IMPROVE- MENTS IN THE MANUFACTURE OF IRON AND STEEL
Year: 1856

page_text: LETTERS PATENT to Henry Bessemer, of 4, Queen Street Place, New
Cannon Street, in the City of London, for the Invention of "IMPROVE-
MENTS IN THE MANUFACTURE OF IRON AND STEEL."
Sealed the 14th November 1856, and dated the 31st May 1856.
PROVISIONAL SPECIFICATION left by the said Henry Bessemer at the
Office of the Commissioners of Patents, with his Petition, on the 31st
May 1856.
I, HENRY BESSEMER, of 4, Queen Street Place, New Cannon Street,
in the City of London, do hereby declare the nature of the Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF IRON. AND STEEL," to be as follows:-
In carrying into practical operation the manufacture of malleable iron and
steel, by forcing atmospheric air or steam into and among the particles of fluid
crude iron, for which Patents have already been granted to me, I have dis-
covered that certain modifications of and additions to the apparatus and
processes therein described may be advantageously used, and the adaptation of
which improvements to the manufacture of iron and steel forms the subject of
my present Invention. In the first place, I construct a cylindrical iron vessel,
one end of which is closed and rests on a brick foundation; the interior of
the cylinder I line with segmental fire bricks, which for some distance from
the bottom rise up as a vertical wall, and then close over, so as to leave only a
small aperture of about onc-twelfth or onc-sixteenth of the arc of the lower

page_text: "ITE
part of the vessel, thus giving to the interior somewhat the form of a pottery
kiln. Above the throat of the chamber I make a second chamber of any con-
venient form; I however prefer it to be cylindrical with a dome shaped crown;
this upper chamber must also be provided with one or more outlets, and also
with a feeding door, and a damper plate to close up the outlets to the extent
desired. Around the lower part of the vessel I insert several tuyere pipes,
formed of fire clay, black lead, sandstone, or other refractory substanco; these
pipes extend through the lining of the chamber, and are held in place with a pack-
ing of loam or sand rammed in around them, the outer ends of the pipes being
connected in any convenient way to the blast or steam pipes, by means of which
air or steam is conveyed into the chamber for the purpose of rendering the crude
iron malleable. And here I would observe, that although I have mentioned air
and steam because they contain or are capable of evolving oxygen at a cheap
rate, it will, nevertheless, be understood that pure oxygen gas, or a mixture
thereof with air or steam, may be used; and so likewise any fluid or solid
matter containing or capable of evolving oxygen gas may be used in con-
junction with air or steam, in the process of converting crude iron into malleable
iron or steel, in vessels or chambers in which fuel is not used, for the purpose
of keeping up the heat of the metal: In some cases I make a portion of the
segmental bricks which form the lower part of the lining of the vessel with
holes in them, in lieu of using the pipes, before named; in which case I make
them of fire stone, fire clay, or of plumbago, or such a mixture of fire clay
and plumbago as is used for making crucibles. When these perforated bricks
are used, I make the iron shell or vessel so as to separate at the part where
they are inserted, in order to afford facility for their removal when worn out.
I The crude metal is to be run into the vessel through a hole made in one
side for that purpose, and, after the completion of the process it is. drawn off
through a tap-hole, secured by loam, similar to the tap-holes used in the
ordinary cupola furnace. As soon as a charge of crude iron is run into the
vessel, a workman'will put into- the-upper chamber the quantity of bar ends,
ingot ends, or other scap metal intended to be mixed with the charge; he
should place these pieces so as to be acted upon by the heat and flame issuing
from the throat of the vessel towards the close of the operation, and after the
scrap metal has attained a very high; temperature, the workman will open the
door of the upper chamber, and with a hook tool he will bring the pieces of
scrap iron or steel over the throat of. the lower chamber, into which they wil
fall, and be there rapidly melted and mixed with the remainder of the charge
In the treatment, of different irons, by the process of forcing atmospheric o
other oxygen therein, it will be found advantageous in some cases to use such

