COAL AND lEON OF CUTTACK. 23 



A moderately rich haematite, yielding about 35 per cent, of metal, was 

 being used when Professor Wilson saw the furnaces in operation, and 

 the balls weighed about 80 lbs. each. The average yield obtained in 

 the furnaces was stated to be about 45 per cent., and the average 

 weight of the balls to be about 100 lbs.* 



Professor Wilson states that the action of this furnace was excellent 



and the production rapid. 



The fuel used in America was coal, but there 

 In America coal is the 

 fuel used, but we might sccms no reason whatever why charcoal should 

 substitute charcoal. 



be less effective if used in proper proportions. 



The second form of furnace to which I referred above, and for 



re-calling my attention to which I am indebted to 

 Ekman'a furnace. .^ 



my colleague, Mr. H. H . islantord, is that known 



as Ekman's, which is used in Sweden for the manufacture of charcoal iron. 

 The principle is simple. The body of the furnace is of the construc- 

 tion of an ordinary reverberatory furnace, the bed 

 Construction, &c. 



of which IS shorter than usual. Upon this bed 



the ore, mixed with charcoal and a small proportion of flux, is laid 



and is here occasionally rubbled. The blast enters at the crown of 



the furnace, but is previously passed through about 6 feet of ignited 



charcoal or coke. By this means a large quantity of carbonic oxide 



(CO.) is formed, and raised to a high temperature. This powerful 



reducing gas then passes through the tuyere, and, 

 Mode of working. . , , 



together with the gases from the furnace, is blown 



directly upon the ore, the flame of the furnace being kept highly 



reducing by regulating, in the ordinary way, the supply of air below the 



bars. By this means a spongy mass of metal containing, mixed with it, 



a considerable quantity of slag, is formed upon the hearth. This is 



balled and shingled in the ordinary way. 



* Vide Journal of Society of Arts, Loudon, 1853-54— J. Wilson's Lecture on Iron 

 Manufactures of America, as exemplified in the Exhibition at New York. 



