Barrow, Isaac, Lectiones opticae & geometricae : in quibus phaenomenon opticorum genuinae rationes investigantur, ac exponuntur: et generalia curvarum linearum symptomata declarantur

Table of figures

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          <p>
            <s xml:id="echoid-s11164" xml:space="preserve">Nam (facto ut priùs) erit IL. </s>
            <s xml:id="echoid-s11165" xml:space="preserve">IK :</s>
            <s xml:id="echoid-s11166" xml:space="preserve">: EG. </s>
            <s xml:id="echoid-s11167" xml:space="preserve">EF :</s>
            <s xml:id="echoid-s11168" xml:space="preserve">: MO. </s>
            <s xml:id="echoid-s11169" xml:space="preserve">MN.</s>
            <s xml:id="echoid-s11170" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s11171" xml:space="preserve">* quapropter erit punctum K extra curvam YFN.</s>
            <s xml:id="echoid-s11172" xml:space="preserve"/>
          </p>
          <note position="right" xml:space="preserve">* 2. Lect. VII.</note>
          <p>
            <s xml:id="echoid-s11173" xml:space="preserve">Poſſit hæc, ut præceden@, aliter oſtendi; </s>
            <s xml:id="echoid-s11174" xml:space="preserve">ſed verbis pluribus.</s>
            <s xml:id="echoid-s11175" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s11176" xml:space="preserve">Curvas ità ſitas concipe quales figura monſtrat. </s>
            <s xml:id="echoid-s11177" xml:space="preserve">nam {στ}ενολχίαν} ego
              <lb/>
            ac{αδολεοιαν} fugitans caſus præ cæteris obvios ac faciles arripiens pro-
              <lb/>
            pono. </s>
            <s xml:id="echoid-s11178" xml:space="preserve">Hoc ubique ſubnotatum velim.</s>
            <s xml:id="echoid-s11179" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s11180" xml:space="preserve">VII. </s>
            <s xml:id="echoid-s11181" xml:space="preserve">Sit punctum datum D, curvæque duæ XEM, YFN, ità
              <lb/>
            relatæ, ut à D projectâ quacunque rectâ DEF, habeant ad ſe rectæ
              <lb/>
              <note position="right" xlink:label="note-0243-02" xlink:href="note-0243-02a" xml:space="preserve">Fig. 81.</note>
            DE, DF rationem ſemper eandem; </s>
            <s xml:id="echoid-s11182" xml:space="preserve">unam verò YFN tangat recta
              <lb/>
            FS; </s>
            <s xml:id="echoid-s11183" xml:space="preserve">cui parallela ſit ER; </s>
            <s xml:id="echoid-s11184" xml:space="preserve">tanget recta ER curvam XEM.</s>
            <s xml:id="echoid-s11185" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s11186" xml:space="preserve">Nam à D utcunque projiciatur recta DK _(_ lineas interſecans, ut
              <lb/>
            vides). </s>
            <s xml:id="echoid-s11187" xml:space="preserve">Eſtque DK. </s>
            <s xml:id="echoid-s11188" xml:space="preserve">DI :</s>
            <s xml:id="echoid-s11189" xml:space="preserve">: DF. </s>
            <s xml:id="echoid-s11190" xml:space="preserve">DE :</s>
            <s xml:id="echoid-s11191" xml:space="preserve">: DN. </s>
            <s xml:id="echoid-s11192" xml:space="preserve">DM; </s>
            <s xml:id="echoid-s11193" xml:space="preserve">ergò quum ſit
              <lb/>
            DK &</s>
            <s xml:id="echoid-s11194" xml:space="preserve">gt; </s>
            <s xml:id="echoid-s11195" xml:space="preserve">DN; </s>
            <s xml:id="echoid-s11196" xml:space="preserve">erit DI &</s>
            <s xml:id="echoid-s11197" xml:space="preserve">gt; </s>
            <s xml:id="echoid-s11198" xml:space="preserve">DM; </s>
            <s xml:id="echoid-s11199" xml:space="preserve">quare tota recta RE extra curvam
              <lb/>
            XEM cadit.</s>
            <s xml:id="echoid-s11200" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s11201" xml:space="preserve">Rectæ NK, MI rationem ſemper eandem obtinent; </s>
            <s xml:id="echoid-s11202" xml:space="preserve">unde res ali-
              <lb/>
            ter conſtat.</s>
            <s xml:id="echoid-s11203" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s11204" xml:space="preserve">VIII. </s>
