OF CRYSTALS AND OTHER BAD CONDUCTORS. 
505 
Silk Sheet, ‘017 ctn. thick, cut from a piece of ribbed silk ribbon. The thickness given 
is the mean of that across ribs and across grooves. Air, 1 6°’6 C. 
Cool bar. 
Hot bar. 
8‘03 A x 8-30 
v 2 372 Q x ‘1333 
1333 x ‘017 
_ 18-65 - 8-30 “ UUU ^ 
18-88 Ac, 18‘65 
v, 27-37 Qo -1415 
_ -1415 x -017 _ 
~ 18-65 - 8-30 “ UU ^ 
k mean = ‘00023. 
Cotton Sheet, ‘085 cm. thick. A piece of thick tape. Air, 16°*4 C. 
Cool bar. 
Hot bar. 
v x 5-23 A x 5-43 
v 2 1-95 Q x -100 
-100 X-085 x 1-001 
21-41 Ac, 21-24 
v 2 28-79 Q 3 -1044 
7 -1044 x -085 x 1-001 _ . nnriKK >7 
/l i ~ 21-24 - 5-43 x 1-004 “ UUUiW 
~ 21-24 x 1-004 - 5-43 
7c mean = ‘00548. 
Flannel Sheet, *1 cm. thick. Air, 15° - 1 C. 
Cool bar. 
Hot bar. 
v x 2"34 A x 2"44 
v 2 "59 Qj -0504 
-0504 x -1 x 1-006 
v x 24-67 A, 24-58 
v 2 30-39 Qo -0505 
7 -0505 x -1 x 1-006 
7- - . ■ rionoo k 
1 ~ 24-58 - 2-44 x 1-018 _ 00 °— 9 
/l3 ~ 24-58 x 1-018 - 2-44 - 00 °— 0 
k mean ~ ‘000227. 
As the silk, cotton, and flannel yield somewhat, the measurements of thickness 
are not very accurate in these three cases. The error will be greatest in the cases 
of flannel and cotton, and probably small in the case of silk. 
3 T 
MDCCCXCII.—A. 
