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

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            <p type="main">
              <s>
                <pb xlink:href="040/01/434.jpg" pagenum="412"/>
              degrees. </s>
              <s>Which may the better be ſeen, by hanging two weights
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              at two ſtrings of equal length, and then removing them from
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              pendicularity, one a little way, and the other very far; the which
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              being ſet at liberty, will go & return under the ſame times, the one
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              by arches very ſmall, & the other by very great ones, from whence
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              followeth the concluſion of an admirable Problem; which is,
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                <arrow.to.target n="marg805"/>
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              That a Quadrant of a Circle being given (take a little diagram of
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              the ſame, [in
                <emph type="italics"/>
              Fig.
                <emph.end type="italics"/>
              3.]) as for inſtance: A B erect to the Hori­
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              zon, ſo as that it reſt upon the plain touching in the point B. and
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              an Arch being made with a Hoop well plained and ſmoothed in
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              the concave part, bending it according to the curvity of the
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              cumference A D B. </s>
              <s>So that a Bullet very round and ſmooth
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              may freely run to and again within it (the rim of a Sieve is very
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              proper for the experiment) I ſay, that the Bullet being put in any
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              what ever place, neer or far from the loweſt term B. </s>
              <s>As for
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              ſtance, putting it in the point C, or here in D, or in E; and then
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              let go, it will in equal times, or inſenſibly different arrive at the
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              term B, departing from C, or from D, or from E, or from
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              ever other place; an accident truly wonderfull. </s>
              <s>We may add
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              another accident no leſs ſtrange than this, which is, That
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              over by all the cords drawn from the point B to the points C,
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              D, E; and to any other whatſoever, taken not onely in the
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              drant B A, but in all the whole circumference of the Circle the
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              ſaid moveable ſhall deſcend in times abſolutely equal; inſomuch
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              that it ſhall be no longer in deſcending by the whole Diameter
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              erect perpendicularly upon the point B, then it ſhall in
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              ing by B. C. although it do ſublend but one ſole degree, or a
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              ſer Arch. </s>
              <s>Let us add the other wonder, which is, That the
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              tions of the falling bodies made by the Arches of the Quadrant
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              A B; are made in ſhorter times than thoſe that are made by the
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              cords of thoſe ſame Arches; ſo that the ſwifteſt motion, and
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              made by a moveable in the ſhorteſt time, to arrive from the
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              point A, to the term B, ſhall be that which is made, not by the
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              right line A, B, (although it be the ſhorteſt of all thoſe that can
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              de drawn between the points A. B.) but by the circumference
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              A D B. </s>
              <s>And any point being taken in the ſaid Arch; as for
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              example: The point D. and two cords drawn A D, and D. B.
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              the moveable departing from the qoint A, ſhall in a leſs time
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              come to B, moving by the two cords A D and D B. than by the
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              ſole cord A, B. </s>
              <s>But the ſhorteſt of all the times ſhall be that of
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              the fall by the Arch A D B. </s>
              <s>And the ſelf ſame accidents are
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              to be underſtood of all the other leſſer Arches taken from the
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              lowermoſt term B. upwards.</s>
            </p>
            <p type="margin">
              <s>
                <margin.target id="marg803"/>
                <emph type="italics"/>
              The ſecond
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              ample.
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              </s>
            </p>
            <p type="margin">
              <s>
                <margin.target id="marg804"/>
                <emph type="italics"/>
              Two particular
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              notable accidents
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              in the
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              penduli
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              and
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              their vibrations.
                <emph.end type="italics"/>
              </s>
            </p>
            <p type="margin">
              <s>
                <margin.target id="marg805"/>
                <emph type="italics"/>
              Admirable
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              blems of
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              bles deſcending by
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              the Quadrant of a
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              Circle, and of thoſe
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              deſcending by all
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              the cords of the
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              whole Circle.
                <emph.end type="italics"/>
              </s>
            </p>
            <p type="main">
              <s>SAGR. </s>
              <s>No more, no more; for you ſo confund and fill me
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              with Wonders, and diſtract my thoughts ſo many ſeveral wayes, </s>
            </p>
          </chap>
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