$92 
Cast Steel, 
finery with the same precautions as at first, and is now 
sufficiently purified to be forged : it is accordingly ex- 
tended under the hammer and cut into bars which are ex- 
amined by their fracture, and separated according to their 
qualities, into hard steel, soft steel, and steely iron ; the lat- 
ter is reserved by itself and used for pointing ploughshares 
and other coarse work ; but the others are made up into 
packets, observing to place the hardest steel on the inside, 
which are then drawn into bars at a lower heat than that 
required for iron, and then the process is compleat. Thus 
the whole art consists in purifying the cast iron, taking 
at the same time particular care that the carbon which it 
contains, is not burnt away. If the original cast iron is 
very highly carbonized, it sometimes happens that the 
steel retains too large a proportion of carbon, which is 
evinced in the refinery by its being more easily fusible, 
and requiring a longer time to become solid again than 
usual : this defect however is speedily remedied, by adding 
iron filings or scraps of bar iron, the quantity of which is 
regulated by the degree of fusibility to be corrected. 
If the manufacturer wishes to procure iron from this 
ore instead of steel, the only difference required in the 
treatment, is to get rid of nearly the whole of the combined 
carbon by roasting the plates in a reverberatory furnace 
before they are brought to the refinery, and by avoiding 
to line the crucible of the refinery with pounded charcoal. 
The iron thus produced is of an excellent quality. 
The best of the Swedish and Norwegian ores are oc- 
casionally wrought into steel of a very good quality by 
nearly the same process of manufacture, provided in the 
smelting a larger proportion than usual of charcoal has 
been employed, to ensure a highly carbonized metal. 
The usual method of converting iron into steel is by 
cementation. For the purposes of manufacture, this is 
performed on large quantities at a time in the following 
