Combined Effects of Torsion and 

 Longitudinal Stress on the Magnetization 



of Nickel. 



By 



H. Nagaoka, Rigakushi. 



of t)ie 

 Imperial Uuivevsity. 



With Plates XYI- XIX. 



The crt'ect of torsion in altorino; tlit' induced inno'netisni of iron 

 lias long' cngaut-il tlic iittontion (^f many physicists. Among the 

 experimenters in this helil of research may he named Wertheim, 

 Wiedemann. Tliomson, and Tomlinson (wliose latest work on such 

 subjects T have not yet seen.) The experiments of Wiedemann were 

 made hv twisting and untwisting the wire, which was placed hori- 

 /.ontallv in a magnetizing solenoid, till the changes of magnetism 

 became cydic. lîui it was Tliomson who tirst investigated the etfect 

 of torsion on the magnetism of iron, the wire being at the same time 

 subject to definite longitudinal stresses, in his experiments, the soft 

 iron wire was placed vertically in the earth's tield. Xo one seems to 

 have made similar experiments in dilfVrent magnetizing fields. Scanty 

 though this kind of investiiration bis been for iron, it is still more 

 scanty for nickel. Indeed, so far as I am aware, the effect of torsion 

 on the mao;netism of nickel wii-e under various longitudinal stresses 

 has not hitherto been investigated. This accordingly was the problem 



