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

Page concordance

< >
Scan Original
261 68
262 69
263 70
264 71
265 72
266 73
267 74
268 75
269 76
270 77
271 78
272 79
273 80
274 81
275 82
276 83
277 84
278 85
279 86
280 87
281 88
282 89
283 90
284 91
285 92
286 93
287 94
288 95
289 96
290 97
< >
page |< < (72) of 393 > >|
    <echo version="1.0RC">
      <text xml:lang="la" type="free">
        <div xml:id="echoid-div331" type="section" level="1" n="34">
          <p>
            <s xml:id="echoid-s11605" xml:space="preserve">
              <pb o="72" file="0250" n="265" rhead=""/>
            interſecans, ut expreſſum vides; </s>
            <s xml:id="echoid-s11606" xml:space="preserve">eſtque jam PK. </s>
            <s xml:id="echoid-s11607" xml:space="preserve">PL :</s>
            <s xml:id="echoid-s11608" xml:space="preserve">: M. </s>
            <s xml:id="echoid-s11609" xml:space="preserve">
              <note position="left" xlink:label="note-0250-01" xlink:href="note-0250-01a" xml:space="preserve">_a Converſ_. 4.
                <lb/>
              Lect. VI.</note>
            :</s>
            <s xml:id="echoid-s11610" xml:space="preserve">: GE. </s>
            <s xml:id="echoid-s11611" xml:space="preserve">GF &</s>
            <s xml:id="echoid-s11612" xml:space="preserve">gt; </s>
            <s xml:id="echoid-s11613" xml:space="preserve">PE. </s>
            <s xml:id="echoid-s11614" xml:space="preserve">PF &</s>
            <s xml:id="echoid-s11615" xml:space="preserve">gt; </s>
            <s xml:id="echoid-s11616" xml:space="preserve">PK. </s>
            <s xml:id="echoid-s11617" xml:space="preserve">PF; </s>
            <s xml:id="echoid-s11618" xml:space="preserve">quare PL &</s>
            <s xml:id="echoid-s11619" xml:space="preserve">lt; </s>
            <s xml:id="echoid-s11620" xml:space="preserve">PF;</s>
            <s xml:id="echoid-s11621" xml:space="preserve"> igitur _Hyperbola_ LBL curvam FB F tangit. </s>
            <s xml:id="echoid-s11622" xml:space="preserve">Protracta jam TB
              <lb/>
              <note position="left" xlink:label="note-0250-02" xlink:href="note-0250-02a" xml:space="preserve">_b_ 11. Lect. VII.</note>
            cum XZ conveniat in R; </s>
            <s xml:id="echoid-s11623" xml:space="preserve">eſtque tum RZ. </s>
            <s xml:id="echoid-s11624" xml:space="preserve">ZB :</s>
            <s xml:id="echoid-s11625" xml:space="preserve">: BS. </s>
            <s xml:id="echoid-s11626" xml:space="preserve">ST. </s>
            <s xml:id="echoid-s11627" xml:space="preserve">unde
              <lb/>
              <note position="left" xlink:label="note-0250-03" xlink:href="note-0250-03a" xml:space="preserve">_c_ @@. Lect. VII.</note>
            RZ xST = BS x ZB = BS x S X. </s>
            <s xml:id="echoid-s11628" xml:space="preserve">atqui propter DS. </s>
            <s xml:id="echoid-s11629" xml:space="preserve">SX :</s>
            <s xml:id="echoid-s11630" xml:space="preserve">: BS. </s>
            <s xml:id="echoid-s11631" xml:space="preserve">SY, eſt DS xSY = BS xSX. </s>
            <s xml:id="echoid-s11632" xml:space="preserve">ergò RZ xST = DS xS Y
              <lb/>
              <note position="left" xlink:label="note-0250-04" xlink:href="note-0250-04a" xml:space="preserve">_d Conſtr_.</note>
            = DS x CX. </s>
            <s xml:id="echoid-s11633" xml:space="preserve">vel RZ. </s>
            <s xml:id="echoid-s11634" xml:space="preserve">CX :</s>
            <s xml:id="echoid-s11635" xml:space="preserve">: DS . </s>
            <s xml:id="echoid-s11636" xml:space="preserve">ST; </s>
            <s xml:id="echoid-s11637" xml:space="preserve">compoſitéque RZ . </s>
            <s xml:id="echoid-s11638" xml:space="preserve">RZ
              <lb/>
            + CX :</s>
            <s xml:id="echoid-s11639" xml:space="preserve">: DS. </s>
            <s xml:id="echoid-s11640" xml:space="preserve">DT :</s>
            <s xml:id="echoid-s11641" xml:space="preserve">: N. </s>
            <s xml:id="echoid-s11642" xml:space="preserve">M :</s>
            <s xml:id="echoid-s11643" xml:space="preserve">: CZ. </s>
            <s xml:id="echoid-s11644" xml:space="preserve">CZ + CX. </s>
            <s xml:id="echoid-s11645" xml:space="preserve">itaque diviſim eſt RZ. </s>
            <s xml:id="echoid-s11646" xml:space="preserve">CX :</s>
            <s xml:id="echoid-s11647" xml:space="preserve">: CZ. </s>
            <s xml:id="echoid-s11648" xml:space="preserve">CX. </s>
            <s xml:id="echoid-s11649" xml:space="preserve">adeóque RZ = CZ; </s>
            <s xml:id="echoid-s11650" xml:space="preserve">unde RB
              <lb/>
            _hyperbolam_ LBL tangit; </s>
            <s xml:id="echoid-s11651" xml:space="preserve">hæc igitur ( RBT) curvam FBF, ipſi
              <lb/>
            LBL contiguam, quoque tanget. </s>
