EFFECT OF TEMPERATURE ON COPPER. 287 
a a 
Ordinates Temperatures F 
bing eer strength “fs. per sq. inch. 
urve A.— t Ser 
Curve B. ~Feekiin Institute Series. 
copper ; hence the above expression for the tenacity at any tem- 
perature can only be used for temperatures within the range 
covered by experiment—i.e. up to 500° F. certainly, and, relying 
upon the Franklin Institute results, up to 1000° F., probably. 
5. Temperature and percentage elongation.— Before being tested 
the working length of test pieces, Nos. 32— 38, ‘eit 41, 42, 
marked off into quarter inches, and the general sical W was 
thus distinguished from the total, according to Tetmaier’s method. 
In the other tensile tests only the total elongations were obtained. 
The following table summarises the results :— 
3 
Table II. 
Test No. akipacbicke ENE Test No. Pre er : ciao 
} Total General | Elongation. 
32 | 166 | 49:2 404 || 2 | 506 | 316. | 
83 | 244 | 392 | 336 || 3 57 | 826 | 
34 | 348 | 43:2 340 |} .9 36 30:8 
35 | 444 | «396 32°4 10 402 37:2 
36 518 21°23 19°6 ll 208 46-0 
87 | 33 | 3864 32-0 31 57. | 508 
38 35 | 47°6 400 | 
41 | 25 | 284 | 264 || 
| 42 | 500 | 300 | 27-7 || 
