Cast Steel. 
395 
,ly two hours, without urging the lire. Small pieces of 
iron wire that have been previously introduced into the 
pan being withdrawn from time to time, are dipped while 
hot in cold water, and by the file and the character of the 
fracture, the progress of the cementation is determined. 
When the intended degree of carburation is obtained, the 
fire is increased and the articles as soon as sufficiently 
heated are taken out of the pan and plunged in cold water. 
The inferior kinds of table-knives and some surgical in- 
struments, where a considerable degree both of toughness 
and hardness is required, are prepared in this way. 
The finest kind of steel however, called English cast 
steel , yet remains to be mentioned. It is commonly pre- 
pared by breaking to pieces the blister steel and then 
melting it in a crucible with a flux composed of carbo- 
naceous and vitrefiable ingredients. When thoroughly 
fused it i cast into ingots, which by gentle heating and 
careful hammering are tilted into bars. By this process 
the steel becomes more highly carbonized in proportion to 
the quantity of flux, and in consequence is more brittle 
and fusible than before ; it is inferior to the other kinds of 
steel in being incapable of welding either with iron or 
steel, but on the ether hand surpasses them all in unifor- 
mity of texture, hardness, and closeness of grain, hence it 
is the material of all the finest articles of English cutlery. 
The composition of the flux used in preparing this steel 
is kept a secret among a few manufacturers, and in conse- 
quence, various experiments have been instituted both 
here and elsewhere to discover either the same or an equal- 
ly successful method of making this beautiful substance. 
In 1795, Clouet published the results of some valuable 
experiments, from which it appears that by simply fus- 
ing bar iron with charcoal, a cast steel may be obtained 
more or less carburetted, according to the proportion of 
charcoal employed, and therefore possessing at pleasure in 
