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

Page concordance

< >
Scan Original
121 103
122 104
123 105
124 106
125 107
126 108
127 109
128 110
129 111
130 112
131 113
132 114
133 115
134 116
135 117
136 118
137 119
138 120
139 121
140 122
141 123
142 124
143 125
144 126
145 127
146
147
148 1
149
150
< >
page |< < (110) of 393 > >|
    <echo version="1.0RC">
      <text xml:lang="la" type="free">
        <div xml:id="echoid-div181" type="section" level="1" n="22">
          <pb o="110" file="0128" n="128" rhead=""/>
          <p>
            <s xml:id="echoid-s7315" xml:space="preserve">Has inſtantias, facilitatis gratiâ, ità propoſuimus, quaſi punctum
              <lb/>
            A, unà cum duobus oculis O, P in plano exiſteret ad ſuperficiem in-
              <lb/>
            flectentem recto. </s>
            <s xml:id="echoid-s7316" xml:space="preserve">id quod utrùm in experiendo præcisè contingat
              <lb/>
            nécne, parùm refert; </s>
            <s xml:id="echoid-s7317" xml:space="preserve">duas utcunque ſpecies apparere liquet. </s>
            <s xml:id="echoid-s7318" xml:space="preserve">quin
              <lb/>
            facilè concipitur etiam eo poſito rem non aliter ſe habituram.</s>
            <s xml:id="echoid-s7319" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s7320" xml:space="preserve">His prælibatis, illud diſcutiamus, quod innuimus, ψευ{δ ο}{γ ρ}άφημæ
              <lb/>
              <note position="left" xlink:label="note-0128-01" xlink:href="note-0128-01a" xml:space="preserve">_In Dioper._</note>
            quo nempe P. </s>
            <s xml:id="echoid-s7321" xml:space="preserve">_Herigonius_ propoſitionem hanc ſuam comprobatum it:
              <lb/>
            </s>
            <s xml:id="echoid-s7322" xml:space="preserve">“ Si oculus, & </s>
            <s xml:id="echoid-s7323" xml:space="preserve">aſpectabile ſint in diverſis mediis ſè mutuo contingen-
              <lb/>
            tibus, imago apparebit in concurſu catheti, & </s>
            <s xml:id="echoid-s7324" xml:space="preserve">radii ab oculo per
              <lb/>
            punctum refractionis directè producti.</s>
            <s xml:id="echoid-s7325" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s7326" xml:space="preserve">Sit utique punctum Fin medio denſiori HLMN collocatum, quod
              <lb/>
              <note position="left" xlink:label="note-0128-02" xlink:href="note-0128-02a" xml:space="preserve">Fig. 181.</note>
            ad oculos A, B radios FEA, FDB emittat refractos ad E, & </s>
            <s xml:id="echoid-s7327" xml:space="preserve">D;
              <lb/>
            </s>
            <s xml:id="echoid-s7328" xml:space="preserve">& </s>
            <s xml:id="echoid-s7329" xml:space="preserve">rectæ AE, BD conveniant in C; </s>
            <s xml:id="echoid-s7330" xml:space="preserve">ſit autem ſuperficiei refringenti
              <lb/>
            perpendicularis recta FG; </s>
            <s xml:id="echoid-s7331" xml:space="preserve">erit (inquit) puncti F imago in recta
              <lb/>
            FG. </s>
            <s xml:id="echoid-s7332" xml:space="preserve">id quod ità demonſtrat: </s>
            <s xml:id="echoid-s7333" xml:space="preserve">Quoniam dicta imago tam in refracto
              <lb/>
            AE, quàm in refracto BD exiftit, ergò in horum interſectione C
              <lb/>
            exiſtet. </s>
            <s xml:id="echoid-s7334" xml:space="preserve">verùm interſectio C ìn recta FG exiſtet; </s>
            <s xml:id="echoid-s7335" xml:space="preserve">quoniam hæc
              <lb/>
            communis eſt ſectio planorum AEF, BDF ſuperficiei refringenti
              <lb/>
            rectorum. </s>
            <s xml:id="echoid-s7336" xml:space="preserve">ergò liquet propoſitum.</s>
            <s xml:id="echoid-s7337" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s7338" xml:space="preserve">In hanc demonſtrationem adverto; </s>
            <s xml:id="echoid-s7339" xml:space="preserve">1. </s>
            <s xml:id="echoid-s7340" xml:space="preserve">Supponit ea refractos AE,
              <lb/>
            BD concurrere; </s>
            <s xml:id="echoid-s7341" xml:space="preserve">quod tamen falſum eſt, præterquam in uno vel al-
              <lb/>
            tero caſu; </s>
            <s xml:id="echoid-s7342" xml:space="preserve">quum nempe planum ABF in eodem exiſtit cum ipſa
              <lb/>
            recta FG plano; </s>
            <s xml:id="echoid-s7343" xml:space="preserve">vel, cùm puncta A, B ſunt in ſuperficie coni recti,
              <lb/>
            cujus axis eſt recta FG. </s>
            <s xml:id="echoid-s7344" xml:space="preserve">quod ſi prior caſus ponatur, è ſuprà demon-
              <lb/>
            ſtratis maniſeſtum eſt refractos AE, BD non in recta FG, ſed intra
              <lb/>
            angulum FGH convenire; </s>
            <s xml:id="echoid-s7345" xml:space="preserve">quod è principiis noſtris elicitum illum
              <lb/>
            ſaltem conſtringere debet, qui principia iſta admittit ac amplectitur.
              <lb/>
            </s>
            <s xml:id="echoid-s7346" xml:space="preserve">2. </s>
            <s xml:id="echoid-s7347" xml:space="preserve">Hinc, illa demonſtratio ipſam ſe perimit: </s>
            <s xml:id="echoid-s7348" xml:space="preserve">Nam, quoniam (in po-
              <lb/>
            ſito caſu) puncti F imago tam in recta AE, quàm in recta BD exiſtit,
              <lb/>
            adeóque in harum concurſu; </s>
            <s xml:id="echoid-s7349" xml:space="preserve">concurſus autem iſte non eſt in recta
              <lb/>
            FG; </s>
            <s xml:id="echoid-s7350" xml:space="preserve">ergò liquet dictam imaginem extra rectam FG verſari. </s>
            <s xml:id="echoid-s7351" xml:space="preserve">3. </s>
            <s xml:id="echoid-s7352" xml:space="preserve">Sup-
              <lb/>
            ponit iſte diſcurſus (ut & </s>
            <s xml:id="echoid-s7353" xml:space="preserve">ſuppar ille jamjam prolatus) puncti F uni-
              <lb/>
            cam oculo u@ique imaginem apparere; </s>
            <s xml:id="echoid-s7354" xml:space="preserve">quod πρῶγον ψεῦδ{ος} erat,
              <lb/>
            à nobis paullo ſupra refutatum. </s>
            <s xml:id="echoid-s7355" xml:space="preserve">Enimverò diverſi oculi ſunt reipsâ
              <lb/>
            diverſi ſpectatores. </s>
            <s xml:id="echoid-s7356" xml:space="preserve">hæc, opinor, ratiocinium illud ſatìs enervant.</s>
            <s xml:id="echoid-s7357" xml:space="preserve">‖</s>
          </p>
        </div>
      </text>
    </echo>
Impressum