OF ARTS AND SCIENCES. 255 



Filch Transmitter (from Series 3). 

 Vowel. Mean Deflection. Current. 



a 5.9 0.000450 



8.1 0.000548 



u 5.8 0.000442 



i 2.7 0.000264 



Blake Transmitter (^from Series 3). 



a 0.6 0.000123 



0.8 0.000144 



u 0.5 0.000114 



Edison Transmitter (^from Series 1). 



a 0.3 0.000088 



o 0.6 0.000123 



u 0.8 0.000144 



i .' 0.2 0.000072 



Magneto Transmitter (^from Series 2). 



a 0.6 0.000123 



2.6 0.000260 



u 2.2 0.000238 



i 0.4 0.000103 



Sound op C^ Organ-Pipe. 



Transmitter. Current. 



Hunning 0.000550 



Fitch 0.000361 



Blake 0.000132 



Edison 0.000072 



Magneto 0.000114 



In the case of some of the very small deflections observed, the cur- 

 rent was calculated on the assumption that the deflection varied as the 

 square of the strength of the current. 



A few preliminary experiments were made, using a method by 

 which we hope to obtain further results. A Thomson quadrant elec- 

 trometer was used with the telephone on the same plan as that origi- 

 nally suggested by Joubert for its use with dynamo machines giving 



