamen insensibili motu oritur, non <lb/>modo ut videamus, quantum vires percussionis <lb/>excedant vires ponderis, ex quo adeo facile li&shy;<lb/>gnum scinditur; sed ex illo itidem oritur difficul&shy;<lb/>tas percipiendi, qua precise proportione per&shy;<lb/>cussio, vi prementi respondeat. </s>

<s>Caeterum haec <lb/>sunt quae mihi in mentem venerunt de vi per&shy;<lb/>cussionis sapientioribus proponenda, ut ad&shy;<lb/>dant meliora.</s></p><p type="foot">

<s><foot.target id="foot.48"></foot.target>1 De vi percussionis.</s></p><p type="foot">

<s><foot.target id="foot.49"></foot.target>2 De activitate securis seu percutientis.</s></p><p type="foot">

<s><foot.target id="foot.50"></foot.target>3 Quia motum plus agit ob impetum.</s></p><p type="foot">

<s><foot.target id="foot.51"></foot.target>4 Et quo per longius spatium impetus est maior.</s></p><p type="foot">

<s><foot.target id="foot.52"></foot.target>5 Proportio inter impetus et spatia.</s></p><p type="foot">

<s><foot.target id="foot.53"></foot.target>6 In quavis percussione.</s></p><p type="foot">

<s><foot.target id="foot.54"></foot.target>7 Etiamsi motus non sit deorsum.</s></p><p type="foot">

<s><foot.target id="foot.55"></foot.target>8 Unde vis percussionis.</s></p><p type="foot">

<s><foot.target id="foot.56"></foot.target>9 Vim impulsus pondus metitur.</s></p><p type="foot">

<s><foot.target id="foot.57"></foot.target>10 De ligni resistentia.</s></p><p type="foot">

<s><foot.target id="foot.58"></foot.target>11 Quae pendet etiam a partibus cohaerentibus.</s></p><p type="foot">

<s><foot.target id="foot.59"></foot.target>12 Quo resistentia est maior minor est motus.</s></p><p type="foot">

<s><foot.target id="foot.60"></foot.target>13 Et inde resistentia augetur.</s></p><p type="foot">

<s><foot.target id="foot.61"></foot.target>14 Et velocitas minuitur. Et deficit.</s></p><p type="foot">

<s><foot.target id="foot.62"></foot.target>15 Et pariter impetus.</s></p><p type="foot">

<s><foot.target id="foot.63"></foot.target>16 Quod est commune cuivis mobili.</s></p><p type="foot">

<s><foot.target id="foot.64"></foot.target>17 Cui addito immoto minuitur impetus.</s></p><p type="foot">

<s><foot.target id="foot.65"></foot.target>18 Qua proportione.</s></p><p type="foot">

<s><foot.target id="foot.66"></foot.target>19 Quod pondus percussionis aequivaleat.</s></p></subchap2></subchap1><pb xlink:href="064/01/137.jpg"/><subchap1 type="postulate"><p type="head">

<s>PETITIONAE</s></p><subchap2 type="postulate"><p type="main">

<s>1. In sectionibus aequalibus quantitates aquae <lb/>sunt ut velocitates.</s></p></subchap2><subchap2 type="postulate"><p type="main">

<s>2. Si velocitates sint aequales, sectiones sunt ut <lb/>quantitates aquae.</s></p></subchap2><subchap2 type="postulate"><p type="main">

<s>3.In canalium sectionibus Impetus, &amp; veloci&shy;<lb/>tates pro eodem sumuntur.</s></p></subchap2></subchap1><pb xlink:href="064/01/138.jpg"/><subchap1 n="1" type="proposition"><p type="head">

<s>PROPOSITIO PRIMA.</s></p><subchap2 n="1" type="statement"><p type="main">

<s>Si sectiones sint aequales; aquarum transeun&shy;<lb/>tium quantitates sunt, ut velocitates.<figure id="id.064.01.138.1.jpg" xlink:href="064/01/138/1.jpg"/></s></p></subchap2><subchap2 n="1" type="proof"><p type="main">

<s>Transeat aqua A per sectionem A, ab A ad <lb/>B; &amp; aqua C per sectionem C aequalem <lb/>sectioni A, a C ad D aequali tempore.</s></p><p type="main">

<s>Dico aquam AB ad aquam CD esse ut velocitas <lb/>aquae A ad velocitatem aquae C.</s></p><p type="main">

<s>Quoniam velocitas in A ad velocitatem in C, est <lb/>ut AB ad CD,<arrow.to.target n="marg207"/> &amp; aqua AB ad aquam CD <lb/>est itidem ut AB ad CD<arrow.to.target n="marg208"/>, sequitur quod velo&shy;<lb/>citas in A ad velocitatem in C, est ut aqua <lb/>AB ad aquam CD<arrow.to.target n="marg209"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg207"></margin.target>Per 32. undec.</s></p><p type="margin">

<s><margin.target id="marg208"></margin.target>Per 11. Quinti.</s></p><p type="margin">

<s><margin.target id="marg209"></margin.target>Per primam huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/139.jpg"/><subchap1 n="2" type="proposition"><p type="head">

<s>PROPOSITIO II.</s></p><subchap2 n="2" type="statement"><p type="main">

<s>Velocitas aquae in pluribus eiusdem canalis <lb/>sectionibus, est reciproca sectionibus ipsis.<figure id="id.064.01.139.1.jpg" xlink:href="064/01/139/1.jpg"/></s></p></subchap2><subchap2 n="2" type="proof"><p type="main">

<s>Sint A, C, canalis sectiones, diversae magnitu&shy;<lb/>dinis.</s></p><p type="main">

<s>Dico esse, ut magnitudo sectionis A ad magnitu&shy;<lb/>dinem sectionis C, ita velocitatem in C, ad ve&shy;<lb/>locitatem in A.</s></p><p type="main">

<s>Fiat sectio B aequalis ipsi A, per quam intelliga&shy;<lb/>tur transire aquam aequaliter velocem ut in <lb/>sectione C.</s></p><p type="main">

<s>Quoniam ut quantitas aquae A seu C, ad quan&shy;<lb/>titatem aquae B, ita est velocitas aquae in A, ad <lb/>velocitatem aquae in B seu C<arrow.to.target n="marg210"/>; sed ut magni&shy;<lb/>tudo sectionis C ad magnitudinem sectionis B, <lb/>seu A, ita quantitas aquae C seu A, ad quanti&shy;<lb/>tatem aquae B<arrow.to.target n="marg211"/>.</s></p><p type="margin">

<s><margin.target id="marg210"></margin.target>Per 2. pet. huius.</s></p><p type="margin">

<s><margin.target id="marg211"></margin.target>Per 2. huius.</s></p><p type="main">

<s>Ergo ut magnitudo sectionis C ad magnitudi&shy;<lb/>nem sectionis A, ita velo&shy;<lb/>citas aquae A ad velocitatem aquae C. </s>

<s>Quod etc.</s></p></subchap2><pb xlink:href="064/01/140.jpg"/><subchap2 type="corollary"><p type="head">

