8 AKT. 9.— K. HONDA AND S. SHIMIZC : CHANGE IN LENGTH 



.5. ll'olfram Steel. Fig. 3 represents the results for wolfmm 

 steel hardened by stretching ; the anomaly of the change of length 

 for the steel Avas already pointed out by Professor Xagaoka and 

 one of us. The anomaly gradually disappears as the tension is 

 increased ; and by a tension of 25.63 kilograms per square millimeter, 

 the steel behaves like a well annealed soft iron. The amount of the 

 diminution of the magnetic elongation per gram is considerably 

 smaller than that of other ferromagnetics. 



Fis;. 4 shows the relation between the chano-e of lenirth and the 

 tension under a constant held. In this case, the proportionality 

 between the tension and its effect on the mao^netic chano;e of length is 

 almost satisfied. 



Another wire of wolfram steel was Avell annealed and tested, 

 giving the results shown in Fig. 5. Here we notice that the anneal- 

 ing quite effaces the anomaly, increasing at the same time, the effect 

 of tension on the changfe of lens'th. 



The following table contains some of the results of observations 

 on tlie hard-drawn wolfram steel : — 



