ON" THE MAGNETIC QUALITIES OF IRON. 
1005 
Ring V.—Soft Thin Sheet Iron. Values of JHc^I and Coercive Force. 
Number of cycle. 
Limits of H. 
Limits of B. 
Limits of I. 
|H dl. 
Coercive force. 
I 
15-72 
12366 
982 
8310 
1-92 
2 
12-4I 
11.390 
905 
7250 
1-87 
3 
9T5 
10120 
882 
6020 
]-80 
4 
6‘95 
8940 
711 
4900 
1-71 
5 
5-03 
75.30 
599 
3670 
1-62 
G 
3-68 
6100 
485 
2520 
1-47 
7 
2-75 
4730 
376 
1760 
1-42 
8 
2-04 
3240 
258 
900 
1-02 
9 
1-27 
1210 
96 
180 
0-68 
10 
0-61 
220 
17 
6 
0-10 
The remaining specimens dealt with in this section of our experiments were of 
iron wire. In Ring No. VI. the core was of fine cotton-covered wire 0'34 millim. in 
diameter, which was kindly supplied to us for the purpose of these experiments by 
a leading firm of manufacturers at the instance of Mr. W. H. Preece. It was 
described as Swedish charcoal iron, but the tests show that it was decidedly hard in 
the magnetic sense, having a rather high coercive force and other characteristics 
resembling those of mild steel. Six cycles were measured, with results which are 
given below and graphically in fig. 16. 
Ring VI.—Fine Iron Wire. 
Cycle (1). 
1 
1 Cycle (2). 
Cycle (3). 
H. 
B. 
H. 
B. 
H. 
B. 
12-34 
11.330 
9-14 
94.30 
7-30 
7730 
6 54 
10760 
5-45 
9070 
4-71 
7410 
3-29 
10280 
2-44 
8540 
2-27 
7000 
1-64 
9960 ; 
0-61 
8140 
0-77 
6680 
0-64 
9720 
0 
7980 
0 
6480 
0 
9470 ‘ 
-0-64 
7730 
-1-28 
6030 
- 1-31 
8910 ' 
-1-54 
7330 
-2-57 
52.30 
- 2-57 
8020 
-2-57 
6360 
-3-85 
1840 
- 3-93 
5110 1 
—3-85 
3610 
-4-50 
-1640 
- 4-37 
2520 
-4-37 
870 
-4-86 
-.3410 
- 5-17 
- 1760 
-4-88 
-2040 
-6-12 
-6560 
- 5-68 
- 4180 
-5-40 
-4460 
-6-38 
-6880 
- 6-41 
- 6360 
-7-.35 
-8100 1 
-7-30 
-7730 
- 9-28 
- 9680 
-7-71 
-8420 
-12-34 
-11330 
-9-14 
-9430 
1 
1 