<s>Corollarium I.</s></p><p type="main">

<s>Idem  sequitur, si sectiones sint canalium diversorum, dummodo ducant aquae quantitates aequales.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium II.</s></p><p type="main">

<s>Impetus sunt ibidem ut sectiones reciproce.</s></p></subchap2></subchap1><pb xlink:href="064/01/141.jpg"/><subchap1 n="3" type="proposition"><p type="head">

<s>PROPOSITIO III.</s></p><subchap2 n="3" type="statement"><p type="main">

<s>Sectiones canalis sunt reciproce in subduplicata ratione longitudinum.</s></p></subchap2><subchap2 n="3" type="proof"><p type="main">

<s>Sit canale AB sectum in C.</s></p><p type="main">

<s>Dico sectiones CB esse in subduplicata ratione AB, AC.</s></p><p type="main">

<s>Quoniam sectiones CB sunt ut velocitates in B, &amp; in C<arrow.to.target n="marg212"/>, at velocitas in B ad velocitatem in C est in subduplicata ratione AB ad AC<arrow.to.target n="marg213"/>, Ergo sectio C ad sectionem B est in subduplicata ratione AB ad AC<arrow.to.target n="marg214"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg212"></margin.target>Per 5. secundi huius.</s></p><p type="margin">

<s><margin.target id="marg213"></margin.target>Per 11. quinti.</s></p><p type="margin">

<s><margin.target id="marg214"></margin.target>Per 33. primi.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium I.</s></p><p type="main">

<s>Igitur si canalis latera sint parallela, altitudines sectionem sunt in subduplicata ratione longitudinum.</s></p><p type="main">

<s>Nam si latera perpendicularia canalis intelligantur bases, &amp; ea ratione latitudines canalis ut altitudines, quae proinde sunt aequales<arrow.to.target n="marg215"/>, sectiones sunt ut dicta latera perpendicularia<arrow.to.target n="marg216"/>,<pb xlink:href="064/01/142.jpg"/>quae cum sint altitudines sectionum, sequitur <lb/>quod propositum fuit.</s></p><p type="margin">

<s><margin.target id="marg215"></margin.target>Per pri. sexti.</s></p><p type="margin">

<s><margin.target id="marg216"></margin.target>Per 3. huius.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium II.</s></p><p type="main">

<s>Si sectiones sint reciprocae in subduplicata ra&shy;<lb/>tione longitudinum, exit aqua aequalis.</s></p></subchap2></subchap1><pb xlink:href="064/01/143.jpg"/><subchap1 n="4" type="proposition"><p type="head">

<s>PROPOSITIO IV.</s></p><subchap2 n="4" type="statement"><p type="main">

<s>Impetus sectionum canalis, sunt in subdupli&shy;<lb/>cata ratione longitudinum ipsarum a pun&shy;<lb/>cto superno.</s></p></subchap2><subchap2 n="4" type="proof"><figure id="id.064.01.143.1.jpg" xlink:href="064/01/143/1.jpg"/><p type="main">

<s>In canali ACB.</s></p><p type="main">

<s>Dico impetum sectionis B ad impe&shy;<lb/>tum sectionis C esse in subduplicata <lb/>ratione longitudinum AB ad AC.</s></p><p type="main">

<s>Quoniam sectio C ad sectionem B est in <lb/>subduplicata ratione AB ad AC<arrow.to.target n="marg217"/>. <lb/>Impetus in B ad impetum in C est in eadem sub&shy;<lb/>duplicata ratione AB ad AC<arrow.to.target n="marg218"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg217"></margin.target>Per 2. huius.</s></p><p type="margin">

<s><margin.target id="marg218"></margin.target>Per 13. sexti.</s></p></subchap2></subchap1><pb xlink:href="064/01/144.jpg"/><subchap1 n="5" type="proposition"><p type="head">

<s>PROPOSITIO V. PROBL. I.</s></p><subchap2 n="5" type="statement"><p type="main">

<s>Data canalis sectione, reperire sectionem in <lb/>quolibet allo dato puncto.<figure id="id.064.01.144.1.jpg" xlink:href="064/01/144/1.jpg"/></s></p></subchap2><subchap2 n="5" type="proof"><p type="main">

<s>Data sectione C, &amp; puncto B in canali AB, <lb/>Venanda est sectio puncti B.</s></p><p type="main">

<s>Fiat AD media inter AC, AB<arrow.to.target n="marg219"/>, &amp; sectio B ad <lb/>sectionem C ut AC ad AD.</s></p><p type="margin">

<s><margin.target id="marg219"></margin.target>Per 20. sexti.</s></p><p type="main">

<s>Dico B esse sectionem quaesitam.</s></p><p type="main">

<s>Quoniam sectio B ad sectionem C est ut AC ad <lb/>AD per constructionem; erit sectio B ad sectio&shy;<lb/>nem C in subduplicata ratione AC ad AB<arrow.to.target n="marg220"/>, <lb/>unde sectio B est sectio puncti B<arrow.to.target n="marg221"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg220"></margin.target>Per 3. huius.</s></p><p type="margin">

<s><margin.target id="marg221"></margin.target>Defini. pr. quarti huius.</s></p><p type="main">

<s>Fiet sectio B ad sectionem C ut AC ad AD, si fiat <lb/>altitudo laterum sectionis B ad altitudinem <lb/>laterum sectionis C ut AC ad AD<arrow.to.target n="marg222"/>.</s></p><p type="margin">

<s><margin.target id="marg222"></margin.target>Per 2. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/145.jpg"/><subchap1 n="6" type="proposition"><p type="head">

<s>PROPOSITIO VI.</s></p><subchap2 n="6" type="statement"><p type="main">

<s>Datis pluribus sectionibus; ratio primae ad ter&shy;<lb/>tiam, est composita ex rationibus velocitatis <lb/>secundae ad velocitatem primae, &amp; velo&shy;<lb/>citatis tertiae ad velocitatem secundae.<figure id="id.064.01.145.1.jpg" xlink:href="064/01/145/1.jpg"/></s></p></subchap2><subchap2 n="6" type="proof"><p type="main">

<s>Dentur in canali AB sectiones B, C, D. <lb/></s>

<s>Dico proportionem  sectionis B ad sectionem <lb/>D, esse compositam ex rationibus velocitatis C <lb/>ad veloci&shy;<lb/>tatem B, &amp; velocitatis D ad veloci&shy;<lb/>tatem C.</s></p><p type="main">

<s>Quoniam sectio B ad sectionem C est ut velocitas <lb/>C ad velocitatem B, item sectio D ad veloci&shy;<lb/>tatem C ut velocitas C ad velocitatem D<arrow.to.target n="marg223"/>.</s></p><p type="margin">

<s><margin.target id="marg223"></margin.target>Per 5. def. sexti.</s></p><p type="main">

<s>Sed ratio velocitatis D ad velocitatem B est com&shy;<lb/>posita ex rationibus velocitatis C ad velocita&shy;<lb/>tem B, &amp; velocitatis D ad velocitatem C<arrow.to.target n="marg224"/>.</s></p><p type="margin">

