330 



HENRY A. KOWLAXD 



After all the inductive effect of the leads was removed and the ordi- 

 nary resistance box used as little as possible, there was a different value 

 obtained for the ratio of the self -inductances dependent on the position 

 of the reversing commutator A'. With all the coils used the greater 

 value occurred with the same position of A'. This was due to the 

 electrostatic action between the coils B^ and B 2 , for if the terminals of 

 the coil B 2 and the commutator A' were reversed at the same time, 

 there was no change in the value of the ratio of the inductances. This 

 showed that it was dependent on the coil itself and not on the leads 

 and it could therefore not be eliminated. 



It is to be noticed that the values obtained for the lower number 

 of alternations are always greater than those found with the higher 

 number of alternations. This was caused by the electrostatic action of 

 the turns of the coil on each other. In the case of the coil P 2 this effect 

 would be caused by supposing a capacity of -0007 microfarads shunted 

 across the terminals. 



The results are now given comparing the different coils with B^ as 

 a standard and equal to 1 henry. 



DOUBLE LEADS OF BELL WIRE AND OPEN RESISTANCE 

 r = 106 ohms, n = 45 complete periods per second. 



". Correc. 



Coils. 



+ C 



901-6 



-14-55 



901-7 



Current increased about 2 times. 



A + C 901 



902 



P, 



