382 H. NAGAOKA. 



the magnetizing force is sufficiently great. If the similarity exists, 



there should be a reversal in the direction of the transient current. 



With the strongest magnetizing current at my disposal (§ = 500) no 



reversal of the transient current was noticed. The analogy thus 



seems to fail in very strong 1 magnetizing" fields. 



The following gives the summary of the results obtained in the 



present investigation. 



1. — The transient current produced by suddenly twisting the iron 

 wire, or by reversing the direction of the magnetizing force while 

 the wire is held twisted, through a constant angle, increases as 

 the field is increased, but after reaching a Wendepunkt, it soon 

 arrives at a maximum point, whence it begins to decrease slowly 

 as the field is further increased. 



2. — The rise of the transient current in gradually increasing fields is 

 smaller for large than for moderate angles of twist, but in strong 

 magnetizing fields, the current becomes greater as the twist is 

 taken larger. 



o. — The maximum point varies with the amount of twist, and occurs 

 in higher fields as the twist is taken larger. 



4. — The transient current in stretched iron wire is less than that 

 in the unstretched. 



5. — The transient current produced in a constant magnetizing field by 

 varving the amount of twist increases at fir.st with the increase of 

 twist. The current, however, arrives at a maximum point, whence 

 it begins to decrease slowly as the twist is increased. 



6. — The initial rise of the transient current as the twist is increased 

 is greater in weak than in strong fields. 



7. — The maximum point varies with the strength of the magnetizing 

 force, and occurs for larger twists as the field is stronger. The twist 

 corresponding to the maximum current is smaller by the method 



