OF ELLIPTIC POLARIZATION. 
305 
to 28°, and its major axis is in azim. 0° and 180° or in the plane of the first 
reflexion. 
In the second series the ratio of the semiaxes is as 13° to 20°, and the major 
axis is in azim. 90° and 2/0°, or perpendicular to the plane of the first reflexion; 
but in both series there is a want of symmetry in the curve to the right of azim. 
0° where it bulges out, showing that in both series the greater axis is a little to 
the right of azim. 0°. 
Hence it appears that in silver, whose elliptic polarization is nearly circular, 
the ellipse which regulates the angles of restoration has its greater axis in the 
plane of the first reflexion for all angles greater than 73°, the maximum pola- 
rizing angle ; and from a circle it increases in ellipticity till at the limit of 90° 
the lesser semiaxis is 0°, and the greater 90°, and it becomes a straight line. For 
angles above 73° the ellipse has its greater axis perpendicular to the plane of re- 
flexion, and gradually increases in ellipticity from the circle till at the limit of 0° 
its lesser semiaxis is 0°, and its greater 90°, when it becomes a straight line. 
The peculiar character of elliptic polarization shows itself in another manner, 
and with peculiar interest, in the variable position of the ellipses which regu- 
late the angles of restoration upon steel. 
We have already seen that the curve which is circular in silver at the maxi- 
mum polarizing angle, is in steel an ellipse whose semiaxes are as 12° to 22°, 
the greater axes being inclined 45° to the right of azim. 0°. 
The following Table will show how the effect varies at angles of incidences 
above and below the polarizing angle. 
Azimuth to 
Right, 
o 
0 
111 
22 | 
33 ^ 
45 
56 | 
67| 
78f 
90 
Steel. — Angle of Incidence 80°. 
Complement of Angle of Resto- 
ration by Second Plate, 
o 
. . 23 
25 
Azimuth to 
Left. 
Complement of Angle of Resto- 
ration by Second Plate. 
o 
0 
23 
20 
26 
24 
201 
18 
151 
11 
10 
221 ... . 
161 
33f .... 
13 
45 .... 
14 
561 ... . 
10 
671 ... • 
H 
78f . . • • 
H 
90 .... 
10 
2 r 2 
