IMPROVEMENTS IN THE MANUFACTURE OF MALLEABLE IRON AND STEEL, AND ALSO IN THE MANUFACTURE OF RAIL WAY BARS, AND OTHER BARS, PLATES, AND RODS FROM IRON OR STEEL SO MANUFACTURED
Year: 1857

page_text: LETTERS PATENT to Henry Bessemer, of Queen Street Place, New
Cannon Street, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
OF MALLEABLE IRON AND STEEL, AND ALSO IN THE MANUFACTURE OF RAIL
WAY BARS, AND OTHER BARS, PLATES, AND RODS FROM IRON OR STEEL SO
MANUFACTURED."
Sealed the 19th January 1858, and dated the 6th November 1857.
PROVISIONAL SPECIFICATION left by the said Henry Bessemer at the
Office of the Commissioners of Patents, with his Petition, on the 6th
November 1857.
I, HENRY BESSEMER, of Queen Street Place, New Cannon Street, do hereby
declare the nature of the Invention for "IMPROVEMENTS IN THE MANUFACTURE
OF MALLEABLE IRON AND STEEL, AND ALSO IN THE MANUFACTURE OF RAILWAY BARS
AND OTHER BARS, PLATES, AND RODS FROM IRON OR STEEL SO MANUFACTURED,"
to be as follows:--
When malleable iron or steel is obtained by the decarbonization of crude
pig or refined iron by the passing of air or steam through the molten metal,
or by the cementation of the iron with oxides and other matters, it frequently
happens that the ingots formed of such molten iron or steel are found to
contain numerous cells or cavities, and in consequence of the peculiar crys-
tallization of the metal, or from the combination of oxygen therewith or from
other causes; that such ingots are more or less hot, short, and are liable to
>

page_text: crack along the edges when subjected to the ordinary process of rolling or
hammering.
Now, the objects of my present Invention is to lessen or entirely remove the
defects which I have herein-before pointed out. For this purpose I construct
a circular mould, which I mount on a vertical axis, in a strong iron frame, and
which axis is made by suitable straps or gearing to revolve at a very rapid
rate in the central part of the mould. I fit a disc of fire-clay, stone, or wood,
around which a cavity is formed somewhat of the shape that would be required
to form the rim of a fly wheel, the upper part of the mould being open in the
central part and covered at the edges, when molten malleable iron or steel,
obtained by either of the methods before referred to, or by any other method,
and is to be cast according to my present Invention. I run or pour such
metal in a stream down upon the revolving disc of fire-clay or other material
from such a height as will cause the fluid metal to divide itself into numerous
globules, and thus favour the extrication of carbonic oxide or other gaseous
matter from the molten metal, and which globules will be again collected at
the periphery of the mould, and be carried round with it, and be thereby
subjected to considerable pressure by reason of the centrifugal forcegenerated
by its rapid rotation, and thus be formed into a ring or hoop, having a square,
octagonal, or other sectional form, depending on the internal form of the
mould, and of a dense and solid texture, owing to the peculiar arrangement of
the particles of molten metal before or during the period of solidification. In
lieu of mounting the mould on a vertical axis, it may be made to revolve on a
horizontal one, and the metal may, if desired, be poured quietly therein. A cast
or wrought-iron mould or chill may be used for this purpose, in which case I
prefer to coat the interior of the mould with a thick wash of clay and charcoal,
or with some other slow conductor of heat, so that a too rapid solidification of
the metal may not take place, or in lieu of using a chill the mould may be
formed of sand or loam, and be dried and heated previous to pouring in the
fluid metal. The crystalline or granular condition of the metal i may be greatly
modified by the temperature and heat-conducting power of the mould, and
also by the uniformity of the rate of rotation, which may be continually varied
if desired, during the solidification of the metal, in order to put in motion the
particles of metal among themselves, independent of the general motion of
which they all partake. When hoops or rings of iron or steel are intended to
be formed into railway bars, their section may be square or rectangular, or
they may be made to partake more or less of the sectional form of the finished
rail; for the rolling of such hoops or rings I employ grooved rolls with over
hanging ends having suitable grooves made therein. The hoop, at a tempera