<s><margin.target id="marg224"></margin.target>Per 8. secundi huius.</s></p><p type="main">

<s>Ergo pariter ratio sectionis B ad sectionem D <lb/>est composita ex rationibus velocitatis C ad <lb/>velocitatem B, &amp; velocitatis D ad velocita&shy;<lb/>tem C. </s>

<s>Quod etc.</s></p></subchap2><pb xlink:href="064/01/146.jpg"/><subchap2 type="corollary"><p type="head">

<s>Corollarium</s></p><p type="main">

<s>Si sint plures sectiones puta B, C, D, E, F, <lb/>pariter ratio sectionis B ad sectionem F com&shy;<lb/>ponitur ex velocitatibus C ad B, D ad C, E ad <lb/>D, F ad E.</s></p></subchap2></subchap1><pb xlink:href="064/01/147.jpg"/><subchap1 n="7" type="proposition"><p type="head">

<s>PROPOSITIO VII.</s></p><subchap2 n="7" type="statement"><p type="main">

<s>Si canales perpendicularis, &amp; inclinatus ter&shy;<lb/>minentur a recta normali ad inclinatum, <lb/>sectio perpendicularis ad sectionem in&shy;<lb/>clinati est, ut inclinatus ad perpendicu&shy;<lb/>larem.<figure id="id.064.01.147.1.jpg" xlink:href="064/01/147/1.jpg"/></s></p></subchap2><subchap2 n="7" type="proof"><p type="main">

<s>Dentur canales AB perpendicularis, &amp; A<lb/>D inclinatus, terminati a recta BD, ut an&shy;<lb/>gulus ADB sit rectus. </s>

<s>Dico sectionem B ad se&shy;<lb/>ctionem D esse ut AD, ad AB.</s></p><p type="main">

<s>Quoniam velocitas in B ad velocitatem in D est <lb/>ut AB ad AD<arrow.to.target n="marg225"/>.</s></p><p type="margin">

<s><margin.target id="marg225"></margin.target>Per 2. huius.</s></p><p type="main">

<s>Erit sectio B ad sectionem D ut AD ad AB<arrow.to.target n="marg226"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg226"></margin.target>Per cor. 8. sexti.</s></p></subchap2></subchap1><pb xlink:href="064/01/148.jpg"/><subchap1 n="8" type="proposition"><p type="head">

<s>PROPOSITIO VIII.</s></p><subchap2 n="8" type="statement"><p type="main">

<s>In canalibus perpendiculari, &amp; inclinato; se&shy;<lb/>ctiones terminatae a linea orizontali sunt <lb/>aequales.<figure id="id.064.01.148.1.jpg" xlink:href="064/01/148/1.jpg"/></s></p></subchap2><subchap2 n="8" type="proof"><p type="main">

<s>Dentur canales AB perpendicularis, &amp; AC <lb/>inclinatus, quorum sectiones CB sint ori&shy;<lb/>zontales.</s></p><p type="main">

<s>Dico eas esse aequales inter se.</s></p><p type="main">

<s>Ducatur normalis BD ad AC.</s></p><p type="main">

<s>Quoniam AB est media inter AD, AC<arrow.to.target n="marg227"/>, AD ad <lb/>AC habet duplicatam rationem AD ad AB<arrow.to.target n="marg228"/>. <lb/>Unde sectio D ad sectionem C est ut AB ad AD<arrow.to.target n="marg229"/>. </s>

<s>Et eadem sectio D ad sectionem B est pariter <lb/>ut AB ad AD<arrow.to.target n="marg230"/>. Ergo sectiones C, B ha<lb/>bentes eamdem rationem ad sectionem D, sunt <lb/>aequales inter se<arrow.to.target n="marg231"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg227"></margin.target>Per 10. def. quin.</s></p><p type="margin">

<s><margin.target id="marg228"></margin.target>Per 3. huius.</s></p><p type="margin">

<s><margin.target id="marg229"></margin.target>Per 7. huius.</s></p><p type="margin">

<s><margin.target id="marg230"></margin.target>Per 9. quinti.</s></p><p type="margin">

<s><margin.target id="marg231"></margin.target>Per 3. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/149.jpg"/><subchap1 n="9" type="proposition"><p type="head">

<s>PROPOSITIO IX.</s></p><subchap2 n="9" type="statement"><p type="main">

<s>Ductis pluribus canalibus a puncto superno <lb/>quomodocunque; reperire rationes data&shy;<lb/>rum sectionum inter se.<figure id="id.064.01.149.1.jpg" xlink:href="064/01/149/1.jpg"/></s></p></subchap2><subchap2 n="9" type="proof"><p type="main">

<s>Dati sint quilibet canales AB, AC, AD, in <lb/>quibus assignentur puncta B, C, D.</s></p><p type="main">

<s>Oportet reperire rationes dictarum sectionum inter se. <lb/></s>

<s>Ducatur perpendicularis AE, &amp; ad eam per&shy;<lb/>pendiculares BF, CG, DE, &amp; sint F, G, E sectio&shy;<lb/>nes canalis AE.</s></p><p type="main">

<s>Quoniam est nota ratio sectionum F, G, E<arrow.to.target n="marg232"/>, &amp; B, C, D <lb/>sectiones aequantur sectionibus F, G, E respective<arrow.to.target n="marg233"/>, <lb/>sequitur notas esse ipsarum rationes. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg232"></margin.target>Per 8. huius.</s></p><p type="margin">

<s><margin.target id="marg233"></margin.target>Per 8. huius.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium I.</s></p><p type="main">

<s>Si sectiones B, C, D terminentur in <lb/>perpendiculari BD, erit pariter <lb/>ratio inter ipsas nota.</s></p></subchap2></subchap1><pb xlink:href="064/01/150.jpg"/><subchap1 n="10" type="proposition"><p type="head">

<s>PROPOSITIO X</s></p><subchap2 n="10" type="statement"><p type="main">

<s>In canalibus inter binas orizontales, sectiones <lb/>inferiores sunt aequales.<figure id="id.064.01.150.1.jpg" xlink:href="064/01/150/1.jpg"/></s></p></subchap2><subchap2 n="10" type="proof"><p type="main">

<s>Sint canales AB, CD inter orizontales AC, BD. <lb/></s>

<s>Dico sectiones B, D esse aequales.</s></p><p type="main">

<s>Fiat canale CE.</s></p><p type="main">

<s>Sectio E aequatur sectioni D<arrow.to.target n="marg234"/>. </s>

<s>Aequatur pariter <lb/>sectioni B, quia est par ratio. </s>

<s>Ergo sectiones B, <lb/>D sunt aequales. </s>

<s>Quod etc.<figure id="id.064.01.150.2.jpg" xlink:href="064/01/150/2.jpg"/></s></p><p type="margin">

<s><margin.target id="marg234"></margin.target>Per 3. huius.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium I.</s></p><p type="main">

<s>Si canales AB, CB ducti ab orizontali A C ter&shy;<lb/>minantur in B, sectio in B erit aequaliter de&shy;<lb/>serviens utrique canali.</s></p></subchap2></subchap1><pb xlink:href="064/01/151.jpg"/><subchap1 n="11" type="proposition"><p type="head">

