592 
PROFESSOR J. A. EWING ON EXPERIMENTAL 
Then the application of load was repeated and carried a step further, to 9 kilos., 
and then (after removal) to 10 kilos. At that point the wire began for the first 
time to draw slightly, and a marked change occurred in the form of the curves of 
magnetism and stress. This will be apparent from the figures given below, as well as 
from the corresponding part of fig. 36. 
Load. 
Magnetometer. 
Load. 
Magnetometer. 
0 
259 
0 
255 
1 
257 
1 
253 
2 
255 
2 
251 
3 
2524 
3 
249 
4 
250 
4 
2464 
5 
247 
5 
243| 
6 
2434 
6 
240 
7 
239 
7 
236 
8 
234 
8 
232 
9 
229 
9 
227 
8 
231 
10 
218| 
7 
233 
9 
2204 
6 
236 
8 
2234 
5 
2384 
7 
2254 
4 
241 
6 
2284 
3 
244 
5 
231 
2 
248 
4 
234 
1 
251 
3 
237 
0 
255 
2 
239 
1 
2404 
0 
2394 
The first of these two cycles agrees in character with the preceding ones ; we are, 
in fact, still dealing with annealed , not drawn wire. But the cycle 0-10-0 begins 
the wire’s passage from the annealed to the hard state, and the curves of magnetism 
exhibit a corresponding transition. The next stage in the loading, up to 11 kilos., 
caused a decided drawing out, and with it a complete transformation of the curves into 
the form which has been already described (§ 71) as characteristic of a stretched piece, 
and substantially the same form was retained with further successive additions of load. 
The load was progressively raised to nearly 15'8 kilos. Each step caused some 
additional stretching, and the act of stretching was accompanied each time by a fall 
of magnetism. The curves of fig. 36, showing the effects of successive cycles of 
loading, consequently became lower and lower as the operation was continued. The 
position of the maximum point, either on the on or the off curve, shifts out to the 
right—that is, it occurs with a higher value of the load, as the cycle of loads is 
extended. The broken lines in the figure refer to the changes which took place while 
the wire was in the act of stretching. At each stage in the stretching enough time was 
given for the wire to draw until the magnetometer reading became stationary. The 
