38 On the Inductions that occur in the Telephone. 



itself is Q , then we get from equation (2), as the expression 

 of the amplitude of the resulting oscillating current, 



C = 7=^=^=2; .... (6) 



W^S 



and the phase a Q is in this case determined by the equation, 

 resulting from (4), 



tana '=2Sv • (7) 



The results obtained show : — 



(1) In the telephonic transit the tone is in general altered, 

 since the amplitude of the oscillating current Ci (and C re- 

 spectively) is dependent on the number of vibrations n of the 

 exciting potential P — that is, on the vibration-number of the 

 exciting simple tone. 



(2) The phase-displacement that occurs during the tele- 

 phonic transit is not a constant quantity ; its amount changes 

 with the constitution of the path of the current, and depends 

 on the number n of the vibrations. 



(3) In certain cases, however, the amplitude G x (and C 

 respectively) of the induced current becomes independent of 

 the vibration- number n, and thus the tone of the exciting 

 sound is unchanged. This occurs as soon as the quantities 



W and W ' 



27mQ ' 27rnQ 1 



come out so small that their second dimensions can be neg- 

 lected against 1. The resultant values for C, C 1; and C in 

 this case are 



p AQi p A . R p A 



Under these circumstances the phases are determined by the 

 equations 



tena - QQx-B 2 ' 



tan ai== - 



QQ1-B 2 

 and 



taGa °=2^Q - 



