165 



Fig. 4. Hysteresis Plot. 



COXCLUSIONS. 



The plot here given establishes the fact that the magnetic properties of 

 iron and steel can be obtained by the permeameter method to a reasonable 

 degree of accuracy, sufficient for student purposes. 



From a number of tests which have been made the permeameter estab- 

 lishes in an interesting way the fact that a much stronger current is required 

 to bring a hard metal to magnetic saturation than a soft metal. 



The permeameter test also demonstrates that the magnetic pull exerted 

 by a soft metal is much stronger than that of a hard metal under the influ- 

 ence of the same current. 



Thes3 peculiarities are more easily shown by this instrument than any 

 toher, owing to the fact that different metals can be examined under the same 

 conditions. 



Physical Laboratory, Earlham College. 



