•Mti 



H. SAliAtJK'A 



r^4°.-j per cm. 



T=9° per cm. 



The curves .showing the temporary and residual magnetisms are given 

 in Figs. 0,1, ()„, 7„, and Figs. 5,,, 6,„ 7,, ; and the curves showing the 

 ratio of the rcsichial to the iiuhiced magnetism in Figs. 5,., 6,., and 7^.. 



The inspection of these figures will show how curious a change 

 is produced in the residual magnetism of twisted nickel wire, when 

 the magnetizing force is that which corrcs[)i)nds to maximum suscep- 

 tibility. In some cases, the amount of residual magnetism is indeed 

 enormous, reaching to .UcS of the induced magnetism. 



Examining the curves obtained f)r the wire which was only 

 subject to till' action of its own weight and the twisting rod, we see 

 that f )r tile untwisted wii'c, the r;itio of residual to temporary magnet- 

 ism increases to a maximum at about field 1(1. Its \alue is then .74. 

 At higher fields, this ratio graduidly dimini^lies. The curve repre- 

 senting these ratios is shown in Fig. .5.. iJut when tlie wire is twisted 

 only through ati angle of (T.!) per cm., the curves of induced and 

 residual magnetisms are cpiite dilfercnt from those of the untwisted 

 wire. The ratio of residual to temporary magnetisms increases up to 



