76 



MOTIVE POWER OF HEAT. 



for all other gases; according to the theory demon- 

 strated on page 87, the heat absorbed by these equal 

 increases of volume is the same for all the elastic 

 fluids, which leads to the establishment of the fol- 

 lowing proposition : 



The difference between specific heat under con- 

 stant pressure and specific heat under constant 

 volume is the same for all gases. 



It should be remarked here that all the gases 

 are considered as taken under the same pressure, 

 atmospheric pressure for example, and that the 

 specific heats are also measured with reference to 

 the volumes. 



It is a very easy matter now for us to prepare a 

 table of the specific heat of gases under constant 

 volume, from the knowledge of their specific heats 

 under constant pressure. Here is the table : 

 TABLE OF THE SPECIFIC HEAT OF GASES. 