            <s xml:id="echoid-s11205" xml:space="preserve">Sint tres curvæ XEM, YFN, ZG O tales, ut ſi ab aſſig-
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            nato puncto D projiciatur utcunque recta DEFG, habeant interceptæ
              <lb/>
            EG, EF rationem ſemper eandem (puta quam R ad _S_) tangant au-
              <lb/>
              <note position="right" xlink:label="note-0243-03" xlink:href="note-0243-03a" xml:space="preserve">Fig. 82.</note>
            tem rectæ ET, GT curvarum duas (puta XEM, ZGO) in E, G;
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            </s>
            <s xml:id="echoid-s11206" xml:space="preserve">oportet curvæ YFN tangentem ad F deſignare.</s>
            <s xml:id="echoid-s11207" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s11208" xml:space="preserve">Concipiatur curva TFV talis, ut à D utcunque projectâ rectâ
              <lb/>
            DM K L, (quæ ſecet rectas TE, TG punctis I, L, & </s>
            <s xml:id="echoid-s11209" xml:space="preserve">iſtam cur-
              <lb/>
            vam in K) habeant ſemper interceptæ IL, IK rationem eandem datæ
              <lb/>
            R ad S; </s>
            <s xml:id="echoid-s11210" xml:space="preserve"> eſt igitur IK &</s>
            <s xml:id="echoid-s11211" xml:space="preserve">gt; </s>
            <s xml:id="echoid-s11212" xml:space="preserve">I N; </s>
            <s xml:id="echoid-s11213" xml:space="preserve">quare curva TFK curvam
              <note position="right" xlink:label="note-0243-04" xlink:href="note-0243-04a" xml:space="preserve">(_a_) 2 Lect.
                <lb/>
              VIII.</note>
            tangit; </s>
            <s xml:id="echoid-s11214" xml:space="preserve"> eſt antem curva TFK _hyperbola_; </s>
            <s xml:id="echoid-s11215" xml:space="preserve">hanc tangat FS; </s>
            <s xml:id="echoid-s11216" xml:space="preserve">
              <note position="right" xlink:label="note-0243-05" xlink:href="note-0243-05a" xml:space="preserve">(_b_) 4 Lect. VI.</note>
              <note position="right" xlink:label="note-0243-06" xlink:href="note-0243-06a" xml:space="preserve">(_c_) 2. _hujus
                <unsure/>
              _</note>
            illa quoque curvam YFN tanget.</s>
            <s xml:id="echoid-s11217" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s11218" xml:space="preserve">Quoniam _hyperbolam_ tangentis hîc primum injecta eſt mentio; </s>
            <s xml:id="echoid-s11219" xml:space="preserve">hu-
              <lb/>
            jus ( unà cum aliarum omnium conſimili ratione procreatarum ſeu _re_-
              <lb/>
            _cipr ocarum linearum tangentibus_) _tangentem_ ità definiemus.</s>
            <s xml:id="echoid-s11220" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s11221" xml:space="preserve">IX. </s>
            <s xml:id="echoid-s11222" xml:space="preserve">Sint VD recta linea, duæque curvæ XEM, YFN ità re-
              <lb/>
              <note position="right" xlink:label="note-0243-07" xlink:href="note-0243-07a" xml:space="preserve">Fig. 83.</note>
            latæ, ut ductâ liberè rectâ EDF ad poſitione datam parallelâ, ſit
              <lb/>
            ſemper _rectangulum_ ex DE, DF par eidem alicui ſpatio; </s>
            <s xml:id="echoid-s11223" xml:space="preserve">tangat au-
              <lb/>
            tem recta ET curvam XEM in E, cum recta VD concurrens in T;
              <lb/>
            </s>
            <s xml:id="echoid-s11224" xml:space="preserve">ſumatúrque DS = DT; </s>
            <s xml:id="echoid-s11225" xml:space="preserve">& </s>
            <s xml:id="echoid-s11226" xml:space="preserve">connectatur F S; </s>
            <s xml:id="echoid-s11227" xml:space="preserve">hæc curvam YFN
              <lb/>
            tanget ad F.</s>
            <s xml:id="echoid-s11228" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s11229" xml:space="preserve">Nam utcunque ducatur IN ad EF parallela; </s>
            <s xml:id="echoid-s11230" xml:space="preserve">lineas expoſitas </s>
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