page_text: ture depending on the quality of the metal, is to be put into the said grooves,
and the tightening screws of the roller mill are to be gradually brought down,
while the rolls and hoop revolve at a high speed, whereby a much more
gradual pressing action will be exerted on the metal than is now generally
employed to roll a bloom or ingot. By this means the rail may be brought to
the desired guage, after which it may be cut by a circular saw, and be opened
out and straightened, or instead of completing the rolling while the metal is
in the form of a hoop, it may in that state be only "bloomed," or partly
extended to the desired guage and be then cut, so as to form either one or more
pieces, which may afterwards be further rolled in the ordinary manner. The
rolling of other bars, plates, or rods of malleable iron or steel may be effected
in the same manner as that described for rolling railway bars, the rolls being
as usual adapted to the required sectional form of such bar, rod, or plate, and
which rolling may be effected while the metal is still in the form of a hoop or
ring, or after it has been cut into pieces, or the hoop may be tilted or "cogged"
to a certainextent, and be then cut intoanydesired number of pieces, which may
be afterwards completed by tilting. But in some cases it may be found more
convenient to tilt or roll in the usual manner iron or steel that has been
formed into hoops or rings, as herein-before described, and which may be
effected by cutting the cast hoop (by preference, while hot from the mould)
into several pieces, each of which having only a comparatively small amount
of curvature, may be treated as ordinary ingots, and be hammered orrolled in
the manner now generally practised. I have herein-before described the mode
by which I form rings or hoops of malleable iron or steel for the purpose of
being extended into rails, bars, rods, or plates; but when it is desired to tilt
or roll ingots of iron or steel in the usual manner, I sometimes use a revolving
mould having several compartments, or I fix several separate moulds about a
common centre, each of such moulds or compartments being placed, by pre-
ference, as radii of a circle, and are of such an internal form as will produce
an ingot of the required size and shape. These moulds may be made of iron,
sand, or loam, and be used in a cold or heated state, and made to revolve at a
high velocity, in order that the fluid metal, when poured into a central opening,
may be by centrifugal force compressed therein, and form solid ingots or
masses of malleable iron or steel suitable for and capable of being tilted or
rolled into rails, rods, bars, or plates of malleable iron or steel. In the manu-
facture of cast steel as heretofore practised, the molten steel is poured with
great care into the mould, a small round string being preferred by the workman;
however carefully this operation is performed, it frequently happens that
enough agitation of the metal is produced to disengage therefrom carbonic

page_text: oxide or other gaseous matter; and thereby produce an unsound bubbly ingot.
When casting ingots of steel without the application of centrifugal force, I
prefer to disengage as much as possible of the carbonic oxide or othergaseous
matter previous to the formation of the ingot, for which purpose I place over
the mould an iron vessel lined with loam, or other slow conductor of heat, or I
use a red-hot fire-clay vessel of such an internal form, that when a stream of
molten iron or steel is poured therein from a height, that the stream may fall.
on a projecting part of the interior of such vessel, and be scattered or divided
into numerous globules which collect in the lower part of such vessel, and pass
through it into the mould. The metal will thus be lowered in temperature,
and will disengage large quantities of carbonic oxide or other gaseous matter;
when employing this mode of forming ingots, I prefer to direct a stream of
carburetted hydrogen or other gas into the said vessel, in order to prevent the
oxidation of the numerous globules of molten metal formed therein.
SPECIFICATION in pursuance of the condition of the Letters Patent, filed
by the said Henry Bessemer in the Great Seal Patent Office on the
6th May 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
BESSEMER, of Queen Street Place, New Cannon Street, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of November, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twenty-first year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Henry Bessemer, Her special licence that I, the said Henry
Bessemer, my executors, 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 make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE
MENTS IN THE MANUFACTURE OF MALLEABLE IRON AND STEEL, AND ALSO IN THE
MANUFACTURE OF RAILWAY BARS, AND OTHER BARS, PLATES, AND RODS FROM IRON
OR STEEL SO MANUFACTURED," 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 par-
ticularly describe and ascertain the nature of the said Invention, and in what

