728 
PROFESSOR F. G. BAILT OR THE HYSTERESIS OF 
lowest value, 8,000 ergs, less than one-fifth of the maximum, being reached without 
any sign of another flexure. 
This corresponds perfectly to the three stages in the B/H curve of hard steel, the 
rapid rise occurring during the rapid rise of the induction, and the maximum value 
being reached just at the bend before the approach to saturation. As saturation is 
more nearly reached, the hysteresis becomes rapidly smaller, the curve showing no 
sign of bending off asymptotically. 
The values given in the tables for hysteresis are corrected for eddy currents, the 
magnitude of the correction being given at the foot. The maximum value of the 
correction at 5G revolutions per second, when B = 18,400 and the hysteresis is small, 
is only 4 per cent, of the hysteresis, and about the same for the smaller value of the 
hysteresis in the stronger field at the slower speed. 
It will be noted that the ballistic curve lies considerably below the rotating field 
curve up to a point close to the maximum, after which it rises far above the other. 
The meaning of this will be discussed later. 
Table I.—Hard Steel Armature of 105 Plates of thickness •0141 centim. 
Diagram 4. Square pole pieces. Speed, 37 revs, per sec. 
1 B 
Hyst. in ergs 
per cub. centim. 
per rev. 
B. 
Hyst. iu ergs 
per cub. centim. 
per rev. 
B. 
Hyst. in ei’gs 
per cub. centim. 
per rev. 
1,700 
2,100 
14,800 
42,500 
18,900 
14,200 
2,200 
3,600 
15,200 
41,000 
19,000 
13,800 
2,520 
5,500 
15,600 
38,800 
19,100 
10,900 
3,100 
7,200 
16,000 
37,400 
3,600 
8,850 
16,400 
36,500 
4,400 
12,300 
] 6,600 
34,600 
18,200 
18,100 
5,100 
15,200 
16,900 
30.500 
18,400 
16,700 
5,500 
16,800 
17,200 
28,100 
18,700 
15,100 
6,400 
20,500 
17,300 
26,000 
18,800 
13,200 
7,000 
23,600 
17,400 
24,500 
19,000 
10,400 
8,000 
27,300 
17,500 
24,300 
19,200 
9,860 
8,800 
30,800 
17,800 
22,000 
19,400 
8,580 
10,200 
35,100 
17,900 
21,200 
11,100 
38,300 
18,100 
20,500 
12,200 
42,000 
18,200 
19,300 
13,300 
43,700 
18,300 
18,200 
Ihdcly currents = 
13,800 
43,800 
18,500 
16,700 
1’5 x 10' 
‘ b B“ ergs 
14,400 
43,300 
18,800 
14,900 
per cub. centim. per rev. 
