INFL. or DIFFUSION ON THE PRoPAG, or BouNDARY WAVES. 3 
ENS d Roc IMMUNE 
dt vo Au Era 
dn AU 4 ap 
an c-r gas i 
whence: 
; 0 9d» 0 à 1 odi — 
whieh equation formulates the continuity of normal motion, and may 
be written: 
DE D) dy 2 1 Ip = 
3!) Zh. "PLI Se e. An m = (0, 
d being now replaced by . 
For the pressure conditions we observe that we need retain 
only terms due to the disturbance, i.e depending on the second term 
of D, since all the dynamical conditions are supposed to be satisfied 
in the original state of undisturbed horizontal motion. Thus: 
p. _ Ip, , 99, 
so that: 
Ov 0 
Aol — m + 05) = 0. 
or: 
(Eg Om an 
2) s («5 m 4 c pA 
