52 



Dr. J. HopMnson and Mr. E. Wilson. [Mar. 17, 



The loss by hysteresis is about 13,000 (' Phil. Trans.,' 1885, p. 463) 

 if the reversals are made by variation of intensity of the magnetising 

 force, and the iion i3 good wrought iron. This result is similar to 

 that in the earlier paper (p. 352), where it is shown that the actual 