page_text: manner the same was to be performed, and cause the same to be 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 :-
When malleable iron or steel is obtained by the decarbonization of crude
pig or refined iron, by the passing of air or steam through the molten metal,
or by the cementation of the iron with oxides and other matters, it frequently
happens that the ingots formed of such molten iron or steel are found to.
contain numerous cells or cavities, and in consequence of the peculiar crys-
tallization of the metal, or from the combination of oxygen therewith, or from.
other causes, that such ingots are more or less "hot short," and are liable to
crack along the edges when subjected to the ordinary process of rolling or
hammering.
Now, the object of my present Invention is to lessen or entirely remove the
defects which I have herein-before pointed out. For this purpose I construct
a circular mould which I mount on a vertical axis in a strong iron frame, and
which axis is made by suitable straps or gearing to revolve at a very rapid
rate. In the central part of the mould I fit a disc of fire-clay, stone, or wood,
around which a cavity is formed, somewhat of the shape that would be required
to form the rim of a fly wheel, the upper part of the mould being open in the
central part and covered at the edges, as will be seen on reference to the
Sheet of Drawings hereunto annexed, where the apparatus is shown in vertical
section at Figure 1, and in plan at Figure 2. a, a, is a stout iron frame,
supported by the masonry b, in which is formed the chamber c, situated below
the level of the floor of the casting house, and is covered by a plate q having a
central hole to afford access to the mould. The axis d of the apparatus rests
in a foot bearing e, which is bolted to the foundation stone f; the axis is
further supported by suitable brasses g let into the central part of the frame a.
The axis carries at its upper end a plate or disc h, made by preference of
malleable iron or steel, and having a boss in the centre which is bored out
to fit the end of the axis d, which is made conical, in order to facilitate its
removal from time to time, as may be required. The lower half m of the.
circular mould is firmly rivetted or bolted to the plate h, and is made to rise
high enough at the outer edge to enclose the upper half m* of the mould; both
the upper and lower halves of the inould may be made of malleable iron or
steel in preference to cast iron, as the latter metal is not capable of withstand-

page_text: ing the great amount of centrifugal force which it may be found desirable in
some cases to employ, in order to render the annular cast ingot as dense and
sound as practicable. The central part of the lower half of the mould has
fitted to it a plate or discs of well-baked fire-clay or fire-stone, having, by
preference, a raised mound formed in its centre to favor the distribution of the
stream of fluid metal, which should be poured on one side of the centre, as
shown at t; but in lieu of the materials before named, a disc of wood or any
other suitable slow conductor of heat, to which the fluid metal will not readily
adhere, may be employed. On the upper half of the mould there are wedges
or bolts n, which enter. into slots o formed in the upper part of the lower half
of the mould. The apparatus may be put in motion by a strap passing round
the flanged drum p, the speed of the mould being regulated as may be found
most suitable for the size of the ingot and the quality of the metal operated
upon; as a general rule, the less carbon the metal contains the greater will be
the tendency to produce unsound ingots, and such metal will therefore require
a higher speed to overcome this tendency. It will be generally found that
from 500 to 2,000 revolutions per minute are the rates of speed within which
the best results may be obtained.
When molten malleable iron or steel, obtained by either of the methods
before referred to, or by any other methods, and is to be cast according
to my present Invention, I run or pour such metal in a stream down upon
the revolving disc of fire-clay or other material from such a height as will
cause the fluid metal to divide itself into numerous globules, and thus favor the
extrication of carbonic oxide or other gaseous matter from thé molten metal,
and which globules will be again collected at the periphery of the mould and
be carried round with it, and be thereby subjected to considerable pressure by
reason of the centrifugal force generated by its rapid rotation, and thus be
formed into a ring or hoop, having a square, octagonal, or other sectional
form depending on the internal form of the mould, and of a dense and solid
texture, owing to the peculiar arrangement of the particles of molten metal
before or during the period of solidification. A mould for forming an ingot
of an octagonal section is shewn in section at Figure 3, where u represents
the disc of the metal to which the lower half v of the mould is attached, the
upper half * being held to it by a flange and bolts; w is the fire-clay disc
on which the metal is poured; and a is the hollow periphery of the mould in
which the octagonal ingot is cast. It will be obvious that hoops or annular
ingots, having a variety of sectional forms, may be cast in moulds made with
an annular space suitable for the production of such forms, and also that
such moulds may be fitted on to the axis of the apparatus, and be removed