page_text: fluxes as will best act upon the different bases associated with the iron: In this
way small quantities of lime, silica, or aluniina may be added with advantage,
and so in like manner chloride' of sodium, iron scales, oxide of manganese,
and other salts or fluxes may be used to assist in the separation of the im-
purities contained in the crude metal; and, further, when it is desired to make
any alloy of zine, copper, silver, or other metals, with iron or steel,. I put
such metals in a fluid or solid state, or as salts or oxides, into the chamber or
vessel before described, where their mixture with the molten iron or steel will
be greatly facilitated by the violent agitation which is produced by the forcing
in of the air or steam, and which continues during the discharge of the metal
from the vessel, so that no time is allowed for subsidence or separation of the
alloy should the chemical affinities of the metals for cach other be so weak as
have a tendency to separate when left in a state of repose..
As soon as the metal has arrived at the condition which the workman
judges suitable for his purpose, he will proceed to tap the furnace and discharge
the metal therefrom, and form it into ingots or otlier castings..
For making large ingots intended to be hammered or rolled into bars, rails,
rods, or plates, I construct a mould in the following manner :-I take a
massive block of iron, of a length somewhat greater than the intended ingot,
and I make an opening through it from end to end of the sectional form to be
given to the ingot; the opening may be planed or bored truly parallel, but I
prefer making it slightly taper; into the bottom end I fit a plunger sufficiently
long to rise above the top of the mould. The lower end of the plunger is con-
nected to the ram of a hydraulic press, the mould: block being firmly attached
to the cylinder of the press; above the mould I place a plate-iron ladle-lined
with loam, and having a hole in the bottom stopped by a plug, into this ladle
the metal is run, and when it has accumulated to a depth of a few inches, the
plug is to be raised and the metal. allowed to descend. vertically into the
mould; by this means any slags or other impurities.which float in the ladle
will be prevented from mixing with and forming part of the ingot.. As soon as
the metal has solidified, the ram of the press is to be acted on: by a force
pump, and the ingot pushed out of the mould; or previous to the discharge of
the ingot in this manner, the hydraulic press may. be used as a means of.com-
pressing or condensing the ingot of metal while still in a semifluid-state, or
as soon as it is solidified, for which purpose a strong slide or cover must be:
made to close the mouth of the mould during such pressing process. A small,
railway truck is then rolled into a position immediately above the ingot mould,
the truck being so made that when the ingot is pushed out of its mould it will;
enter up between two moveable pieces jointed to the truck frame, which will;

page_text: prevent its return into the mould, when the ram again descends, so that the
suspended ingot may be readily wheeled away while still in a highly heated
state to the place where it is to be pressedl, rolled, or hammered; or it may be
removed to a suitable oven or furnace, so that it may retain its heat until the
rolls or other machinery intended to act on it may be at liberty.
In this way a second casting may follow rapidly the first by tapping out an
additional quantity from the vessel, or the mould may be made with several
openings for the purpose of making several smaller ingots. In order to keep
down the temperature of the ingot mould, I either form passages through the
metal of the mould, or I enclose its sides with a jacket, through either of
which I pass water for the purpose of absorbing the surplus heat of the mould.
I have, however, observed, that at the high temperature necessary to retain
malleable iron and steel in a fluid state, that the contact of atmospheric air
with the fluid metal produces combustion in the act of casting such metal, and
thereby tends to render the metal cellular; to lessen this defect, I place the
ladle before named so closely on the top of the mould as to cut off the free
communication with the external atmosphere with the interior of the ingot or
other mould; I then force into or through the mould carbonic acid gas, or other
vapour or gas not capable of supporting combustion, so that the metal from
the ladle is effectually excluded from atmospheric oxygen during its descent
into the mould; I have also observed that the cellular condition of steel, and
more especially of malleable iron castings, is more or less owing to the sponta-
neous disengagement of gaseous matter in the interior of the fluid mass.
Now it is well known that substances capable of vapourizing or of evolving
gaseous matters do so with greater difficulty if surrounded by a dense atmo-
sphere, I therefore make use of this peculiar property of matter in order to
increase the soundness of ingots or other articles formed by casting in fluid
malleable iron and steel; for this purpose I form a very strong vessel of plate
or cast iron, in which the mould for the required casting is placed with a
ladle and plug, as before described; above it, the vessel is then closed, and its
joints well secured and rendered air-tight. In the upper part of the vessel
there is an opening, which may be rapidly closed by a slide valve. I also
provide another vessel or reservoir, into which I force air or any other gascous
matter, alone or mixed with air, preferring in all cases that the gaseous
matter should be such as will extinguish flame; a pipe and valve is made to
communicate between the reservoir and the vessel in which the mould is
placed. The apparatus being thus arranged, the fluid metal is to be run in
a large stream into the ladle, and the slide valve rapidly closed, so as to cut off
all communication with the external atinosphere, the valvo communicating

