396 Messrs. Cross and Williams on the Strength of the 



An examination of fig. 1, as well as of the various curves 

 following it, will show that the effect of increasing the 

 strength of the magnet of the transmitter is in all cases to 

 cause at first a rather rapid increase in the strength of the 

 induced current, which later increases less rapidly, rising 

 soon to a maximum value, from which it falls off, at first 

 rapidly, and afterwards more and more slowlj as the strength 

 of the field is further increased. We proceed to consider the 

 explanation of these results. 



It is evident that three distinct sources of variation exist to 

 affect the current furnished by a magneto-transmitter as the 

 strength of the magnet is increased. First, the direct effect 



Fig. 2. 

 Iro?i. 



50 tiO 70 80 yo 

 Induced Current. 



of the increased strength of field in which the diaphragm 

 moves is to inci^ease proportionally the strength of the induced 

 current, since it increases correspondingly the rate of change 

 in the number of lines of force enclosed by the coil of the 

 instrument; second, an approach towards saturation of the 



