236 Treatmenc of Melted Cast Iron 
with any idea of producing either malleable iron or steel 
by that process, but simply a highly decarbonized refined 
metal. About the year 1850, I made experiments with some 
very highly blown refined iron from the Parkend Iron- 
works, in the Forest of Dean,and found that when alloyed 
with manganese, this refined metal could be forged into 
sound bars of very hard steel, too hard for any practical 
purpose, but, nevertheless, solid and free from seams or 
flaws, indicating if the iron could be sufficiently decar- 
bonized whilst in the melted state, steel of marketable 
quality might be obtained by simply adding some metal- 
lic manganese to the decarbonized metal. In the Autumn 
of 1856, Mr. Henry Bessemer read a paper at a meeting of 
the British Association at Cheltenham, which, whilst it 
filled the scientific as well as the practical world with 
astonishment, did not in the least surprise me, except, in 
the one circumstance of its being possible to maintain a 
tuyere beneath a heavy column of melted cast iron. That, 
indeed, appeared to me most surprising, as I was well 
aware of the highly destructive action of the iron slag 
which is generated by the action of atmospheric air upon 
melted cast iron. However, what I considered impossible 
had actually been accomplished by Mr. Bessemer, and the 
first great advance towards rendering steel as cheap as iron 
had been inaugurated by that gentleman. Mr. Bessemer’s 
process consisted in forcing airthrough melted cast iron by 
means of tuyeres situated beneath the surface of the 
melted iron. When melted cast iron is subjected to this 
process, the silicon contained in the iron is first combined 
with the oxygen of the blast and thrown to the surface as 
a light frothy slag. Next, the carbon of the melted iron 
enters into combustion, and lastly, the iron itself is at- 
tacked and consumed with the development of an intense 
temperature, sufficient to keep the iron, though freed from 
carbon, in a perfectly liquid state. When the silicon and 
the carbon have been nearly or wholly eliminated from the 
cast iron operated upon, the product obtained is either 
crude cast steel or iron, according to the decarbonization 
arrived at. Ingots cast from this metal are more or less 
unsound, and when forged they frequently crack or break 
off, owing to their red shortness, and are wholly unfit for 
the requirements of commerce. Moreover, whenever the 
melted cast iron operated upon contains sulphur and phos- 
phorous to any notable extent, the decarbonized iron is 
found to be so crude and brittle that it cannot be forged at 
