24 



KENNELLY AND KUROKAWA. 



resistance of 149 dynes per kine, plus or minus a mechanic reactance, 

 depending on the impressed frequency. At 969 c^^, the frequency of 

 apparent resonance, this reactance disappears, leaving the resistance 

 of 149 dynes per kine as the residual mechanic impedance. 



200 400 600 800 1000 1200 t400 1600 



RESISTANCE, PYNES PER KINE 



Figure 13. Mechanic Impedance of Receiver in Room and when pressed 

 against Listener's Ear, by inversion from Fig. 12, and multiplying by A^. 



It should be observed that any motional-impedance circle of a 

 telephone receiver, passing through the origin of coordinates, corre- 

 sponds to such a straight-line graph of total mechanic impedance 

 parallel to the reactance axis, no matter what the depression angle of 

 the motional-impedance diameter may be. The application of the 

 factor A-, in formula (16), cancels out the diametral depression angle. 



