456 Proceedings of Royal Society of Edinburgh. [sess. 
And from these readings we derive the following values : — 
m= 3*64 
E = 28,450,000 
C = 11,160,000 
I) = 21,048,000 
Other metals were also experimented upon, and in some cases 
under compression, when the longitudinal strain was measured by 
a compressometer of Professor Ewing’s design. It will he suffi- 
cient to quote the results of these experiments without the detailed 
observations, which present no peculiarity except that, in the 
cases of cast-iron, brass, and copper, the stress strain curve for a 
complete cycle of stress was a very narrow loop. In these cases 
the mean value of the strains for the whole range of stress was 
taken for calculating the values of the constants. The results, 
including the tests above cited, were as follows : — 
Tension Experiments. 
Specimen. 
m 
E 
C 
D 
Machinery Steel, . 
4-01 
30,250,000 
12,378,000 
20,603,000 
Wrought- Iron, 
3-64 
28,450,000 
11,160,000 
| 21,048,000 
Rolled-Brass, 
3-10 
14,700,000 
5,557,000 
13,809,000 
Rolled-Copper, 
3-02 
10,100,000 
3,791,000 
9,640,000 
Compression Experiment. 
Specimen. 
m 
E 
c 
D 
Machinery Steel, . 
4-09 
29,600,000 
11,891,000 
19,310,000 
Wrought-Iron, 
3-58 
28,100,000 
11,000,000 
21,200,000 
Rolled- Brass, 
3-12 
14,820,000 
5,620,000 
13,750,000 
Cast-Iron, 
4*07 
14,900,000 
5,950,000 
9,750,000 
