Properties of an Extensive Series of Alloys of Tron. 15 
In Table VIII. the hysteresis loss from reversals of a frequency of 100 is 
given in the commercial form of watts per lb. of material, the specimens being 
further compared with ordinary good soft iron, and a common maximum 
induction B of 5000 lines per sq. cm. is taken in each case. 
TABLE VIII. 
Hysteresis Losses in S. C. I. anp 898 E comparrp with Goop Sort Irony, 
For Maximum Jnpuction B = 5,000 LINES PER 8Q. OM., AND FREQUENCY 
n = 100, DEDUCED rrom Figs. 3 & 4. 
Hysrerzsts Losses. 
, Watts. 
Hysteretic 
Constant Microwatts 
Mark. n per c.c. Per cubic inch. Per Ib. 
Soft Iron 0:002 16,576 0:272 0°9688 
8. C. T. 0:0011 9,116 0°149 0°5266 
898 EK 0:0009 7,457 0:1238 0°4415 
As a maximum induction of from 4000 to 8000 is that usually employed in 
transformers, it will be seen that this silicon-iron is considerably better than 
Swedish charcoal-iron for the construction of transformers; the commercial 
value of this alloy is therefore great if its ‘‘ ageing” quality is equally good. 
This latter point we have not yet fully determined, but experiments are in 
progress with small model transformers immersed in oil, which so far appear to 
indicate the extremely valuable magnetic properties of this alloy, and also of the 
low aluminium-iron alloy which is next discussed. Possibly an alloy having a 
small percentage of silicon and aluminium with iron, very free from carbon and 
manganese, will prove the best magnetic material for transformers and similar 
machines. 
(3). Aluminium-iron alloy. 
When iron is alloyed with a small percentage of aluminium, the magnetic 
permeability is increased to an even greater extent than in the case of the silicon- 
iron alloy. ‘This discovery was made early in the course of our investigation, 
and was referred to in the paper we read before the Society on May 17, 1899.* 
The practical as well as the theoretic importance of this discovery made it 
Trans. Roy. Dub. Soe., vol. vii., p. 116. 
