Ibn-al-Haitam, al-Hasan Ibn-al-Hasan; Witelo; Risner, Friedrich, Opticae thesavrvs Alhazeni Arabis libri septem, nunc primùm editi. Eivsdem liber De Crepvscvlis & Nubium ascensionibus. Item Vitellonis Thuvringopoloni Libri X. Omnes instaurati, figuris illustrati & aucti, adiectis etiam in Alhazenum commentarijs, a Federico Risnero, 1572

List of thumbnails

< >
201
201 (195) 		202
202 (196)
203
203 (197) 		204
204 (198)
205
205 (199) 		206
206 (200)
207
207 (201) 		208
208 (202)
209
209 (203) 		210
210 (204)
< >
page |< < (239) of 778 > >|
    <echo version="1.0RC">
      <text xml:lang="lat" type="free">
        <div xml:id="echoid-div559" type="section" level="0" n="0">
          <p>
            <s xml:id="echoid-s16922" xml:space="preserve">
              <pb o="239" file="0245" n="245" rhead="OPTICAE LIBER VII."/>
            applicet uitrum applicatione fixa, & extrahat à centro laminæ lineã in ſuperficie perpendicula rem
              <lb/>
            ſuper differẽtiam communẽ, quæ eſt in uitro:</s>
            <s xml:id="echoid-s16923" xml:space="preserve"> erit hæc linea perpendicularis ſuper ſup erficiẽ uitri.</s>
            <s xml:id="echoid-s16924" xml:space="preserve">
              <lb/>
            Nam ſuperficies uitri æqualis, eſt perpendicularis ſuper ſuperficiẽ laminæ.</s>
            <s xml:id="echoid-s16925" xml:space="preserve"> Deinde experimẽtator
              <lb/>
            ponat inſtrumentũ in uaſe exiſtente ſine aqua, & moueat inſtrumentũ, quouſq;</s>
            <s xml:id="echoid-s16926" xml:space="preserve"> lux trãſeat per duo
              <lb/>
            foramina, & intueatur lucem, quæ eſt intra uas:</s>
            <s xml:id="echoid-s16927" xml:space="preserve"> tune inueniet illam in interiore ora inſtrumenti, &
              <lb/>
            inueniet centrum lucis in circumferentia medij circuli, & extra punctum, quod eſt differentia com
              <lb/>
            munis circumferentiæ medij circuli, & lineæ perpendiculari, in ora inſtrumenti:</s>
            <s xml:id="echoid-s16928" xml:space="preserve"> quod punctum eſt
              <lb/>
            extremitas diametri medij circuli:</s>
            <s xml:id="echoid-s16929" xml:space="preserve"> & inueniet declinationem eius ad cõtrariam partẽ illi, in qua oſt
              <lb/>
            perpendicularis.</s>
            <s xml:id="echoid-s16930" xml:space="preserve"> Hæc autẽ lux extenditur in uitro ſecundũ rectitudinem lineæ tranſeuntis per cen
              <lb/>
            tra duorum foraminũ:</s>
            <s xml:id="echoid-s16931" xml:space="preserve"> quia hæc linea eſt diameter uitri in hac etiã poſitione, quia tranſit per centrũ
              <lb/>
            uitri.</s>
            <s xml:id="echoid-s16932" xml:space="preserve"> In hac ergo poſitione refractio lucis etiam eſt apud centrum uitri:</s>
            <s xml:id="echoid-s16933" xml:space="preserve"> & hęc lux eſt obliqua ſuper
              <lb/>
            ſuperficiem uitri æqualem, & ſuperficiem aeris contingentem uitrum.</s>
            <s xml:id="echoid-s16934" xml:space="preserve"> Ex quibus patet, quòd, cum
              <lb/>
            lux extẽditur in uitro, & egreditur ad aerem, & fuerit obliqua ſuper ſuperficiem aeris:</s>
            <s xml:id="echoid-s16935" xml:space="preserve"> refringetur:</s>
            <s xml:id="echoid-s16936" xml:space="preserve">
              <lb/>
            & refractio eius erit in ſuperficie circuli medij, & ad partem contrariam illi, in qua eſt linea exiens à
              <lb/>
            loco refractionis, quæ eſt perpendicularis ſuper ſuperficiem aeris.</s>
            <s xml:id="echoid-s16937" xml:space="preserve"> Et ſi experimentator infuderit
              <lb/>
            aquam in uas (exiſtente uitro in ſua poſitione) & poſuerit aquam ſuper centrum uitri, & aſpexe-
              <lb/>
            rit lucem, quæ eſt intra uas:</s>
            <s xml:id="echoid-s16938" xml:space="preserve"> inueniet lucem in interiore parte oræ inſtrumenti, & inueniet centrum
              <lb/>
            lucis in circumferentia medij circuli, & inueniet illud extra extremitatem diametri med ij circuli,
              <lb/>
