Iron under Alternating Magnetic Force. 



221 



frequency with a 1 mm. wire. Figs. 5 and 6 show the relation between 

 the frequency in complete periods per second for a 1 mm. wire and the 

 same two quantities respectively. Since a plate, with regard to 



Fig-. 5. 



Fro. 6. 



induced currents in its substance, is comparable to a wire, the thick- 

 ness of the plate being half the diameter of the wire, the above curves- 

 may be taken to apply also to a J mm. plate. In figs. 3, 4, 5, 6 the 

 points indicated by x are the result of experiment when the magnet 

 had a temperature of about 15° C. 



R 2 



