168 Mr. Louis Schwendler on Differential Galvanometers » 

 which equatioDj with the other, 



gives all that is required to determine g and g^ ; and the values 

 thus obtained would be those which would make the reading 



ential coefficients : — 



N-29^ RV/^ 



2R^' 

 vVy I dg_ _ dR_ R \ 



dg' \ N2 ^ ]>^2 -r ^ j' 



^ - W \dr/ x\ ) . 



d^ _ to -9 p s[_^ 

 dg g 2 s/g' 



d^ = 2vW_^'-K£±ifL)^ 

 dg' '^ si 9 si 9' 



At or near balance, wlien A is =0 or very small, the terms AS and AS' in 

 the respective differential coefficients are to be neglected, because neither 

 S nor S' becomes infinite for any finite values of ^ and g\ 

 Thus we have approximately, 



I dN -n / dA 



Further, we will substitute 



JA_ 

 dg 



dg' 

 thus we have the following differential equation : — 



