Brown — Subsidence of Oscillations of Iron Wires and Alloys. 395 



From these values in Table I it will be seen that, for the hard wire, the 

 amplitude of the 70 th vibration is diminished for the increased load in both 

 the D.C. and A.C. magnetic field, wliereas, for the soft wire (Tables II and 

 III below), the amplitude of tlie 70th vibration is decreased in the D.C. field 

 and increased in. the A.C. field for increased load. 



The wire was then taken down and liung vertically and loosely under its 

 own weight only, and heated to a bright-red heat three times, from the top 

 downwards, by means of a Bunseu flame, so as to make it as soft as possible. 

 It was then cleaned and its rigidity again measured, and, when replaced in 

 the solenoid, it was put through the same tests as before. The results are 

 shown in Table II, and part of them, in tlie form of curves, in fig. 1, in 

 which, for comparison, is also put the corresponding curve for nickel wire.^ 



"^200- 



Q 100- 



"^ 



I' 



25 50 



Number of Vibrations. 



Fig. 1. 



1 Scient. Proc. Roy. Dub. Soc, vol. xiv, 191i, iS'o. 14, p. 221. 



3 s2 



