Salusbury, Thomas, Mathematical collections and translations (Tome I), 1667
page |< < of 701 > >|
    <archimedes>
      <text>
        <body>
          <chap>
            <p type="main">
              <s>
                <pb xlink:href="040/01/230.jpg" pagenum="212"/>
              it will paſſe any further, or elſe that there it would immediately
                <lb/>
              ſtand ſtill, and move no further?</s>
            </p>
            <p type="main">
              <s>SIMP. </s>
              <s>I believe that it would continue to move a great way
                <lb/>
              further.</s>
            </p>
            <p type="main">
              <s>SALV. </s>
              <s>But this motion beyond the centre, would it not be
                <lb/>
              wards, and according to your aſſertion preternatural, and violent?
                <lb/>
              </s>
              <s>And yet on what other principle do you make it to depend, but
                <lb/>
              only upon the ſelf ſame, which did carry the ball to the centre,
                <lb/>
              and which you called intrinſecal, and natural? </s>
              <s>Finde, if you can,
                <lb/>
              another external projicient, that overtaketh it again to drive it
                <lb/>
              upwards. </s>
              <s>And this that hath been ſaid of the motion thorow
                <lb/>
              the centre, is alſo ſeen by us here above; for the interne
                <emph type="italics"/>
              impetus
                <emph.end type="italics"/>
                <lb/>
                <arrow.to.target n="marg418"/>
                <lb/>
              of a grave body falling along a declining ſuperficies, if the ſaid
                <lb/>
              ſuperficies be reflected the other way, it ſhall carry it, without a
                <lb/>
              jot interrupting the motion, alſo upwards. </s>
              <s>A ball of lead that
                <lb/>
              hangeth by a thread, being removed from its perpendicularity,
                <lb/>
              ſcendeth ſpontaneouſly, as being drawn by its internal inclination,
                <lb/>
              and without any interpoſure of reſt, paſſeth beyond the loweſt
                <lb/>
              point of perpendicularity: and without any additional mover,
                <lb/>
              moveth upwards. </s>
              <s>I know that you will not deny, but that the
                <lb/>
              principle of grave bodies that moveth them downwards, is no leſs
                <lb/>
              natural, and intrinſecal, than that principle of light bodies, which
                <lb/>
              moveth them upwards: ſo that I propoſe to your conſideration a
                <lb/>
              ball of lead, which deſcending through the Air from a great
                <lb/>
              titude, and ſo moving by an intern principle, and comming to a
                <lb/>
              depth of water, continueth its deſcent, and without any other
                <lb/>
              terne mover, ſubmergeth a great way; and yet the motion of
                <lb/>
              deſcent in the water is preternatural unto it; but yet nevertheleſs
                <lb/>
              dependeth on a principle that is internal, and not external to the
                <lb/>
              ball. </s>
              <s>You ſee it demonſtrated then, that a moveable may be
                <lb/>
              moved by one and the ſame internal principle, with contrary
                <lb/>
              tions.</s>
            </p>
            <p type="margin">
              <s>
                <margin.target id="marg418"/>
                <emph type="italics"/>
              The natural
                <lb/>
              tion changeth it
                <lb/>
              ſelfe into that
                <lb/>
              which is called
                <lb/>
              ternatural and
                <lb/>
              olent.
                <emph.end type="italics"/>
              </s>
            </p>
            <p type="main">
              <s>SIMP. </s>
              <s>I believe there are ſolutions to all theſe objections,
                <lb/>
              though for the preſent I do not remember them; but however it
                <lb/>
              be, the Author continueth to demand, on what principle this
                <lb/>
              cular motion of grave and light bodies dependeth; that is,
                <lb/>
              ther on a principle internal, or external; and proceeding
                <lb/>
              wards, ſheweth, that it can be neither on the one, nor on the other,
                <lb/>
              ſaying;
                <emph type="italics"/>
              Si ab externo; Deuſne illum excitat per continuum
                <lb/>
              culum? </s>
              <s>an verò Angelus, an aër? </s>
              <s>Et hunc quidem multi
                <lb/>
              nant. </s>
              <s>Sed contra----[In Engliſh thus]
                <emph.end type="italics"/>
              If from an externe
                <lb/>
              ciple; Whether God doth not excite it by a continued Miracle?
                <lb/>
              </s>
              <s>or an Angel, or the Air? </s>
              <s>And indeed many do aſſign this. </s>
              <s>But
                <lb/>
              on the contrary-----.</s>
            </p>
            <p type="main">
              <s>SALV. </s>
              <s>Trouble not your ſelf to read his argument; for I am </s>
            </p>
          </chap>
        </body>
      </text>
    </archimedes>
Impressum