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

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    <archimedes>
      <text>
        <body>
          <chap>
            <p type="main">
              <s>
                <pb xlink:href="040/01/161.jpg" pagenum="143"/>
              I will not conſent that our Poem ſhould be ſo confined to that
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              unity, as not to leave us fields open for Epſody's, which every
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              ſmall connection ſhould ſuffice to introduce; but with almoſt as
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              much liberry as if we were met to tell ſtories, it ſhall be lawful
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              for me to ſpeak, what ever your diſcourſe brings into my mind.</s>
            </p>
            <p type="main">
              <s>SAGR. </s>
              <s>I like this motion very well; and ſince we are at this
                <lb/>
              liberty, let me take leave, before we paſſe any farther to ask of
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              you
                <emph type="italics"/>
              Salviatus,
                <emph.end type="italics"/>
              whether you did ever conſider what that line may
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              be that is deſcribed by the grave moveable naturally falling down
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              from the top of a Tower; and if you have reflected on it, be
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              pleaſed to tell me what you think thereof.</s>
            </p>
            <p type="main">
              <s>SALV. </s>
              <s>I have ſometimes conſidered of it, and make no
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              ſtion, that if one could be certain of the nature of that motion
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              wherewith the grave body deſcendeth to approach the centre of
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              the Terreſtrial Globe, mixing it ſelf afterwards with the common
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              circular motion of the diurnal converſion; it might be exactly
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              found what kind of line that is, that the centre of gravity of the
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              moveable deſcribeth in thoſe two motions.</s>
            </p>
            <p type="main">
              <s>SAGR. </s>
              <s>Touching the ſimple motion towards the centre
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              pendent on the gravity, I think that one may confidently,
                <lb/>
              out error, believe that it is by a right line, as it would be, were
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              the Earth immoveable.</s>
            </p>
            <p type="main">
              <s>SALV. </s>
              <s>As to this particular, we may not onely believe it, but
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              experience rendereth us certain of the ſame.</s>
            </p>
            <p type="main">
              <s>SAGR. </s>
              <s>But how doth experience aſſure us thereof, if we
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              ver ſee any motions but ſuch as are compoſed of the two, circular
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              and deſcending.</s>
            </p>
            <p type="main">
              <s>SALV. </s>
              <s>Nay rather
                <emph type="italics"/>
              Sagredus
                <emph.end type="italics"/>
              we onely ſee the ſimple motion of
                <lb/>
              deſcent; ſince that other circular one common to the Earth, the
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              Tower and our ſelves remains imperceptible, and as if it never
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              were, and there remaineth perceptible to us that of the ſtone,
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              ly not participated by us, and for this, ſenſe demonſtrateth that
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              it is by a right line, ever parallel to the ſaid Tower, which is
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              built upright and perpendicular upon the Terreſtrial ſurface.</s>
            </p>
            <p type="main">
              <s>SAGR. </s>
              <s>You are in the right; and this was but too plainly
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              monſtrated to me even now, ſeeing that I could not remember ſo
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              eaſie a thing; but this being ſo manifeſt, what more is it that you
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              ſay you deſire, for underſtanding the nature of this motion
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              downwards?</s>
            </p>
            <p type="main">
              <s>SALV. </s>
              <s>It ſufficeth not to know that it is ſtreight, but its
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              ſite to know whether it be uniform, or irregular; that is,
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              ther it maintain alwayes one and the ſame velocity, or elſe goeth
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              retarding or accelerating.</s>
            </p>
            <p type="main">
              <s>SAGR. </s>
              <s>It is already clear, that it goeth continually
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              rating.</s>
            </p>
          </chap>
        </body>
      </text>
    </archimedes>