233 
1910-11.] Young’s Modulus under an Electric Current. 
Table XIV. 
Field. 
Load in kilos, 
per sq. mm. 
Elongation for 
5 kilos. 
No. of 
Observations. 
M. 
35*4 
13-0 
•02042 cm. 
7 
15-21 x 10 11 
15-0 
•02046 
8 
15T8 
173 
•02053 
7 
15T3 
21*6 
•02065 
9 
1504 
26-0 
•02077 
6 
14-95 
30 3 
•02085 
6 
1489 
34-6 
•02098 
5 
14-80 
30-3 
•02086 
5 
14-88 
26 0 
•02074 
6 
1497 
21-6 
•02064 
8 
15-05 
17*3 
•02053 
8 
15T3 
15-0 
•02047 
7 
15T7 
13-0 
•02043 
9 
15-20 
Load = 25 kilos. 
Table XV. — Ordinary Heating. 
No. 
Temp. 
Elongation for 
5 kilos. 
No. of 
Observations. 
M. 
1 
11 "2 C. 
•02100 cm. 
8 
14-79 x 10 11 
2 
35-0 
•02103 
7 
1476 
3 
78-0 
•02105 
9 
14-75 
4 
100-0 
•02108 
6 
14-73 
5 
1300 
•02111 
8 
14-71 
Copper. 
The course of the experiments on copper was exactly the same as that 
described for the other metals. 
The results are represented in fig. 18. The curves show how the 
modulus varies as the current is increased, also how the maximum values 
get less as the load is increased, and how with increase of load the maximum 
is reached at an earlier stage in the cyclic process. 
The curves resemble those for steel and cobalt, as the curve for diminish- 
ing current lies at first above that for increasing current, attains a maximum 
for the diminishing current, which is lower than that for the increasing 
current, and finally, has a value less than what it was for the increasing 
current. 
The results for those experiments in which the current was constant 
and the load altered are shown in figs. 19 and 20 ; but a minute description 
of them would merely be a repetition of statements already made in 
connection with the other metals. 
