New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1857-05-25
Nsppork Daily Gibn,re
INDUSTRIAL AND SCIENTIFIC INTEL
LIGENCE.

gether from the very slight differences in
the proportions of carbon and of the few other elements
which alone distinguish them chemically. Iron ores
melted in bs- furnace, yield the metal in The midst
Of carbonaceou. matters and this IT, IN the moment OF
its birth imprecnated more or less with carbon and
with the metal sicium and other matters regarded Sc
impurities The metal drops down in the state Of cast
IRON compound Of metallic iron and carbon, the lat
ter varying form two TO FIVE per cent, and sicun,
which varie. from four per cent. This eGst
pig iron is Of several varieties known Nos. l. , 3,
&c. It is distinguished into the two kinds called
foundery iron, and high iron or forge metal the former
more suitable for ecasting and the latter 0r being
converted into wrought bar iron by The separation
Of the carbon sicun and any impurities contains
which effected by the process called pudding The
real difference in the composition of the varieties Of
pig iron is not fully UNDERWOOD Authorities differ
to their various percentages Of carbon TO which, as
well as TO its manner OF combination, the different quail
tiles are attributed In the foundery iron, which is soft
and Of dark gray color il is generally supposed that
the carbon is only ntennixed with the iron, while in
the high iron which is white ike silver. end almost
hard as STEEL il is chemically united with the metal
The iron manufacturers all believe that the darker the
iron, the more carbon it contains but chemical al
slysi- does not sustain this opinion. High iron con-
lHDs muCD less lLt tOIt uOH 40
.cum is more Difficult, TO separate from the iron than
carbon il, II may be that it, deficiency is the cause
why the former is easily converted into metallic
IRON and very possibly it has quite much TO do in
causing the peculiartes Of cast iron carbon has
Cast iron is easily melted and is less brittle,
but deprived of carbon and other mixtures, metallic or
wrought iron is melted with extreme difficulty-ndeed
it is regarded as nfusbe by any heat that can be pro-
duced by melting furnaces, provided it is protected
from contact with any form of carbon, and that there
is none of this left in It's composition. The more it is
refined or rendered pure, the tougher it is, and it Is
probable have not yet learned the character and
strength of absolutely pure Metallic iron dis
tngushed by its sotness when highly heated, and its
great maeability being then easily hammered into any
shape. Cast iron be melted and run into any
shapes and the surface of the castings may by pro-
cess as yet comparatively new, be deprived of por-
ton of its carbon and be converted almost into me-
talHc iror in which condition they are called maeable
castings.
Steel IL another combination of iron and carbon the
latter being present in the proportion of only one to
two per cent. Its properties very different from
those Of cast iron and of metallic iron, considering the
very slight difference in their composition. Like the
former it is fusibe; and like the latter is maleable,
and Gun be welded
It's most remarkable peculiarly is its quality of
being tempered to greater less degree of hardness
by heating and suddenly cooling skillfu workman
takes bar of STEEL heats it 10 proper temperature
in his forge-re, places it upon his anvil and with his
hammer works it, if it were wax into the form he
wishes Judging by slight changes Of its color what its
peculiar properties are, and by the mode in which he
chills it in cold water giving to it the hardness re-
quired for any particular purpose. Ii he wishes to
change s temper another heat soens it, few more
blows of the hammer shape it, dip in the water, and
look at its color, and it is done
These forms of iroD all easily converted nom one
into the other, give from the one metal the quah-
ties we would naturally look for in three four differ
metals and the chaeges being very obscure IN Their
nature and inexplcabe in their effects it is likely
are with all our experience, still far from understand
ing the best method of working irop well the full
benefits to be derived from it. The difference in price
seems as rreconcilable with the different compositions
as the difference in quality. Cast iron IL worth from
cent TO two cents pound, msllesbe iron from two
to seven or eight cents, and steel from ten to sixteen
cents II the working of the metal were thoroughly
understood it does probable that there would
be this great difference in price for articles nearly
alike in composition.
The English method Of making steel from bars of
iron is tedious process and be extensively
introduced into this country any more than the long
process adopted by the English of smelling copper
! ores We have not the patience to prosecute an
operation which requires fifteen days more to in
fuse little carbon into some bars of iron. ANY Yam
| kee would ruin himself in experiments TO hasten the
process, before he could make anything by the esao-
| Gshed method. We may make Us good iron from our
ores a. the Swedish bars from the Of the Dane
mora mine but though admirably adapted for making
the best Steel we prefer pay the Sheffield manufac-
| turer, and import the immense quantities which we
consume. The English process of making cast-steei
consists in carboDizing iron bars, which have already
been decarbolized from the pgmeal and then break
Ing them into small pieces and melting them in cruci
bles. From these the steel il into ingots, which
are then hammered into bars rolled into plates. The
first part Of the operation is called the concentration pro-
cess. The bars piled up in layers in tight oven
| or chamber, with fine charcoal intermixed between
| them and all buried with several inches
| thick. A fire circulating round the heats the
| whole mass red hot and il continues SIX or eight
days aud another week passes while it is slowly cool
| ing. Twenty charges IN year are considered good
| work for cementiug furnace The bars, when taken
out are found to be blstered all over their surface
they have become brittle, the ibrous texture has
changed 10 granular, and the color is white, Ike
frosted pr. The hardness is increased, and the
property Of tempering is acquired. The bars are now
steel, of the variety called bisered. When broken up
and melted, the quality is improved andrenderedmo
uniform. This is east-stoe The great advantage Of
this process consists in the Of refined iron, toler
ably free from foreign matters.
On the continent of Europe simpler process and it
would rational one is adopted Of efecting
the same result by deprving some of the better quail