436 
Proceedings of the Royal Society of Edinburgh. [Sess. 
line including all the points over the period of 100 oscillations, and the 
tendency towards a straight line after heating to redness is quite an opposite 
result to that noted for brass. 
Copper Wire. 
Length of wire used =12 inches. Diameter = *80 mm. This wire, 
tested at the ordinary temperature, with values of log y plotted against 
those of log gave with <x = 5 an s-shaped curve (see diagram 8). 
•20 -30 *40 *50 -60 ‘70 ’80 *90 1’0 
It was found possible to obtain two straight lines here by taking different 
values of a for the two parts, the actual figures being 
A: a= 0, w = 3*80, 6 = 446. 
B: a= 15, ?i = L60, 6 = 317. 
Another specimen cut from a different part of the wire gave 
A: a = 0, n = 3*20, 6=1030. 
B: a= 10, n= L70, 6= 216. 
