432 Proceedings of the Royal Society of Edinburgh. [Sess. 
A thicker wire, of diameter T65 mms., gave the results 
« = 85, n = ‘66, b = 360. 
In this case the readings had to be taken very quickly, since the oscilla- 
tions died down with extreme rapidity, and thus the accuracy could not be 
so great as in the former experiments. This was found to be even more 
apparent in the next experiment, with a wire of diameter 2 0 mms. It was 
found impossible to take readings with any degree of accuracy with 12 
inches of this wire, and so a double length was taken. Distinct pendulum 
oscillations were also of more frequent occurrence when the thick wire was 
used, and the curve obtained showed a wavy appearance. By drawing a 
straight line through the observed points, so as to eliminate the disturbing 
effect, the following results were obtained : — 
<2 = 90, n=' 84, 6 = 427. 
This value of b, as shown on page 427, can be compared with the values 
got with the wires already discussed. For it was shown that in a wire of 
half length 
Thus the value of b will be got for that of double length by 
6 = 6 ' * 2 n 
= 238. 
The value of b, then, although not exactly under control, is seen to 
decline steadily with increases of diameter, thus : — 
Diameter 
a. 
n. 
b. 
1 mm. 
About 100 
•70--80 
700-1000 
l - 2 mm?. 
95 
•70 
439 
1-65 1 
80 
•66 
360 
2-0 „ 
90 
•84 
238 
The values of a and n, then, are independent of change of sectional area, 
just as they were of change of length taken. This is to be expected, in 
accordance with the original assumption that the loss of energy for a given 
material depends solely on a power of the angle of distortion. 
Annealing from High Temperatures. 
A length of brass wire heated to 535° C. was annealed and then tested. 
The values got were 
A: a=l, n= 2-30, 
B: <2=1, 72 = 2*70, 
