Galilei, Galileo, The systems of the world, 1661

List of thumbnails

< >
201
201 		202
202
203
203 		204
204
205
205 		206
206
207
207 		208
208
209
209 		210
210
< >
page |< < of 948 > >|
    <archimedes>
      <text>
        <body>
          <chap>
            <p type="main">
              <s>
                <pb xlink:href="065/01/210.jpg" pagenum="202"/>
              turn round, ſtaying there above, and moving along with the
                <lb/>
              urnal converſion. </s>
              <s>Now I tell him, that that ſame ball falling from
                <lb/>
              the concave unto the centre, will acquire a degree of velocity
                <lb/>
              much more than double the velocity of the diurnal motion of the
                <lb/>
              Lunar concave; and this I will make out by ſolid and not
                <lb/>
                <arrow.to.target n="marg404"/>
                <lb/>
              tinent ſuppoſitions. </s>
              <s>You muſt know therefore that the grave
                <lb/>
              body falling and acquiring all the way new velocity according
                <lb/>
              to the proportion already mentioned, hath in any whatſoever
                <lb/>
              place of the line of its motion ſuch a degree of velocity, that if it
                <lb/>
              ſhould continue to move therewith, uniformly without farther
                <lb/>
              encreaſing it; in another time like to that of its deſcent, it would
                <lb/>
              paſſe a ſpace double to that paſſed in the line of the precedent
                <lb/>
              motion of deſcent. </s>
              <s>And thus for example, if that ball in coming
                <lb/>
              from the concave of the Moon to its centre hath ſpent three hours,
                <lb/>
              22 min.
                <emph type="italics"/>
              prim.
                <emph.end type="italics"/>
              and 4 ſeconds, I ſay, that being arrived at the
                <lb/>
              tre, it ſhall find it ſelf conſtituted in ſuch a degree of velocity, that
                <lb/>
              if with that, without farther encreaſing it, it ſhould continue to
                <lb/>
              move uniformly, it would in other 3 hours, 22 min.
                <emph type="italics"/>
              prim.
                <emph.end type="italics"/>
              and
                <lb/>
              4 ſeconds, paſſe double that ſpace, namely as much as the whole
                <lb/>
              diameter of the Lunar Orb; and becauſe from the Moons
                <lb/>
              cave to the centre are 196000 miles, which the ball paſſeth in 3
                <lb/>
              hours 22
                <emph type="italics"/>
              prim.
                <emph.end type="italics"/>
              min. </s>
              <s>and 4 ſeconds, therefore (according to what
                <lb/>
              hath been ſaid) the ball continuing to move with the velocity
                <lb/>
              which it is found to have in its arrival at the centre, it would
                <lb/>
              paſſe in other 3 hours 22 min. </s>
              <s>prim. </s>
              <s>and 4 ſeconds, a ſpace
                <lb/>
              ble to that, namely 392000 miles; but the ſame continuing in
                <lb/>
              the concave of the Moon, which is in circuit 1232000 miles, and
                <lb/>
              moving therewith in a diurnal motion, it would make in the ſame
                <lb/>
              time, that is in 3 hours 22 min. </s>
              <s>prim. </s>
              <s>and 4 ſeconds, 172880
                <lb/>
              miles, which are fewer by many than the half of the 392000
                <lb/>
              miles. </s>
              <s>You ſee then that the motion in the concave is not as the
                <lb/>
              modern Author ſaith, that is, of a velocity impoſſible for the
                <lb/>
              ing ball to partake of,
                <emph type="italics"/>
              &c.
                <emph.end type="italics"/>
              </s>
            </p>
            <p type="margin">
              <s>
                <margin.target id="marg404"/>
                <emph type="italics"/>
              The falling
                <lb/>
              able if it move with
                <lb/>
              a degree of
                <lb/>
              ty acquired in a
                <lb/>
              like time with an
                <lb/>
              uniform motion, it
                <lb/>
              ſhall paß a ſpace
                <lb/>
              double to that
                <lb/>
              ſed with the
                <lb/>
              leratedmotion.
                <emph.end type="italics"/>
              </s>
            </p>
            <p type="main">
              <s>SAGR. </s>
              <s>The diſcourſe would paſs for current, and would give
                <lb/>
              me full ſatisfaction, if that particular was but ſalved, of the
                <lb/>
              ving of the moveable by a double ſpace to that paſſed in falling
                <lb/>
              in another time equal to that of the deſcent, in caſe it doth continue
                <lb/>
              to move uniformly with the greateſt degree of velocity acquired
                <lb/>
              in deſcending. </s>
              <s>A propoſition which you alſo once before
                <lb/>
              ſed as true, but never demonſtrated.</s>
            </p>
            <p type="main">
              <s>SALV. </s>
              <s>This is one of the demonſtrations of
                <emph type="italics"/>
              Our Friend,
                <emph.end type="italics"/>
              and
                <lb/>
              you ſhall ſee it in due time; but for the preſent, I will with ſome
                <lb/>
              conjectures (not teach you any thing that is new, but) remember you
                <lb/>
              of a certain contrary opinion, and ſhew you, that it may haply ſo be.
                <lb/>
              </s>
              <s>A bullet of lead hanging in a long and fine thread faſtened to the </s>
            </p>
          </chap>
        </body>
      </text>
    </archimedes>
Impressum