<s>PROPOSITIO XI.</s></p><subchap2 n="11" type="statement"><p type="main">

<s>Dato canali inflexo quomodolibet, venari quan&shy;<lb/>titatem datae sectionis.<figure id="id.064.01.151.1.jpg" xlink:href="064/01/151/1.jpg"/></s></p></subchap2><subchap2 n="11" type="proof"><p type="main">

<s>Canalis AB inflectatur in B quovis angulo <lb/>ABC, in quo data sectione C venanda sit <lb/>eius quantitas.</s></p><p type="main">

<s>Protrahatur CB ad orizontalem AD, &amp; fiat DE <lb/>media inter DB, DC, &amp; sectionis C altitudo <lb/>ad altitudinem sectionis B fiat ut DB ad DE.</s></p><p type="main">

<s>Dico C esse sectionem in C.</s></p><p type="main">

<s>Quoniam si canale sit DC, sectio C ad sectionem B <lb/>est ut DB ad DE<arrow.to.target n="marg235"/>. At sectio B est eadem <lb/>etiam, respectu canalis AB<arrow.to.target n="marg236"/>. </s>

<s>Ergo sectio <lb/>C ad sectionem B est ut DB ad DE.</s></p><p type="margin">

<s><margin.target id="marg235"></margin.target>Per co. decimae huius.</s></p><p type="margin">

<s><margin.target id="marg236"></margin.target></s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium I.</s></p><p type="main"><figure id="id.064.01.151.2.jpg" xlink:href="064/01/151/2.jpg"/>

<s>Eadem via reperietur quantitas se&shy;<lb/>ctionis C, si canalis sit declinans, <lb/>&amp; demum perpendicularis ut A, B, C.</s></p></subchap2></subchap1></chap><pb xlink:href="064/01/152.jpg"/><pb xlink:href="064/01/153.jpg"/><chap type="bk"><p type="main">

<s>DE MOTV<lb/>GRAVIVM<lb/>LIBER SEXTVS<lb/>ET LIQUIDORVM TERTIVS<lb/>VBI DE FORAMINIBVS VASIS.</s></p><subchap1 type="preface"><p type="main">

<s>Non alienum ab instituto <lb/>arbitratus sum adhuc ali&shy;<lb/>quid huic postremo prae&shy;<lb/>fari libro, ubi nodum sol&shy;<lb/>vere conabor ab eruditis&shy;<lb/>simo Mersenno proposi&shy;<lb/>tum prop. 15. Ballist. <lb/>quod quidem, explican&shy;<lb/>do, quantum ingenhuius fert imbecilitas, qua diu&shy;<lb/>turnitate pendulum, tam prius descendendo, <lb/>quam inde ascendendo feratur, suppositis ex&shy;<lb/>perimentis cum ipso primo habitis, postmo&shy;<lb/>dum a me repetitis, quibus percipere mihi vi&shy;<lb/>sus sum diuturnitatem penduli in integra <lb/>vibratione aequari diuturnitati gravis moti per<pb xlink:href="064/01/154.jpg"/>spatium eius quadruplum, &amp; in descensu, <lb/>aequari diuturnitati gravis moti per eiusdem <lb/>penduli duplum: quod non omnino congruit <lb/>cum eo quod prop. 9. Terthuius huius proba&shy;<lb/>tum fuit, quoniam experimenta veritatem <lb/>proxime, at non praecise patefaciunt. </s><figure id="id.064.01.154.1.jpg" xlink:href="064/01/154/1.jpg"/>

<s>Sit pen&shy;<lb/>dulum AB, quod in C translatum sua integra <lb/>vibratione describat circulum CBD: ex dictis <lb/>experimentis compertum est diuturnitatem il&shy;<lb/>lius percurrentis per quadrantem CB, aequari <lb/>diuturnitati gravis descendentis per FB dia&shy;<lb/>metrum, ipsius penduli duplam; diuturnita&shy;<lb/>tem vero eiusdem conficientis integram vibra&shy;<lb/>tionem CBD, aequari diuturnitati eiusdem gravis <lb/>descendentis per duplum ipsius FB, puta per FG. <lb/></s>

<s>Quibus positis, mihi assequi visus sum, qua pro&shy;<pb xlink:href="064/01/155.jpg"/>portione sibi respondeant diuturnitates pen&shy;<lb/>duli moti in descensu a C in B, &amp; in ascensu <lb/>a B in D, secta CD in E tali ratione, ut E tan&shy;<lb/>tundem destet a C, quantum B; existimans diu&shy;<lb/>turnitates motuum per CB, &amp; BD quadrantes, <lb/>esse inter se ut CE ad ED. </s>

<s>Quoniam ratio diu&shy;<lb/>turnitatum  per FB, &amp; FG est eadem ac per <lb/>AB, &amp; FB, cum utrobique sit subdupla pro&shy;<lb/>portio, quae ratio est pariter inter CB, &amp; <lb/>FB<arrow.to.target n="marg237"/>, cum CB sit media inter AB, FB,<arrow.to.target n="marg238"/> erit <lb/>ratio diuturnitatum  per FB, &amp; FG, &amp; itidem <lb/>per quadrantem CB, &amp; per semic. CBD eis <lb/>aequalium<arrow.to.target n="marg239"/> ut CB ad FB, seu ut CE ad CD eis <lb/>aequales: &amp; dividendo, ratio diuturnitatum <lb/>per CB, &amp; BD quadrantes erit ut CE ad ED<arrow.to.target n="marg240"/>. <lb/></s>

<s>Quod etc. </s>

<s>Unde si ex Mersenno, grave ab A in <lb/>B pedum 3 regiorum, qui quatuor palmis nostra&shy;<lb/>tibus proxime respondent, descendit in 30 ter&shy;<lb/>thuiuss, a C in B fertur non in 30 sed in 42, unde <lb/>a B in D ascendit in 17 sibi respondentes ut <lb/>99 ad 41. Caeterum ex dictis facile demonstrabi&shy;<lb/>tur quod si vibrationes sint minores, v.g. ab <lb/>H in I, pariter diuturnitates per HB, &amp; per <lb/>BI erunt ut CE ad ED, cum iam probatum <lb/>fuerit, &amp; experientia constet vibrationes CB, HB <lb/>nec non CD, HI esse aequediuturnas. </s>

<s>Ex his <lb/>etiam constat esse aequales diuturnitates per <lb/>BG, &amp; BD, etiamsi per BD fiat ascensus, &amp;<pb xlink:href="064/01/156.jpg"/>proinde motus successive tardior, &amp; per BG <lb/>descensus, &amp; proinde motus successive velo&shy;<lb/>cior. </s>

<s>Quem nodum, de quo in praesentia <lb/>nil addam, alhuiuss enodandum relinquo.</s></p><p type="margin">

<s><margin.target id="marg237"></margin.target>Per 3. pr. huius.</s></p><p type="margin">

