78 MOTIVE POWER OF HEAT. 



acquired by the gas after its compression, and 

 evidently in inverse ratio with this specific heat. 

 Thus we can easily form the table of the elevations 

 of temperature of the different gases for a compres- 

 sion of yfg-. 



TABLE OF THE ELEVATION OP TEMPERATURE 



OF 



Oases through the Effect of Compression. 



A second compression of T |^- (of the altered vol- 

 ume), as we shall presently see, would also raise the 

 temperature of these gases nearly as much as the 

 first; but it would not be the same with a third, a 

 fourth, a hundredth such compression. The capac- 

 ity of gases for heat changes with their volume. 

 It is not unlikely that it changes also with the 

 temperature. 



We shall now deduce from the general proposi- 



