S/R WILLIAM SIEMENS, F,R.S. 231 



from Gornal, near Birmingham, will set under these circum- 

 stances into a hard impervious crust, capable of surviving 

 from L'<) to 80 charges of liquid steel, without requiring material 

 repairs. If no natural sand of proper quality is available, white 

 sand, such as Fontainebleau sand, may be mixed intimately 

 with about 25 per cent, of common red sand, to obtain the same 

 results. 



In tapping the furnace, the loose sand near the tapping-hole is 

 removed, when the lower surface of the hard crust will be reached. 

 The lowest point of this surface is thereupon pierced by means of a 

 pointed bar, upon the withdrawal of which the fluid metal runs 

 out from the hottest and deepest portion of the bath into the ladle 

 in front of the furnace. 



M. Le Chatelier now proposes to mix the natural Bauxite, of 

 which the bottom of the experimental furnace at the works of 

 MM. Boignes, Ilambourg and Co., near MontluQon was first made, 

 with about 1 per cent, of chloride of calcium dissolved in water, 

 to calcine the mixture, and to form it into moulded masses of 

 highly refractory material. 



A hard bottom being thus prepared, and the heat of the furnace 

 being raised to whiteness, it is ready to receive the materials to be 

 melted. 



If these materials consist of bar iron, or of old iron and steel 

 rails, they are cut into lengths of about six feet, and are intro- 

 duced into the furnace through slanting hoppers from the elevated 

 platform at the back, so that their ends rest upon the sand bottom 

 forming the bath. 



If the capacity of the furnace is such, that charges of 3 tons can 

 be formed, about 6 cwt. of grey pig-iron is introduced through 

 the ports or short hoppers, below the main charging-hoppers 

 before-mentioned. As soon as a bath of pig metal is formed, the 

 heated ends of the rails or bars begin to dissolve, causing the bars 

 gradually to descend. By partially closing the mouths of the 

 charging-hoppers, a regulated quantity of flame is allowed to 

 escape from the furnace, in order to heat the descending bars of 

 metal previous to their entry into the melting-chamber, the 

 object being to maintain the high temperature of the furnace, 

 notwithstanding the constant introduction of cold metal. The 

 escaping products of combustion, which are thus withdrawn from 