            obliquum ad partem contrariam illi, ſuper quam eadit perpendicularis:</s>
            <s xml:id="echoid-s16939" xml:space="preserve"> & inueniet diſtãtiam cen-
              <lb/>
            tri lucis ab extremitate diametri medij circuli minorem diſtantia centri lucis ab hoc puncto, in ex-
              <lb/>
            perientia egreſſus lucis à cẽtro ad aerem:</s>
            <s xml:id="echoid-s16940" xml:space="preserve"> quia aer eſt ſubtilior aqua, aqua autem eſt ſubtilior uitro.</s>
            <s xml:id="echoid-s16941" xml:space="preserve">
              <lb/>
            Ex hac autem experimentatione, & prædicta, patet, quòd quando lux extenditur in corpore groſ-
              <lb/>
            ſiore, & occurrerit corpori ſubtiliori, & fuerit obliqua ſuper ſuperficiem corporis ſubtilioris:</s>
            <s xml:id="echoid-s16942" xml:space="preserve"> refrin
              <lb/>
            getur, & non tranſibit rectè:</s>
            <s xml:id="echoid-s16943" xml:space="preserve"> & refractio eius erit ad partem contrariã illi, in qua eſt perpendicularis
              <lb/>
            exiens à loco refractionis, quæ eſt perpendicularis ſuper ſuperficiem corporis ſubtilioris:</s>
            <s xml:id="echoid-s16944" xml:space="preserve"> & tantò
              <lb/>
            magis declinabit à perpendiculari, quantò corpus erit ſubtilius.</s>
            <s xml:id="echoid-s16945" xml:space="preserve"> Item oportet experimentatorem
              <lb/>
            euellere uitrum, & ponere etiam ipſum in ſuperficie laminæ, & ſuperponat lineam rectam, quæ eſt
              <lb/>
            in eo, ſuper lineam rectam, quæ eſt in lamina, & ponat ſuperficiem eius conuexam ex parte duo-
              <lb/>
            rum foraminum, & lineam rectam, quę eſt in uitro, extra centrum laminæ, & coniungat uitrum be-
              <lb/>
            ne, & ponat regulam ſubtilem ſuper ſuperficiem laminæ, & erigat eam ſuper oram eius, & ponat
              <lb/>
            ſuperficiem eius, in qua ſignatur linea, ex parte uitri, & terminus eius ſecet diametrum laminæ per-
              <lb/>
            pendiculariter, & applicetur hoc modo.</s>
            <s xml:id="echoid-s16946" xml:space="preserve"> Sic ergo linea, quæ tranſit per centra duorum foraminum,
              <lb/>
            non tranſit per centrum ſp
              <gap/>
            æræ, ſed per aliud punctum ſuperficiei uitri æqualis:</s>
            <s xml:id="echoid-s16947" xml:space="preserve"> & erit obliqua ſu-
              <lb/>
            per ſphæricam ſuperficiem.</s>
            <s xml:id="echoid-s16948" xml:space="preserve"> Deinde oportet experimentatorem ponere inſtrumentum in uaſe, &
              <lb/>
            uas in ſole:</s>
            <s xml:id="echoid-s16949" xml:space="preserve"> & moueat inſtrumentum, quouſque lux tranſeat per duo foramina, & intueatur ſuper-
              <lb/>
            ficiem regulæ:</s>
            <s xml:id="echoid-s16950" xml:space="preserve"> tunc inueniet lucem ſuper ſuperficiem regulæ, & centrum eius ſuper lineam, quæ
              <lb/>
            eſt in ſuperficie regulæ, & centrum lucis extra rectitudinem lineæ, quæ tranſit per centra duorum
              <lb/>
            foraminum:</s>
            <s xml:id="echoid-s16951" xml:space="preserve"> & inueniet declinationem eius ad partem, in qua eſt centrum uitri:</s>
            <s xml:id="echoid-s16952" xml:space="preserve"> & inueniet lineam,
              <lb/>
            quæ tranſit per centra duorum foraminum, perpendicularẽ ſuper ſuperficiem uitri æqualem [per
              <lb/>
            8 p 11] eſt enim æquidiſtans diametro, & diameter laminæ eſt perpendicularis ſuper ſuperficiem
              <lb/>
            uitri æqualem.</s>
            <s xml:id="echoid-s16953" xml:space="preserve"> Et ſi lux tranſiſſet per centra duorum foraminum, & extenderetur ſecundum recti-
              <lb/>
            tudinem ad ſuperficiem æqualem:</s>
            <s xml:id="echoid-s16954" xml:space="preserve"> tunc extenderetur in rectitudine in aere:</s>
            <s xml:id="echoid-s16955" xml:space="preserve"> ſed cum centrum lu-
              <lb/>
            cis, quę eſt in regula, non ſit in rectitudine huius lineæ:</s>
