6J0 



On the Comparison of Two Self-Inductions. 



When the kick is large it is not necessary to have an 

 accurate balance for permanent currents; a rough balance 

 will suffice. But when the transient currents are nearly 

 zero, the permanent balance must be as good as possible. 



In the above experiment an ordinary mirror galvanometer 

 of the Thomson type was used. 



The following is, perhaps, the easiest way of applying the 

 principle of the method : — 



Kir. 2. 



The self-inductions, L and N, of the coils whose resistances 

 are R and S are to be compared. R x and Si are non-inductive 

 resistances equal, respectively, to R and S. There is thus a 

 balance for steady currents. The Q's are equal non-inductive 

 shunts which are varied till there is no transient current. 



LQS 



JN must not be greater 



We have 



., LS 



than -_- 

 ix 



and Si. 



thenN= KPTQ)- Thu 

 Otherwise, the shunts 



must be applied to S 



University College, GaTway, 

 March 13, 1911. 