            <s xml:id="echoid-s11652" xml:space="preserve">quod erat Propoſitum.</s>
            <s xml:id="echoid-s11653" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s11654" xml:space="preserve">VII. </s>
            <s xml:id="echoid-s11655" xml:space="preserve">Hinc ſi perſiſtentibus reliquis, recta tantùm DF jam inter
              <lb/>
            D G, DE perpetuò Geometricè media ſtatuatur ( eodem qui priùs fuit
              <lb/>
            ordine) eadem BT curvam FBF quoque continget.</s>
            <s xml:id="echoid-s11656" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s11657" xml:space="preserve">Etenim ex mediis ejuſdem ordinis _Aritbmetice Geometricéque_ pro-
              <lb/>
            portionalibus efformatæ lineæ ſe mutuò contingunt, adeóque commu-
              <lb/>
            ni rectâ tangente gaudent.</s>
            <s xml:id="echoid-s11658" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s11659" xml:space="preserve">VIII. </s>
            <s xml:id="echoid-s11660" xml:space="preserve">Porrò _(_ſtantibus reliquis ut in poſtremâ) quodvis in curva
              <lb/>
              <note position="left" xlink:label="note-0250-05" xlink:href="note-0250-05a" xml:space="preserve">Fig. 98.</note>
            FB F deſignetur punctum F, quæ curvam ad hoc tanget recta ſimili
              <lb/>
            pacto determinatur.</s>
            <s xml:id="echoid-s11661" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s11662" xml:space="preserve">Connectatur utique recta DF curvam EB E ſecans ad E ; </s>
            <s xml:id="echoid-s11663" xml:space="preserve">item du-
              <lb/>
            catur DQ ad DG perpendicularis ipſam EO interſecans ad X; </s>
            <s xml:id="echoid-s11664" xml:space="preserve">fiat
              <lb/>
            etiam DX. </s>
            <s xml:id="echoid-s11665" xml:space="preserve">DY :</s>
            <s xml:id="echoid-s11666" xml:space="preserve">: N. </s>
            <s xml:id="echoid-s11667" xml:space="preserve">M ; </s>
            <s xml:id="echoid-s11668" xml:space="preserve">& </s>
            <s xml:id="echoid-s11669" xml:space="preserve">connectatur EY; </s>
            <s xml:id="echoid-s11670" xml:space="preserve">ipſi demum EY pa-
              <lb/>
            rallela ducatur FZ; </s>
            <s xml:id="echoid-s11671" xml:space="preserve">hæc curvam FBF continget.</s>
            <s xml:id="echoid-s11672" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s11673" xml:space="preserve">Nam centro D per E ducatur circulus CEI; </s>
            <s xml:id="echoid-s11674" xml:space="preserve">concipiatúrque linea
              <lb/>
            HEH talis, ut à D eductâ quacunque rectâ DI ( quæ circulum CE
              <lb/>
            ſecet in I, curvam HEH in H, & </s>
            <s xml:id="echoid-s11675" xml:space="preserve">ipſam EB E in L ) ſit pepertuò
              <lb/>
            DH eodem inter DI, DL ordine proportionalis, quo DF inter DG,
              <lb/>
            DE; </s>
            <s xml:id="echoid-s11676" xml:space="preserve">palam eſt tunc (è præcedente) quòd recta EY curvam HEH
              <lb/>
            tanget; </s>
            <s xml:id="echoid-s11677" xml:space="preserve">verùm ipſi HEH analoga eſt curva FBF; </s>
            <s xml:id="echoid-s11678" xml:space="preserve">
              <note position="left" xlink:label="note-0250-06" xlink:href="note-0250-06a" xml:space="preserve">_a_ 9. Lect. VII.</note>
            recta FZ curvam FBF quoque tanget.</s>
            <s xml:id="echoid-s11679" xml:space="preserve"/>
          </p>
          <note position="left" xml:space="preserve">_b_ 7. Lect. VIII.</note>
          <p>
            <s xml:id="echoid-s11680" xml:space="preserve">Exhinc nedum innumerarum ſpiralium; </s>
            <s xml:id="echoid-s11681" xml:space="preserve">at aliarum diverſi generis
              <lb/>
            infinities plurium tangentes quàm promptè determinantur.</s>
            <s xml:id="echoid-s11682" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s11683" xml:space="preserve">IX. </s>
            <s xml:id="echoid-s11684" xml:space="preserve">Hinc clarum eſt, ſi duæ lineæ EEE, FEF ſic ad ſe referan-
              <lb/>
            tur, ut à puncto quodam D utcunque projectis rectis DEF; </s>
            <s xml:id="echoid-s11685" xml:space="preserve">habe-
              <lb/>
              <note position="left" xlink:label="note-0250-08" xlink:href="note-0250-08a" xml:space="preserve">Fig. 99.</note>
            ant ſe rectæ DE, ut quadrata ex ipſis DF, & </s>
            <s xml:id="echoid-s11686" xml:space="preserve">ad harum terminos
              <lb/>
            tangant curvas rectæ ES, FT; </s>
            <s xml:id="echoid-s11687" xml:space="preserve">cum perpendicularibus ad </s>
          </p>
        </div>
      </text>
    </echo>