434 
Proceedings of the Royal Society of Edinburgh. [Sess. 
had reached the value of 100 that the remaining points could be fitted into 
one straight line. Of course, as cc is increased, the curve tends to flatten in 
any case, but in the present case the slope of the line is still large, so that 
the linearity is real. 
The values got here are 
Line A: a= 0, n= 1*34, 6 = 31 T. 
„ B: a=100, n = -20, 6 = 212. 
This wire, then, offers a marked contrast to brass, as not only is it found 
•06 *08 *10 *12 *14 '16 *18 -20 *22 ’24 *26 *28 *30 -32 *34 *36 *38 
impossible to group the points along one line, but very different values of a 
have to be taken to cause them to lie along two lines. 
The effect of heating the wire to redness was next studied, and, whilst a 
double line was still the result, the curve showed a marked tendency to 
assume the condition of one straight line, as the two values of a required 
were identical, and n did not have greatly differing values. 
The values got were 
1st line, a— 1, n = 4 65, 6 = 150. 
2nd ,, a = 1, n = 3-75, 6= 109. 
