MAGNETISATION OF IRON AND OTHER MAGNETIC METALS. 
241 
magnetising forces.* It contained about 075 per cent, of iron. The bar was 
annealed and was built into a bobbin with wrought iron cones, and the neck was 
turned down to a diameter of 4 mm. (fig. 18). 
Fig. 18. 
Table XIII.—Annealed Nickel (075 per cent, of Iron). 
Outside field. 
i8. 
S3 — outside field 
dTT 
outside field 
3,450 
9,850 
510 
2-86 
6,420 
12,860 
510 
2 00 
8,630 
15,260 
530 
177 
11,220 
17,200 
480 
1-53 
12,780 
19,310 
520 
1-51 
13,020 
19,800 
540 
1-52 
Here 3 is sensibly constant, with a mean value of 515, of which about 160 was 
residual. 
§ 36. The second samjDle was a hard-drawn wire, not annealed before testing, which 
contained less iron than the other (0‘56 per cent.). Perhaps for this reason, the value 
of 3 in it was less. The nickel formed the central spindle of a bobbin with wrought 
non cones, and with a neck 57 mm. in diameter. 
Table XIV.—Hard-drawn Nickel (0'56 per cent, of Iron) 
Outside field. 
SB. 
33 — outside field 
SS 
47r 
outside field 
2,220 
7,100 
390 
3'20 
4,440 
9,210 
380 
2-09 
7,940 
12,970 
400 
1-63 
14,660 
19,640 
400 
1-34 
16,000 
21,070 
400 
1-32 
* Ewing, “Magnetic Qualities of Nickel, Supplementary Paper,” ‘ Pliil. Trans.,’ A, 1888. 
MBCCCLXXXIX.—A. 2 I 
