Galilei, Galileo, Mechanics, 1665

List of thumbnails

< >
31
31
32
32
33
33
34
34
35
35
36
36
37
37
38
38
39
39
40
40
< >
page |< < of 40 > >|
    <archimedes>
      <text>
        <body>
          <chap>
            <p type="main">
              <s>
                <pb xlink:href="070/01/035.jpg" pagenum="305"/>
              weigh equally it would be neceſſary to hang it nearer to the
                <lb/>
              Perpendicular C, as
                <emph type="italics"/>
              v. </s>
              <s>gr.
                <emph.end type="italics"/>
              in E: and look how many times the Di­
                <lb/>
              ſtance C A ſhall contain A E, ſo many times ſhall the Metal
                <lb/>
              weigh more than the Water. </s>
              <s>Let us therefore ſuppoſe that the
                <lb/>
              Weight in B be Gold, and that weighed in the Water it with­
                <lb/>
              draws the Counterpoiſe D into E; and then doing the ſame with
                <lb/>
              pure Silver, let us ſuppoſe that its Counterpoiſe, when afterwards
                <lb/>
              it is weighed in the Water, returneth to F: which point ſhall be
                <lb/>
              nearer to the point C, as Experience ſheweth, becauſe the Silver
                <lb/>
              is leſs grave than the Gold: And the Diſtance that is between
                <lb/>
              A and F ſhall have the ſame Difference with the Diſtance A E,
                <lb/>
              that the Gravity of the Gold hath with that of the Silver. </s>
              <s>But if
                <lb/>
              we have a Mixture of Gold and Silver, it is clear, that by reaſon it
                <lb/>
              participates of Silver, it ſhall weigh leſs than the pure Gold, and
                <lb/>
              by reaſon it participates of Gold, it ſhall weigh more than the
                <lb/>
              pure Silver: and therefore being weighed in the Air, and deſiring
                <lb/>
              that the ſame Counterpoiſe ſhould counterpoiſe it, when that
                <lb/>
              Mixture ſhall be put into the Water it will be neceſſary to draw
                <lb/>
              the ſaid Counterpoiſe more towards the Perpendicular C, than the
                <lb/>
              point E is, which is the term of the Gold; and more from C
                <lb/>
              than F is, which is the term of the pure Silver; Therefore it ſhall
                <lb/>
              fall between the points E and F: And the proportion into which
                <lb/>
              the Diſtance EF ſhall be divided, ſhall exactly give the proportion
                <lb/>
              of the two Metals which compound that Mixture. </s>
              <s>As for exam­
                <lb/>
              ple: Let us ſuppoſe the Mixture of Gold and Silver to be in B,
                <lb/>
                <figure id="id.070.01.035.1.jpg" xlink:href="070/01/035/1.jpg" number="29"/>
                <lb/>
              counterpoiſed in
                <lb/>
              the Air by D,
                <lb/>
              which Counter­
                <lb/>
              poiſe when the
                <lb/>
              Compound Me­
                <lb/>
              tal is put into the Water returneth into G: I ſay now, that the
                <lb/>
              Gold and the Silver which compound this Mixture are to one ano­
                <lb/>
              ther in the ſame proportion, as the Diſtance F G is to the Diſtance
                <lb/>
              G E. </s>
              <s>But you muſt know that the Diſtance G F terminated in
                <lb/>
              the mark of the Silver, ſhall denote unto us the quantity of the
                <lb/>
              Gold, and the Diſtance G E, terminated in the mark of the Gold,
                <lb/>
              ſhall ſhew us the quantity of the Silver: inſomuch that if F G
                <lb/>
              ſhall prove double to G E, then that Mixture ſhall be two parts
                <lb/>
              Gold, and one part Silver: and in the ſame method proceeding in
                <lb/>
              the examination of other Mixtures, one ſhall exactly find the
                <lb/>
              quantity of the ſimple Metals.</s>
            </p>
            <p type="main">
              <s>To compoſe the Ballance, therefore, take a Rod at leaſt a yard
                <lb/>
              long, (and the longer it is, the exacter the Inſtrument ſhall be)
                <lb/>
              and divide it in the midſt, where place the Perpendicular: then
                <lb/>
              adjuſt the Arms that they may ſtand in
                <emph type="italics"/>
              Equilibrium,
                <emph.end type="italics"/>
              by filing or </s>
            </p>
          </chap>
        </body>
      </text>
    </archimedes>