page_text: with the reservoir of highly compressed gaseous matter is then opened, by:
which an equilibrium of pressure will be immediately produced in the two
vessels; the workmen will then draw the plug from the ladle by means of a
rod passing through a stuffing box into the vessel and allow the metal to
flow into the mould, which in this mode of casting I prefer to be formed of
sand, loam, or some other slow conductor of heat, so that the metal may be
retained therein in a fluid state for a suflicient time to disengage any of the
gaseous matters taken into it by the fluid metal, and which might otherwise
produce some blow-holes, notwithstanding the disengagement of gaseous
matters from the metal being prevented by the excess of pressure under
which the casting is effected. It will be understood that the forcing in of the'
gaseous matters into the reservoir before described may be effected by any of
the known means for effecting such purposes, and also that the mode of dis->
charging the metal into the inould may be varied.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by tho said Henry Bessemer in the Great Seal Patent Office on the
29th November 1856..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
BESSEMER, of 4, Queen Street Place, New Cannon Street, in the City of
London, send greeting.
WHEREAS IIer most Excellent Majesty Queen Victoria, by Her Letters.
Patent, bearing date the Thirty-first day of May, in the year of our Lord
One thousand eight hundred and fifty-six, in the nineteenth year of Iler reign,
did, for Herself, Her leirs and successors, give and grant unto me, the
said Henry Bessemer, Her special licence that I, the said Henry Bessemer,
my exccutors, administrators, and assigns, or such others as I, the said
Henry Bessemer, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might niake, use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF IRON AND STEEL," upon the condition (amongst others)
that I, the said Henry Bessemer, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and seals,
should particularly describe. and ascertain the nature of the said Invention,

page_text: and in what manner the same was to be performed, and cause the same to
he filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Henry Bessemer, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:
In carrying into practical operation the manufacture of malleable iron and
steel, by forcing atmospheric air or steam into and among the particles of fluid
crudo iron, for which Patents have already been granted to me, I have dis-
covered that certain modifications of and additions to the apparatus and
processes therein described may be advantageously used, and the adaptation
of which improvements to the manufacture of iron and steel forms tho subject
of my present Invention.
In the first place, I construct a cylindrical iron vessel, one end of which is
closed, and rests on a brick foundation. The interior of the cylinder I lino
with segmental fire bricks, which for some distanco from the bottom rise up
as a vertical wall, and then close over, so as to leave only a small aperture
of about one twelfth or one sixteenth of the area of the lower part of the
vessel, thus giving to the interior somewhat the form of a pottery kiln.
Above the throat of the chamber I make a second chamber of any convenient
form. I, however, prefer it to be cylindrical with a dome-shaped crown.
This upper chamber must also be provided with one or more outlets, and also
with a feeding door, and a damper plate to close up the outlets to the extent
desired. Around the lower part of the vessel I insert several tuyere pipes
formned of fire clay, black lead, sandstone, or other refractory substance.
These pipes extend through the lining of the chamber, and are held in place
with a packing of Icam or sand rammed in around them, the outer ends of
the pipes being connected in any convenient way to the blast or steam pipes,
by means of which air or steam is conveyed into the chamber for the purpose
of rendering the crude iron malleable.
And in order that the peculiar form and arrangement of the various parts
of the said apparatus may be fully understood, I have hereunto annexed a
Sheet of Drawings on which the same is represented.
Figure 1 being an elevation thereof; Figure 2, a vertical section taken on
the line C, D, of Figure 4; Figure 3 is a vertical section taken on the
line E, F, of Figure 4; Figure 4 is a horizontal section on the line G, I
of Figure 3; and Figure 5 is a horizontal section taken on the line A, B, of
Figure 3. The outer cylindrical shell or vessel a is made of iron plates

