A7A' WILLIAM .S7A-.J//:.\.s, l-.R.S. 215 



furnace, or by the partial application of any of the older methods 

 nf decarburetting cast iron in an open In-aith in direct contact 

 \\ith the fuel. A modified form of the decarhuri/ution process has 

 '(vntly introduced to some extent by Messrs. Heaton and 

 Hariri-raves. They remove the carbon of the pig-iron by the 

 action of oxydizing salts, principally nitrate of soda, and either 

 fuse the crude metal obtained, producing cast steel, or work it up 

 into blooms under the hammer. 



The Bessemer process, now so well known, is also a method of 

 producing steel by the decarbonization of cast iron : but it 

 presents a vast advantage over those just named, in the fact that 

 the steel is obtained in the liquid state, and may be cast, free 

 from flaws, into homogeneous ingots of any size. As Bessemer 

 steel is produced much more cheaply than the cast steel obtained 

 by any other process yet extensively in use, its introduction has 

 opened out a vast field for the application of steel where iron 

 alone could formerly be thought of. Thus many parts of steam 

 and other machinery, railway plant, boiler-plates, and even rails, 

 are now made of Bessemer steel, and are found to be cheaper in 

 the end when made of that material rather than when made of 

 iron, although their absolute cost is fully twice as great. 



CAST STEEL. The remaining methods of producing cast steel, 

 are those in which it is obtained by the fusion either of steel 

 already made by other processes, or of its component materials, 

 iron or iron-ore, on the one hand, and carbon, either as charcoal 

 or already combined in the form of cast iron, on the other. 



The oldest known steel of high quality, the Indian Wootz, is 

 obtained by the fusion of compact iron and carbonaceous sub- 

 stances in small crucibles, but it is only in the course of the last 

 century that the manufacture of cast-steel was first introduced in 

 Europe. 



Reaumur states, in his work on the conversion of forged iron 

 into steel, published in 1722, that he had succeeded in producing 

 steel by the fusion together of cast and wrought iron in a common 

 forge ; but steel melting was first practically carried out in the 

 latter half of the century by Huntsman, of Sheffield ; the process 

 he employed, consisting in " the fusion in closed crucibles of steel 

 already made by cementation in cJiarcoal" is still universally in use 

 for the production of the finest qualities of steel for tools and 



