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ROYAL SOCIETY OF CANADA 



where the increase of resistance is so small as to be hardly measurable, 

 and accuracy cannot be depended on. This result is an evidence that the 

 assumplïion on which the results are based is not far astray. 



Constantin. 



A piece of wire of the same material as described in my paper on 

 " The Effect of an Electric Current on the Modulus of Elasticity was, 

 used. Eesults are given on data sheet P. Fig, 2 shows the increase per 

 cent resistance on per cent stretch, up to a few point? beyond the elastic 

 limit the position of which is marked on the curve. This curve is a 

 straight line with slope equal to 2. 



i6 



•* 6 a 



INCftCASC PER CCN-r S-TRE-rCH 



Fig 3, 



Fig. 3 corresponds to the full extension undergone by the wire. 

 This cur\ie bends in the direction opposite to that which we should ex- 

 pect, owing t(0 the low value for specific resistance which the calculations 

 for the last four points sihow. (tSee data, Sheet i:*.) It must be noted 

 that the extensions corresponding to thesie points were obtained simply 

 by pressing downward on the scale pan with the hand, the material being 

 so plastic as to allow this to be done with ease. Probably a large part of 

 this extension took place just at the suspension, for it was noticed that 

 in all cases, whenever the wire broke, this was where the breaking took 



