STEEL, AND THE BESSEMER PROCESS. 217 
uniform than wronght-iron can be in all its qualities. The stiffness of 
this steel, proportionate to its tenacity, adapts it to girder and ship- 
building, and peculiarly fits it to resist compressive as well as tensile 
strains, as in piston-rods. While the elasticity, and hence the safe 
working load, of the lowest steel is much greater than that of wrought- 
iron, its ductility is equal to that of the best wrought-iron. Two-inch 
bars may be bent double, when cold, under the steam-hammer. This 
property insures its safety in the form of axles and tires. The hardness 
of the material, as well as its homogeneity, increases its durability in 
the form of rails, guns, and parts subjected to abrasion. It is peculiarly 
adapted to plates requiring intricate flanging, aud subjected to the im- 
mediate contact of fire. For a given strength it may be thinner than 
wrought-iron ; it does not blister, and the carbon in it protects it against 
corrosion. 
The kind of products, now regularly ordered and produced at Troy, 
are railway axles, marine crank-pins and small shafting, connecting-rods, 
piston-rods, locomotive crank axles, boiler-plate, machinery steel forg- 
ings, such as lathe-spindles, &c, rolled and tilted bars for pistols, rifles, 
hammers, and agricultural machinery, waggon axles, and bars and rods 
for miscellaneous purposes. The old works produce ingots up to 
two tons weight ; the new works will produce ingots up to fifteen tons 
weight. 
A few experimental rails and tires without welds have been produced, 
but the present machinery is not nearly heavy enough for regular 
service. A heavy plate mill, a heavy mill to roll ingots into blooms, a 
tire mill requiring 300 horse-power, and several steam-hammers, will 
be soon added to the works. 
This process of making steel was brought out by Mr. Bessemer in 
1856. English and European manufacturers began to adopt it in 1859 
and 1860, and at the present time not less than 100,000 tons of Bes- 
semer steel are produced per year. 
The idea of blowing air into cast-iron is at least three hundred years 
old. The fusing furnace for partially decarbonising cast-iron, prepara- 
tory to puddling, has been worked on this principle for more than one 
hundred years. Since Mr. Bessemer's patents were issued, and since his 
practice began, claims have been made by two or three other persons for 
making steel by the Bessemer process ; but not a pound of steel or mal- 
leable iron was e^er made by either of these processes, and it is physi- 
cally impossible to make steel or malleable iron by any of them. 
Mr. Bessemer spent a large fortune in his effort to carry the process 
away beyond the highest stage of decarbonisation that could be reached 
by the fusing or any of its modifications ; and I can say, from personal 
experience, that in his process the use of air as a mechanical agent is 
quite as indispensable as the use of air as a chemical decarboniser. The 
attempt to completely decarbonise cast-iron without the use of the appa- 
ratus for which Mr. Bessemer has not only one but many distinct 
