746 HYSTERESIS OF IRON AND STEEL IN A ROTATING MAGNETIC FIELD. 
Table XIY. —Soft Iron Armature of 156 Plates, of thickness - 0031 centim. Varia¬ 
tion of Hysteresis with Speed ; Diagram 17 ; Deflexions : 1 division = 775 ergs 
per cub. centim. per revolution. 
Speed. 
B = 5150 
11,000 
16,500 
18,600 
14 
.. 
16-9 
17 5 
5-5 
21 
5-5 
13-9 
16-1 
16-9 
24-5 
5-5 
13-9 
16-6 
28 
5-6 
14-4 
18-0 
17-3 
3L5 
5'6 
14-7 
18-0 
35 
5-6 
14-9 
16-0 
16-8 
385 
5-6 
14-8 
42 
53 
14-6 
18-4 
16-2 
45-5 
5-2 
14-6 
19-3 
49 
5-3 
14-8 
18-9 
16-7 
52-5 
5-7 
147 
19-9 
56 
6-0 
14-4 
18-8 
17-1 
59-5 
6-2 
14-7 
17-8 
63 
5-9 
15-2 
16-9 
17-6 
66-5 
5-8 
17-3 
17-0 
Value of Eddy cur- ~] 
rents in scale > 
= ‘0006w 
= ’003 n 
— '006w 
= -007n 
divisions . . . J 
Hysteresis mean f 
value in ergs . . J 
4350 
11,200 
13,700 
13,000 
The foregoing experiments were carried out in the electro-technical laboratory in 
University College, Liverpool. My best thanks are due to Mr. E. H. Morgan, my 
assistant, for his help in the construction of the apparatus and the performance of 
the experiments. 
