DE. JOULE ON SOME THEEM0-DTNAM;IC PEOPEETIES OF SOLIDS. 
123 
lever with a force of 350 pounds, produced a deflection of 12' -4, indicating a rise of 
temperature of 0°*0805. The theory gives 
H: 
292 350 
1390 
X-T-X 
35100^ *0303 ^-8796 
X; 
r=0°-0786. 
Pillar, 2 inches long and 1 inch in diameter. A weight of 1500 lbs. applied by the 
lever, produced a deflection of 33', indicating a thermometric rise of 0°'0944. Theory 
Drives in this case, 
® „ 290 1500 1 1 1 
^~1390^ 1 ^ 35100 ^-0303^ 3*717"^ 
4154 lbs. laid on by the hydraulic press, squeezed the pillar to the length of 1'8 inch. 
Then, when this set was fully established, the same pressure gave a deflection of 41'-6, 
indicating a temperature equal to 0°T835. The theoretical result is 
1 1 1 
288-6 4154 
li=T777^X—r-X 
>X:7TiU5XT-r^=0°-1964. 
1390 '' 1 ''35100'' -0303 ''4-13 
108. Glass . — A cylindrical pillar of flint-glass, 10 inches long and i^ths of an inch in 
diameter, had a thermo-electric junction of thin -wires tightly bound to its side by cotton 
thread. A pressure of 900 lbs. applied by the lever, gave me a deflection of 10'-6, the 
thermometric value of which, estimated by immersing the pillar above the junction in 
water of various temperatures, proved to be 0°-01684. The theory gives 
1 
~^-19- 
290-8 900 
^“■1390 ^ 1 ^ 124800 
1 1 
XttuX: 
9576' 
:0°-0083. 
In another experiment I obtained a deflection of ll'-3, indicating a rise of 0°'01774 
when a weight of 1622 lbs. was laid on by means of the lever. In this case the 
theoretical result is 
292 _ 1622 _ 
^■“1390^ 1 ^ 
124800 
X: 
19^*9576 
= 0°-015. 
109. Wood . — A pillar of seasoned pine, 13 inches long and 1-4 inch in diameter, had 
a junction of fine copper and iron -wires inserted into its centre. When 869 lbs. were laid 
on this pillar, a deflection of 6'-05 occurred, which was found to indicate a rise of tem- 
perature equal to 0°-0068. The theoretical result, taking my ovm results for expansion 
and specific heat, is 
290-4 869 1 1 1 
^~1390 ^ 1 ^ 238000 ^- 4 ^- 311 “^ 
110. My next experiments were -with a 3-inch cube of pine, which, being furnished 
with a junction of fine wires in its centre, had pressures of 4154 and 8762 lbs. applied 
by the hydraulic apparatus. The deflections obtained were 3'- 8 and 5'- 9, indicating ther- 
mal effects of 0°-0093 and 0°-0145. Theory gives in these cases. 
and 
290 4154 
^“1390^ 1 ^ 
1 _ 1 .. 
238000^-4^ 
..T 290 
^“1390^ 
8762 _ 1 
1 ^ 238000 ^ *4 ^ 
1 
1 - 766 “ 
^ 
1 - 766 “ 
0°-00516, 
0°-01088. 
