On the Manufacture of Bar Iron in India. Ill 



because in them a portion of the product of the operation 

 unites with the iron formed to make cast iron, which is 

 again separated in the refining furnace in the form of 

 " finery cinder." Besides, what are called the slags of 

 bloomery furnaces are pure silicates of iron, or else pure 

 fused oxide, according as the ore is silicious or not, and is 

 fit for again smelting into cast iron in the high blast fur- 

 nace, so that no loss really has taken place. 



20. The largest furnaces which I have yet tried are very 

 much smaller than the " steuch often" yet from being better 

 managed, expense is much the same — about 35 rupees a ton 

 on the bar iron ; but in larger furnaces, the expense will be 

 very much less, and besides J of the whole expense is for 

 men's labour in blowing; also the estimate is based upon 

 the equivalent quantity of charcoal, which in my furnaces 

 is not used ; the flame of the gases of the furnace being 

 applied to carbonise green brush wood, and the flame from 

 this again might be used to heat the boiler of the blowing 

 engine. Instead of 12 hours being required as in the steuch 

 often, to produce the result, in mine three hours is more 

 than sufficient ; and each furnace can thus be worked three 

 times a day. I find also that these furnaces cost so little, 

 that with all the apparatus, the capital sunk to make 500 

 tons of bar iron a month need be only 25,000 rupees, and 

 with 80,000 rupees more for a rolling mill, would give only 

 10,000£, instead of 27,000£, as required by Dr. Ure's esti- 

 mate. A rough approximation to the expense of working 

 these furnaces may be made, by estimating the cost in bar 

 iron at sixteen times its weight in firewood. 



21. I have had as yet no opportunity of trying coal in 

 bloomery furnaces, but I have no doubt it can be used, 

 because the principles upon which these furnaces act, are 

 applicable to any kind of carbon, and besides Dr. Ure 

 alludes to the use of coke in the Catalonian forges. It is 

 probable therefore that the coal of Bengal can be turned to 



