OX TRANSIENT ELECTRIC CURRENTS. 



341 



magnetism, a transient electric current will be produced, when it is 

 twisted even in zero magnetic field. In fact, one can test whether 

 the wire is completely deprived of magnetism or not. simply by 

 twisting it with its length placed due magnetic cast and west, and 



O Ol K -> ' 



observing if there exist any transient current or not. The wire thus 

 prepared was placed within the magnetizing solenoid, and suddenly 

 twisted through an angle of 1.")°. It was then twisted back through 

 zero to an equal angle of twist on the opposite side of zero. The 

 total twisting was therefore through an angle of 30°, namely, + 15° — 

 ( — 15 e ). This twisting I denote as on previous occasions, by ±15°; and 

 generally the twisting ±0 means a twisting to and fro through an 

 angular range 20 about the original position of no twist. Generally 

 the transient current did not settle to a constant value until the wire 

 was twisted several times between the two extreme limits of twist. 

 For each of a series of gradually increasing values of the magnetizing 

 force, the transient current produced by one sudd.cn twisting from 

 limit to limit was measured on the ballistic galvanometer after the 

 system had through repeated to and fro twistings reached a steady 

 cyclic condition. The following are the values in successive fields : — 



* One scale division corresponds to 1.1 x 10-° Coulomb. 



