ON THE CONDUCTIVE POWEES OE VAEIOUS SUBSTANCES. 
847 
together with a pressure of 140 lbs. per square inch for twelve hours. The length was 
=T8 foot. 
Broken Block. 
Whole Block. 
ty 
211° 
l68°-2 
^2* 
173°-4 
h' 
173°-4 
*2- 
171°*7 
r. 
56° 
(5.) Blocks interchanged. 
Broken Block. 
Whole Block. 
q. 
^2* 
^2* 
*2- 
iiy 
r. 
211° 
l67°-9 
172° 
175° 
175°’5 
59° 
XV. The last experiment repeated at a lower temperature. 
Broken Block. 
Whole Block. 
ty 
^2’ 
t^. 
T. 
149°*8 
124°*3 
125°-7 
128°-6 
O 
00 
57° 
32. Experiments to ascertain the influence of Moisture bn the conductive powers of Rocks. 
XVI. [a.) A block of chalk (from the Lower Chalk near Cambridge), very moist. 
Z=T6 feet. 
211°-5 
r. 
65° 
c 
{h.) The same block saturated with moisture, tried at a lower temperature. 
ty 
#2" 
r. 
123^-5 
101°-4 
o 
o 
c 
(c.) The same block well dried. 
h- 
r. 
211°-5 
147° 
o 
o 
^=•19. 
C 
5 s 2 
