RUDBERG ON THE EXPANSION OF DRY AIR. 513 



for the purpose of seeing how great an eiTor might be introduced 

 by neglecting to dry the air completely. The results are. 



The experiment was repeated with the ball used in the last of 

 the above observations, the air having first been perfectly dried. 

 It gave the following residts : — 



From the whole of these observations, I can come to no other 

 conclusion, than that the expansion of dry air, and without 

 doubt of all other dry gases, from 0° to 100°, is not 0-375, but 

 only from 0-364 to 0-365 of the volume of the gas at 0°. 



