of Steel, Nickel, Cobalt, and Nickel- St eels. 



49 



The curves of magnetization are represented in fig. 1. 

 The most magnetic of the metals here examined is cast steel, 



Fig. 1. 



ST.fc.cs.) 











ST 



££t 













































7, 



r 







*6 9 /o 





























innn 



1 









CAST 



-OBAi-1 











800 

 600 



y 









36% 



VlCHEi 



ST££i 



















alzd^ 



*0B*rf 











Nic 



«£L 

















400 



























29% 



N/cke 



L Stci 



L 







200 



' ' 



















V 



















$< 



500 600 700 800 900 1000 



whose magnetization comes very near to that of soft iron. 

 Of the two kinds of cobalt the cast specimen lies between 

 steel and nickel ; but with the annealed specimen the suscepti- 

 bility is small in weak fields, and less than in nickel, and the 



differential susceptibility ( -77^ J is greater in the strong, so 



that the intensity of magnetization becomes greater than in 

 nickel. 



Of the three kinds of reversible nickel-steels the 46 per 

 cent. Ni specimen approaches steel, the 36 per cent. Ni lies 

 near cast cobalt, and the 29 per cent. Ni is less magnetic 

 than pure nickel. The magnetization reaches asymptotic 

 value in fields less than those for steel or cobalt. The 

 25 per cent. Ni specimen is only feebly magnetic, so that its 

 magnetization is scarcely to be detected by the magnetometer. 

 Here we notice a singular fact, that the intensity of mag- 

 netization in nickel-steel is not proportional to that of the 

 constituent metals. 



§ 3. Change of Length by Magnetization. 



(a) Cast Steel (fig. 2). 



Dr. H. da Bois was kind enough to give us a piece of cast 

 steel which w;is regarded as the most homogeneous specimen 



Phil. Mag. S. 6. Vol. 4. No. 19. July 1902, E 



