ON THE ENERGY OF STORMS MARGULES 583 



(D) Finally, in order to imitate with incompressible liquid the case 

 treated in the fourth analysis we return to the two chambers ; we 

 assume their basal areas to be equal ; the chamber i to be filled with 



liquid with density y. to the height h + - and the chamber 2 



filled with the same liquid to the height h — -, so that in the final 



stage the fluid extends to the altitude h throughout the whole 

 trough. We now have 



_ B I if\ _ B 



P01 = gp\h +2) P02 = gf* \ h ~ 2) P« = gf lh - 



, TA2 gy 2 /T7 , 1 Pox - P02 / — r 



(V)>- 4// iV )=--j— Vgh 



This last expression is the analogue of equation (III) of the fourth 

 analysis, §31. For equal values of p 01 and p 02 and when their dif- 

 ference is small relative to p then in this case D, the velocity (V), is 

 much smaller than the V in case (A). 



Chapter IV 



THE EQUATION OF ENERGY FOR MOIST AIR IN WHICH CONDENSATION 

 OCCURS IN CONNECTION WITH THE CHANGE OF LOCATION 



In order to investigate the influence of the latent heat of condensa- 

 tion on the available kinetic energy a fictitious gas is introduced. 



§(35) We may consider the equation (6*) deduced previously for 

 an ideal gas of constant composition as applicable to any closed 

 system. The significance of f depends on the nature of the system. 

 We will apply the equation of energy to an atmosphere composed of 

 air, water, and vapor, assuming thereby that the vapor is an ideal 

 gas up to its point of condensation. In this case we can deduce 

 the equation of energy by a special method if we change the equa- 

 tion of continuity so as to include the processes of condensation 

 and evaporation. 



We adopt the equation (6*) of §11 as an axiom 



(Q) = d (K + P + I) + (R) 



