350 Proceedings of the Poyal Society of Edinburgh. [Sess. 
would pass through the values on opposite sides of it. After this, there 
was again a steady fall, and at 25 0, 3, the last reading taken with a current, 
the value was the lowest obtained. 
The last reading of all was at the temperature of the room, and the 
value was higher than that got before any current was passed through 
the wire. The current had thus produced a permanent increase in the 
modulus. 
Steel Wire. 
Length = 97*60 cms. 
Area of cross-section = *0004714 sq. cms. 
Stretching weight = 500 grams. 
No. 
Temp. 
Elongation for 
500 grams. 
No. of 
Observations. 
M. 
1 
13°*7 C. 
*04697 cm. 
8 
21-63x10 11 
2 
15 *0 
*04791 
8 
21-21 
3 
19 *0 
*04744 
4 
21-42 
4 
24 *2 
•04702 
6 
21-58 
5 
30 *0 
•04686 
6 
2T68 
6 
34 *0 
•04682 
8 
2T70 
7 
37 *0 
•04678 
8 
21-72 
8 
41 *0 
•04682 
10 
21-70 
9 
46 *4 
•04697 
7 
21-63 
10 
59 *2 
•04706 
8 
21-59 
11 
72 *6 
•04717 
8 
21-54 
12 
83 *2 
•04735 
8 
21-46 
13 
98 *6 
•04779 
8 
2T26 
14 
108 *0 
•04814 
9 
21-15 
15 
100 *3 
*04763 
6 
21*33 
16 
88 *8 
•04702 
8 
21-58 
17 
85 *8 
•04697 
10 
21*63 
18 
76 *9 
•04662 
12 
21-79 
19 
64 *2 
•04637 
9 
2T91 
20 
57 *0 
•04631 
8 
21-94 
21 
45 *0 
•04659 
8 
21-82 
22 
40 *3 
•04691 
8 
21-66 
23 
34 *5 
•04750 
8 
21-39 
24 
25 *0 
•04891 
8 
20*77 
25 
15 *6 
•04622 
8 
2T98 
Vertical Wire. 
26 
17 *3 
•04815 
1 6 
21-10 
Steel Wire. 
As stated in the general description, the same series of experiments was 
followed with all the wires ; therefore the first reading was taken at the 
temperature of the room before any current had been passed. A weak 
current was then used, and it produced a fall in the modulus. The current 
