SIR WILLIAM THOMSON ON THE 
Table IY.—Bar of Wrought Nickel—concluded. 
o 
Operations. 
Readings. 
Differences. 
Total 
magnetization. 
Strength of 
magnetizing 
current. 
361 lbs. on ... 
92 
+ 16 
+ 479 
708 
„ off ... '. 
80 
- 12 
+ 491 
„ on ... 
93 
+ 13 
+ 478 
„ off ... . 
80 
- 13 
+ 491 
285 lbs. on ... 
91 
+ 11 
+ 480 
., off ... . 
85 
- 6 
+ 486 
„ on ... . 
94 
+ 9 
+ 477 
„ off ... . 
85 
— 9 
+ 486 
2111bs.on and off 5 times 
90 
+ 5 
+ 481 
211 lbs. on ... 
96 
+ 6 
+ 475 
„ off ... . 
90 
- 6 
+ 481 
„ on ... . 
96 
+ 6 
+ 475 
„ off ... . 
91 
- 5 
+ 480 
136 lbs. on . 
96 
+ 5 
+ 475 
„ off ... . 
93 
- 3 
+ 478 
,, on ... . 
97 
+ 4 
+ 474 
., off ... . 
93 
- 4 
+ 478 
B . . . . 
350 
+ 257 
+ 221 
136 lbs. on ... 
380 
+ 30 
+ 191 
„ off ... . 
863 
- 17 
+ 208 
„ Oil ... 
384 
+ 21 
+ 187 
„ off ... . 
365 
- 19 
+ 206 
„ on ... . 
384 
+ 19 
+ 187 
„ off ... . 
365 
- 19 
+ 206 
361 lbs. on ... 
418 
+ 53 
+ 153 
„ off ... . 
377 
- 41 
+ 194 
,, on ... 
420 
+ 43 
+ 151 
,, off ... 
379 
- 41 
+ 192 
285 lbs. on . 
412 
+ 33 
+ 169 
„ off ... . 
379 
- 33 
+ 202 
,, on ... 
411 
+ 32 
+ 170 
„ off ... . 
378 
- 33 
+ 203 
237. The preceding table shows that the effect of the application of pull was to 
diminish, and of the removal of pull to increase the magnetism of the bar, whether 
induced or residual ; and that a series of these operations increased on the whole the 
magnetism induced by +M or —M, but diminished on the whole the residual 
magnetism after B. Further, as stated above, the effect of “ on” or “ off” on the 
induced magnetism of the bar increases up to a certain point, and then diminishes as 
the magnetizing force is increased from zero upwards ; while, on the other hand, the 
effect of “ on” or off ” on the residual magnetism goes on increasing as the residual 
magnetism is increased, and, as does also the residual magnetism, approaches more and 
more to a certain constant value. 
238. On account of the thickness of the bar, a large amount of wire was required to 
make a coil which would give a sufficiently powerful magnetizing force to reach or pass 
the critical value to which the magnetizing force seemed in the preceding experiments 
