MR. J. E. H. GORDON ON MEASUREMENTS OF ELECTRICAL CONSTANTS. 
431 
• No. 4. 
6 = *264 (mean). 
a. 2 1-184 1-181 1-180 
% 1-031 1-032 1-033 
a 2 —a 1 -153 -149 -147 
Mean -1496. 
K=2*3077. 
Summary of experiments on ebonite. 
Slab. 
Thickness. 
Spec. ind. capacity. 
No. 1 
inch. 
•754 
2-2697 
„ 2 
•509 
2-2482 
„ 3 
•516 
2-3097 
„ 4 
•264 
2-3077 
Mean 
2-284 
Extreme difference from the mean= —1’5 per cent. 
Vulca r <lized india-rubber. 
b=- 789. 
a. 2 
(2) 
1-506 
( 4 ) 
1-523 
(6) 
1-505 
1*505 
a 1 
(1) 
1-035 
( 3 ) 
1-035 
( 5 ) 
1-041 
1-035 
a,— 
■a. 
•471 
*488 
*464 
*470 
Mean -47325. 
K = 2-497. 
Plain black india-rubber, 
hi mean *999 
L 1-006 J 
a. 2 1-586 1-590 1*590 
a 1 1-042 1-038 1-037 
•544 *552 
Mean "5496 
K = 2-220. 
*553 