<s><margin.target id="marg238"></margin.target>Per cor. 8. sexti.</s></p><p type="margin">

<s><margin.target id="marg239"></margin.target>Per Observat.</s></p><p type="margin">

<s><margin.target id="marg240"></margin.target>Per 17. quinti.</s></p></subchap1><pb xlink:href="064/01/157.jpg"/><subchap1 type="definition"><p type="head">

<s>DEFINITIONES.</s></p><subchap2 type="definition"><p type="main">

<s>1 Vas aquae intelligitur, cuius latera sint <lb/>retangula, &amp; basis orizontalis.</s></p></subchap2><subchap2 type="definition"><p type="main">

<s>2. Foramen intelligitur rectangulum cuius basis <lb/>orizontalis.</s></p></subchap2><subchap2 type="definition"><p type="main">

<s>3. Foramina inaequalia eiusdem altitudinis, quo&shy;<lb/>rum inaequalitas pendet a sola latitudine.</s></p></subchap2></subchap1><pb xlink:href="064/01/158.jpg"/><subchap1 type="axiom"><p type="head">

<s>DIGNITATES</s></p><subchap2 type="postulate"><p type="main">

<s>Ubi omnia sint paria, effectus sunt aequa&shy;<lb/>les.</s></p></subchap2></subchap1><subchap1 type="postulate"><p type="head">

<s>PETITIONES</s></p><subchap2 type="axiom"><p type="main">

<s>1 Quantitates eiusdem generis sunt omnes <lb/>commensurabiles.</s></p></subchap2><subchap2 type="axiom"><p type="main">

<s>2. Aqua transiens per vasis foramen, decurrit a <lb/>summo vasis ad foramen tanquam per cana&shy;<lb/>lem perpendicularem.</s></p></subchap2><subchap2 type="axiom"><p type="main">

<s>Quod experieris, si vas aqua plenum, in cuius <lb/>imo sit foramen, sit perspicuum; videbis etenim <lb/>in eo formari canale, per quod aqua supe&shy;<lb/>rior exeat.</s></p></subchap2></subchap1><pb xlink:href="064/01/159.jpg"/><subchap1 n="1" type="proposition"><p type="head">

<s>PROPOSITIO PRIMA</s></p><subchap2 n="1" type="statement"><p type="main">

<s>Aquarum quantitates exeuntium per forami&shy;<lb/>na aequalia, aeque distantia a summo vasis, <lb/>aequali tempore; sunt aequales.<figure id="id.064.01.159.1.jpg" xlink:href="064/01/159/1.jpg"/></s></p></subchap2><subchap2 n="1" type="proof"><p type="main">

<s>In vase AB, sint foramina C, D aequalia, &amp; <lb/>orizontalia, per quae aqua aequali tempore de&shy;<lb/>currat.</s></p><p type="main">

<s>Dico aquas decursas esse aequales inter se.</s></p><p type="main">

<s>Quoniam ubi omnia sunt paria, effectus sunt <lb/>aequales<arrow.to.target n="marg241"/>.</s></p><p type="margin">

<s><margin.target id="marg241"></margin.target>Per ax. huius.</s></p><p type="main">

<s>Sed hic sunt omnia paria ex constructione.</s></p><p type="main">

<s>Ergo habent effectus aequales.</s></p><p type="main">

<s>Sed aquae decursa sunt effectus, &amp; proinde aequa&shy;<lb/>les. </s>

<s>Quod etc.</s></p><p type="main">

<s>Seu mavis.</s></p><p type="main">

<s>Ubi omnia paria effectus sunt aequales, &amp; <lb/>proinde si effectus sunt aquae decursae,  ipsae <lb/>sunt aequales.</s></p><p type="main">

<s>Sed hic sunt omnia paria, &amp; effectus sunt aquae <lb/>decursae, ex constructione. </s>

<s>Ergo aquae decursae sunt aequales. </s>

<s>Quod etc.</s></p></subchap2></subchap1><pb xlink:href="064/01/160.jpg"/><subchap1 n="2" type="proposition"><p type="head">

<s>PROPOSITIO II.</s></p><subchap2 n="2" type="statement"><p type="main">

<s>Si foramina sint orizontalia, eiusdem altitudi&shy;<lb/>nis, quantitates aquarum decursarum sunt <lb/>inter se ut foramina.<figure id="id.064.01.160.1.jpg" xlink:href="064/01/160/1.jpg"/></s></p></subchap2><subchap2 n="2" type="proof"><p type="main">

<s>In vase AB dentur foramina orizontalia aeque <lb/>alta C minus, D vero maius.</s></p><p type="main">

<s>Dico aquam decursam per C, quae sit E, se habere ad aquam <lb/>decursam per D, quae sit F, ut foramen C ad foramen D.</s></p><p type="main">

<s>Longitudinum C, &amp; D commensurabilium,<arrow.to.target n="marg242"/> <lb/>sit G communis mensura, &amp; secentur lon&shy;<lb/>gitudines C, D in partes, quae sint aequales ipsi <lb/>G, quibus divisis a perpendicularibus, producan&shy;<lb/>tur tot foramina, quot sunt dictae partes.</s></p><p type="margin">

<s><margin.target id="marg242"></margin.target>Per pr. pet.</s></p><p type="main">

<s>Quoniam huiusmodi foramina erunt inter se <lb/>aequalia<arrow.to.target n="marg243"/>. Ex eis effluent quantitates aquae <lb/>aequales<arrow.to.target n="marg244"/>. </s>

<s>Quot igitur sunt foramina in C, D, <lb/>tot sunt quantitates aquarum in E, F. </s>

<s>Igitur <lb/>sunt quatuor quantitates C, D, E, F, quarum <lb/>prima, C, est ad E, 2., ut D, 3., ad F, 4.; &amp; per&shy;<lb/>mutando erit C ad D ut E ad F<arrow.to.target n="marg245"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg243"></margin.target>Per 36. primi.</s></p><p type="margin">

<s><margin.target id="marg244"></margin.target>Per primum huius.</s></p><p type="margin">

<s><margin.target id="marg245"></margin.target>Per 16. quinti.</s></p><p type="main">

<s>Dices, quod fieri potest quod longitudines C, D, <lb/>non sint commensurabiles, nec proinde G sit eo&shy;<lb/>rum communis mensura: sed hic non sumus in <lb/>Mathematicis, sed in physicis, ubi non habetur <lb/>ratio insensibilium.</s></p></subchap2></subchap1><pb xlink:href="064/01/161.jpg"/><subchap1 n="3" type="proposition"><p type="head">

<s>PROPOSITIO III.</s></p><subchap2 n="3" type="statement"><p type="main">

<s>Foramina vasis perinde se habent ac sectio&shy;<lb/>nes canalis, respectu impetus.<figure id="id.064.01.161.1.jpg" xlink:href="064/01/161/1.jpg"/></s></p></subchap2><subchap2 n="3" type="proof"><p type="main">

<s>Sit vas CD in quo foramen D, &amp; sit AB ca&shy;<lb/>nalis perpendicularis in quo sectio B, &amp; <lb/>AB, CD, altitudines sint aequales.</s></p><p type="main">

