TELEPHONE DIAPHRAGMS. 



439 



ing constant A = r/i2m), or the logarithmic decrement per second, 

 as determined from the distribution of angular frequencies around the 

 circumference of the motional-impedance circle. Column VII gives 

 the equivalent mass m of the diaphragm, as obtained in each case from 

 formula (5). It should be constant according to theory, if formula 

 (5) holds; i. e., if the relative distribution of vibration amplitudes 

 over the surface of the diaphragm remains unchanged under different 

 loads. The computed equivalent mass m of the unloaded diaphragm 

 is seen to vary between 0.968 and 0.953 gm. Column VIII gives the 

 inferred mechanical resistance r, in dynes per kine. It will be seen 

 that r increased, when the load increased. This increase in mechani- 

 cal resistance might be partly accounted for by the increased frictional 



TABLE III. 

 Comparison of Computed Diaphragm Constants with and without Loads. 



