130 H. Nagaoka on Transient Electric Current produced 



changing the amount of twist while the magnetizing force is 

 kept constant. 



The following Table gives the readings of the first swing, 

 in weak as well as strong magnetizing fields. 



Iron Wire (V = *51 millim., 

 Z=30 centim., £ = 2'15). 



Iron Wire (r = *73 millim., 

 1 = 30 centim., £ = 112). 





Eeacling of 



r. 



ballistic 





galvanometer. 



o 





10 



4-0 



15 



159 



20 



30-2 



25 



43-4 



30 



529 



40 



63-5 



50 



687 



60 



71-7 



70 



70-7 



80 



70-3 



90 



68-8 





Eeacling of 



T. 



ballistic 





galvanometer. 



O 



15 



3-7 



20 



61 



25 



7-1 



30 



9-1 



40 



13-2 



50 



161 



60 



19-0 



70 



21-5 



80 



234 



90 



247 



100 



24-3 



The results of these and other experiments (September 

 22-26, 1888) are plotted in fig. 4. 



Examining the curves obtained in weak magnetizing fields, 

 we notice that the transient current increases with the 

 increase of twist at first very rapidly, but after passing the 

 "Wendepunkt" becomes very gradual. The current ulti- 

 mately attains maximum strength, and then begins to diminish. 

 In a strong magnetizing field the current is greatly diminished, 

 and the curve becomes less steep. The increase goes on 

 slowly with the increase of twist up to the maximum. Com- 

 paring the results obtained in different magnetizing fields, 

 we notice that the twist for which the current is maximum 

 becomes greater as the magnetizing force is increased. In 

 fact the maximum for the wire of radius *73 millim. occurs 

 when the twist is about ±60° for £ = 5'0, while for £ = 112 

 the twist of 100° is barely sufficient to make the current 

 reach the maximum strength. 



With nickel wire treated in the same way as above, the 

 following readings were taken (October 1, 1888): — 



