Page:Encyclopædia Britannica, Ninth Edition, v. 6.djvu/139

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Coppée's Coke Oven.

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Coke is used for all purposes where a smokeless fire is required, as, for instance, in drying malt or hops, or in raising steam in locomotives within the limits of towns, also for producing strong local heat, as in melting metals (gold, silver, brass, or steel) in crucibles in air furnaces. In blast furnaces its value depends upon the difficulty of combustion, so that the particles keep their form until they reach the proper place of combustion at the point of entry of the blast in the lower part of the furnace. The great economy of fuel tliat has been effected in the process of iron smelting in the Cleveland district by increasing the height of the furnaces, is in great part due to the strength of the coke used, which is made in the south part of the Durham coal-field, and has sufficient cohesive power to bear the pressure of a column of iron-making materials from 80 to 100 feet in height without crushing, a result which cannot be obtained with the coke of other districts. Finely ground coke is used mixed with clay for making crucibles for steel melting, and also for filling the hearths of blast-furnaces in many German smelting works. Apart from its convenience for special purposes, coke is not an economical fuel, the useful heating effect being about the same as that of an equal weight of coal. This circumstance lias led to the nearly general abandonment of coke and the substitution of raw coal as fuel in locomotive engines on railways. For full accounts of the different systems of coke ovens and details of their construction, see Percy s Metallurgy, introductory volume on fuel, &c., 2d edition, London, 1875, and Jordan s Album du Cours de Metalhirgie, Paris, 1874.  COKE, (1552-1633), one of the most erudite of English lawyers, was born at Mileham, in Nor folk, on February 1, 1552. When only ten years old he lost his father, who was a bencher of Lincoln s Inn. From the grammar-school of Norwich he passed to Trinity College, Cambridge ; and after a course of three years, in 1572 ho entered the Inn to which his father had belonged, To the study of law he devoted himself from 