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A supplement to Ures Dictionary of Arts, Manufactures, and Mines, : containing a clear exposition of their principles and practice. . k in theirneighborhood. In this state of things the ores in the external portions of the furnace would 640 IRON. become reduced and converted into gray metal; while those in the central portions would,according to the degree of deviation of the ascending current of heated gases from themdescend to the point of fusion either thoroughly deoxidized, and slightly carbonized, orpossibly with a portion still in the state of oxide, and mixing there with the properly re
A supplement to Ures Dictionary of Arts, Manufactures, and Mines, : containing a clear exposition of their principles and practice. . k in theirneighborhood. In this state of things the ores in the external portions of the furnace would 640 IRON. become reduced and converted into gray metal; while those in the central portions would,according to the degree of deviation of the ascending current of heated gases from themdescend to the point of fusion either thoroughly deoxidized, and slightly carbonized, orpossibly with a portion still in the state of oxide, and mixing there with the properly reducedores, enter into fusion with them, producing a mixture of irons which must necessarilyprove of inferior quality, and a black cinder from the unreduced oxides. When the irontube in the throat of the furnace was kept only partially filled with minerals, much moregas escaped into the open air, as might have been expected, and consequently more trav-ersed the central parts of the furnace ; and it was always observed that when that modeof filling was adopted, the furnace worked much better: but then the object, viz. that of 343. economizing the gases, was not attained. Differently formed furnaces were found to be dis-turbed in different degrees by this system of drawing off the gases : the old conical narrowtopped furnaces were affected very much less than the improved modern domed top furnaceof large capacity, from which all attempts to take off any useful portion of the gases provedabsolute ruin. It might be argued, that as the same quantity of blast and fuel was usedas heretofore, the ascending current of heated gases ought to produce the same deoxidizingand carbonizing efFect on the superincumbent mass, whatever direction they might take inmaking their escape at the upper region of the furnace ; for if the central part should nothave been sufficiently acted upon, the external annulus would have more than its usual IROiT. 641 share of chemical influences. But when it is cons
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Keywords: ., bookcentury1800, bookdecade1860, bookpublishernewyo, bookyear1864