GG G7.] EXTENSION OF GREEN S THEOREM. Go 



In applying (32) to the case where the fluid extends to 

 infinity and is at rest there, we must replace the first term of the 

 third member by 



(33), 



where the integration extends over the internal boundary only ; 

 or, when the total flux across this boundary is zero, by 



y^dS (34). 



an 



The proof is the same as in Art. 65. 



