124 
MR. H. TOMLINSON ON THE INFLUENCE OF STRESS 
•> Experiment XLIX. 
An annealed copper wire, 7 feet in length and '095 centim. in diameter, treated in 
a manner similar to that in which the last iron wire had been treated, and tested at 
12° C. and 100° C. with a load of 5 kilogs. 
Alteration of resistance in terms 
Temperature in degrees 
Centigrade. 
of the divisions of the platino- 
iridium wire produced by 
5 kilogs. 
O 
12 
4213 
100 
45-34 
12 
44-31 
100 
45-14 
Experiment L. 
A piece of the same nickel wire, which had been previously broken by testing for 
alteration of resistance at the ordinary temperature of the room, was annealed again 
and adjusted in the air chamber in the manner previously described. A load of 
18 kilogs. was then suffered to remain on the wire for several minutes, and after its 
removal the nickel was allowed to rest unloaded for 24 hours. The wire was now 
tested with loads up to 12 kilogs. at the temperature of 13° 0., then after heating to 
100° C., and again, 24 hours afterwards, when cooled to 10° C. 
Load in kilogs. 
Alteration of resistance at 13° C. 
in terms of the divisions of the 
platino-iridium wire. 
— signifies decrease of resistance 
of stretched wire. 
Alteration 
of resistance 
at 100° C. 
Alteration of 
resistance after 
cooling to 10° C. 
2 
- 58-3 
-36-1 
— 606 
4 
-114-0 
-62-8 
-110-0 
6 
-148-4 
-68-2 
-137-7 
8 
-159-1 
-62-5 
-155-9 
10 
-151-3 
-49-6 
-160-7 
12 
-123-8 
-33-8 
-149-4 
The effect of change of temperature on the temporary decrease of resistance 
produced by loading is also shown in Table XXIII. 
