Polynesian., 1856-11-29
No. SO

ing weight, can easily be turned t!rauo5 anv angI
The blast is admitted by a pipe RAISING fbr71ob
the axle OF one of the cranks and thus revol, in,
with the converting vessel. The tuyercs enter the
converting vessel By a series OF sgerlures f,rn,ir
a horizontal row. The cylinder can thrs be mad9
to reyOlve round the axis of the crank with,nt
turning upon any axis OF its. own /; and thus the
Iapertures OF the tuyerCS mey be raised till they
are brought above the surface of the metal Tue
blast can then be turned off and the agi;ati IN of
the metal allowed to sUi siih Ir,n melted rv cx
listing processes sots in ah1ut three or E,ur r,i.
utes but Mr.. Besseuer finds that ne e,n iI,,r :,
to stand for ten or twelve minutes-a period orut.
sufficient to allow all the air-bubbles to ese,na
and the cylinder may then be raised still further
and the metal poured off as gently as ninv BE re-
qulsite, through spout at the top or in the side
OF the vessel. The quality of the steel pruluced
admits OF no doubt. fragment broken off from
an lngot cast when we the experiment was
compared with fragment broken of from the end
oil hle. 1t was harder, and far finer in the grain
| The experiment in question was conducted with
SIX or seven hundred weight of Yorkshire iron of
common quality. An ingot Of six hundred
weight was produced in one piece in about 25 min
utes. There will be no difficulty in PRODUCING
masses of any size or shape. The size Of the con-
verting vessel and the number of tuyeres may b.
increased to any requisite-extent. The blast need
not be increased In strength it will only be ne
cessary to enlarge the area of the floor of the yes
sci, so that the iron may not rise to a heisl Of
more than or inches. The loss was about Is
| per cent; but OF this a considerable quantity
might be recovered, as the Stag thrown out duIinc
the boil contains about 30 per cent of iron in tie
shape OF little gobules, like shot, set in the slag
1t Is extremely porous, and erumbles to the touch
so that it might be broken up, and the iron separ-
ated by washing, with little difficulty and labor
In the ordinary pudding process from II to p per
cent is lost, and in the Catalan and Corscan pro
1iy-Y ai.-tf &c ~, /
from three to seven times that of the iron produc
ed, but 5l3ths, or about SO per cent of the metal
Is sacrificed to secure the purity of the remainder
! MIR. Nasmyth tried some years ago to dec lrburize
cast iron by blowing steam into the melted metal
This attempt tailed the separation Of the oxygen
from the steam exhausted 50 much Of the heat of
the metal that the heat evolved in the c0mbnat1r,
of the oxygen with the carbon in the iron was in
sufficient to compensate the waste and the iron
was cooled instead of being heated. With the
freedom from jealousy which marks truly great
mind, Mr.. Nasmyth paid, as we have said. at the
late meeting at Cheltenham, a graceful tribute b
the Importance OF the invention and spoke in terms
no less honorable to himself than to Mr. Bessemer
Of the ingenuity of the process and the vastncss Of
the results to which it would unquestonably lead
Mr.. Bessemer, on the other hand derives from the
experience of Mr. Nasmyth the important knowl-
edge that, by the joint use of Jets of steam and
blasts Of air. he will be able to regulate with the
utmost niccty the amount of heat generated and
the rapidty Of the process.
| The history Of this invention Is curious Some
two years ago, Mr.. Bessemer's attention was az
tractcd to a subject happily now of less pressing
interest than 1t then was-namely, the manufac-
ture of riacd cannon. The object of rifing musk
cts ard cannon is to secure u control over the d.
rection OF that rotation which is part Of the motion
Of every proectie and to that it shall take
place round an axis cOiucldent with the direction
nf he is FL, 4ba
musket and Lancaster gan, an elongated ball is
used, and the interior OF the projecting tube is cut
with a curved groove grooves. When a leadcn
ball is shot, appreciuble injury is caused to the
blrrel of the gun, but when an iron ball is usei,
in the case of cannon the wear and tear is yerv
great indeed. The Lancaster guns are seriously
injured, If not rendered unseryicable after a very
few hundred rounds. 1t occurred to Mr. ,Bessemrr
that the object might be attained, without riilng
the cannon, by using an elongated ball, with a
hole drilled halfway down its longer axis and
prolonged into two channels opening by a curved
arm upon each side Of the ball. The effect of the
air passing through these bent pipes and out at tie
back of the ball, as it flew through the air, would
be to create motion Of rotation round the longer
axis Of the ball, just as, in emission steam en-
gine, a rotation Is created by the backward pres
sure Of steam issuing from bent pipe. Finding
difficulties III the way of testing the invention in
England, and ayailiug himself Of certain crcum-
stances into which it is not necessary to enter, be
applied to the Emperor of the French, who in
stInty placed the resources Of the arsenal at Vim
cennes at his disposal and afforded him every fl-
cilitv for his experiments. The balls were found
to rotate as expected fact which was proved hv
causing small projection t. spring out OF the s1le
of the ball the moment it left the mouth of the
cannon, and observing the positi "a in which this
cut targets of thu boards placed int rvals in the
flight OF the ball but it was also found that the
cannon could not safely carry the increased weight
OF metal rendered necessary by the elOngltiOn os
the ball. Hence, Mr.. Bessemer was led to make
experiments on the production of tougher metal
for cannon. lie tried numerous mixtures Of vari-
Gus kinds of fusile metal, until at last he began
20 consider whether 1t night not be practicable to
produce malleable iron in state in which it woull
be easier t. mold it t, the required form than by
the expensive process of forging. The result of
his experiments has been the discovery of n 'rru-
applicable to the arts of peace less than to
these of war.
1t is difficult to assign any limits to the import
ance of an invention whose influence vii! be fes
throughout the civilized world in AN improved
quality and diminished cost of one of the great
staples of modern industry. The first axiom Of the
iron trade Is demonstrated to be Il Eilacy; and, to
a mind familiar with the subject, the magnitude of
the change cannot be mOie cmphaticilly expressed
than in the simple proposition that the ancient and
fundamental antagOnism between the terms cast
iron and mlleable iron has ceased to exist for
malleable iron will now always be cast. 1t is im-
possible 10 doubt the truth Of the opinion modestly
expressed by Mr. Bessemer, that others will in-
prove on his invention, and that his process will
not receive its fpl development for many years to
come: There is no country in which its influence
Will he as extended as our own, in which 50 large
a portion of the community is engaged, directlyOr
indirectly, in arts connected with the manufacture
Of iron and steel; but there arc others where its
effects within n narrow sphere will be yet more