2',) 'J 11. XAGAUKA 



The curve thus oljtiiined (see Fig. 5) is nearly j)erleetly .symiiietrieai 

 with resjiect In the hue of zero twisting. Also, the magnetization 

 I'eniains positiN'e thi'oughoiit the whole cyi/le. It is inoreoNei' interest- 

 ing to observe, that tlie curve is exactly the reverse for tli;it uf irun 

 as obtaineil li\' Thoni-nn. 'i'his sliows that the lieha\iiim' nf nickel 

 twisted in a niagildic hi'M inider I'eehle loads is opposite to that 

 of iron. 



Wheu the stress was inereased to 1-1.5 kgä. weight per m^. eui.. 

 the nia"'netization curve lost its sviunietrv and l)ecanie as shown in 

 Fio-, G. 'I'hc intensity of inaonetization became greatly diminished, 

 but still remained positive thronghout the whole eyele of operations. 

 The features to be noted are that, although suggestive (jf the sym- 

 metrical I'orni given in Fig. T). the eur\e is now distinctly one-sided 

 with respect to the line of zero twisting, and indicates nni<h greater 

 magnetization for positive than for negative twists. The>c peculiari- 

 ties are still more pronounced when the stress is increa.^cd lo 209 kgs. 

 as shown in Fig. 7. 



This experiment is of special interest, illustrating as it doe>. the 

 manner in which the magnetization cycle changes character just as 

 the extraordinary phenomenon of change of sign is about lo show 

 itself. 



As usual the lirst effect of twisting the wire i.^ lo increase the 

 intensity of magnetization, while the elt'ect of untwisting is to decrease 

 it. Then as the untwisting is continued as negative twisting, the 

 mao'netization tends to recover its former ^'aluc. But for the maxi- 

 niuin iiet^^ative twi«t of two ri^lit aiiu'les, the iiia2:i)etization dot's act 

 nearly recover its former value. Thus it is evident that in such a 

 strenath of field, the increase of lono-itudinal stress tend.s to make the 

 increase of magnetization during negative twisting gradually less ami 

 les> until linallv I'oi- a certain load ihe increase does not take place at 