<s>Dico in B, &amp; D esse impetus aequales.</s></p><p type="main">

<s>Quoniam aqua fluens a foramine D decurrit per <lb/>spatium CD, ac si decurreret per canalem AB <lb/>perpendicularem, eiusdem longitudinis<arrow.to.target n="marg246"/>, in <lb/>D, &amp; B sortitur impetus aequales. </s>

<s>Quod, etc.</s></p><p type="margin">

<s><margin.target id="marg246"></margin.target>Per 2. pet.</s></p></subchap2></subchap1><pb xlink:href="064/01/162.jpg"/><subchap1 n="4" type="proposition"><p type="head">

<s>PROPOSITIO IV.</s></p><subchap2 n="4" type="statement"><p type="main">

<s>Impetus foraminum aequalium vasis, sunt in <lb/>duplicata ratione distantiae a summo va&shy;<lb/>sis.<figure id="id.064.01.162.1.jpg" xlink:href="064/01/162/1.jpg"/></s></p></subchap2><subchap2 n="4" type="proof"><p type="main">

<s>In vase AC, distantiae foraminum aequalium <lb/>B, C a summo vasis AB, AC; media sit AD.</s></p><p type="main">

<s>Dico impetus in C ad impetum in B esse ut AD <lb/>ad AB.</s></p><p type="main">

<s>Quoniam foramina B, C, sunt ac si essent sectio&shy;<lb/>nes canalis AC respectu impetus<arrow.to.target n="marg247"/>, impetus in <lb/>B &amp; C sunt ut AB ad AD<arrow.to.target n="marg248"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg247"></margin.target>Per 3. huius.</s></p><p type="margin">

<s><margin.target id="marg248"></margin.target>Per 4. quinti huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/163.jpg"/><subchap1 n="5" type="proposition"><p type="head">

<s>PROPOSITIO V.</s></p><subchap2 n="5" type="statement"><p type="main">

<s>Altitudines a foraminibus aequalibus ad sum&shy;<lb/>mum vasis, sunt in duplicata ratione aqua&shy;<lb/>rum per ea decurrentium.<figure id="id.064.01.163.1.jpg" xlink:href="064/01/163/1.jpg"/></s></p></subchap2><subchap2 n="5" type="proof"><p type="main">

<s>In vase AC altitudines a foraminibus aequa&shy;<lb/>libus B, C, ad summum vasis A sint AB, <lb/>AC, quarum media sit AD.</s></p><p type="main">

<s>Dico AD ad AB esse ut aqua fluens per C ad <lb/>aquam fluentem per B.</s></p><p type="main">

<s>Quoniam ut AD ad AB ita est impetus in C ad <lb/>impetum in B<arrow.to.target n="marg249"/>, &amp; impetus sunt ut velocita&shy;<lb/>tes<arrow.to.target n="marg250"/>; impetus in C ad impetum B est ut aqua <lb/>fluens per C ad aquam  effluentem per B. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg249"></margin.target>Per quartam huius.</s></p><p type="margin">

<s><margin.target id="marg250"></margin.target>Per 3. petit.</s></p></subchap2></subchap1><pb xlink:href="064/01/164.jpg"/><subchap1 n="6" type="proposition"><p type="head">

<s>PROPOSITIO VI. PROBL. II.</s></p><subchap2 n="6" type="statement"><p type="main">

<s>Secto foramine in partes aliquotas a rectis <lb/>orizontalibus, venari rationes aquarum ex <lb/>eis fluentium.<figure id="id.064.01.164.1.jpg" xlink:href="064/01/164/1.jpg"/></s></p></subchap2><subchap2 n="6" type="proof"><p type="main">

<s>Secetur foramen AB in partes AC, CD, DB <lb/>aequales, quorum altitudines sint notae, &amp; <lb/>ab AC fluat aqua E, a CD aqua F, a DB <lb/>aqua G, tempore aequali.</s></p><p type="main">

<s>Venanda proportio aquarum E, F, G.</s></p><p type="main">

<s>Fiant HI, KL, MN, altitudines foraminum A<lb/>C, CD, DB a summo vasis; &amp; inter ipsas <lb/>mediae OP, QR<arrow.to.target n="marg251"/>.</s></p><p type="margin">

<s><margin.target id="marg251"></margin.target>Per 13. sexti.</s></p><p type="main">

<s>Quoniam aqua E ad aquam F, est ut HI ad OP<arrow.to.target n="marg252"/>, <lb/>Nota est ratio aquae E ad aquam F. Item quoniam <lb/>aqua F ad aquam G est ut KL, ad QR<arrow.to.target n="marg253"/>, <lb/>nota est pariter ratio aquae F ad aquam G. <lb/>at ratio aquae E ad aquam G, composita ra&shy;<lb/>tionum inter EF &amp; FG notarum, est pariter <lb/>nota. </s>

<s>Reperta est igitur ratio aquarum E, F, G. </s>

<s>Quod, etc.</s></p><p type="margin">

<s><margin.target id="marg252"></margin.target>Per 5. huius.</s></p><p type="margin">

<s><margin.target id="marg253"></margin.target>Per 5. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/165.jpg"/><subchap1 n="7" type="proposition"><p type="head">

<s>PROPOSITIO VII. PROBL. III.</s></p><subchap2 n="7" type="statement"><p type="main">

<s>Secto foramine vasis in partes a recta orizon&shy;<lb/>tali, reperire rationes aquarum effluen&shy;<lb/>tium ab ipsis.<figure id="id.064.01.165.1.jpg" xlink:href="064/01/165/1.jpg"/></s></p></subchap2><subchap2 n="7" type="proof"><p type="main">

<s>Foramen CD vasis AB secetur a recta E in <lb/>partes CE, CD, &amp; effluat a parte superio&shy;<lb/>ri CE aqua F, &amp; ab inferiori ED aqua G eo&shy;<lb/>dem tempore.</s></p><p type="main">

<s>Quaeritur proportio F ad G.</s></p><p type="main">

<s>Si ED foramen minus non mensurat CE, repe&shy;<lb/>riatur eorum maxima communis mensura<arrow.to.target n="marg254"/>, <lb/>quae sit H, &amp; iuxta eam secetur CE in partes <lb/>CQ, QK, KE, item ED in partes EI, ID.</s></p><p type="margin">

<s><margin.target id="marg254"></margin.target>Per 3. decimi.</s></p><p type="main">

<s>Quoniam foramen CD sectum est in partes CQ, <lb/>QK, KE, EI, ID aequales per constructionem; <lb/>venabitur ratio aquarum per eos fluentium<arrow.to.target n="marg255"/>, &amp; <lb/>proinde aquarum per CE, &amp; ED. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg255"></margin.target>Per 6. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/166.jpg"/><subchap1 n="8" type="proposition"><p type="head">

<s>PROPOSITIO VIII. PROBL. IV.</s></p><subchap2 n="8" type="statement"><p type="main">

