Galilei, Galileo, Discourse concerning the natation of bodies, 1663

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            <pb pagenum="406"/>
            <p type="main">
              <s>And ſo I ſay, that Lead is more grave
                <emph type="italics"/>
              in ſpecie
                <emph.end type="italics"/>
              than Tinn, becauſe
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              if you take of them two equall Maſſes, that of the Lead weigheth
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              more.</s>
            </p>
            <p type="head">
              <s>DEFINITION IV.</s>
            </p>
            <p type="main">
              <s>
                <emph type="italics"/>
              But I call that Body more grave abſolutely than this, if
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              that weigh more than this, without any reſpect had to
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              the Maſſes.
                <emph.end type="italics"/>
              </s>
            </p>
            <p type="main">
              <s>And thus a great piece of Wood is ſaid to weigh more than a
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              little lump of Lead, though the Lead be
                <emph type="italics"/>
              in ſpecie
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              more heavy than
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              the Wood. </s>
              <s>And the ſame is to be underſtood of the leſs grave
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              in
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              ſpecie,
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              and the leſs grave abſolutely.</s>
            </p>
            <p type="main">
              <s>Theſe Termes defined, I take from the Mechanicks two Princi­
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              ples: the firſt is, that</s>
            </p>
            <p type="head">
              <s>AXIOME. I.</s>
            </p>
            <p type="main">
              <s>
                <emph type="italics"/>
              Weights abſolutely equall, moved with equall Velocity,
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              are of equall Force and Moment in their operations.
                <emph.end type="italics"/>
              </s>
            </p>
            <p type="head">
              <s>
                <emph type="italics"/>
              DEFINITION V.
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              </s>
            </p>
            <p type="main">
              <s>Moment, amongſt Mechanicians, ſigrifieth that
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              Vertue, that Force, or that Efficacy, with which
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              the Mover moves, and the Moveable reſiſts.</s>
            </p>
            <p type="main">
              <s>
                <emph type="italics"/>
              Which Vertue dependes not only on the ſimple Gravity, but on the
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              Velocity of the Motion, and on the diverſe Inclinations of the Spaces
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              along which the Motion is made: For a deſcending Weight makes a
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              greater
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              Impetus
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              in a Space much declining, than in one leſs declining;
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              and in ſumme, what ever is the occaſion of ſuch Vertue, it ever retaines
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              the name of
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              Moment;
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              nor in my Judgement, is this ſence new in our
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              Idiome, for, if I mistake not, I think we often ſay; This is a weighty
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              buſineſſe, but the other is of ſmall moment: and we conſider lighter mat­
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              ters and let paſs thoſe of Moment; a Metaphor, I ſuppoſe, taken from
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              the Mechanicks.
                <emph.end type="italics"/>
              </s>
            </p>
            <p type="main">
              <s>As for example, two weights equall in abſolute Gravity, being
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              put into a Ballance of equall Arms, they ſtand in
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              Equilibrium,
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              nei­
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              ther one going down, nor the other up: becauſe the equality of the
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              Diſtances of both, from the Centre on which the Ballance is ſuppor­
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              ted, and about which it moves, cauſeth that thoſe weights, the ſaid
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              Ballance moving, ſhall in the ſame Time move equall Spaces, that is,
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              ſhall move with equall Velocity, ſo that there is no reaſon for which </s>
            </p>
          </chap>
        </body>
      </text>
    </archimedes>