Observations on Iron and Steel. 113 
is called the refinery: which is an open charcoal- 
fire, urged by a pair of bellows, worked by water 
or a steam engine; but the compression of air, in 
the refinery, ought to be less than that in the blast 
furnace. After the metal is melted, it is let out of 
the fire by the workmen, to discharge the scorie; and 
then returned and subjected to the blast as before. 
This operation is sometimes repeated two or three 
times before any appearance of malleability (or what- 
the workmen call coming into nature) takes place; 
this they know by the metal’s first assuming a 
granular appearance, the particles appearing to re- 
pel each other, or at least to have no signs of attrac- 
tion. Soon afterwards they begin to adhere, the at- 
traction increases very rapidly, and it is with great 
difficulty that the whole is prevented from running 
into one mass, which it is desirable to avoid, it be- 
ing more convenient to stamp small pieces into thin 
cakes: this is done by putting the iron immediately 
under the forge hammer and beating it into pieces 
about an inch thick, which easily break from the rest 
during the operation. These small pieces are then 
collected and piled upon circular stones, which are 
‘an inch thick, nine inches in diameter, and about 
ten inches high. ‘They are afterwards put into a 
furnace, in which the fire is reverberated upon them . 
until they are in a semi-fluid state. The workmen 
then take one out of the furnace and draw it into a 
bar under the hammer ; which being finished, they 
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