page_text: rivetted to the bottom plate a", which rests on the brick foundation b. The
vessel is lined with fire bricks c, which I prefer to make of a segmental form,
so as to facilitate the relining of the vessel when necessary; fire stone may
however be used in lieu thereof, and in either case the lining may be pro-
tected from the action of the heat and fluid materials by a coating of loam,
sand, or such other matters as are generally employed to line up the interior
of furnaces. By reference to Figures 2 and 3, it will be observed that the
lining c is brought over so as to form an arch or dome, leaving the throat or
passage to form a communication between the converting chamber e and
the heating or melting chamber f; the form of which chamber f may be
greatly varied. In the Drawing, the floor of this chamber f is shown to be
sloped downward to the centre in order to facilitate the running of fluid
any
iron that may be remelted there by the great heat of the converting process,
or be thrown from the converting chamber below by the upward current of
flame and gases. In forming the bottoni of this, or a like second chamber
of a converting vessel, provision may be made to retain any metal which may
be melted therein from flowing into the converting vessel below till such fluid
metal is tapped, and allowed to flow through a suitable opening or openings
previously kept closed. By thus combining a second compartment with a
converting vessel or apparatus the great heat evolved by the converting
process (when no fuel is used) will be most beneficially employed in heating
and melting the metal put into such heating chamber, and the heat produced
in this peculiar converting process will be economised and advantageously
employed. The chamber f is covered by the crown c2, and is provided with
an opening on one side for the introduction of ingot ends or other waste or
seap metal, and is closed, when desired, by the door g, which consists of an
iron frame having a fire tile fitted therein, and provided with hinges ; the
chamber has another opening, to which is fitted a damper plate i hung on
horizontal hinges, the mouth of the opening projecting forward more at the
lower part than above, so that the damper plate may lie against it after the
manner of a "clack valve." The plate i may be made of iron, but I prefer
using a fire-tile held in an iron framic, as represented in the Drawings.
Around the exterior of the vessel is an iron channel or pipe resting on an
angle iron rivetted to the vessel a, and extending entirely around it; a pipe
is connected thereto for the purpose of supplying air or steam whenever the
cock is opened. Into the under side of the channel I screw the vertical
blast pipes m, cach of which has a T-piece at m*, through the horizontal part
of which a sliding tube n is fitted. It is made conical at its outer end, so as
to fit a conical recess made in the end of the tuyeres s, the other end of the

page_text: tube n is pressed on by a spiral spring (contained in the piece m*) in order
to keep it in close contact with the tuyere. A small screw plug p is fitted
to one end of the piece me for the purpose of admitting a plug or rod for
the
.
purpose of clearing out the tuyere should it become obstructed when in
use. By reference to Figure 4, it will be scen that the tuyero pipes s are
inserted in the spaces left between the segmental lining bricks c, and that
they are tapered off toward their outer ends, so as to leave a space for a
packing of loam around them, square holes being left in the cylinder a in
order to admit of their removal when worn out, and of their being replaced
by others while the vessel is still in a heated state. An opening at t is made
in the vessel for the purpose of removing any remnants of fuel that may be
left in it after the preliminary heating of the vessel. This opening is secured
by a stopper t composed of fire brick, clay, or loam, and held in place by an
iron plate u having a bar across the outside of it, which is held there by
hooks attached to the vessel a. A spout w, lined with loam, is provided for
the running out of the fluid malleable iron or steel whenever the stopping of
sand at a is removed. The mode I prefer of stopping the tapping hole is
simply to ram it in with loam, as commonly practised in cupola furnaces used
for remelting iron. At y I form a spout lined with loam, for the purpose
of receiving the stream of molten metal as it flows from the blast or other
furnace, the opening allowing it to flow from thence into the chamber e.
In using this form of apparatus for obtaining steel or malleable iron a fire is
first made in the chamber e in order to dry or heat the lining c; such part of
the fuel as may not have been consumed in so doing is then raked out at the
opening t, which is again closed and secured. A blast of air or steam from
a suitable blast engine or steam boiler is then allowed to pass through the
cock into the channel . and from thence by means of the pipes m and
tuyeres s into the lower part of the chamber e. Molten crude iron from the
smelting furnace or re-melted pig or refined iron is then allowed to flow into
the chamber e through the opening, which may be then partially closed by
placing a piece of brick against the exterior of the hole. The blast
of air and steam mixed will be forced into and among the particles of
fluid iron, and, by its action thereon, the carbon mechanically or chemically.
combined therewith will unite with the oxygen of the air or decomposed
steam and increase the temperature of the metal, and drive off so much of the
impurities contained in the iron as to bring it to a malleable condition, without
however allowing the metal to solidify, and hence the iron or steel so produced
may be run off in a fluid state from the tap-hole a, and formed into ingots.
And here.I would observe, that although I have mentioned air and steam