<s>Datis foraminibus inaequalibus super eadem <lb/>orizontali, venari rationes aquarum.<figure id="id.064.01.166.1.jpg" xlink:href="064/01/166/1.jpg"/></s></p></subchap2><subchap2 n="8" type="proof"><p type="main">

<s>Sint foramina AB, &amp; CD super orizontali <lb/>BD.</s></p><p type="main">

<s>Quaerenda proportio aquarum ex eis eodem tem&shy;<lb/>pore fluentium.</s></p><p type="main">

<s>Producatur CE FG parallela DB.</s></p><p type="main">

<s>Quoniam nota est ratio aquarum fluentium ex <lb/>CD, &amp; FB<arrow.to.target n="marg256"/>, item per FB, &amp; AG<arrow.to.target n="marg257"/>, Nota est <lb/>pariter ratio ex eis composita inter aquas flu&shy;<lb/>entes per CD, &amp; AG. </s>

<s>Cum igitur sit nota ra&shy;<lb/>tio aquae fluentis per CD, ad fluentem per <lb/>FB, &amp; per AG partes, nota erit ratio eiusdem <lb/>ad totam fluentem per AB. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg256"></margin.target>Per 2. huius.</s></p><p type="margin">

<s><margin.target id="marg257"></margin.target>Per 7. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/167.jpg"/><subchap1 n="9" type="proposition"><p type="head">

<s>PROPOSITIO IX. PROBL. V.</s></p><subchap2 n="9" type="statement"><p type="main">

<s>Datis foraminibus, quorum unum superius, <lb/>alterum inferius inter easdem parallelas <lb/>perpendiculares: Reperire rationes aqua&shy;<lb/>rum.<figure id="id.064.01.167.1.jpg" xlink:href="064/01/167/1.jpg"/></s></p></subchap2><subchap2 n="9" type="proof"><p type="main">

<s>Dentur foramina AB, CD inter parallelas <lb/>AC, &amp; DB.</s></p><p type="main">

<s>Venanda ratio aquarum ex eis, aequo tempore, <lb/>fluentium.</s></p><p type="main">

<s>Concipiatur BC tanquam foramen.</s></p><p type="main">

<s>Quoniam nota est ratio aquarum fluentium ex CD, <lb/>&amp; ex CB, item ex CB, &amp; ex AB<arrow.to.target n="marg258"/>, nota est <lb/>pariter ratio ex eis composita aquarum fluen&shy;<lb/>tium per CD, &amp; per AB. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg258"></margin.target>Per 7. huius.</s></p></subchap2></subchap1><pb xlink:href="064/01/168.jpg"/><subchap1 n="10" type="proposition"><p type="head">

<s>PROPOSITIO X. PROBL. VI.</s></p><subchap2 n="10" type="statement"><p type="main">

<s>Datis foraminibus venari aquas.<figure id="id.064.01.168.1.jpg" xlink:href="064/01/168/1.jpg"/></s></p></subchap2><subchap2 n="10" type="proof"><p type="main">

<s>Data sint foramina AD, EH.</s></p><p type="main">

<s>Oportet reperire rationem aquarum per <lb/>illa aequo tempore fluentium.</s></p><p type="main">

<s>Duc orizontales HI, FK, &amp; producta DB in L, con&shy;<lb/>cipiatur IL tanquam foramen; &amp; quaeratur <lb/>ratio aquarum per AD, IL<arrow.to.target n="marg259"/>, &amp; sit ut M ad N. <lb/></s>

<s>Item quaeratur ratio IL ad EH,<arrow.to.target n="marg260"/>, &amp; sit ut N ad O.</s></p><p type="margin">

<s><margin.target id="marg259"></margin.target>Per 9. huius.</s></p><p type="margin">

<s><margin.target id="marg260"></margin.target>Per 2. huius.</s></p><p type="main">

<s>Dico M ad O esse rationem aquarum per AD, HE.</s></p><p type="main">

<s>Quoniam ut M ad N ita est AD ad IL, &amp; ut <lb/>N ad O, ita IL ad EH per constr. </s>

<s>Erit ex <lb/>aequo ut M ad O, ita AD ad EH<arrow.to.target n="marg261"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg261"></margin.target>Per 22. quinti.</s></p></subchap2></subchap1><pb xlink:href="064/01/169.jpg"/><subchap1 n="11" type="proposition"><p type="head">

<s>PROPOSITIO XI. PROBL. VII</s></p><subchap2 n="11" type="statement"><p type="main">

<s>Dato foramine, &amp; linea orizontali intermi&shy;<lb/>nata; constituere super illa foramen, a quo <lb/>aequalis aqua fluat.<figure id="id.064.01.169.1.jpg" xlink:href="064/01/169/1.jpg"/></s></p></subchap2><subchap2 n="11" type="proof"><p type="main">

<s>Dato foramine AB, &amp; orizontali CD.</s></p><p type="main">

<s>Describendum sit foramen super CD, a <lb/>quo effluat aqua ut per AB.</s></p><p type="main">

<s>Erigantur perpendiculares AE, BC, &amp; produca&shy;<lb/>tur DC in E, &amp; super EC fait foramen aequale <lb/>AB, &amp; sit FC, &amp; ducta FG parallela CD, fiat <lb/>HI media inter K summum vasis B, &amp; KE, <lb/>&amp; ut HI ad KE, ita DL ad EC.</s></p><p type="main">

<s>Dico per LG foramen fluere aquam ut per AB.</s></p><p type="main">

<s>Quoniam aqua LG ad aquam FC est ut HI ad <lb/>KE<arrow.to.target n="marg262"/>, &amp; aqua AB ad aquam CF est ut HI ad <lb/>KE<arrow.to.target n="marg263"/>, erit ut aqua LG ad CF, ita aqua AB <lb/>ad CF<arrow.to.target n="marg264"/>, &amp; proinde aqua AB aequalis aquae <lb/>LG<arrow.to.target n="marg265"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg262"></margin.target>Per 2. huius.</s></p><p type="margin">

<s><margin.target id="marg263"></margin.target>Per 5. huius.</s></p><p type="margin">

<s><margin.target id="marg264"></margin.target>Per 11. quinti.</s></p><p type="margin">

<s><margin.target id="marg265"></margin.target>Per nonam quinti.</s></p></subchap2></subchap1><pb xlink:href="064/01/170.jpg"/><subchap1 n="12" type="proposition"><p type="head">

<s>PROPOSITIO XII. PROBL. VIII.</s></p><subchap2 n="12" type="statement"><p type="main">

<s>Dato foramine, &amp; latere alterius, reperire fo&shy;<lb/>ramen, e quo aequalis aqua effluat.<figure id="id.064.01.170.1.jpg" xlink:href="064/01/170/1.jpg"/></s></p></subchap2><subchap2 n="12" type="proof"><p type="main">

<s>Datum sit foramen AB, &amp; latere DC. </s>

<s>Oportet describere foramen, a quo effluat <lb/>aqua ut ab AB, cuius latus sit CD.</s></p><p type="main">

