WILLIAM SIEMENS, F.R.S. 295 



The ore employed was Moktaore, of the following description : 



\ Fe 60-8 



FcO 



Mn 3 4 



CaO 



SiO a . 



Loss on ignition 



82 charges, 14,338 Ibs. ore 

 5,952 coal 



7G8 ,, lime 



7:i-7 I 

 6-48 

 52-92 

 52 

 25 

 4-75 

 5-11 



99-72 



Yield in slabs. 



> 8,115 Ibs. = 56-6 per cent. 



Other specimens of steel shown are produced by fusion of the 

 iron thus obtained on the open hearth of a regenerative gas 

 furnace, which are undoubtedly of superior quality. 



The furnace used for carrying out this process of fusion and 

 precipitation consists of a reverberatory gas furnace having two 

 beds formed by the ore itself ; on the upper bed a lake of fused 

 ore is formed which can be let off into the lower bed by piercing 

 the intervening bank of unfused ore ; the lower bed is divided 

 into two compartments, used alternately, each provided with a 

 working door. The dense carbonaceous material, such as an- 

 thracite or hard coke, to be used for the precipitation of the iron 

 in the lower bed, is reduced to a state of powder and mixed with 

 about an equal weight of pulverulent ore. This mixture is spread 

 over the bottom surface of the working bed, and the fluid ore is let 

 in upon it. By stirring with a rabble it is transformed into a 

 pasty and foaming mass, which in the course of from 40 to 50 

 minutes is shaped into a metallic ball in a bath of fluid cinder, which 

 may be shingled in the usual manner and formed into bar iron or 

 transferred to the pig-iron bath of a steel-melting furnace, where 

 it readily dissolves. The accomplishment of this process involves, 

 however, a certain degree of manual labour and skill, as, if it be 

 carelessly conducted, the yield of iron will be unsatisfactory ; the 

 analysis of the slags shows a variable percentage of iron amounting 

 rarely to less than 15 per cent., but reaching occasionally up to 40 

 per cent. 