page_text: because they contain, or are capable of evolving, oxygen at a cheap rate, it will
nevertheless be understood that pure oxygen gas or a mixture thereof with air
or steam may be used, and so likewise any fluid or solid matter containing or
capable of evolving oxygen may be used in conjunction with air or steam, in
the process of converting crude iron into malleable iron or steel, in vessels,
or chambers in which fuel is not used, for the purpose of keeping up the heat.
of the metal. I would however remark, that the use of such matters in.
addition to air or steam is not new or claimed by me under the present Letters
Patent. If solid matters containing or capable of evolving oxygen be employed
in this manner, I prefer to introduce such matters by the door, g₁ and allow.
them to occupy the upper chamber f until they are brought to a high tem-
perature, and then push them through the opening into the chamber:
below; in this way the various oxides of iron may be used to assist decarboni-
zation in my improved apparatus. In some cases I make a portion of the.
segmental bricks, which form the lower part of the lining of the vessel, with
holes in them, in lieu of using the pipes before named, in which case I make
them of fire stone, fire clay, or of plumbago, or such a mixture of fire clay and
plumbago as is used for making crucibles. When these perforated bricks are
used I make the iron shell or vessel so as to separate at the part where they
are inserted, in order to afford facility for their removal when worn out. The
crude metal is to be run into the vessel through a hole made in one side for
that purpose, and after the completion of the process it is drawn off through a
tap-hole secured by loam, similar to the tap-holes used in the ordinary cupola.
furnace. The shape of the perforated segmental bricks, before described, will
be understood by reference to the Sheet of Drawings hereunto anuexed, where.
Figure 18 is a side elevation of one of them; Figure 7 a plan; Figure 8 a
longitudinal section; and Figure 9 an end view of the same. 1 represents.
the brick; 2, the tnyere hole, with an enlarged conical orifice 3, which.
receives the end of the blast pipe. When fire stone, plumbago, or other natural
substance in a solid form is used, the hole or tuyere passage must be formed.
by boring. As soon as a charge of crude iron is run into the vessel a work-
man will put into the upper chamber the quantity of bar ends, ingot ends, or
other scrap metal intended to be mixed with the charge; he should place.
these pieces so as to be acted upon by the heat and flame issuing from the
throat of the vessel towards the close of the operation, and after the scrap
metal has attained a very high tempe ature the workman will open the door
of the upper chamber, and with a lock tool be will bring the pieces of serap
iron or steel over the throat of the lower chamber, into which they will fall.
and be there rapidly melted and mixed with the remainder of the charge.

page_text: In the conversion of crude into malleable metal by forcing air or steam
therein, a portion of the fluid scoria formed in the process is carried upwards
with the gascous matters and flame, and is expelled from beneath the damper
plate i, which, however, serves to prevent the too easy egress of these matters,
and thus assists in retaining the necessarily high temperature of the contents of
the vessel; should, however, an accumulation of hardened scoria at any time
obstruct the exgress of flame from beneath the damper plate, the opening must
be cleared by a workman, using a suitable iron rod.
In the treatment of different irons by the process of forcing atmospheric or
other oxygen therein, it will be found advantageous in some cases to use such
fluxes as will best act upon the different bases associated with the iron; in this
way small quantities of lime, silica, or alumina may be added with advantage,
and so in like manner chloride of sodium, iron scales, oxide of manganese,
and other salts or fluxes may be used to assist in the separation of the im-
purities contained in the crude metal, as have before been used for like
purposes, and the application of the same is not claimed by me under the
present Letters Patent.
These fluxes, or any of them that it may be found necessary to use when
treating iron in my improved apparatus, may be introduced into the metal in
the form of powder at the tuyerers, by allowing such powders to fall from a close
vessel gradually into the blast pipes, so that they be blown in with currents of
air or stean, and be thus made to act direct upon the fluid metal; or, in lieu of
this mode of introducing the fluxes, they may be put in at the feeding door, and
be allowed to fall through the opening d, before or during the continuation of
the process. And, further, when it is desired to make any alloy of zinc, copper,
silver, or other metals with iron or steel, I put such metals in a fluid or solid
state, or assalts or oxides, into the chamber or vessel, before described, where
their mixture with the molten iron or steel will be greatly facilitated by the
violent agitation which is produced by the forcing in of the air or steam, and
which continues during the discharge of the metal from the vessel, so that no
time is allowed for subsidence or separation of the alloy should the chemical
aflinities of the metals for each other be so weak as to have a tendency to
separate when left in a state of repose.
When employing fluid metal for alloying with malleable iron or steel, I
pour it through an opening in the converting vessel, so that it may fall direct
into the fluid mass below; but when employing metal in a solid form, I put it
into the upper chamber through the door g, and allow it to acquire a high
temperature, after which it may be pushed with a rod through the opening d
into fluid iron or steel; and when using salts or oxides of metals for the

