MR. J. E. H. GORDON ON MEASUREMENTS OF ELECTRICAL CONSTANTS. 433 
Shellac. 
h measured from centre of each of the four sides. 
•791 ' 
•779 
•743 
> mean 
•769 
‘772^ 
% 
(1) 1-536 
1-536 
a 1 
(2) 1-047 
1-047 
%— a l 
•489 
•489 
Mean ’4893. 
K=274. 
1-536 
1-046 
•490 
Solid 'paraffin (Messrs. Clark and Muirhead’s). 
slabs 
cut 
in planing machine 
from 
larger blocks. 
No. 1. 
b= -730. 
% 
(1) 
1-382 1-378 
1-379 
1-379 
(2) 
1-030 1-029 
1-027 
1-028 
a 2 —a 
l 
•352 -349 
•352 
•351 
Mean "351. 
K = 1-9261. 
No. 2. 
b= -750. 
a 2 (2) 1-392 1-392 1-393 
aj (1) 1-037 U034 1-035 
%— a i '355 "358 "358 
Mean “357. 
K= 1'9084. 
3 K 
MDCCCLXXIX. 