<s>Ductis CE, &amp; DF, orizontalibus; protrahatur B<lb/>E, &amp; FE intelligatur foramen, &amp; reperiatur ra&shy;<lb/>tio aquarum fluentium ab AB, &amp; ab FE<arrow.to.target n="marg266"/>, <lb/>quae sit ut C ad H; &amp; fiat ut H ad G, ita <lb/>FI ad FK, &amp; a K erigitur perpendicularis KL, <lb/>&amp; fiat foramen cuius latus DC aequale, &amp; <lb/>simile ipsi FL, et sit DM.</s></p><p type="margin">

<s><margin.target id="marg266"></margin.target>Per 9. huius.</s></p><p type="main">

<s>Dico a foramine DM fluere aquam, ut ab AB.</s></p><p type="main">

<s>Quoniam aqua fluens per AB ad fluentem per FE <lb/>est ut G ad H per const. item aqua fluens per FL <lb/>seu ei aequale DM ad fluentem per eandem F<lb/>E est itidem ut G ad H<arrow.to.target n="marg267"/>, aquae fluentes per A<lb/>B &amp; per DM sunt inter se aequales<arrow.to.target n="marg268"/>, DM ig. </s>

<s>Est foramen quaesitum. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg267"></margin.target>Per secundum huius.</s></p><p type="margin">

<s><margin.target id="marg268"></margin.target>Per 9. quinti.</s></p></subchap2></subchap1><pb xlink:href="064/01/171.jpg"/><subchap1 n="13" type="proposition"><p type="head">

<s>PROPOSITIO XIII. PROBL. IX.</s></p><subchap2 n="13" type="statement"><p type="main">

<s>Dato foramine, reperire aliud aequale, a quo <lb/>fluat aqua in ratione data.<figure id="id.064.01.171.1.jpg" xlink:href="064/01/171/1.jpg"/></s></p></subchap2><subchap2 n="13" type="proof"><p type="main">

<s>Detur in vase AB foramen C, &amp; data sit <lb/>ratio aquarum D, E, quarum D fluat in <lb/>dato tempore per foramen C.</s></p><p type="main">

<s>Reperiendum ubi fiat aequale foramen, a quo fluat <lb/>in aequali tempore aqua E.</s></p><p type="main">

<s>Fiat ad D, E, AC quarta preportionalis AF<arrow.to.target n="marg269"/>, <lb/>&amp; ad AC, AF tertia proportionalis AG<arrow.to.target n="marg270"/>, &amp; <lb/>in G fiat foramen: quod si fieri nequit proble&shy;<lb/>ma est insolubile. </s>

<s>Dico G esse locum forami&shy;<lb/>nis quaesitum.</s></p><p type="margin">

<s><margin.target id="marg269"></margin.target>Per 12. sexti.</s></p><p type="margin">

<s><margin.target id="marg270"></margin.target>Per 11. sexti.</s></p><p type="main">

<s>Quoniam aquae fluentes per dicta foramina sunt <lb/>in subduplicata ratione altitudinum AC, AG<arrow.to.target n="marg271"/>, <lb/>&amp; aquae D, E, sunt pariter in subduplicata ra&shy;<lb/>tione eorumdem altitudinum AC, AG<arrow.to.target n="marg272"/>, aquae <lb/>fluentes per dicta foramina sunt ut aquae D, <lb/>&amp; E<arrow.to.target n="marg273"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg271"></margin.target>Per 5. huius.</s></p><p type="margin">

<s><margin.target id="marg272"></margin.target>Per eamdem.</s></p><p type="margin">

<s><margin.target id="marg273"></margin.target>Per 9. quinti.</s></p></subchap2><pb xlink:href="064/01/172.jpg"/><subchap2 type="corollary"><p type="head">

<s>Corollarium I.</s></p><p type="main">

<s>Parum refert sint foramina quadrata nec ne.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium II.</s></p><p type="main">

<s>Idem sequitur si ambo foramina sint rotunda.</s></p></subchap2></subchap1><pb xlink:href="064/01/173.jpg"/><subchap1 n="14" type="proposition"><p type="head">

<s>PROPOSITIO XIV.</s></p><subchap2 n="14" type="statement"><p type="main">

<s>Dato foramine, aptandum sit aliud datum <lb/>simile, magnitudinis diversae, a quo aqua <lb/>fluens cum fluente a primo, habeat ratio&shy;<lb/>nem datam.<figure id="id.064.01.173.1.jpg" xlink:href="064/01/173/1.jpg"/></s></p></subchap2><subchap2 n="14" type="proof"><p type="main">

<s>In vase AB, dato foramine C, &amp; alio D ut <lb/>supra dictum est; &amp; data sit ratio aquarum E, F.</s></p><p type="main">

<s>Aptandum est foramen D ea lege, ut aqua per il&shy;<lb/>lud fluens, cum aqua fluente a C, sit ut F ad E.</s></p><p type="main">

<s>Super orizontali ducta CG fiat foramen G, <lb/>aequale foramini D; &amp; perquiratur ratio <lb/>aquarum fluentium per C, &amp; G<arrow.to.target n="marg274"/>, &amp; sit ut E <lb/>ad H: quae si est eadem quae est inter E, &amp; F, <lb/>habemus intentum; ni sit, fiat aliud foramen <lb/>infra seu supra G ei simile, &amp; aequale a quo <lb/>fluat aqua quae cum fluente ab ipso G habeat <lb/>rationem ut H ad F<arrow.to.target n="marg275"/>, &amp; sit I. </s>

<s>Quod si fieri <lb/>nequit problema est insolubile. </s>

<s>Dico I esse <lb/>foramen quaesitum.</s></p><p type="margin">

<s><margin.target id="marg274"></margin.target>Per 8. huius.</s></p><p type="margin">

<s><margin.target id="marg275"></margin.target>Per 13. huius.</s></p><pb xlink:href="064/01/174.jpg"/><p type="main">

<s>Quoniam probatum fuit aquam C ad aquam <lb/>G esse ut E ad H, &amp; aquam G ad aquam I <lb/>esse ut H ad F, constat aquam C ad aquam I <lb/>esse ut E ad F<arrow.to.target n="marg276"/>. </s>

<s>Quod etc.</s></p><p type="margin">

<s><margin.target id="marg276"></margin.target>Per 22. quinti.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium I.</s></p><p type="main">

<s>Parum refert sint ne foramina quadrata, <lb/>nec ne.</s></p></subchap2><subchap2 type="corollary"><p type="head">

<s>Corollarium II.</s></p><p type="main">

<s>Idem sequeretur si essent ambo rotunda<arrow.to.target n="marg277"/>.</s></p><p type="margin">

<s><margin.target id="marg277"></margin.target>Per 3. pet.</s></p><p type="main">

<s>FINIS</s></p></subchap2></subchap1></chap> <pb xlink:href="064/01/175.jpg"/><pb xlink:href="064/01/176.jpg"/><pb xlink:href="064/01/177.jpg"/><pb xlink:href="064/01/178.jpg"/><pb xlink:href="064/01/179.jpg"/><pb xlink:href="064/01/180.jpg"/><pb xlink:href="064/01/181.jpg"/></body><back/></text></archimedes>