page_text: from time to time, as required. For the purpose of forming hoops or ingots
suitable to rolling into plates, the interior of the mould should be formed
into a plain upright cylinder, so that a broad cylindrical hand of metal may
be cast therein of any desired thickness. Annular ingots of malleable iron
or steel cast in the manner described will be found to have a more or less
crystalline or lamela texture,depending on the speed at which the fluid metal
is poured into the mould, for if the metal be run in very rapidly, then the
whole or nearly the whole of it will occupy the mould in a fluid state, and
will there solidify under the influence of considerable pressure, accompanied
by a sliding or other movement of the particles of metal among themselves,
caused by the vis inertia of the successive portions of metal as they are poured.
in, resisting the sudden tendency to move at the same vel city, which the
former portions of the fluid mass have acquired. The effect produced by this
motion of the particles of metal among themselves (in consequence of the
different velocity at which one part of the fluid mass is moving, as compared
with the other) may be still further increased by altering the speed of the
apparatus by a break or otherwise from time to time. The workman will
thus be enabled to alter cr modify the crystalline structure of the whole mass,
while the great pressure under which the casting of the ingot is effected will
tend to prevent. the liberation of gaseous matter from the metal, and the
displacement of any bubbles that may be enclosed or generated in the liquid
mass will also be greatly facilitated by reason of the powerful centrifugal
action exerted by each particle of metal which endeavours to fly further from
the centre, and replace any lighter matter which is capable of motion towards
the centre. If, however, the metal be very slowly poured into the mould,
then the successive portions added will continue to form a succession of thin
films or layers of metal, in consequence of the first portions of metal poured
into the mould becoming solidified or partially solidified by the absorbtion of
their heat by the mould, and consequently each successive portion of fluid
metal afterwards poured in will be collected on a solid or solidifying surface
of metal at a high welding heat, whereby the fluid portions will be caused
to unite or adhere firmly to the previously solidified surface of the mass, and
thereby prevent the formation of that peculiar crystalline structure which so
much lessens the cohesive force of any mass of metal in which it occurs, and
by such preventive action render the annular ingot less liable to crack or
give way under the action of the hammer or rolls, while at the same time it
confers a greater cohesive force on the finished bar or plate. It will also be
understood that the rate of supplying the fluid metal to the mould may vary
to any extent between the very rapid rate first mentioned, and the slower one

page_text: lastly described, and that in each case a modified action on the metal will
result approaching the one or the other condition as the rate of supply is
varied, and thus the workman will be enabled by regulating the rate of
pouring in the metal to obtain results suitable to his particular requirements.
but I would observe as a general rule that malleable iron admits of a slower
supply than steel, because both its temperature and its welding property is
greater. The pouring in slowly of the fluid metal and the constant accumu-
lation or building up of a solid mass in the ingot mould offers great facility
for changing the quality of the metal during the process, either suddenly or
by almost imperceptible gradations, so that an ingot may be composed or
distinctly different qualities of metal, and pass gradually from steel to iron, o f
from hard steel to soft steel, or it may be made to pass from steel toiron by
a sudden transition. The gradual transition from steel to iron is most easily
obtained by allowing steel to flow slowly into the mould from a converting
vessel, while the process of decarbonization by jets of air is still is progress,
and whereby the metal will gradually approach to and at last become
malleable iron, so that the exterior part of the ingot will be formed of hard
steel; and this will gradually come less so until it approaches to and finally
becomes malleable iron. On the interior side of the ingot, or in lieu of this
gradual change, two vessels or crucibles may be employed, one containing
steel and the other iron; one of which will be first emptied into the mould,
and then the second may be used, each quality being added in any desired
proportion. To prevent oxydation of the solidifying surface, carburetted
hydrogen, or any other gaseous matter in which oxygen does not predominate,
may be directed into mould during its rotation, or slag flux or any suitable
fluid matter may be employed to protect the surface of the metal from
oxydation during the building up or formation of the annular ingot. But
although I have herein pointed out how an ingot may be formed of different
qualities of steel or of steel and iron, and also how the metal may be protected
from oxydation in such process, I desire it to be understood that I make no
claim thereto except in so far as such process necessarily involves the use of
my Invention of manufacturing annular ingots of iron or steel in a revolving
mould for the purpose of being made into railway bars and other bars, plates
and rods.
Although the apparatus herein-before described is shewn as fixed in a bed
of masonry below the level of the floor of the casting house, it will be obvious
that the same may be placed, if required, at any desired height above the level
of the floor, the mould and its axis being supported in such case in a suitable
iron frame constructed according to the plans already in use in centrifugal

