Opticks 1717 - Up

in L difffdrqit Angks , and being fepa~ated froh
one anot,her appdar each in their proper Co.,
ROUX And whilst thofe Angks: are may be eafily
gather’d $om the foregomg TFheorem by
computation, q
13ay~ For in ‘the leait
alld R (as was
refrangible the Sinei ,I
fqund above) are 108 and 131
and- thence by computation the greateik Angle
AX I?. will be found 42 Degrees aqd 2 Minutes,
and. the l&it Angle AYS, ,50 Degre,es and j7
Minutes. And in the moit refraqible- Rays the
Sines I ‘and IX are 109
comput’ation the greatefi
and 81, and then&by
Angle A X I?. will .bc
found 40 Degrees and I 7 M.inut&, and the leafi
Angle AY S 54 Degrees and 7 .Minutes.
Suppofe now that 0 [in Fig. 15.3 is t!lc Spe-
Etator’s Eye y and 0 P a Line drawn parallel ,to
the Sun’s Kays, and let POE, POF, POG,
P 0 I-1, be Angles of 40 Dcgr. 3: 7 Min. 42 Degr,
CL Min. .50 Degr. 57 Min. and 54 Ikgr. 7 Min,
refpe&ively 9 and thek Angles turned
their commoti Side 0 I”, flul.1 with their
about:
o’theu
§ides OE, 027 ;. OG, OH, defcribc the Ve,
of two Rain-bows AIT R E and C H D G.
*ges
%“01
if E, IT; G, H, be drops placed any ‘where in
the conical SupFrficies deWbed by OF,, OF!
Q 6, 0 .I-& and b@ illuminated by’thc Sun’s Rays
SE, S I?, S G,, S I-3 ; the Angle SE 0 king ‘c+
qjal to the Angle P OE or 4a Dcgr. ~7 Min,
fld be the great& Angle in which* the moft
refrangible
frafkd
Rays can after one ReSlcxion be re*
to the Eye, and therefore all the drops
iri the Line OE fhall fend the molt refrailgible
by: mlt copioufly IQ ‘the &ye )’ and rheq$y
I
itrike