ON THE INFLUENCE OF SILICON ON THE PROPERTIES OF STEEL. 281 



solving drillings of ferro-silicon ; so tedious is the process that recourse is 

 usually made to the sodium carbonate process. This is not requisite with 

 silicon steel, which requires only the ordinary hydrochloric-acid method. 

 The silica residue is very clean and free from iron. 



A considerable number of estimations have proved that the silicon is 

 very uniform and homogeneous in this steel. Analyses taken from dif- 

 ferent parts of the same ingot and bar give results very similar to each 

 other. No traces of graphite are noticed, the carbon always being present 

 in the combined form. If the material analysed is in the form of drillings 

 they keep their shape, the iron being dissolved out. 



Experiments have been made with this steel in comparison with other 

 material as regards its corrosion. The following table gives the time of 

 immersion in the sulphuric acid, and the loss : — 



Moisture Test. 



SUicon steel (C) . 



Bar 



Per- Weight before 



centage placing in Moist 

 of Sihcon Atmosphere 



1-60 



20-634 grams. 



Weight after 

 keeping 21 days in 

 Moist Atmosphere 



20-644 grams. 



Increased in Weight 



-01 gram. 



The following table gives the specific gravities of the silicon steel ; 

 ilso ferro-silicon : — 



Table VI. — Specific Gravities. 



