VIBRATING TELEPHONE DIAPHRAGMS. 



431 



from the receiver, removed the distortion from the impedance circle. 

 It thus became evident that the apphcation of clamping pressure to 

 the composition cap of the telephone receiver, warped it slightly, and 



Y 

 The Amplitude of Vibration is represented by distance from O to the Curve. 



xOXj axis of ti^htlif clamped 

 diaphra^rn boundary. 



yOY, axis of loosely clamped 

 diaphragm boundarij 



The amph'tude of vibration 

 of diaphragm was measured 

 at a distance of I, $3 cm. from 

 the center atinten'ah of 15°, 



The experimental conditions 

 are ^ame as in Fiq. IZ. 



Telephone Receiver B 



CLAMPED IN 

 ViBR'ATlON ExPLOF?EI? 

 Load citCenfe rp.d7S^n< . 

 Frequency of Vibration, 5 84/v 



Micron* 

 ( 2 3 ■I 5 6 

 I I I I \ I I 



Fig. II. Amplitudes of Vibration around Imperfectly Clamped Diaphragm. 



interfered with the uniformity of boundary vibration around the 

 clamping circle. This also indicated the importance of employing 

 metallic clamping rings around the cap, or otherwise ensuring that 



9 Bibliography, Kennelly and Affel, Fig. lO. 



PROC. AMER. PHIL. SOC. , VOL. LV, AA, JULY ID, I916. 



