Elasticity of 'Ferromagnetic Substances by Magnetization. 51 



Table XII. 

 AT=±816 gr./mm. 2 





T=1692gi\'miu.- 



T = 4947gr>m/- 



H. 





( - 1 / X102. 

 J- II 



50 





0-4 



100 



0-2 



0-5 



200 



0-3 



o-o 



300 



05 



06 



400 



05 



07 



Thus, in the case o£ iron and steel, relation (3) does not 

 hold, even approximately, when the tension is small. But as 

 the tension is increased the discrepancy becomes less. 



Nickel-Steels. 



(i.) 28*74 per cent. Nickel-Steel PI. I. figs. 9 & 10. 



The specimen first elongates rapidly and then almost pro- 

 portionally with the field. The effect of tension is generally 

 to depress the change of length. The general feature of the 

 change may be seen in the following table and in fig. 9. 



Table XIII. 



* = 10°"3. 



T=1427 



gr. nun. 2 



T=21K 



gr./mm. 2 



T=279S 



gr./mm. 2 



H. 



j X 10". 



H. 



^xW. 



H. 



fxl0«. 



0-2 



-o-oi 



0-3 



-0-04 



02 



-001 



0-6 



-0-05 



0-6 



-0-09 



0-6 



- 0-06 



12 



4-0-13 



11 



4-0-07 



1-3 



4-0-13 



20 



4-0-27 



21 



+0-26 



2*2 



4-026 



4*1 



4-0-52 



4-2 



4-0-51 



5-4 



4-049 



8-9 



+ 0-80 



12-8 



4-0-34 



15-3 



4-0-71 



261 



4-1-11 



25-4 



4-1-04 



26-0 



4-0-85 



439 



4-l'29 



433 



+ 1-22 



43-4 



-fl-04 



68-3 



4-1-52 



68-1 



4-1-47 



(58-5 



4-130 



113-0 



4-1-98 



113 6 



+ 1-93 



1141 



4-1-74 



207 



4-2-87 



206 



4-2-78 



208 



+2-66 



303 



+3-77 



302 



4-3-71 



305 



4-3-57 



404 



4-467 



404 



+4-66 



405 



4-4-50 



E 2 



