200 



H. XAGAOKA. 



again double looped as in Fig. 21. 



( 'urvesfor large twists. — When the range of twist is increased to 3° 

 or 4° per em., a reversal of hysteresis by increasing the magnetizing 

 force is not obtained. The curves are generally of the same character 

 as those already described for the twist of 4°. 5. Even for such large 

 twists as '.>° or 10° (see Fig. 22 and Fig. 23) the above remark hold« 

 true, the hysteresis being such that the going always passes above 

 the returning curve. To give detailed description on this point would 

 be merely repeating the earlier paper, and I feel no need of entering 

 into the discussion of the results for these twists. 



Effect of holst in sinnig magnetizing fields. — Another thing which 

 calls lor remark is the behaviour of nickel in strong magnetizing fields, 

 during cyclic twist ings. It was already noticed for the twist of ± 1°.5, 

 how the magnetization diminishes on twisting, and increases on un- 

 twisting and how a particular complexity in the curve precedes the 

 transference into such a state. The same curve of transition is also 

 observed when the amount of twist is so large that the reversal of 

 hysteresis takes place in a low magnetizing field. This is well ex- 

 emplified in Fig. 24, which was obtained for Jq=20.8 with a thicker 

 wire twisted ± 2° per cm. But owing to the reversal of hysteresis, 

 the course of the curve is different as the comparison of Figs. 13 

 and 24 will shew. The general character of the magnetization curve 

 in strong magnetizing field, during cyclic changes of torsion, is 

 shewn in Fig. 2ô, which is given, as a type of such curves. It 

 was obtained with a wire of 0.43 mm. radius in a held of 24.7. There 

 is constant decrease of magnetization during twisting, and increase 

 during untwisting up to a certain angle of twist, where if reaches a 

 maximum. It then diminishes, and returns to its former value when 

 the wire is brought to the initial position of zero twisting. The in- 

 tensify of magnetization is alwavs greater during untwisting than 



