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

Page concordance

< >
Scan Original
311 118
312 119
313 120
314 121
315 122
316 123
317 124
318 125
319 126
320 127
321 128
322 129
323 130
324 131
325 132
326 133
327 134
328 135
329 136
330 137
331 138
332 139
333 140
334 141
335 142
336 143
337 144
338 145
339 146
340 147
< >
page |< < (118) of 393 > >|
    <echo version="1.0RC">
      <text xml:lang="la" type="free">
        <div xml:id="echoid-div480" type="section" level="1" n="47">
          <p>
            <s xml:id="echoid-s14675" xml:space="preserve">
              <pb o="118" file="0296" n="311" rhead=""/>
            dinatam BDin I, & </s>
            <s xml:id="echoid-s14676" xml:space="preserve">lineam RSin X) ſit MP. </s>
            <s xml:id="echoid-s14677" xml:space="preserve">ME:</s>
            <s xml:id="echoid-s14678" xml:space="preserve">: VG. </s>
            <s xml:id="echoid-s14679" xml:space="preserve">IX;
              <lb/>
            </s>
            <s xml:id="echoid-s14680" xml:space="preserve">vel, ſit linea AL talis, ut ductâ MPY ad BDparallelâ (quæ ſecet
              <lb/>
            axem ADin P, & </s>
            <s xml:id="echoid-s14681" xml:space="preserve">lineam ALin Y) ſit PE. </s>
            <s xml:id="echoid-s14682" xml:space="preserve">ME:</s>
            <s xml:id="echoid-s14683" xml:space="preserve">: VG. </s>
            <s xml:id="echoid-s14684" xml:space="preserve">PY; </s>
            <s xml:id="echoid-s14685" xml:space="preserve">erit
              <lb/>
              <note position="left" xlink:label="note-0296-01" xlink:href="note-0296-01a" xml:space="preserve">Fig. 177.</note>
            tunc utrumque _ſpatium_ (ſingillatim) BRS D, vel ADL duplum _ſu-_
              <lb/>
            _perfici@i conicœ_, quod ex recta per V & </s>
            <s xml:id="echoid-s14686" xml:space="preserve">curvam AMB mota progene-
              <lb/>
            ratur.</s>
            <s xml:id="echoid-s14687" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s14688" xml:space="preserve">Nam ſumatur MNindefinita curvæ particula; </s>
            <s xml:id="echoid-s14689" xml:space="preserve">& </s>
            <s xml:id="echoid-s14690" xml:space="preserve">per N ducantur
              <lb/>
            rectæ NOKTad ipſam AD, & </s>
            <s xml:id="echoid-s14691" xml:space="preserve">NQZ ad BDparallelæ (quæ li-
              <lb/>
            neas expoſitas, ut _Schema_ monſtrat, ſecent) connectantúrque rectæ
              <lb/>
            VM, VN. </s>
            <s xml:id="echoid-s14692" xml:space="preserve">eſtque MO. </s>
            <s xml:id="echoid-s14693" xml:space="preserve">MN:</s>
            <s xml:id="echoid-s14694" xml:space="preserve">: MP. </s>
            <s xml:id="echoid-s14695" xml:space="preserve">MF:</s>
            <s xml:id="echoid-s14696" xml:space="preserve">: VG. </s>
            <s xml:id="echoid-s14697" xml:space="preserve">IX. </s>
            <s xml:id="echoid-s14698" xml:space="preserve">quare
              <lb/>
            MN x VG = MO x IX = IK x IX. </s>
            <s xml:id="echoid-s14699" xml:space="preserve">Item eſt NO. </s>
            <s xml:id="echoid-s14700" xml:space="preserve">MN:</s>
            <s xml:id="echoid-s14701" xml:space="preserve">: PE.
