334 H. R. Hamley and A. L. Ross iter : 



Tables IV., V., VI., give the corresponding results for the un- 

 annealed ring. 



In each set a space is left in the rows below which the in- 

 fluence of the higher harmonics begin to be noticeable. Gen- 

 erally the sign of these higher harmonics is negative in 

 the magnetizing force, and in the induction always positive. 

 S. P. Thompson's method of analysis was used for these more 

 distorted waves and the inclusion of the higher harmonics con- 

 siderably modified the total losses. 



A])ove the space in the rows, the readings may be taken as 

 Ijelonging to approximately sinusoidal waves. In the graphs 

 all the chief characteristics of the induction waves are plotted 

 against the amplitude of their first harmonic (Bj). 



The results of the statical experiments show several inter- 

 esting features. The hysteresis constant has its masimum value 

 uljout .0015 which is about the same as Epstein's value. On 

 plotting it against the induction a smooth curve was obtained 

 which rises from the origin to a maximmn value at an induc- 

 tion of 3000 (the value of a- being .00122), it then decreases 

 to a minimum at 4000, after which there is a steady rise which 

 continues as far as the experiments go. This curve is similar 

 in shape to that obtained when using ordinary iron.^ 



" Stalloy " needs careful handling especially in the unan- 

 nealed state in order to obtain symmetrical results. When the 

 magnetizing current is gradually increased and reversals are 

 freipiently the hysteresis loops are symmetrical and the Stein- 

 metz coefficient when plotted against the maximum induction 

 gives a smooth graph. But if, after working at high densities, 

 an experiment is made with a small magnetizing foi'ce the loop 

 will be found to be unsyunnetrical and the corresponding value 

 ■of o- will lie outside the previously obtained cr graph. This 

 has also been drawn attention to by Wilson. In the unannealed 

 state therefore '" Stalloy " seems to be magnetically unstable so 

 that the previous history of the material has a very marked 

 effect upon its subsequent behaviour. The annealed " Stalloy " 

 showed similar results but these were very little more notice- 

 able than those obtained for ordinary iron. 



1 T. R. Lvle. Loc. cit. 



