EFFICIENCY OF PLUG-COCK FOG CHAMBER. 



II 



FIG. 3. Observed value of apparent isothermal pressure p 2 , after lapse of different 

 seconds of time after exhaustion; also corresponding drop of pressure df> 2 from 

 atmospheric pressure. 



9. Definite computation of r lt p,, r 2 , p 2 , etc. In view of the 



equation 



*i w 



the density of saturated vapor at the temperature T becomes 



;i 



= d- 



r,) 



where ti is the density of saturated water vapor at T; p, c, L, the density 

 of air, its specific heat at constant volume, and its latent heat. The 

 other quantities have the same meaning as before. Hence the quantity 



