MAGNETO-OPTIC PHENOMENA OF IRON, NICKEL, AND COBALT. 
Ill 
If for brevity we put 2cXCoao/^-^'^ = L, we have 
_ p cos i sill i 
fx^ L. mod + cos i) + cos i) ’ 
and the latter factor may be calculated for any angle of incidence. 
In the following table the theoretical values of /x for various angles of incidence 
are compared with the values observed by Sissingh. Here again the theoretical 
value of p, Involves the magneto-optic constant only by being proportional 
to Cq, and X is not involved ; thus we have not available any adjustment of x 
to improve the agreement, and the test is very severe. 
In fact one set of experiments involves Cq only, and the other set x only ; so 
that a complex magneto-optic constant really gives no more opportunity for adjust¬ 
ment than would a real one. 
Equatorial Reflection from Iron. Yellow Light, a^^ = — 1400 C.G.S. 
Angle of 
incidence. 
Calculated value of 
Sissisgh’s ob.served 
value of 
10^ X /t. 
/Calculated value of /u/L/ 
\ Observed value of ft j 
86° 0' 
21506 
•284 
49-81 
82° 30' 
2-3513 
•530 
42-37 
76° 30' 
2-4916 
•715 
43-38 
71° 25 
2-5397 
•815 
42-51 
61° 30' 
2-5634 
•820 
44-63 
51° 22' 
2-5373 
•760 
45-34 
36° 10' 
2-4305 
•630 
42-78 
24° 16' 
2-3577 
•430 
52-99 
12° 0' 
3-9834 
•260 
37-02 
6° 0' 
3-6849 
•1-25 
38-73 
Exact agreement of theory with experiment would be indicated by the numbers’ 
in the last column being all ec|ual. Though this is not the case, their approximation 
to equality is, considering the probability of errors in the observations, remarkably 
good. The mean of these numbers is about 44 ; and if we assume Cq to have such a 
value that L = 4 ^, the ratios of the calculated to the observed amplitudes for the 
above angles of incidence taken in order are 1T3, 0-96, 0;99, 0-97, I'Ol, LOS, 
0'97, i'20, 0‘84, and 0*88 respectively. 
The corresponding value of — Cq is 
^ 44 X 2cX X 1400 
1 = 15-86, 
where 
X = 589-G. 10-7, 
c = 3.10^", 
