ON THE MAGNETISATION OF COBALT. 
359 
The compensating coil was intentionally placed so as to somewhat more than 
balance the magnetising coil, and so, in some of the strongest fields, the spot was off 
the scale wdien the rod was removed. Thus, in these fields, there were no data for 
calculating 3i, and in calculating 3^ — 3i and 3^ ~ Sa it had to be assumed that the 
magnetometer zero had not altered in the intervals that elapsed during the application 
of the pressure cycles and during the absence of the rod from the coil. The latter 
interval was always short, so that any sensible alteration during it was improbable. 
During these observations the end A of the rod w^as always the north pole. 
There then followed in general, while the current remained unchanged, some 
observations intended to test the residual effects of the pressure cycles. In these 
the rod was repeatedly removed from the coil, it might be when free from or when 
subjected to pressure, and while out its state, as regards pressure, miglit or might 
not be changed. Not infrequently, too, the ends were changed while it was out, so 
that on its re-introduction the end A might be either a north or a south pole. 
Sometimes on the re-introduction of the rod Jirst “ ons ” or Jii'st “ offs ” of pressure 
were taken, with the object of determining whether their magnitude was affected by 
repetition or by a change in the end of the rod. The results of this last series of 
experiments are contained in Tables IX. and X. They are the results on wdiich most 
of the curves in figs. 1-8 (Plate 15) are based. 
Table IX. 
3]- 
Ky 
A-3i. 
/t’o. 
CV O' 
0 
<ir> 1 
0 
3b 
“on”—“off.” 
“Off” 
3a 3b- 
“ On ” 
3a-3b. 
1-8 
4T 
2-3 
2-4 
3-6 
1-4 
2-2 p 
8-2 
3-8 
1-9 
4-7 
1-4 
-2 
*3-4 
110 
3-2 
3-4 
5-0 
2-7 
3-8 
4-3 p 
20-2 
4-7 
-3 
4-8 
2-7 
T7 
8T u 
41-5 
5-1 
5-0 
5-8 
5-2 
2-4 
9-9 
8-6 
37-3 
4-3 
10-2 
5-5 
5-1 
9-7 
n2'5 
617 
4-6 
5-1 
6-2 
10-3 
23-4_p 
147-1 
6-8 
3-4 
6-4 
13-5 
237 
141-1 
6-0 
13-2 
6-5 
11-6 
5-3 
35'2 p 
253-8 
7-2 
6-2 
7-4 
16-5 
357 
233-4 
6-5 
13-3 
6-9 
10-4 
2-9 
46-0 
290-0 
6-3 
12-3 
6-6 
12-0 
9-0 
47-5 _p 
312-3 
6-6 
4-7 
6-7 
9-2 
•5 
57-5 
3.39-5 
5-9 
10-6 
6-1 
9-5 
bl-^p 
375-7 
6-5 
-4-1 
6-5 
11-6 
8-1 
-5 
72-6 
397-3 
5-5 
6-9 
5 6 
10-5 
7-4 
-6 
79-8 
405-8 
5-1 
8-6 
5-2 
10-2 
6-3 
1-9 
92-0 
427-0 
4-6 
8-1 
4-7 
8-4 
7-3 
-6 
1C3-5 
491-5 
4-7 
6-1 
4-8 
4-5 
4-2 
3-0 
115 
510-4 
4-4 
3-8 
4-5 
4-7 
1-8 
2-i 
2-2 
128 
530 
4-1 
2-4 
4-2 
4-4 
2-1 
1-8 
144 
550 
3-8 
3-0 
3-8 
1-4 
158 
554 
3-5 
2-8 
3-5 
2-8 
-5 
. , 
174 
1-0 
1-1 
-0-6 
0 
198 
1-6 
1-6 
-1-6 
-0-4 
-1-i 
224 
. . 
1-4 
-1-6 
-0-7 
, , 
270 
1-2 
0-2 
-4-1 
— 2-2 
-4-4 
-5-0 
351 
• . 
-4-1 
-3-1 
-5-1 
-5-6 
* Ouu’ent fell markedly during pre.ssure cycles, is calculated on its initial, ko on its final value. 
