1904.] Length in Annealed Rods of Cobalt and Nickel. 63 



200 



400 



FIG. 3. 



600 800 



1000 



1400 



150 



-f) 



Magnetic held 



Drawn nickel, (e) unannealed, (f) annealed. 



length produced by magnetisation, and the changes of magnetisation 

 attending mechanical strain,* it, may be inferred that there would be no 

 Villari reversal in well-annealed iron, like that of which the ring above 

 referred to consisted, nor in annealed cast cobalt. In the rolled cobalt, 

 however, to which the curves in fig. 2 relate, it might be expected that 

 the effect would be considerably increased by annealing. 



* J. J. Thomson, 'Applications of Dynamics to Physics and Chemistry,' 

 pp. 4759. 



VOL. LXXIV. 



