RESEARCHES IN MAGNETISM. 
037 
While steam 
was passing . 
3- 
. . . 39-00 
water 
>> ... 
. . . 38-16 
)) 
steam 
... 
. . . 38-16 
water 
3, ... 
. . . 37-74 
Decidedly over 
steam 
3, ... 
. . . 37-89 
critical point. 
water 
,3 ... 
. . . 37-53 
steam 
33 ... 
. . . 37-65 
Here the critical point appears to be reached when 3 is about 20 , but its position 
is not very sharply defined. 
§ 120 . The same two wires were also tested by finding, in the ordinary way by the 
direct magnetometric method, the relation of 3 to <§ during magnetisation : ( 1 ) when 
the temperature was that of the atmosphere, or about 7° C. ; ( 2 ) when the tempera¬ 
ture was maintained at 100 ° C. by the continuous passage of a current of steam 
through the tube on which the magnetising solenoid was wound. The following table 
gives the results, reduced to absolute measure. In each state several successive 
determinations of the curve of 3 and were made, but as these agreed very exactly 
with each other, only one set of readings for each state has been reduced :— 
Effect of Temperature on the Magnetic Susceptibility of Iron Wire, Plate 68, fig. 59. 
Soft annealed wire. 
Wire hardened by stretching. 
At 7 
° C. 
At 100° C. 
At 8 
° C. 
At 100° C. 
3. 
3- 
3- 
rv 
3- 
0 
0 
0 
0 
0 
0 
0 
0 
1-36 
120 
1-24 
125 
2-16 
23 
2-16 
28 
1-70 
184 
1-70 
193 
3-60 
51 
3-60 
60 
2-27 
298 
2-27 
306 
7-21 
162 
7-21 
186 
2-84 
389 
2-84 
405 
10-88 
305 
10-81 
341 
3-69 
539 
3-97 
612 
1442 
449 
14-49 
490 
4-54 
673 
5-67 
850 
18-02 
589 
18-02 
623 
5-67 
827 
7-09 
960 
21-63 
711 
21-63 
741 
7-09 
942 
8-50 
1021 
25-37 
825 
25-23 
848 
8-50 
1012 
11-34 
1088 
29-20 
918 
28-91 
936 
11-34 
1088 
14-18 
1119 
32-45 
983 
33-27 
1017 
14-80 
1122 
17-01 
1140 
36-19 
1038 
36-77 
1065 
17-01 
1145 
19-84 
1151 
39-66 
1079 
46-36 
1150 
22-79 
1169 
22-96 
1158 
53-21 
1206 
30-33 
1183 
28-01 
1160 
0 
363 
0 
341 
0 
911 
0 
894 
residual. 
residual. 
residual. 
residual. 
4 n 
MDOCCLXXXY. 