page_text: drying machines. It will also be understood that in lieu of mounting the
mould on a vertical axis, it may be made to revolve on a horizontal one, and
the metal may, if desired, be poured quietly therein; a cast or wrought-iron
mould or chill may be used for this purpose, in which case I prefer to coat the
interior of the mould with a thick wash of clay and charcoal, or with some
other slow conductor of heat, so that a too rapid solidification of the metal may
not take place; or in lieu of using a chill, the mould may be formed of sand or
loam, and be dried and heated previous to pouring in the fluid metal. The
crystalline or granular condition of the metal may be greatly modified by the
temperature and heat-conducting power of the mould, and also by the
uniformity of the rate of rotation, which may be continually varied if desired
during the solidification of the metal, in order to put in motion the particles of
metal among themselves independent of the general motion of which they all
partake. In order that the mode of forming hoops or angular ingots of
malleable iron and steel in moulds revolving on a horizontal axis may be fully
understood, I have represented so much of the said apparatus at Figure 4 of
the annexed Sheet of Drawings as is necessary to mark the distinctive
character of this mode of casting annular ingots. At Figure 4, A represents
the axis on which the mould revolves; Bis an iron frame, of a shape similar
to the head stock of a lathe, in which the axis A is made to revolve. One half
of the mould D forms a sort of face plate, firmly fitted to the axis A; at its
outer edge is a flange, to which the ring D* is bolted, and thus forms the other
half of the annular mould; the apparatus so formed is to be put in rapid
motion; the metal may then be poured from a crucible or other vessel into the
mould, as represented at E. The rotation of the mould must be continued
until the whole of the metal has solidified, when it may be stopped, and the
mould unscrewed in order to liberate the hoop or ingot of cast metal. When
moulds formed of sand, loam, or other slow conductor of heat are employed,
either in a cold or heated state, the annular cavity intended to form the ingot
may be almost entirely closed, small openings or runners only being left by
which the metal which is poured into the central part of such mould may find
its way into the annular space in which the hoop or ingot is to be formed; it
will also be understood that sand, loam, or other moulds formed of any
suitable refractory substances which are slow conductors of heat, may also be
used with the herein firstly described apparatus, as well as in that lastly
described.
When hoops or rings of iron or steel are intended to be formed into railway
bars, their section may be square, or rectangular, or they may be made to
partake more or less of the sectional form of the finished rail. For the rolling
R

page_text: of such hoops or rings, I employ grooved rolls with overhanging ends, having
suitable grooves made therein. The hoop, at a temperature depending on the
quality of the metal, is to be put into the said grooves, and the tightening
screws of the roller mill are to be gradually brought down while the rolls and
hoop revolve at a high speed, whereby a much more gradual pressing action
will be exerted on the metal than is now generally employed to roll a bloom
oringot. By this means the rail may be brought to the desired guage, after
which it may be cut by a circular saw, and be opened out and straightened;
or instead of completing the rolling while the metal is in the form of a hoop,
it may in that state be only bloomed or partly extended to the desired guage,
and be then cut so as to form either one or more pieces, which may afterwards
be further rolled in the ordinary manner. The rolling of other bars, plates, or
rods of malleable iron or steel may be effected in the same manner as that
described for rolling railway bars, the rolls being, as usual, adapted to the
required sectional form of such bar, rod, or plate, and which rolling may be
effected while the metal is still in the form of a hoop or ring, or after it has
been cut into pieces; or the hoop may be tilted or "cogged" to a certain
extent, and be then cut into any desired number of pieces, which may after-
wards be completed by tilting.
:
But in some cases it may be found more convenient to tilt or roll in the
usual manner iron or steel that has been formed into hoops or rings, as herein-
before described, and which may be effected by cutting the cast hoop (by
preference while hot from the mould) into several pieces, each of which
having only a comparatively small amount of curvature may be treated as
.ordinary ingots, and be hammered or rolled in the manner now generally
practised.
In rolling annularingots of iron or steel the continuous passing of the metal
through the mill in one direction will admit of a more rapid rotation of the
rolls than is now generally employed, while the whole of the time and labor
which is expended in returning the ingot over the rolls will be saved, so that
in order to complete the rolling of a heavy ingot at one heat it will not be
necessary to effect the same amount of reduction in its sectional area each
time the metal passes between the rolls as would be required by the present
system in order to effect an equal reduction of the ingot in a given time. This
method also affords great facility in producing rails, hars, and plates of great
length, and it effects this desirable object without the waste or crop pieces
which have now to be cut from each end of the rail or bar.
The apparatus
used for rolling such ingots may be constructed after the manner already
known and practised in the construction of mills with outside or overhanging