              <lb/>
            </s>
            <s xml:id="echoid-s14702" xml:space="preserve">ME:</s>
            <s xml:id="echoid-s14703" xml:space="preserve">: VG. </s>
            <s xml:id="echoid-s14704" xml:space="preserve">PY. </s>
            <s xml:id="echoid-s14705" xml:space="preserve">unde MN x VG = NO x PY = QP x PY. </s>
            <s xml:id="echoid-s14706" xml:space="preserve">
              <lb/>
            Eſt autem MN x VG duplum trianguli MVN. </s>
            <s xml:id="echoid-s14707" xml:space="preserve">quapropter tam IK
              <lb/>
            x IX, quàm QP x PY duplum eſt _trianguli_ MVN. </s>
            <s xml:id="echoid-s14708" xml:space="preserve">pariter autem
              <lb/>
            ubique fit. </s>
            <s xml:id="echoid-s14709" xml:space="preserve">ergò conſtat Propoſitum.</s>
            <s xml:id="echoid-s14710" xml:space="preserve"/>
          </p>
        </div>
        <div xml:id="echoid-div482" type="section" level="1" n="48">
          <head xml:id="echoid-head51" style="it" xml:space="preserve">Exemplum.</head>
          <p>
            <s xml:id="echoid-s14711" xml:space="preserve">Sit curva AMB _byperbola æquilatera_, cujus _Centrum_ C, ſitque
              <lb/>
              <note position="left" xlink:label="note-0296-02" xlink:href="note-0296-02a" xml:space="preserve">Fig. 177.</note>
            CV = CA = _r._ </s>
            <s xml:id="echoid-s14712" xml:space="preserve">& </s>
            <s xml:id="echoid-s14713" xml:space="preserve">CP = _x_ (nam hujuſmodi _calculo_ plerunque
              <lb/>
            rem expedit peragere) tum connexâ MC; </s>
            <s xml:id="echoid-s14714" xml:space="preserve">patet eſſe EC = {_rr_/_x_};
              <lb/>
            </s>
            <s xml:id="echoid-s14715" xml:space="preserve">& </s>
            <s xml:id="echoid-s14716" xml:space="preserve">MCq = 2 _xx_ - _rr_ (nam PMq = _xx_ - _rr_) item eſt MCq. </s>
            <s xml:id="echoid-s14717" xml:space="preserve">
              <lb/>
            CPq:</s>
            <s xml:id="echoid-s14718" xml:space="preserve">: MEq. </s>
            <s xml:id="echoid-s14719" xml:space="preserve">MPq; </s>
            <s xml:id="echoid-s14720" xml:space="preserve">hoc eſt MCq.</s>
            <s xml:id="echoid-s14721" xml:space="preserve">CPq:</s>
            <s xml:id="echoid-s14722" xml:space="preserve">: ECq. </s>
            <s xml:id="echoid-s14723" xml:space="preserve">CGq. </s>
            <s xml:id="echoid-s14724" xml:space="preserve">hoc
              <lb/>
            eſt 2 _xx_ - _rr_. </s>
            <s xml:id="echoid-s14725" xml:space="preserve">_xx_:</s>
            <s xml:id="echoid-s14726" xml:space="preserve">: {_r_
              <emph style="sub">4</emph>
            /_xx_}. </s>
            <s xml:id="echoid-s14727" xml:space="preserve">CGq = {_r_
              <emph style="sub">4</emph>
            /2 _xx_ - _rr_}. </s>
            <s xml:id="echoid-s14728" xml:space="preserve">quare VGq = {_r_
              <emph style="sub">4</emph>
            /2 _xx_ - _rr_} +
              <lb/>
            _rr_ = {2 _rrxx_/2 _xx_ - _rr_} = {VAq x CPq/MCq}.</s>
            <s xml:id="echoid-s14729" xml:space="preserve">vel VG = {VA x CP/MC}. </s>
            <s xml:id="echoid-s14730" xml:space="preserve">quare
              <lb/>
            VG. </s>
            <s xml:id="echoid-s14731" xml:space="preserve">VA:</s>
            <s xml:id="echoid-s14732" xml:space="preserve">: (CP. </s>
            <s xml:id="echoid-s14733" xml:space="preserve">MC):</s>
            <s xml:id="echoid-s14734" xml:space="preserve">: MP. </s>
            <s xml:id="echoid-s14735" xml:space="preserve">ME. </s>
            <s xml:id="echoid-s14736" xml:space="preserve">hinc conſectatur in hoc
              <lb/>
            caſu, quum ubique ſit IX = VA, _lineam_ RS fore _rectam_; </s>
            <s xml:id="echoid-s14737" xml:space="preserve">& </s>
            <s xml:id="echoid-s14738" xml:space="preserve">_rectan-_
              <lb/>
            _gulum_ BRSD _ſuperficiei conicœ_ AMBV _duplum eſſe._</s>
            <s xml:id="echoid-s14739" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s14740" xml:space="preserve">Cæterùm hoc _elegans exemplum_ ſuppeditavit Generoſus, ingenio ac
              <lb/>
            eruditione præſtans, Vir (_Collegii noſtri, quod olim Sociorum Com-_
              <lb/>
            _menſalis incoluit_, ornamentum) D. </s>
            <s xml:id="echoid-s14741" xml:space="preserve">_Franciſcus Feſſopius_, Armiger;
              <lb/>
            </s>
            <s xml:id="echoid-s14742" xml:space="preserve">cujus in hanc rem perquam ingenioſo mihi comiter impertito ſcripto
              <lb/>
            (ipſius injuſſu quidem, at ſpero non ingratiis) ſeu _Gemmâ_ quâdam au-
              <lb/>
            debo mea condecorare.</s>
            <s xml:id="echoid-s14743" xml:space="preserve"/>
          </p>
        </div>
      </text>
    </echo>