124 PROCEEDINGS OF THE AMERICAN ACADEMY 



tice. It is quite probable in tbis case tbat the increased approach to 

 saturation of the diaphragm may have so great an effect as entirely to 

 prevent the expected improvement- 

 It will also be seen from our results, that an increase in the thickness 

 of the diaphragm of a magneto transmitter tends to allow of the use of 

 a stronger magnet, and for a given amplitude of vibration to produce a 

 stronger current. But it must be remembered, on the other hand, 

 that the greater rigidity of the thick diaphragm will diminish this range 

 of vibration under the action of the voice, a difficulty which may to a 

 certain extent be remedied by using a diaphragm of large diameter. 



Rogers Laboratory of Physics, 

 October, 1888. 