page_text: purpose of producing an alloy or mixture with the iron or steel, I prefer to
introduce such salts or oxides in the form of powder at the tuyeres, or to put
them into the vessel previous to running in the fluid metal. I would observe,
that I am aware that zinc, copper, silver, and other metals have before being
combined with iron and steel otherwise manufactured, I therefore make no
general claim thereto.
As soon as the metal has arrived at the condition which the workman
judges suitable for his purpose, he will proceed to tap the furnace and dis-
charge the metal therefrom, and form it into ingots or other castings. For
making large ingots intended to be hammered or rolled into bars, rails, rods,
or plates, I construct a mould in the following manner :-I take a massive
block of iron, of a length somewhat greater than the intended ingot, and I
make an opening through it from end to end of the sectional form to be given
to the ingot; the opening may be planed or bored truly parallel, but I prefer
making it slightly taper; into the bottom end I fix a plunger, sufficiently long
to rise above the top of the mould. The lower end of the plunger is connected
to the ram of a hydraulic press, the mould block being firmly attached to the
cylinder of the press; above the mould I place a plate iron ladle, lined with
loam and having a hole in the bottom stopped by a plug, into this ladle the
metal is run, and when it has accumulated to a depth of a few inches the plug
is to be raised and the metal allowed to descend vertically into the mould; by
this means any slags or other impurities which float in the ladle will be pre-
vented from mixing with and forming part of the ingot. As soon as the metal
has solidified, the ram of the press is to be acted on by a force pump, and the
ingot pushed out of the mould, or previous to the discharge of the ingot. In
this manner the hydraulic press may be used as a means of compressing or
condensing the ingot of metal while still in a semifluid state, or as soon as it
is solidified, for which purpose a strong slide or cover must be made to close
the mouth of the mould during such pressing process; a small railway truck is
then rolled into a position immediately above the ingot mould, the truck being
so made that when the ingot is pushed out of its mould it will enter up
between two moveable pieces' jointed to the truck frame, which will prevent its
return into the mould, when the ram again descends, so that the suspended
ingot may be readily wheeled away while still in a highly heated state to the
place where it is to be pressed, rolled, or hammered; or it may be removed to
a suitable oven or furnace, so that it may retain its heat until the rolls or other
machinery, intended to act on it may be at liberty. In this way a second
casting may rapidly follow the first by tapping out an additional quantity from
the vessel; or the mould may be made with several openings for the purpose

page_text: of making several smaller ingots. In order to keep down the temperature of
the ingot mould, I either form passages through the metal of the mould or I
inclose its sides with a jacket, through either of which I pass water for the
purpose of absorbing the surplus heat of the mould.
"
In order that the apparatus herein-before described for casting ingots of
iron or steel may be more fully understood, and also that the manner in which
the pressing of the ingots, the cooling of the mould, and the way in which the
hot masses of iron or steel are removed therefrom, and conveyed to the oven
or to the rolls, may be clearly ascertained, I have shown on the Sheet of
Drawings hereunto annexed, a vertical section of the casting apparatus at
Figure 9, in the position it is intended to occupy, with reference to the con-
verting vessel, Figure 2; Figure 10 is a cross section of the casting apparatus,"
taken on the line A, B, of Fig. 9; another cross; section is also shown at
Figure 11, it is taken on the line C, D, of Figure 9; Figure 12 is a plan;
and Figure 13 is a vertical section taken at right angles to the section
Figure 9, showing the ram raised, and the truck in the position in which it is
placed to receive the ingot of nictal; a side elevation of the truck is also shown
at Figure 14. A is a ladle or receiving vessel, made of plate iron, and
supported on legs A*, it has a hole in the centre of the sloping bottom, and is
lined with loam to protect it from the action of the fluid metal; B is an iron
rod having a conical lump of loam on its lower end, by means of which the
hole in the bottom of the ladlo is shut or opened when desired; the spout w
delivers the fluid metal from the converting vessel, and when the whole has
run into the mould, the ladle is to be removed; C is the ingot mould, made
sufficiently massive to resist the force applied by the hydraulic ram, when the
same is employed to compress tho metal in a semi-fluid or solid state. A
flange C1, at its lower part, rests on four massive columns D, through which
the bolts E pass downwards, and passing also through the flange F* of the
hydraulic cylinder F, they serve to connect the mould B with the cylinder F,
securely together; G is a plunger or ram fitted to the upper part of the
cylinder F, and made water-tight by a leather ring F; the upper part of
the ram has a piece G fitted to it by a bolt and cotters, so as to be removed
at any time should it be injured by the hot metal falling on to it; the piece
of iron G fits accurately to the mould, and serves to form the bottom of it;
around the mould there is formed a jacket or casing II, which may be filled
with water by means of the pipe I; the pipe J serving as an overflow pipe to
take off any surplus of water or steam forined by the heated mould. There is
also formed around the top of the hydraulic cylinder an open cistern K,
supplied with water by the pipe L, for the purpose of cooling the rau, and

