Salusbury, Thomas, Mathematical collections and translations (Tome I), 1667

List of thumbnails

< >
151
151 		152
152
153
153 		154
154
155
155 		156
156
157
157 		158
158
159
159 		160
160
< >
page |< < of 701 > >|
    <archimedes>
      <text>
        <body>
          <chap>
            <pb xlink:href="040/01/155.jpg" pagenum="137"/>
            <p type="main">
              <s>SALV. </s>
              <s>I believe that you very much deceive your ſelf, and am
                <lb/>
              certain, that experience will ſhew you the contrary, and that the ball
                <lb/>
              being once arrived at the ground, will run together with the horſe,
                <lb/>
              not ſtaying behind him, unleſs ſo far as the aſperity and
                <lb/>
              neſs of the Earth ſhall hinder it. </s>
              <s>And the reaſon ſeems to me
                <lb/>
              very manifeſt: for if you, ſtanding ſtill, throw the ſaid ball
                <lb/>
              long the ground, do you think it would not continue its motion
                <lb/>
              even after you had delivered it out of your hand? </s>
              <s>and that for ſo
                <lb/>
              much a greater ſpace, by how much the ſuperficies were more
                <lb/>
              ſmooth, ſo that
                <emph type="italics"/>
              v. </s>
              <s>g.
                <emph.end type="italics"/>
              upon ice it would run a great way?</s>
            </p>
            <p type="main">
              <s>SIMP. </s>
              <s>There is no doubt of it, if I give it
                <emph type="italics"/>
              impetus
                <emph.end type="italics"/>
              with my
                <lb/>
              arm; but in the other caſe it is ſuppoſed, that he who is upon the
                <lb/>
              horſe, onely drops it out of his hand:</s>
            </p>
            <p type="main">
              <s>SALV. </s>
              <s>So I deſire that it ſhould be: but when you throw it
                <lb/>
              with your arm, what other remaineth to the ball being once gone
                <lb/>
              out of your hand, than the motion received from your arm, which
                <lb/>
              motion being conſerved in the boul, it doth continue to carry it
                <lb/>
              forward? </s>
              <s>Now, what doth it import, that that
                <emph type="italics"/>
              impetus
                <emph.end type="italics"/>
              be
                <lb/>
              ferred on the ball rather from the arm than from the horſe? </s>
              <s>Whilſt
                <lb/>
              you were on horſeback, did not your hand, and conſequently the
                <lb/>
              ball run as faſt as the horſe it ſelf? </s>
              <s>Doubtleſs it did: therefore
                <lb/>
              in onely opening of the hand, the ball departs with the motion
                <lb/>
              ready conceived, not from your arm, by your particular motion,
                <lb/>
              but from the motion dependant on the ſaid horſe, which cometh to
                <lb/>
              be communicated to you, to your arm, to your hand, and laſtly to
                <lb/>
              the ball. </s>
              <s>Nay, I will tell you farther, that if the rider upon his
                <lb/>
              ſpeed fling the ball with his arm to the part contrary to the courſe,
                <lb/>
              it ſhall, after it is fallen to the ground, ſometimes (albeit thrown to
                <lb/>
              the contrary part) follow the courſe of the horſe, and ſometimes lie
                <lb/>
              ſtill on the ground; and ſhall onely move contrary to the ſaid
                <lb/>
              courſe, when the motion received from the arm, ſhall exceed that
                <lb/>
              of the carrier in velocity. </s>
              <s>And it is a vanity, that of ſome, who
                <lb/>
              ſay that a horſeman is able to caſt a javelin thorow the air, that
                <lb/>
              way which the horſe runs, and with the horſe to follow and
                <lb/>
              take the ſame; and laſtly, to catch it again. </s>
              <s>It is, I ſay, a vanity,
                <lb/>
              for that to make the project return into the hand, it is requiſite to
                <lb/>
              caſt it upwards, in the ſame manner as if you ſtood ſtill. </s>
              <s>For, let
                <lb/>
              the carrier be never ſo ſwift, provided it be uniform, and the
                <lb/>
              ject not over-light, it ſhall always fall back again into the hand of
                <lb/>
              the projicient, though never ſo high thrown.</s>
            </p>
            <p type="main">
              <s>SAGR. </s>
              <s>By this Doctrine I come to know ſome Problems very
                <lb/>
                <arrow.to.target n="marg324"/>
                <lb/>
              curious upon this ſubject of projections; the firſt of which muſt
                <lb/>
              ſeem very ſtrange to
                <emph type="italics"/>
              Simplicius.
                <emph.end type="italics"/>
              And the Problem is this; I
                <lb/>
              firm it to be poſſible, that the ball being barely dropt or let fall,
                <lb/>
              by one that any way runneth very ſwiftly, being arrived at the </s>
            </p>
          </chap>
        </body>
      </text>
    </archimedes>
Impressum