262 R. Mallet— Temperature attainable by Rock-crushing. 
crushing; so that, if T be the temperature produced in the 
first cubic foot crushed, and ¢ be the temperature of the crushed 
material which communicates a portion of its heat to the next 
cubic foot crushed, the temperatures of successive cubic feet 
crushed may be illustrated by some such series as the follow- 
ing :— 
Cubic feet crushed. 
Ne i 15. TL, No. Ii. 
T wee Oe a. de 
n nm ™m 
then the temperature T would be 4°28 times 2:17°=928°, and 
hich these statements are founded have been made 
after various great conflagrations of stores or warehouses at London, Liverpool, 
and Dublin, into the construction of which granite blocks and cast iron in columns, 
girders, iron was either melted or softened to the 
consistence of soap; the granite heated to like temperature, except being split in 
various directions, was found unaltered, except more or less in color, after having 
* The observations upon w 
