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

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    <archimedes>
      <text>
        <body>
          <chap>
            <p type="main">
              <s>
                <pb pagenum="434"/>
              to the Surface, more ſlowly than a Ball of Ebony of the ſame bigneſſe,
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              ſo that it is manifeſt, that the Ball of Ebony more readily divideth the
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              water in deſcending, than the other in aſcending; as for Example, let
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              the Wood be Walnut-tree. </s>
              <s>Then take a Board of Walnut-tree, like
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              and equall to that of Ebony of the Antagoniſts, which ſwims; and if
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              it be true, that this floats above water, by reaſon of the Figure, unable
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              through its breadth, to pierce the Craſſitude of the ſame, the other of
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              Wallnut-tree, without all queſtion, being thruſt unto the Bottom, will
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              ſtay there, as leſs apt, through the ſame impediment of Figure, to
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              vide the ſaid Reſiſtance of the water. </s>
              <s>But if we ſhall find, and by
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              experience ſee, that not only the thin Board, but every other Figure
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              of the ſame Wallnut-tree will return to float, as undoubtedly we ſhall,
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              then I muſt deſier my oppoſers to forbear to attribute the floating of
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              the Ebony, unto the Figure of the Board, in regard that the Reſiſtance
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              of the water is the ſame, as well to the aſcent, as to the deſcent, and the
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              force of the Wallnut-trees aſcenſion, is leſſe than the Ebonys force in
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              going to the Bottom.</s>
            </p>
            <p type="main">
              <s>Nay, I will ſay more, that if we ſhall conſider Gold in compariſon
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                <arrow.to.target n="marg1472"/>
                <lb/>
              of water, we ſhall find, that it exceeds it in Gravity almoſt twenty times,
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              ſo that the Force and Impetus, wherewith a Ball of Gold goes to the
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              Bottom, is very great. </s>
              <s>On the contrary, there want not matters, as
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              Virgins Wax, and ſome Woods, which are not above a fiftieth part leſs
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              grave than water, whereupon their Aſcenſion therein is very ſlow, and
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              a thouſand times weaker than the
                <emph type="italics"/>
              Impetus
                <emph.end type="italics"/>
              of the Golds deſcent: yet
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              notwithſtanding, a plate of Gold ſwims without deſcending to the
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              Bottom, and, on the contrary, we cannot make a Cake of Wax, or thin
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              Board of Wood, which put in the Bottom of the Water, ſhall reſt there
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              without aſcending. </s>
              <s>Now if the Figure can obſtruct the Penetration,
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              and impede the deſcent of Gold, that hath ſo great an
                <emph type="italics"/>
              Impetus,
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              how
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              can it chooſe but ſuffice to reſiſt the ſame Penetration of the other
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              ter in aſcending, when as it hath ſcarce a thouſandth part of the
                <emph type="italics"/>
              Impetus
                <emph.end type="italics"/>
                <lb/>
              that the Gold hath in deſcending? </s>
              <s>Its therefore, neceſſary, that that
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              which ſuſpends the thin Plate of Gold, or Board of Ebony, upon the
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              water, be ſome thing that is wanting to the other Cakes and Boards of
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              Matters leſs grave than the water; ſince that being put to the Bottom,
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              and left at liberty, they riſe up to the Surface, without any obſtruction:
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              But they want not for flatneſs and breadth of Figure: Therefore, the
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              ſpaciouſneſſe of the Figure, is not that which makes the Gold and Ebony
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              to ſwim.</s>
            </p>
            <p type="margin">
              <s>
                <margin.target id="marg1472"/>
              An
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              ment in Gold, to
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              prove the
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              operating of
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              gure in Natation
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              and Submerſion.</s>
            </p>
            <p type="main">
              <s>And, becauſe, that the exceſs of their Gravity above the Gravity of
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              the water, is queſtionleſs the Cauſe of the ſinking of the flat piece of
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              Ebony, and the thin Plate of Gold, when they go to the Bottom,
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              fore, of neceſſity, when they float, the Cauſe of their ſtaying above
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              water, proceeds from Levity, which in that caſe, by ſome Accident, </s>
            </p>
          </chap>
        </body>
      </text>
    </archimedes>
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