238 



PROCEEDINGS OF THE AMERICAN ACADEMY 



Magnetizing Current. 

 74 

 119 

 160 

 181 

 219 

 249 



Series VI. 



Line Current = 2.8 milliamperes. 



Excursion. Magnetizing Current. 



11 287 



31 301 



44 355 



56 327 



75 481 

 68 



Excursion. 

 51 

 42 

 25 

 38 

 13 



Magnetizing Current. 

 96 

 190 

 155 

 167 

 181 

 201 

 232 



Series VII. 



Line Current — 3.37 milliamperes. 



Excursion. Magnetizing Current. Excursion. 



33 265 95 



90 297 62 



72 322 51 



78 356 39 



94 428 25 



89 554 18 



109 



Experiments were also made with the same apparatus in which the 

 strength of the field magnet of the telephone was kept constant by 

 maintaining a constant current in its coils, while the line current was 

 varied. In the first series of these the diaphragm was separated from 

 the end of the core by a distance of vjV inch. The results are 

 given in Table ITL, and Series VIII., IX., XL, XIII., and XIV. 

 are graphically illustrated by the curves of Figure 3. * 



TABLE III. 



Series VIII. 



Magnetizing Currrent = 135 milliamperes. 



Line Current. Excursion. 



3.15 33 



2.76 27 



2.05 14 



Series IX. 

 Magnetizing Current = 160 milliamperes. 



Line Current. Excursion. Line Current. 

 3.46 73 2.29 



2.98 56 1.72 



2.74 46 



Excursion. 

 32 

 23 



