744 PROFESSOR F. G. BA1LY ON THE HYSTERESIS OF 
Table XI.—Soft Iron Armature of' 250 Plates, of thickness '0081 centim. Varia¬ 
tion of Hysteresis with Speed. 
Speed in revs, 
per sec. 
Deflexion. 
7-5 
109 
10 
108 
23 
109 
27 
109-5 
31-5 
1105 
37 
112 
43 
111-5 
525 
111 
61 
110 
71 
107-5 
B = 4800 
Hysteresis — 3500 
Eddy currents 
= 12 X 10 -2 n divisions 
1 scale division = 32 ergs 
per cub. centim. per rev. 
Speed in revs, 
per sec. 
Deflexion. 
7 
69 
10 
69 
14 
67"5 
17 
68 
21 
67-5 
23 
70-5 
26-5 
70 
34 
71 
40 
71 
45-5 
71 
51 
71-5 
57 
71 
62 
69 
65 
67-5 
70-5 
69 
B - 3400 
Hysteresis = 2200 
Eddy currents 
= 6 X 10~ 3 n divisions 
Table XII.—Soft Iron Armature of 250 Plates, of thickness ’0081 centim. Varia¬ 
tion of Hysteresis with Speed. 
Speed iu revs, 
per sec. 
Deflexion. 
Speed. 
Deflexion. 
0 
8-0 
0 
35-5 
23-5 
8-5 
25 
35-5 
30 
8-5 
32 
35'6 
36 
8-5 
38 
35-6 
43 
9-0 
44-5 
35"5 
50 
8-5 
51 
36-1 
57 
8-5 
57"5 
36-0 
62 
9-0 
64 
35-9 
B = 4800 
Hysteresis = 3800 
Eddy currents 
-IT x 10 -3 n divisions 
B - 14,000 
Hyster-esis = 14,000 
Eddy currents 
=9’0 x 10 -3 n divisions 
I division = 385 ergs per cub. centim. per rev. 
Speed. 
Deflexion. 
Speed. 
Deflexion. 
Repeated.* 
Repeated.* 
15 
41-2 
0 
315 
18-5 
40-7 
29 
32-0 
23 
40-1 
32 
32-4 
27 
38-6 
40 
31-8 
30 
38-1 
42 
31-3 
34 
38-2 
45 
31-2 
38 
37-6 
54 
32-1 
41 
37-5 
59 
31-5 
49 
38-0 
62 
31-4 
57"5 
38-2 
67 
314 
62 
38-8 
] 
66 - 5 
38-2 
B = 17,100 
Hysteresis = 14,700 
Eddies 
B = 17,100 
= 1-3x10“ 
2 n divisions 
* This series was repeated later, and the spring was not calibrated. It had evidently changed in 
strength or method of applying restoring force. 
