Gravesande, Willem Jacob 's, An essay on perspective

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          <p>
            <s xml:id="echoid-s477" xml:space="preserve">
              <pb o="15" file="0035" n="36" rhead="on PERSPECTIVE."/>
            to the Eye. </s>
            <s xml:id="echoid-s478" xml:space="preserve">Now, as in the latter Situation,
              <lb/>
            Repreſentatious are drawn upon the Face of the
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            Perſpective Plane next to the Object, the Per-
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            ſpective Plane lying down upon its other Face;
              <lb/>
            </s>
            <s xml:id="echoid-s479" xml:space="preserve">what ought to be on the Right Hand, appears on
              <lb/>
            the Left; </s>
            <s xml:id="echoid-s480" xml:space="preserve">and that on the Left, appears on the
              <lb/>
            Right; </s>
            <s xml:id="echoid-s481" xml:space="preserve">producing exactly the ſame Effect, as
              <lb/>
            looking thro’ the Back-ſide of a Paper, at a Pi-
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            cture drawn thereon.</s>
            <s xml:id="echoid-s482" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s483" xml:space="preserve">Yet, notwithſtanding this Deficiency, we pre-
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            fer the latter way of the Perſpective Plane’s ly-
              <lb/>
            ing down to the former, for the following Rea-
              <lb/>
            ſons.</s>
            <s xml:id="echoid-s484" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s485" xml:space="preserve">1. </s>
            <s xml:id="echoid-s486" xml:space="preserve">When the Perſpective Plane lies down in
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            the former manner, it lies upon the Part of the
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            Geometrical Plane wherein Figures have been
              <lb/>
            drawn; </s>
            <s xml:id="echoid-s487" xml:space="preserve">which, together with the new Lines that
              <lb/>
            muſt be drawn, cauſes a very great Confuſion,
              <lb/>
            and always obliges one to copy his Work. </s>
            <s xml:id="echoid-s488" xml:space="preserve">An
              <lb/>
            Inconveniency which the latter Method is ſel-
              <lb/>
            dom ſubject to.</s>
            <s xml:id="echoid-s489" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s490" xml:space="preserve">2. </s>
            <s xml:id="echoid-s491" xml:space="preserve">We work with much more Eaſe in the
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            manner I have choſen.</s>
            <s xml:id="echoid-s492" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s493" xml:space="preserve">Finally, The Default we have obſerv’d, may
              <lb/>
            ſeveral ways be remedied. </s>
            <s xml:id="echoid-s494" xml:space="preserve">For, in drawing up-
              <lb/>
            on the Geometrical Plane, we need but place
              <lb/>
            that on the Right Hand which we have a mind
              <lb/>
            ſhould appear on the Left; </s>
            <s xml:id="echoid-s495" xml:space="preserve">or if the Geometri-
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            cal Plane be drawn upon Paper, it may be oil’d,
              <lb/>
            or dipp’d in Varniſh, which will render it tran-
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            ſparent; </s>
            <s xml:id="echoid-s496" xml:space="preserve">and then the Back-ſide of the Paper
              <lb/>
            may be thrown into Perſpective.</s>
            <s xml:id="echoid-s497" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s498" xml:space="preserve">If all this be not found convenient, the ſaid
              <lb/>
            Default may be eaſily corrected geometrically,
              <lb/>
            in copying the Work after the Drawings are fi-
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            niſhed. </s>
            <s xml:id="echoid-s499" xml:space="preserve">And this may be yet eaſier done, if
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            the Figures are expoſed before a Looking-glaſs;</s>
            <s xml:id="echoid-s500" xml:space="preserve"/>
          </p>
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