Ma>;nctic Separations of the Lines of Iron, Nickel and Zinc in Different Fields, -3 



II. The Method of Experiment. 



1. Light Source. A spark discharge between nickel steel and 

 zinc wires by an induction coil was used as the source of light 

 throughout the experiment. The primaiy current of the coil was 

 supphed at 100 volts and 50 cycles from the secondary of the pole 

 transformer of the laboratory, run at 3500 volts of the city main. 

 The current strength was usually from 3 to 4 amperes, 



The spark discharge, as the source of hght, was placed in 

 the middle between the two poles of the electromagnet and 

 the spark gap made as small or large as the case required. 

 In Fig. 1. the spark can be displaced by means of screw 



A. With a view of 

 changing the spark gap, 

 C can be moved up and 

 down by means of D, 

 and a small adjustment 

 made it possible to keep 

 the ends at a constant 

 distance from each other, 

 when the ends of the 

 electrodes move away 

 during the sparking. B 

 and C are insulated by 

 pieces of ebonite e and 

 e'. 



As the terminals for 

 the spark must be put 

 in high magnetic fields, 

 it was necessary to use 

 pieces which were made non-magnetic if possible. A non- 

 magnetic nickle-steel alloy containing about 25^ nickel'^ is most 

 recommendable for this purpose as a portion of the photograph of 



-^lovn .tfxc -inOsiciloit Colt. 



JoJ;hc -InDtvct tC4 1 Colt, 



1) Nagaoka and Honda, Journ. Coll. Sc, Imperial University, Tokyo, 19 (1903-1904) 

 Art. 11. 



