Gravesande, Willem Jacob 's, An essay on perspective

Table of handwritten notes

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[Handwritten note 1]
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[Handwritten note 2]
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[Handwritten note 3]
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page |< < (vii) of 237 > >|
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            <s xml:id="echoid-s117" xml:space="preserve">
              <pb o="vii" file="0015" n="15" rhead="The PREFACE."/>
            This I have done ſometimes; </s>
            <s xml:id="echoid-s118" xml:space="preserve">but it often
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            would have been very long and troubleſome.
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            </s>
            <s xml:id="echoid-s119" xml:space="preserve">In Geometry, the eaſieſt and ſhorteſt Way, is
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            not always that which leads to Diſcoveries.</s>
            <s xml:id="echoid-s120" xml:space="preserve"/>
          </p>
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            <s xml:id="echoid-s121" xml:space="preserve">In the following Chapter, the Practice of Per-
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            ſpective upon the perſpective Plane, or Picture,
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            conſider’d as upright, is explain’d: </s>
            <s xml:id="echoid-s122" xml:space="preserve">Wherein,
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            among the different Ways laid down for the
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            Solution of general Problems, you will find
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            ſome effected by a Ruler only; </s>
            <s xml:id="echoid-s123" xml:space="preserve">ſo that after
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            ſome Preparations, all Kinds of Objects may
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            be drawn without Compaſſes, and that eaſier
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            than by the common Operations. </s>
            <s xml:id="echoid-s124" xml:space="preserve">In that
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            Problem, to find the Appearance of a Point
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            out of the Geometrical Plane, it is commonly
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            conſider’d as the Extremity of a Perpendicu-
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            lar, whoſe Repreſentation muſt first be found,
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            before that of the Point can be had. </s>
            <s xml:id="echoid-s125" xml:space="preserve">But here
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            we avoid this round-about Way, and ſhew how
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            to find the Appearance of the Point given,
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            without being obliged to find the Perſpective
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            of its Seat.</s>
            <s xml:id="echoid-s126" xml:space="preserve"/>
          </p>
          <p style="it">
            <s xml:id="echoid-s127" xml:space="preserve">As to the Appearance of a Cone and Cy-
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            linder, we determine the viſible Portions of
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            the Baſe, and by this means avoid the uſe-
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            leſs Operations which the common Way is
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            ſubject to. </s>
            <s xml:id="echoid-s128" xml:space="preserve">It is very difficult, if not impoſ-
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            ſible, to throw a Sphere into Perſpective, by
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            means of general Problems; </s>
            <s xml:id="echoid-s129" xml:space="preserve">and in the Re-
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            preſentation of the Torus of a Column, it </s>
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