212 STEEL, AND THE BESSEMER PROCESS. 
silex, and manganese, or some substitute for manganese, are poured into 
the decarbonised iron. 
The steel thus produced is cast into ingots, which are then ready for 
the hammer or the rolls. The apparatus employed is, first, a large 
melting furnace, to melt the cast-iron to be converted ; second, a con- 
verting vessel, into which the melted iron is run, and where the air is 
blown into it to decarbonise it ; third, a small melting furnace, where 
the small quantity of cast-iron or other material for recarbonising is 
melted ; fourth, a ladle, ladle-crane, &c, into which the steel is poured 
from the converting vessel, and from which it is" let out into the ingot 
moulds. 
The melting furnaces used in England and on the Continent are 
reverberatory furnaces — that is, furnaces in which the flame of the fuel 
is thrown down upon the iron, instead of the iron being mixed up with 
the coal. Thus the impurities of the coal do not mix with the iron. 
The furnaces are similar to common puddling furnaces. They were 
at first used in this country, but the cupola has now been substituted. 
The converting vessel is a cylindrical vessel of plate iron, with 
rounded or dome ends. It is (for making two tons of steel at a charge) 
about five feet in diameter and ten feet high. It is mounted on trun- 
nions, so that it may be turned either end upward. On one end is an 
inclined mouth or spout, and on the other a tuyere box, to which air is 
admitted from the blowing engine by means of a hollow trunnion and 
pipes connected with it. The converter is lined with a refractory 
material about a foot thick — any silicious stone ground fine and rammed 
in ; and the air is carried through this lining, from the tuyere box, by 
means of six fire-clay tuyeres, each tuyere having a dozen holes about a 
quarter of an inch in diameter. To the other trunnion is attached gear- 
ing and a crank to revolve the converting vessel. 
The ladle is a plate-iron vessel some three feet high and three feet 
in diameter, lined say two inches thick with refractory material, chiefly 
moulding sand. In the bottom of it is a hole in which is set a fire-clay 
nozzle. A fire-clay stopper, lifted and lowered by a hand-lever fastened 
to the outside of the ladle, fits into this nozzle, and thus forms a valve 
by which the hole in the bottom of the ladle is opened and closed. 
The ladle is mounted on a crane, which allows it to move up and 
down and to swing round in a fixed circle — that is, to swing under the 
converter to catch the steel, and then to be hoisted and moved over the 
ingot moulds in succession. The process is as follows : — Two tons of 
pig-iron are melted in the large furnace ; time, one hour and a-half. 
Meanwhile the converter has a fire made in it, and two or three pounds 
per square inch pressure of blast let in, to heat the lining red-hot, and 
the ladle is turned bottom upwards over a little furnace to heat. By 
means of another crane, the ingot moulds are also arranged in the pit in 
a half-circle, so that the ladle can swing over them. When the iron in 
the large furnace is nearly melted, a small quantity of pig-iron or other 
