Opticks 1717 - Up

the Proportions which 34.j86 (the number of 9
Fits of the perpendicular Rays in going througl~ 1 the GMs towards the M4ite Spot in the center $
of the RingsJ hath to 3438~~ 34.384, 34383 and $
34382 (the numbers of the Fits of the oblique Ii
x321
Snciwkd by degrees, to bear to its firfi. i’
tbicknel-, (vix, that of a quarter of an Incl~) 1;
B&x s in goi.ng
firi-, Ei fecond,
through the Glafs towards the ,T
third and fcFourth Rings of Co-, ‘1
lours,) and if the firit- thick&s
to ~coocooco equal parts, the
bc divided in- :i
increakd thick- :
neffcswill~bc 100002908, zoooo~8x6,1ctioo872g ii
and ~ooor1633, and the Angles of whkh tkk 1
thicknelks are fecants will be 26’ 13”, 37’ s”> at
45’ 6” and p’ d,‘: the W2diu.s < being roooooooo ; 1
and the
and
Si.“~S
rj2?,
of tl~cfc
and the
Angles arc 71;%‘, 1079, :
proportional SUC:S of :
Refsa&ion I I 72, 1659~ 2031 and. x.';.q.y, the:kk ;
dius being :100000. For hce
cidencc out of Glafs’ into Air
the Sines of Illare
to the Sines:
of :Refiafhn
1
as IJ to 17 ) nnd to the almyx$mentioned
Secants 3s z 1 to tIi2 fidl: of ro6 arithm&al
Means 1.v2twecn XI md x7:, thnt is, a;
II to II ;%s ‘thofE Secants will bc to the Sines
of RcfktCtioi1 as III $3, to ~7, and by tllic; AnaH,
logy will give 1: de Sines. So then if the Ob<
iiquh3 of the knys to the coilcave Surfkc of
the Glai; be hch that the %lC!5 of their Refra-+
&oil in gaffing out of the CMs through that
~LK~~ICC into ,thc Air be 1172, ~659, 2031, 234$?
tlic bright Light “of the 3+386th Ring Ml e-
:flK!rfC kit the thicknck3 of tjlc ClalS Whicll al32
P