354 



H. NAGAOKA. 



10 



Fia, ß. current and the angle of 



torsion. F. is for the me- 

 thod of sudden twisting", 

 while II. is for the method 

 of sudden reversal. 



Tn the preliminary in- 

 vestigation on this subject, 

 r I have already noticed the 



*'0 III 50 80 100 120 n ,i ,i ,• • 



fact that the magnetizing 



field giving the maximum transient current by sudden twisting is 

 less than that obtained by Professor Ewing by the method of 

 reversal. I then thought the discrepancy to be probabty due to 

 difference of procedure. On experimenting in these two ways 

 with the same wire. T now find that the difference in the position of 

 the maximum is certainly due to the différence in the method. But 

 it seems inexplicable why this should be so, unless the ultimate causes 

 of the transient current are known. 



Corresponding to the experiments made by twisting the wire 

 through different ranges in constant magnetizing fields, another set of 

 experiments was tried by reversing the direction of the magnetizing 

 force for different amounts of steady twist. Curves showing the 

 relation between the transient current and the amount of twist are 

 given in Fig. TV. These curves were obtained for the following 

 different strengths of the field. 



Curve I for £>= 1.6 



II „ ©= 5.2 



III „ §= 8.3 



IV „ § = 13.0 

 V „ \v 51.8 



VI „ §= 5.1 (loaded 4 kg.) 



