SIR WILLIAM SIEMENS, J-.K.S. 343 



and the conclusions I am disposed to draw, from past experience, 

 regarding the direct process of the future. 



The leading idea which guided me in these researches was to 

 operate upon such mixtures of ores, fluxes, and reducing agents as 

 would, under the influence of intense heat, resolve themselves 

 forthwith into metallic iron and a fluid cinder, differing essentially 

 f roiii the methods pursued by Chenot, Gurlt, Blair, and others, 

 who prepared spongy metal in the first place, by a slow process, 

 which is condensed into malleable iron or steel by after processes, 

 but assimilating to some extent to the process first proposed by 

 .Mr. \Vrn. Clay. In my paper of 1873, I described two modes of 

 effecting my purpose, the one by means of a stationary, and the 

 other by means of a rotative furnace chamber, the former being 

 applicable chiefly where comparatively rich ores are available, and 

 the latter for such poorer ores as occur near Towcester. 



At the Towcester works, three rotative furnaces have beeu 

 erected, two of them with working drums 7 ft. in diameter, and 

 9 ft. in length, and the third of smaller dimensions. The gas 

 flame both enters and passes away from the back end of the fur- 

 nace, leaving the front end available for the furnace door, which 

 is stationary. The ends of the furnace chamber are lined with 

 Bauxite bricks, and the circumference with iron oxides, resulting 

 from a mixture of furnace cinder enriched with roll-scale, or 

 calcined blackband in lumps. About 30 cwts. of ore mixed with 

 about 9 cwts. of small coal having been charged into the furnace, 

 it is made to rotate slowly for about 2 hours, by which time the 

 reduction of the metal should be completed, and a fluxed slag be 

 formed containing the earthy constituents and a considerable per- 

 centage of ferrous oxide. The slag having been tapped, the heat 

 of the furnace and the speed of rotation are increased to facilitate 

 the formation of balls, which are, in due course, taken and treated 

 in the manner to be presently described. 



These balls contain on an average 70 per cent, metallic iron and 

 30 per cent, of cinder, and upon careful analysis it is found that 

 the particles of iron, if entirely separated from the slag, are pure 

 metal, although the slag may contain as much as G per cent, and 

 more of phosphoric acid, and from 1 to 2 per cent, of sulphur. In 

 shingling those balls in the usual manner, the bulk of the cinder 

 is removed, but a sufficient residue remains to impart to the 



