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ON PRIMARY ORES OF IRON.

but the column of blast able to support 6, 6or 7inches of mercury.

3rd. In the application of the ore itself, great atten-tion ought to be given to the quantity of iron contained,as also to the quantity of oxygen combined with it, inorder that a quantity of coke might be applied ade-quate to what a similar portion of iron would require inusing iron-stone.

4th. The ore should be dried in a red heat, thatwhat portion of water and sulphur it contained mightgently be dissipated; care to be taken, however, to pre-vent a high degree of heat, that a greater quantity ofoxygen from the atmosphere might not be united to it.

5th. It would be highly proper to reduce the ore tosmall pieces : this would not only greatly facilitate theescape of the water and sulphur by diminishing thepoints of contact, but also, by exposing a larger surface,enable the ore in the smelting furnace to take up thecoaly principle with greater facility : the pieces not toexceed \ or f of an inch in their thinnest diameters.

6th. The earthy mixtures of ores being chiefly sili-ceous, the application of pure calcareous earth as a fluxor solvent would be requisite; and, according to ex-istent circumstances, a limestone containing fine clay,slightly coloured by the presence of the oxyde of iron,might be used: the bulk of the pieces of limestoneought also to be a matter of attention, and should notgreatly exceed the ore in size.

In the end, should an association of these requisitesproduce the desired effect, and crude iron of all thevarious degrees of carbonation be obtained from primaryores of iron, it would render many situations in thiscountry eligible for iron-works, which are at presentonly so on account of the immense profusion of coalwith which they abound; it would call into profitable