RESEARCHES IN MAGNETISM. 
593 
stretching took place in several steps, and its final effect was to change the diameter 
of the wire from 079 to 076 mm. The highest load reached was 15'8 kilos., after 
which a second application of the cycle 0-15‘8-0 was made. The observed readings 
are all given below, but to avoid confusion the final off curve after the last loading is 
not plotted in the figure. 
Same wire, becoming hardened by stretching, Plate 62, fig. 36. 
Loart. 
Magneto¬ 
meter. 
Load. 
Magneto¬ 
meter. 
Load. 
Magneto¬ 
meter. 
Load. 
Magneto¬ 
meter. 
Load. 
Magneto¬ 
meter. 
0 
239| 
0 
137 
0 
119 
0 
112 
0 
104 
1 
239 
1 
140 
1 
121 
1 
115 
1 
106 
2 
239 
2 
147 
2 
1271 
4-8 
150 
2 
1104 
3 
239 
3 
158 
3 
137 
5-8 
1641 
5-8 
150| 
4 
2384 
4 
1701 
4 
1514 
6-8 
1754 
6-8 
161 
5 
237| 
5 
185 
5 
166 
7-8 
184 
7-8 
1684 
6 
235 
6 
196 
6 
1804 
8-8 
188 
8-8 
1724 
7 
2314 
7 
2031 
7 
1914 
9-8 
188 
9-8 
174 
8 
228 
8 
206 
8 
198 
10-8 
1861 
10-8 
1731 
9 
2241 
9 
206 
9 
198 
11-8 
184 
11-8 
172 
10 
2191 
10 
2041 
10 
197 
12-8 
181 
12-8 
169 
11 
201 
11 
201 
11 
195 
13-8 
178 
13-8 
166 
10 
202 
11-8 
198 
11-8 
192 
14-8 
174 
14-8 
163 
9 
2034 
12-6 
187 
12-6 
189 
15-8 
1581 
153 
1614 
8 
205 
11-8 
188 
13-6 
179 
15-3 
158f 
15-8 
1594 
7 
207 
11 
1891 
14 
1741 
14-8 
1591 
15-3 
160 
6 
208 
10 
191 
136 
175 
138 
1601 
14-8 
1604 
5 
208 
9 
193 
12-6 
1764 
12-8 
162 
13-8 
162 
4 
204 
8 
195 
11-8 
1771 
9 
1681 
12-8 
1634 
3 
1961 
7 
1961 
11 
179 
8 
170 
9 
170 
2 
181 
6 
1971 
10 
181 
7 
171 
8 
171 
1 
163 
5 
196 
9 
183 
6 
169 
7 
172 
0 
137 
4 
191 
8 
1841 
5 
168 
6 
171 
3 
179 
7 
186 
4 
162 
5 
1681 
2 
165 
6 
186 
3 
153 
4 
163 
1 
1444 
5 
183 
2 
140 
3 
1524 
0 
119 
4 
176 
1 
123 
2 
140 
3 
165| 
0 
104 
1 
124 
2 
152 
0 
106 
1 
134 
0 
112 
§ 77. The foregoing observations show with sufficient distinctness how a wire which 
has been stretched behaves, as regards magnetism induced by the earth’s field, when 
successively loaded and unloaded. But the behaviour of the wire while still in the 
soft annealed state, that is before the stress has been allowed to pass the limit of 
elasticity, requires further elucidation. A number of other experiments have helped 
in the analysis of the somewhat complex phenomena which are produced by loading 
and unloading an iron wire while in the annealed state. 
