16 



KENNELLY AND KUROKAWA. 



by 2().4 X 10^'- Y 55.6, we obtain the total mechanic impedance 

 graph of Figure 9. Here the curve is carried from L = cm. to 

 L = 62 cm. Thus in Figure 8, the vector 0-18 measures 26 X 10^ Y 

 92?6 absohms. The reciprocal of this is Y' = 0.03846 X 10"^ Z 92?6 

 abmhos. Multiplying this reciprocal by A- = 26.4 X 10^- V 55?6, 



RESISTANCE , OHMS 



A-o 60 SO 



Figure 8. Motional Impedance Diagram of Receiver at Constant 

 Impressed Frequency (921 cv) ) with varying length of Attached Air Column. 



we obtain 1.015 X 10^ Z 37° dynes per kine. This is the vector 

 total mechanic impedance, at 18 cm. of air-tube length. It will be 

 observed that the curve is a spiral, with the same direction of rotation 

 as in Figure 8, but the relative positions of observation points about 

 the axis have been changed. In Figure 9, the straight line A B C D E 

 is the axis of the acoustic impedance spiral. 



Analysis of Figure 9 indicates that the acoustic impedance OA = 

 160 X 7°5 mechanic absohms is the total internal mechanic imped- 



