16 Metallurgy of Iron. 



Such is an outline of the long and expensive processes by which 

 malleable iron and steel are obtained from the ores of iron. The 

 reduction of the iron to the metallic state constitutes but a small 

 part of the operation, and consumes comparatively but little fuel, 

 but as we have already seen the reduced iron is first carburetted 

 as it descends in the furnace, then melted by an intense heat into 

 the form of cast iron, which is again fused in the puddling fur- 

 nace before being converted into malleable iron, the transforma- 

 tion of which into cast steel requires a long continued heat for the 

 cementation, and still another fusion. 



In Derbyshire in England, there are consumed for the fabrica- 

 tion of one ton of cast iron, two tons and twelve quintals of ore, 

 and two tons of mineral coal, while in Staffordshire two tons eight 

 quintals of coal, and two tons seven quintals of ore are employed 

 for the production of a ton of cast metal. In the furnaces of the 

 Department of the Dordogne, in France, where charcoal is 

 employed, two tons and seven quintals of ore, one ton and 

 three quintals of charcoal are employed for a ton of iron. 

 For the production of a ton of wrought iron in England about 

 one ton and one-third of cast iron, and from two to two 

 and a-half tons of mineral coal are consumed, while the 

 same amount of the cast iron of the Dordogne requires to 

 convert it into a ton of wrought iron, one ton and a-half of 

 charcoal. Thus in England the fabrication of a ton of wrought 

 iron, from poor ores yielding from thirty-eight to forty per cent, 

 of metal, requires a consumption of about five tons of mineral coal 

 and in Dordogne a little over three tons of wood charcoal, which 

 costs there about fifty-eight shillings currency the ton. The aver- 

 age price of charcoal in France, however, according to Dufrenoy, 

 is about seventy-four shillings, while in Sweden it costs only about 

 fourteen shillings, and in the Ural Mountains eleven shillings the 

 ton. In France, much of the pig iron manufactured with charcoal 

 is refined by the aid of mineral coal. 



The questions of the price and the facility of obtaining fuel are 

 of the first importance in the manufacture of iron. The ores of this 

 metal are very generally diffused in the earth's surface, and occur 

 abundantly in a great many places where fuel is dear. The iron 

 which is manufactured either wholly or in part with wood-char- 

 coal, is of a quality much superior to that obtained with mineral 

 coal, and commands a higher price. One principal reason of this 

 difference is that the impurities present in the coal contaminate 

 the iron, but it is also true that the ores treated with mineral coal 



