730 
PROFESSOR F. G. BAILY ON THE HYSTERESIS OF 
Hysteresis of Soft Charcoal Iron. 
The steel armature was replaced by the soft iron armature of 250 plates, '0081 
centim, thick. This was subsequently reduced to 156 plates, the calibration curves 
being given in Diagram 3. Curve 2 was carried further in later experiments, the 
maximum induction attained being’ 20,200. 
Several sets of readings were taken at different speeds with both sizes of armature, 
some of the results being shown in Diagram 5, together with the ballistic curve. The 
general shape of the curve is similar to that of the steel, the three stages being 
Diagram 5. 
clearly marked—the slow beginning, then a long straight rise, with a less distinctly 
shown flexure in the middle, and a sharply defined maximum, followed by a sudden 
drop. The maximum occurs at a higher induction than in the steel, and the drop 
afterwards is more rapid. 
