30 



AKT. 8.— H. XAGAOKA AND K. HONDA 



45% nickel steel, 

 (annealed) 



34.0 f^^^ 

 V cm-. 



30.2% nickel steel, 

 (unannealed) 



c = 371.5 



anip. \ 

 cnr. / 



23.6% nickel steel, 

 (unannealed) 



c = 310.0 f-^ü^ 

 \ cm-'. 



H 



H 



H 



Tlie direction in whicli a nickel steel wire twists is the same as 

 in iron. If the north pole of the wire suspended vertically be at tlie 

 free end, and the direction of the current traversin«: the wire be down- 

 wards, the torsion of nickel steel seen from above is in the direction 

 of the hands of a watch. 



The amount (^f torsion (Fig. 9.) increases with the magnetic field, 

 but it soon reaches a maximum, to decrease afterwards quite slowlv 

 as the field becomes stronger, and the torsion of the wire is reversed in 

 strong fields. With the samples tested, the torsion increases with 

 the percentage of nickel. The 23.6% Xi and 39.2% Xi samples were 

 examined in a hard drawn state ; but the 45% Xi wire was exam- 

 ined after annealing- it in hvdroo'en, as alreadv described. 