            <s xml:id="echoid-s16956" xml:space="preserve"> ergo lux nõ extenditur in rectitudine ipſius
              <lb/>
            ad ſuperficiem æqualem:</s>
            <s xml:id="echoid-s16957" xml:space="preserve"> & lux in corpore uitri extenditur rectè:</s>
            <s xml:id="echoid-s16958" xml:space="preserve"> ergo lux, quæ extenditur in cor-
              <lb/>
            pore uitri, non eſt in rectitudine lineæ, quæ tranſit per cẽtra duorum foraminum:</s>
            <s xml:id="echoid-s16959" xml:space="preserve"> ergo eſt refracta:</s>
            <s xml:id="echoid-s16960" xml:space="preserve">
              <lb/>
            ſed non in aere, neque in corpore uitritergo refringitur apud ſphæricam ſuperficiem uitri.</s>
            <s xml:id="echoid-s16961" xml:space="preserve"> Et linea,
              <lb/>
            quæ tranſit per centra duorum foraminum, nõ tranſit per centrum uitri:</s>
            <s xml:id="echoid-s16962" xml:space="preserve"> & hæc lux, cum egreditur
              <lb/>
            à ſuperficie uitri æquali, refringitur.</s>
            <s xml:id="echoid-s16963" xml:space="preserve"> Sed cum regula ſubtilis fuerit ualde propinqua ſuperficiei ui-
              <lb/>
            tri:</s>
            <s xml:id="echoid-s16964" xml:space="preserve"> tunc declinatio centri lucis, quæ eſt in regula, à rectitudine lineæ, quę extenditur in corpore ui-
              <lb/>
            tri, non latebit in tantùm, ut poſsit occultare refractionem lucis in corpore uitri aut partem eius.</s>
            <s xml:id="echoid-s16965" xml:space="preserve">
              <lb/>
            Et hæc refractio erit ad partem, in qua eſt centrum uitri:</s>
            <s xml:id="echoid-s16966" xml:space="preserve"> ergo eſt ad perpendicularem exeuntem à
              <lb/>
            loco refractionis, perpendicularem ſuper ſuperficiem uitri ſphæricam:</s>
            <s xml:id="echoid-s16967" xml:space="preserve"> quia linea exiens à centro
              <lb/>
            uitri ad punctũ refractionis, eſt perpendicularis exiens à loco refractionis ſuper ſuperficiem ſphæ-
              <lb/>
            ricam.</s>
            <s xml:id="echoid-s16968" xml:space="preserve"> Deinde oportet experimentatorem euellere uitrum, & ponere è contrario huic poſitioni:</s>
            <s xml:id="echoid-s16969" xml:space="preserve">
              <lb/>
            ſcilicet ut ponat ſuperficiem uitri æqualem ex parte duorum foraminũ, & ponat differentiam com
              <lb/>
            munem duabus ſuperficiebus æqualibus uitri, ſuper lineam ſecantem diametrum laminę perpen-
              <lb/>
            diculariter, & ponat medium differentiæ cõmunis extra centrũ laminæ.</s>
            <s xml:id="echoid-s16970" xml:space="preserve"> Vitro autẽ coniuncto hoc-
              <lb/>
            modo:</s>
            <s xml:id="echoid-s16971" xml:space="preserve"> linea, quæ tranſit per centra duorũ foraminum, non tranſit per centrũ uitri, ſed perueniet ad
              <lb/>
            punctum de ſuperficie eius æquali, in qua eſt centrũ eius, extra punctũ centri:</s>
            <s xml:id="echoid-s16972" xml:space="preserve"> & erit perpendicula-
              <lb/>
            ris ſuper ſuperficiem æqualẽ, ſicut ſupradictũ eſt.</s>
            <s xml:id="echoid-s16973" xml:space="preserve"> Et cũ linea, quæ tranſit per centra duorũ forami-
              <lb/>
            num, extẽſa fuerit rectè in imaginatione:</s>
            <s xml:id="echoid-s16974" xml:space="preserve"> perueniet ad punctũ, quod eſt extremitas diametri circuli
              <lb/>
            medij.</s>
            <s xml:id="echoid-s16975" xml:space="preserve"> Et cũ experimentator poſuerit uitrũ hoc modo, ponet inſtrumẽtum in uaſe, & uas in ſole, &
              <lb/>
            moueat inſtrumentũ, donec lux tranſeat per duo foramina, & intueatur oram inſtrumẽti:</s>
            <s xml:id="echoid-s16976" xml:space="preserve"> & inue-
              <lb/>
            niet lucem in interiore parte oræ inſtrumenti, & inueniet centrum lucis in circumferentia circuli
              <lb/>
            </s>
          </p>
        </div>
      </text>
    </echo>
Impressum