Brown — The Change of Length in Nickel Wires. 



49 



Magnetic Field. 



IQO 



The figure shows in the form of curves the results obtained with the wires 

 having the highest and the lowest rigidity of those used in the experiments 

 when the longitudinal load of 05 x 10 5 grammes per sq. cm. was on the wires, 

 and when the wires were under the influence of magnetic fields D.C. and A.C. 

 of frequency 150 per second. 



The two higher curves are those obtained with the wire having rigidity 

 810 x 10 6 grammes per sq. cm., and the two lower curves those obtained with 

 the wire of rigidity 708 x 10 6 grammes per sq. cm. 



From these curves, as well as from Tables II and IV, above, it will be seen 

 that for a decrease in the rigidity of about 12^ per cent, the contraction of the 



SOIENT. PROC. K.D.S., VOL. XV., NO. V. H 



