8G 



K. HONDA. 



I 



air 



l + ßH" ' 



where «, ^9 and n are constants and H is assumed to be positive. 

 The determination of these constants from the experimental 

 curve gave the following results : 



« = 5.18, ^9=0.0164 and n = 1.017. 



In the calculation, only the fields H = 20, 80, 320 were 

 chosen to simplify the calculation. Using these values of the 

 constants, the change of length due to fields of different strength 

 was calculated and compared with the experimental value as 

 shown in the followinir table : 



TABLE III. 