page_text: preventing it from conducting heat downwards to the hydraulic leather, which
might otherwise be destroyed; any excess of water let into the cistern K will
find an escape by the pipe M. On two opposite sides of the ingot mould
there is screwed to it two iron bars P, which serve for supporting the anti-
friction rollers R; on these rollers the covering plate S of the mould may be
rolled backward and forward; at C the ingot mould has a projecting flange
extending along each side of it, and the covering plate S is also made with
projecting flanges S*, which pass beneath the flanges C, and thus prevent the
pressure exerted on the ingot by the ram from lifting it upwards. At the time
of casting, the covering plate occupies the position shewn in Figures 9 and 12,
and if it be intended to subject the ingot to pressure, the covering plate is to
be rolled forward until it covers the top of the mould, when the pressure may
be applied by admitting water from a suitable force pump through the pipe Q
into the cylinder C, as is well understood in working hydraulic presses. When
it is desired to remove the ingot from the mould, the covering plate must be
moved into the position shewn in Figures 9 and 12, and a small truck
represented in Figures 13 and 14 is also moved on rails over the mould; the
truck consists of a frame T, mounted on four wheels U; the axles, on which the
wheels are keyed, move in bearings formed on the under side of the frame T;
at V there are two palls or falling catches, between which the ingot rests.
Whenever the ram is caused to rise by the force of the injected water, will
lift
up with it the ingot, in doing which, the palls will lift up and bear against
the sides of the ingot, when the ram head has risen some few inches above the
top. of the mould, the connection with the pump may be shut off, and a cock
opened to discharge the water from the cylinder F, which will allow the ram
again to sink down, in doing which, the ingot will commence lowering also,
until the palls jamb against the sides of it, and prevent its further downward
movement, the truck may then be wheeled away, and the ingot put into the
rolls, and into an oven or furnace to await a convenient time for rolling. The
ram having arrived at the bottom of the mould, another casting may be made;
but, previous to doing so, the mould should have its interior surface coated
with a mixture of plumbago and oil, or other substance capable of preventing
the molten metal from adhering to the mould; care must also be taken that
the ladle A is so placed, as to direct the stream of fluid metal down the centre
of the mould, as near as ucar as may be, as any contact with the sides of the
mould may cause a union of the mould and ingot, by the melting of the mould
at that part where the stream of fluid metal comes in contact with it. I have,
however, observed, that at the high temperature necessary to retain malleable
iron and steel in a fluid state, that the contact of atmospheric air with the fluid

page_text: metal produces.combustion in the act of casting such metal, and thereby tends
to render the metal cellular; to lessen this defect, I place the ladle before-
named so closely on the top of the mould as to cut off the free communication
with the external atmosphere with the interior of the ingot or other mould, I
then force into or through the mould carbonic acid gas, or other vapour or
gas not capable of supporting combustion, so that the metal from the ladle
is effectually excluded from the atmospheric oxygen during its descent into the
mould. In carrying this into practice, I find it sufficient to make a small hole
or holes in the lower part of the mould, of about the size. of the holes of an
ordinary gas burner, through which the incombustable gases may be forced by
any: convenient apparatus; or, in the case of carbonic acid gas being used, the
pressure caused by its formation in a close chamber will be sufficient to forco
it through the mould, and drive out the air, previously occupying it, through
the joints or pores of the mould. It will be found that the metal will not flow
so far into the perforators before described, as to cause any permanent.
obstruction of them, so that no precaution will be necessary to prevent tho
metal flowing into them. I have also observed that the cellular condition of
steel, and more especially of malleable iron castings, is more or less owing to
the spontaneous disengagement of gaseous matter in the interior of the fluid
mass; now. it is well known that substances capable of vapourizing, or of
evolving gaseous matters, do so with greater difficulty if surrounded by a
denise, atmosphere. I, therefore, make use of this peculiar property of matter,
in order to increase the soundness of ingots or other articles formed by
casting in fluid malleable iron and steel. For this purpose, I form a very
strong vessel of plate or cast iron, in which the mould for the required
casting is placed with a ladle and plug, as before described, above it; the
vessel is then closed, and its joints well secured and rendered air-tight;
in the upper part of the vessel there is an opening, which may be rapidly
closed by a slide valve; I also provide another vessel or reservoir, into which
I force air, or any other gaseous matter; alone or mixed with air;-pre-
ferring, in all cases, that the gaseous matter should be such as will extinguish
flame; a pipe and valve is made to communicate between the reservoir and
the vessel in which the mould is placed. The apparatus being thus arranged,
the fluid metal is to be run in a large stream into the ladle, and the slide valve
rapidly closed, so as to cut off all communication with the external atmosphere;
the valve communicating with the reservoir of highly compressed gaseous
matter is then opened, by which an equilebrium of pressure will be imme-
diately produced in the two vessels;, the workmen will then draw the plug
from the ladle by means of a rod passing through a stuffing box into the vessel,

