Metallurgy of Iron. 17 



are for the greater part of inferior quality. Interstratified with 

 the beds of coal in many parts of Great Britain, Europe and North 

 America there are found beds of what is called clay iron-stone, or 

 argillaceous carbonate of iron, yielding from twenty to thirty-five 

 per cent, of the metal. This association of coal with the ore offers 

 great facilities for the fabrication of iron, which is made in large 

 quantities, and at very low prices from these argillaceous ores. 



These poor ores will not admit of being carried far for the pur- 

 pose of smelting, and it is not less evident that the large quantity 

 of coal required for their treatment could not be brought from any 

 great distance to the ores. As a general rule the richest and 

 purest ores of iron belong to regions in which mineral coal is 

 wanting, while the carboniferous districts yield only poorer and 

 inferior ores. On this continent, which contains vast areas 

 of coal-bearing rocks, the great deposits of magnetic and hematitic 

 iron ores are chiefly confined to the mountainous district north ot 

 the Saint Lawrence, and the adjacent region of northern New 

 York, to which may be added a similar tract of country in Mis- 

 souri. In the old world it is in Sweden, the Ural Mountains, 

 Elba and Algiers, that the most remarkable deposits of similar 

 ores are met with ; and it is not, perhaps, 'too much to say, that if 

 favourable conditions of fuel and labour were to be met with in 

 these regions, these purer and more productive otes would be 

 wrought to the exclusion of all others. But where charcoal 

 is employed the forests in the vicinity of large iron furnaces 

 are rapidly destroyed, and fuel at length becomes scarce. 

 In a country like ours where there is a ready market for fire-wood 

 near to the deposits of ore, the price of fuel will one day become 

 such as to preclude their economic working by the ordinary pro- 

 cesses. As the industrial arts progress, the consumption of fuel 

 is constantly increasing, and its economic employ becomes an 

 important consideration. 



From these preliminaries it is evident that a great problem with 

 regard to the manufacture of iron, is to find a process which shall 

 enable us to work with a small amount of fuel, those rich ores 

 which occur in districts remote from mineral coal. Such was the 

 problem proposed by Adrien Chenot, and which in the opinion of 

 the International Jury, he has in a great measure resolved. 



To return to the blast furnace; we have seen that the second 

 and moderately heated region, is that in which the reduction of 

 the ore is effected, and that the intense heat of the lower regions 

 of the furnace only affects the carburation and fusion of the metal. 



