122 
MR. H. TOMLINSON ON THE INFLUENCE OF STRESS 
Number of trial. 
Alteration, of resistance 
-in terms of the divisions of 
the platino-iridium wire 
produced by 3 kilogs. at 13° C. 
Alteration of resistance * 
in terms of the divisions of 
the platino-iridium wire 
at 100° C. 
Alteration of resistance 
after cooling again to 13° C. 
1 
51-85 
51-13 
51'25 
2 
51-85 
51-25 
51-33 
3 
51-88 
50-25 
51-27 
4 
51-98 
49-80 
51-18 
5 
52-02 
51-65 
51-08 
6 
51-80 
53-15 
. # 
7 
51-82 
52-00 
, , 
8 
51-73 
51-75 
, , 
9 
52-38 
50-33 
10 
52-08 
50-22 
11 
51-85 
50-75 
12 
51-92 
51-15 
13 
, t 
52-43 
14 
52-43 
Mean 
51-93 
51'30 
51-23 
Probable error per cent. 
•06 
•16 
•03 
It will be observed that even at 100° C. the probable error does not amount to 
‘2 per cent., and, moreover, besides the set of readings recorded in the experiment 
two others of a similar kind were made afterwards, giving mean values of 51*21 and 
51 '26, and a total mean of 51*28 as the alteration of resistance caused by a load of 
3 kilogs. at 100° C., as against 51'23, the alteration produced on cooling again to 13° C. 
Experiment XLVI. 
The same wire was again heated to 100° C. and tested with loads of 1, 2, and 3 
kilogs., and afterwards, having cooled down to 16° C., the effects of the same loads 
were redetermined. 
Number of 
kilogs. in the 
load. 
Alteration of resistance 
produced by 
the load at 100° C. 
Average alteration 
per kilog. at 100° C. 
Alteration of resistance 
after cooling for 
24 hours to 16° C. 
Average alteration 
per kilog. at 16° C. 
1 
16-89 
16-89 
17-40 
17-40 
2 
35-82 
17-91 
34-33 
17-17 
3 
54-99 
18-33 
5F62 
17-21 
