CHANGE OF ELASTIC CONSTANTS OF FERROMAONETICS. 



on 



ly resembles that of 'j as given by tbe flexure method. Jii 

 both cases, the right order of applying the stress and the field 

 is inverted. 



Soft Iron. Figs. 09 and 70. 

 TABLE XXXIX. 



Since the time of the previous experiment, the si»ecimen had 

 been once annealed at a temperature of about 1100° C, so that 

 the chano;e of ridditv "1^ was somewhat increased in the present 

 experiment. The effect of the amplitude of twist on the change 

 of rigidity is very small ; the increase of the twist slightly aug- 

 ments the change of rigidity up to the range of the twist used. 

 The residual twist is always positive as in the case of nickel. 

 "j^ is always inappreciable in the present arrangement ; if it exist 

 at all, it can not be greater than O.Oô ç^, for the maximum field used. 



Thus, in nickel and iron rods, j^ is always far greater than 