page_text: and allow the metal to flow into the mould, which, in this mode of casting, I
prefer to be formed of sand, loam, or some other slow conductor of heat, so
that the metal may be retained therein in a fluid state for a sufficient time to
disengage any of the gaseous matters taken into it by the fluid metal, and
which might otherwise produce some blow holes, notwithstanding the dis-
engagement of gascous matters from the metal being prevented by the excess
of pressure under which the casting is effected. It will be understood that
the forcing in of the gaseous matters into the reservoir, before described, may
be effected by any of the known means for effecting such purposes, and also
that the discharging of the metal into the mould may be varied...
In order that the mode of constructing and arranging the apparatus used
for casting in close vessels under pressure may be fully understood, I have
shewn, at Figure 15, on the Slicet of Drawings hereunto annexed,.a vertical
section of the apparatus. Figure 16 is a plan, and Fig. 17 is an elevation of
the same.. 10 is a cylindrical vessel of great strength, having a moveable
cover 11, secured by. bolts passing through its outer edge; and through the
upper flange of the vessel. 10 an air-tight joint is formed by the accurate
grinding of the two surfaces together. 12 represents a flask or mould in eleva-
tion, placed inside the vessel 10, and above it is supported an iron ladle 13,
loamed up on its interior surface, after the manner generally employed
for such purposes by founders in iron. In the central part. of. the bottom
of the ladle there is a hole stopped with a. plug 14, the rod 15 of
which passes up through a stufling box formed in the centre of the
cover 11; at 16 there is formed a slide valve, which is fitted closely to the
under side of the cover 11, and may be moved by means of the handle 17,
which passes through a stuffing box 18, formed in one side of cover 11. A
hole for the admission of the molten metal is shewn at 19, which may be
opened or shut, as desired, by the slide valve 16; at 20 there is a pipe
communicating with a strong vessel or reservoir filled with compressed atnio-
spheric air, or, by preference, with carbonic acid gas, or with other gases not
capable of supporting combustion. The pipe 20 should be provided with a
valve for the purpose of opening or shutting the communication between the
vessel 10 and the reservoir of compressed air when desired, and which
reservoir may be supplied with a force pump, in a manner well understood,
and should, by preference, be made of a capacity several times greater than
the vessel 10, so that when the compressed air or gases are admitted into
the vessel 10 that the resulting pressures should not be too much dimished.
The action of the apparatus will be as follows:-The mould is first lowered
into the vessel 10, the ladle is then suspended on pins projecting from it,

page_text: which rest on an inner flange of the vessel, the cover is then placed on the
vessel and securely bolted to it, the plug of the ladle is then lowered in place,
and the slide valve opened; the fluid metal is theu to be poured through the
opening 19, the slide closed, and the valve opened to admit the highly
compressed air or gases, which will rush in and occupy the vessel and mould,
the plug is then raised, when the fluid metal will descend into the mould.
After the lapse of sufficient time for the metal to solidify, the compressed
gaseous matters are to let out, after which the mould and its casting may be
removed.
Having thus described the nature of my Invention, and the manner in
which the same is performed, I desire it to be understood that I do not
confine myself to the precise details herein explained, as they may be varied
without departing from my improvements, so long as the peculiarities of my
said Invention herein described be retained.
In witness whereof, I, the said Henry Bessemer, have hereunto set my
hand and seal, this Twenty-ninth day of November, in the year of our
Lord One thousand eight hundred and fifty-six.
Witness,
B. GOBEY,
24, Southampton Buildings,
Chancery Lane.
HENRY BESSEMER. (L.S.)