Newton, Isaac, Philosophia naturalis principia mathematica, 1713

Page concordance

< >
Scan Original
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
< >
page |< < of 524 > >|
    <archimedes>
      <text>
        <body>
          <chap>
            <pb xlink:href="039/01/015.jpg"/>
            <p type="main">
              <s>Ex iis quæ hactenus dicta ſunt, conſtat Planetas in Orbitis ſuis
                <lb/>
              retineri per Vim aliquam in ipſos perpetuo agentem: conſtat
                <lb/>
              Vim illam dirigi ſemper verſus Orbitarum centra: conſtat hujus
                <lb/>
              efficaciam augeri in acceſſu ad centrum, diminui in receſſu ab eo­
                <lb/>
              dem: & augeri quidem in eadem proportione qua diminuitur qua­
                <lb/>
              dratum diſtantiæ, diminui in eadem proportione qua diſtantiæ
                <lb/>
              quadratum augetur. </s>
              <s>Videamus jam, comparatione inſtituta inter
                <lb/>
              Planetarum Vires centripetas & Vim Gravitatis, annon ejuſdem
                <lb/>
              forte ſint generis. </s>
              <s>Ejuſdem vero generis erunt, ſi deprehendan­
                <lb/>
              tur hinc & inde leges eædem eædemque affectiones. </s>
              <s>Primo ita­
                <lb/>
              que Lunæ, quæ nobis proxima eſt, Vim centripetam expendamus. </s>
            </p>
            <p type="main">
              <s>Spatia rectilinea, quæ a corporibus e quiete demiſſis dato tem­
                <lb/>
              pore ſub ipſo motus initio deſeribuntur, ubi a viribus quibuſcun­
                <lb/>
              que urgentur, proportionalia ſunt ipſis viribus: Hoc utique con­
                <lb/>
              ſequitur ex ratiociniis Mathematicis. </s>
              <s>Erit igitur Vis centripeta
                <lb/>
              Lunæ in Orbita ſua revolventis, ad Vim Gravitatis in ſuperficie
                <lb/>
              Terræ, ut ſpatium quod tempore quam minimo deſcriberet Luna
                <lb/>
              deſcendendo per Vim centripetam verſus Terram, ſi circulari om­
                <lb/>
              ni motu privari fingeretur, ad ſpatium quod eodem tempore quam
                <lb/>
              minimo deſcribit grave corpus in vicinia Terræ, per Vim gravita­
                <lb/>
              tis ſuæ cadendo. </s>
              <s>Horum ſpatiorum prius æquale eſt arcus a Luna
                <lb/>
              per idem tempus deſcripti ſinui verſo, quippe qui Lunæ tranſla­
                <lb/>
              tionem de Tangente, factam a Vi centripeta, metitur; atque adeo
                <lb/>
              computari poteſt ex datis tum Lunæ tempore periodico tum di­
                <lb/>
              ſtantia ejus a centro Terræ. </s>
              <s>Spatium poſterius invenitur per Ex­
                <lb/>
              perimenta Pendulorum, quemadmodum docuit
                <emph type="italics"/>
              Hugenius.
                <emph.end type="italics"/>
              Inito
                <lb/>
              itaque calculo, ſpatium prius ad ſpatium pofterius, ſeu vis cen­
                <lb/>
              tripeta Lunæ in Orbita ſua revolventis ad vim Gravitatis in ſu­
                <lb/>
              perficie Terræ, erit ut quadratum ſemidiametri Terræ ad Orbitæ
                <lb/>
              ſemidiametri quadratum. </s>
              <s>Eandem habet rationem, per ea quæ
                <lb/>
              ſuperius oſtenduntur, vis centripeta Lunæ in Orbita ſua revol­
                <lb/>
              ventis ad vim Lunæ centripetam prope Terræ ſuperficiem. </s>
              <s>Vis
                <lb/>
              itaque centripeta prope Terræ ſuperficiem æqualis eſt vi Gravita­
                <lb/>
              tis. </s>
              <s>Non ergo diverſæ ſunt vires, ſed una atque eadem: ſi enim
                <lb/>
              diverſæ eſſent, corpora viribus conjunctis duplo celerius in Ter­
                <lb/>
              ram caderent quam ex vi ſola Gravitatis. </s>
              <s>Conſtat igitur Vim
                <lb/>
              illam centripetam, qua Luna perpetuo de Tangente vel trahitur
                <lb/>
              vel impellitur & in Orbita retinetur, ipſam eſſe vim Gravitatis
                <lb/>
              terreſtris ad Lunam uſque pertingentem. </s>
              <s>Et rationi quidem con­
                <lb/>
              ſentaneum eſt ut ad ingentes diſtantias illa ſeſe Virtus extendat, </s>
            </p>
          </chap>
        </body>
      </text>
    </archimedes>