Properties of an Extensive Series of Alloys of Iron. IL 
Here are the results for S. C. I. :— 
TABLE VI. 
DererMINATION oF THE Magnetic Inpuction (B) 1x Pure Iron sy tHe Batuisric 
Mernop (ring), COMPARED WITH THE Macneromerric Mrrnop (rod, LENGTH 
= 255 DIAMETERS), THE LATTER CORRECTED FOR Reaction or Enps. 
SaC ale 
H. B. Difference. 
Ring. Rod. 
4 12,250 11,050 1,200 
6 13,600 13,000 600 
8 14,300 14,000 250 
Upeoine C 10 14,700 14,700 0 
Peo S ULNE 12 15,200 15,200 * 
14 15,460 15,400 o 
16 15,700 15,700 * 
1 15,800 15,800 ye 
f 60 17,600 17,600 a 
| 18 16,200 16,200 e 
| 26 16,100 16,100 - 
| i 16,000 16,000 es 
DownCurve...< 12 15,900 15,900 - 
| 10 15,700 15,700 i 
| = § 15,500 15,200 300 
| 6 15,250 14,650 600 
lL 4 14,800 13,600 1,200 
It will be seen that in fields of ten units and over, the two results agree, but 
in the steep part of the curve, as the field gets lower, an increasing difference 
is perceived. This shows that either the correction is insufficient, at least for 
bodies of high permeability, in this part of the curve, or, much more probably, 
that the ring and rod were somewhat differently annealed, the ring being 
the better of the two, a difference which would reveal itself, as it does, in 
the lower magnetic fields. 
From the cyclic curves in Plates IT. and III., the hysteresis of the specimens can 
be compared ; mere inspection shows that the area of the cyclic curve of the silicon- 
iron is considerably less than that of the Swedish charcoal-iron. From the areas of 
the curves the work done in going through a complete cycle can be estimated, and 
the hysteretic constant found. Another series of cyclic curves were obtained for a 
maximum induction B varying from 5000 to nearly 12,000, and the coercive force, 
remanence or residual induction, the hysteresis loss, or energy dissipated per 
cycle in ergs per c.c., and the hysteretic constant, 7, were determined for each 
cycle. The results are given in Table VII., p. 12, and the upper part of the 
latter cyclic curves are shown in figs. 8 and 4 on next page. 
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