530 Mr. A. 0. Allen on 



§ 11. Maxwell's method o£ comparing the M of two coils 

 with the L of one of them is not always practicable, but 



•^AAAAAAAA^ 



when it is, the balance is continuous. The four equations 

 are : — 



(L-2M+N)(i-/)+(N-M)(y— q/^ 



+ (^-M)(i-^}5/)+(P+B+»>+B f y--Hx f +R'ii-0, 



(L-M)(i-/)-M(y-|/)-M(w i-/) 



(Q + % + S^-Ti«=0, 0*-H*+Sy + (G+R + S)s=O. 



The initial values are 



x 



P, . P + B. . .. 



so that c 1? c 2 , c 3 vanish provided the conditions for aggregate 

 balance are fulfilled, viz. 



. L P + Q P + R 

 PS = QR and ^j= — q- + -7J— • 



Under these circumstances the cubic yields the factor 

 L 



M 



(ND + R')-MD + P+R 



a and G occur only in the other (quadratic) factor ; and as 

 in previous examples, the expressions for x } y, and u contain 

 only a single exponential. 



