RESEARCHES IN MAGNETISM. 
G29 
§ of 29-16, and then removing that force. The following values of 3 induced and 3 
residual were determined in this way :— 
Load. 
3 induced. 
3 residual. 
Ratio. 
0 
1157 
423 
0-37 
2 
1183 
588 
0'50 
4 
1193 
757 
0-63 
6 
1189 
845 
0-71 
8 
1180 
809 
0-69 
10 
1157 
757 
0-65 
12 
1138 
683 
0-60 
14-8 
1105 
598 
0-54 
From this it will be seen that (for Jp = 29T6) a load of 6 kilos, gives maximum 
retentiveness, and that the retentiveness under that load is nearly twice as great as 
when the same wire is not loaded. 
§ 112. The same piece of iron was now re-annealed, and the effect of stress on its 
retentiveness when in the soft state was examined in the same way (June 16, 1882). 
The only states of load tested were 0 and 4 kilos, (a load so well within the limit of 
elasticity as to produce no important permanent mechanical change in the specimen). 
The results are given below, and also in Plate 68, fig. 58, where, in the lower group 
of curves, the two full lines show the induced, and the two dotted lines the residual 
magnetism, w-hile the lines above show the ratio in the same way as before :— 
Annealed Iron Wire, Plate 68, fig. 58. 
Load = 0. 
Load = 
= 4 kilos., or 9' 
76 kilos, per sq. mm. 
«$• 
3 induced. 
3 residual. 
Ratio. 
•8. 
3 induced. 
3 residual. 
t 
Ratio. 
0 
0 
0 
0 
0 
0 
1-08 
66 
32-5 
0-49 ■ 
0-54 
38 
21 
0-53 
1-62 
202 
141 
0-70 
1-08 
141 
94 
0-69 
2-16 
460 
381 
0-83 
1-62 
325 
242 
0-745 
2-70 
684 
601 
0-879 
216 
532 
419 
0-788 
3-24 
846 
767 
0-907 
2-70 
677 
543 
0-802 
3-78 
939 
860 
0-916 
3-24 
796 
640 
0"804 
4-32 
999 
920 
0-921 
3-78 
876 
705 
0-805 
5-40 
1071 
994 
0-928 
4-37 
937 
754 
0-805 
6-48 
1109 
1024 
0-923 
4-86 
978 
787 
0-805 
7'56 
1139 
1046 
0-919 
5-51 
1022 
816 
0-800 
8‘64 
1157 
1063 
0-919 
6-48 
1067 
856 
0-800 
9-72 
1168 
1074 
0-919 
8-64 
1121 
891 
0-795 
10-8 
1178 
1082 
0-918 
10-8 
1162 
913 
0-786 
13-5 
1196 
1095 
0-916 
13-5 
1186 
926 
0-781 
16-2 
1210 
1105 
0-913 
16-2 
1204 
933 
0-775 
18-9 
1219 
1111 
0-911 
18-9 
1211 
939 
0-775 
21-6 
1226 
1116 
0-910 
21-6 
1219 
942 
0-773 
25-6 
1236 
1119 
0-905 
26-2 
1232 
946 
0-768 
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