114 On the Effect of Stress on Magnetization. 



Among all the specimens tested, nickel affords the best 

 evidence in favour of the theories above tested. The dis- 

 crepancies due to the difference of the orders of applying 

 the stress and the field, are generally small, when compared 

 with those in the case of other specimens. The agreement 

 is especially good in the case of tension effect, if the term 



TT T^TT ^ e su PP res ?ed ; the differences between the values 



^yj and ^7p are of such an order of magnitude that they 



maybe explained by the errors introduced in estimating these 

 values from the corresponding diagrams. For the rest of 

 the specimens, the agreement is tolerably good in many cases, 

 except a few cases in which it completely fails. Generally 

 speaking, the tension effect shows a better agreement between 



theory and experiment, if ^yt be compared with ^= ; 

 r'dll d LoIJh 



while ^7n deduced from the (I, H)t curve is often of a 



different order of magnitude, as in the case of 28*74 percent. 



Ni. As for the comparison between — ^2^5- an d ^r 2 , 



the agreement is less remarkable, but the discrepancies may 

 in many cases be due to the errors introduced in estimating 



the curvature of the curves for obtaining ^7^ > ^^ 



deduced from (I, H)t curve is often of a different order of 

 magnitude, as in the case of Swedish iron. For torsion 

 effect, things are much more complicated, except in the case 

 of nickel and nickel-steels of 28' 74 and 70'32 per cent, of 

 nickel, in which the agreement is fairly good. For the last 



two specimens, - ^ generally agrees with - 4S 1 



'lr;w-| T Lo-kJii r LafiJ H 



or - ^-77 , while in the case of 50*72 per cent. M, the 



former is of a different sign from the latter for small twist. 

 In all cases, the discrepancies become less in high fields. 



2-7rBI 2 

 As to the term ^ ^^ obtained by Gans and Sano, it may 



be noticed that its introduction makes the agreement between 

 theory and experiment rather worse. The origin of this term 

 is, however, to be traced to the fundamental assumption that 

 at the ends of the specimen wire, the lines of induction issue 



