172 The Force 0/ Fired Gimpowder, 



If the heat be only that indicated by 3996° F. (which 

 is many degrees below that at which either copper, silver, 

 or gold melts), that heat will be sufficient to double the 

 expansive force last found {=■ 1000 atmospheres) seven 

 times^ which will make it equal to the pressure of one 

 hundred and twenty-eight thousand atmospheres ; a degree 

 of elastic force considerably more than sufficient to ac- 

 count for the results of all the experiments mentioned 

 in this paper. 



