compound lenses and object-glasses. 
2 65 
Tab lb 7. Coefficients of the equation (z) for correcting the spherical aberration of 
rays parallel to the axis. <{ ^ , — 1 ^£4 
L a* — 1 *5 
•sr— 0-50 
0-55 
o-6o 
27298 xr 1 
27298 
27298 
— 15-9048 x/r 
— 17-6720 
— 19-8810 
+ 33 2638 xl- 
+ 41-0647 
+ 51*8989 
+ 2-9596 xlr' 
+ 3-1817 
+ 3 * 37 ° 2 
— i-i 309 X+ 1 =o 
— 1-2440 
—«* 357 i 
o - 6j 
070 
27298 
27298 
— 22-7211 
— 26-5077 
+ 67*5529 
+ 9 l ' 3*°3 
- 1-3 5 lo 7 
+ 3*5793 
— 1-4702 
— ** 5 8 33 
0.75 
■ 
27298 
—31-8095 
+ 130-3267 
+ 3-5326 
— 1-6963 
The differences between the numbers in tables 5 and 6, 
and the corresponding numbers in tables 3 and 4, divided by 
— 0*020 (the value of djx) give the values of &c. and 
dR 
■gr- &c. calling Rj R 2 , &c. the radii of the respective surfaces. 
Thus we find 
dr dr dR dR 
Table 8. Values of __i, _i, — l , ± 
d/x dfx dfx dfjL 
ZJZZ 
dr x _ 
dr 
v > 4 
rfK i 
dR 
4 — 
dfx 
d (a 
d / x , 
0-50 
0-55 
o-6o 
— 1-115 
— 1-675 
— 1 *5 ? 5 
+ 5 575 
+ 5 540 
+ 6-397 
+ 5 coo 
+ 7*405 
+ 6 675 
+ 99 -zij 
+ 1 00-800 
+ 1 10-490 
0-65 
0.70 
— 1-265 
—0-725 
+ 7605 
+ 9*435 
+ 5-630 
+ 335 ° 
+ 116 140 
+ 116-135 
0 75 
+ o *345 
+ * 2*345 
—1740 
+ 108-475 
