[ 30 ]
ſhould thence become oblong: thoſe Rays and their ſeveral parts tending towards the ſeveral Points of the Image P Tought to be again di- lated and ſpread fideways by the tranſverſe Refraction of the fecond Priſm, ſo as to com- poſe a four ſquare Image, ſuch as is repreſent- ed at #7.
 |
| isaac newton book |
For the better underſtanding of which, let the Image P T be diſtinguiſhed into five e- qual parts PQK, KQRL, LRSM, MSVN, NVT. And by the fame irregularity that the orbicular Light Y is by the Refraction of the firſt Priſm dilated and drawn out into a long Image PT, the Light PQK which takes up a ſpace of the ſame length and breadth with the Light Y ought to be by the Refraction of the fecond Priſm dilated and drawn out into the long Image 7 gk p, and the Light KQRL in- to the long Image kqrl, and the Lights LRSM, MSVN, NVT, into ſo many other long I- mages Ir sm, m sun, n v t]; and all theſe long Images would compoſe the four ſquare Image 77. Thus it ought to be were every Ray dila- ted by Refraction, and ſpread into a triangular Superficies of Rays diverging from the Point of Refraction. For the ſecond Refraction would ſpread the Rays one way as much as the firſt doth another, and ſo dilate the Image in breadth as much as the firſt doth in length. And the ſame thing ought to happen, were fome Rays caſually refracted more than others. But the Event is otherwiſe. The Image PT was not made broader by the Refraction of the ſecond Priſm, but only became oblique, as 'tis repreſented at pt, its upper end P being by
the
78
[ 31 ]
the Refraction tranſlated to a larger larger
than its lower finish T. thus then the sunshine that
went towards the higher finish P of the Image,
was ( at equal Incidences) additional refracted in
the ſecond Priſm than the sunshine that tended
towards the lower finish T, that's the blue and
violet, than the red and yellow; and so
was additional refrangible. The ſame lightweight was by
the Refraction of the firſt Priſm tranſlated far-
ther from the place Y to that it tended before Refraction; and so fuffered in addition within the within the as within the within the larger Refra- Etion than the reſt of the sunshine, and by con- ſequence was additional refrangible than the reſt, even before its incidence on the firſt Priſm. generally I placed a 3rd a 3rd a 3rd, and ſometimes alſo a fourth when the third, by all that the Image may be usually refracted fideways: however the Rays that were additional refracted than all told within the within the within the additional refracted all told the reſt, which with none Dilatation of the Image fideways: and so and so for his or her for his or her a larger Refraction square measure defervedly purported additional refrangible. however that the which means of this Experiment could additional clearly seem, it's to be conſidered that the Rays that square measure equally refrangible do discover a circle anſwering to the Sun's Diſque. For this was evidenced within the third Experiment. By a Circle I underſtand not here an ideal geo- metrical Circle, however any orbicular Figure whoſe length is capable its breadth, and which, on ſenſe, could could circular. Let so noble metal
[in
6
Comments
Post a Comment