30 AliT. 7. K. HONDA AND Ï. TEKADA. 



It is to be noticed tkat in nickel, the initial and the cyclic 

 effects of tension or twist on magnetization nearly coincide with 

 each other except in weak fields, and that the change of mag- 

 netization does not much depend on the order of magnetizing 

 and straining. Thus, in nickel, the hysteresis effect is compara- 

 tively small except in weak fields ; and therefore the agreement 

 between the theory regarding mngnetostriction and the experi- 

 ment might well have been expected. Thus, in our previous 

 experiment, we found that the changes of the modulus of elasticity 

 by magnetization for different ordeis of magnetizing and straining 

 fairly coincided with each other, while in the case of rigidity, 

 the diflei'ence w'hs somewhat greater. In the present experiment 

 also, the tension effect shows a better aoreement for different 

 orders of magnetizing and straining than for the torsion effect. 



III. NICKEL STEELS containing 28.74, 50.72 and 

 70.32 per cent of Nickel. 



As for nickel steels, experiments on the effect of stress on 

 magnetization have been very few. So far as we know, the 

 effect of tension only was studied by H. Tomlinson^' with nickel 

 steels of 22, 25 and oO per cent of nickel, and by Professor H. 

 Nagaoka and one of us'"' with nickel steels of -îô and 45 per 

 cent of nickel. Hence somewhat detailed desci'iptions of the 

 phenomena will not be unnecessary. 



(a) Change of inagnelizaUon bij lenalon under cundant 



field: {of, T)j, 



The magnetization increases at first rather rapidly, l)ut after- 



Ij Tonilinson, Proc. Roy. S, c. 56, p. lO:), 1894; Beibl. 1», M2. 

 ■1) Xii,'iioka ami HoikUi, Juur. C .11. Sei., 1«, Art. 8, lUO'J. 