page_text: rolls as employed for rolling wheel tyres. The tightening down of the rolls
may be effected during the rolling process by means of gearing acting on the
set screws, or by hydraulic pressure after the manner already known and
practised for bringing together the rolls of other rolling mills at present in use;
but I would observed than when it is desired to roll angular ingots in order to
form bars of a very great length, it will be necessary to form a channel or pit
in the masonry on which the mill is fixed, in order to receive the hoop as it
becomes enlarged in diameter. The apparatus used for rolling such annular
ingots may, if desired, be so constructed that both ends of the rolls are
supported, either by making one end or a part of one end of the roller frame
moveable, so that it may slide away from the rolls, and allow the angular ingot
to be put on to the lower roller and then be replaced, or by carrying a strong
bracket above the top roll and another one below the bottom roll, and forming
in such brackets suitable bearings for the journals of the rolls to revolve in,
these brackets projecting from and forming part of the side frame or cheek of
the roller mill, so that the hoop or annular ingot may be got on to and off of
the roll without the removal of any part of the mill frame, the hoop in that case
passing over both the lower roll and its supporting bracket. This mode of
constructing a rolling mill for rolling annular ingots admits of several
modifications, as will be readily understood by persons practically acquainted
with this class of machinery; but I wish it distinctly understood that I lay no
claim to any particular form of rolling mill in these Letters Patent. I have
herein-before described the mode by which I form rings or hoops of malleable
iron or steel for the purpose of being extended into rails, bars, rods, or plates,
but when it is desired to tilt or roll ingots of iron or steel in the usual manner
I sometimes use a revolving mould having several compartments, or I fix
several moulds about a common centre, each of such moulds or compartments
being placed by preference as radii of a circle, and are of such an internal
form as will produce an ingot of the required size and shape; these moulds
may be made of iron, sand, or loam, and be used in a cold or heated state and
made to revolve at a high velocity, in order that the fluid metal when poured
into a central opening may be by centrifugal force compressed therein, and
form solid ingots or masses of malleable iron or steel suitable for and capable
of being tilted or rolled into rails, rods, bars, or plates of malleable iron
and steel.
When it is desired to cast ingots of a similar form to those generally made
by manufacturers of cast steel, I prefer to construct the centrifugal apparatus
as represented in the annexed Sheet of Drawings, where Figure 5 is a vertical
section through the centre of the series of ingot moulds, and Figure 6 is a plans

page_text: of the same, one half being shown in horizontal section; the axis (which I
prefer to be vertical) is shown at G; it has keyed on it a drum H, by means
of which rotatory motion is communicated to it. The supporting framework,
which is omitted in the Drawings, may be made similar to that represented in
Figure 1 or otherwise. K is a disc of malleable iron or steel, having a central
boss K', which is fitted on to the conical end of the axis; the outer part or
periphery of the disc is provided with a rim or flange K2, in order to retain
the ingot moulds J more securely during their rapid rotation; each of the
moulds are composed of two pieces, the lower having flanges J* on each side,
by means of which they are firmly bolted to the disc K; the upper half of
each mould abuts endwise against the rim K2, and is further held in place by
means of the set screws L, which pass through the rings M. These rings are
held at a fixed distance above the disc K by means of pillars N, the lower ends
of which pass through the flanges of the lower half of the mould, and also
through the disc K, and are held firmly there by the screw nuts P, while the
upper ends of them pass through the rings M, which are held down on to the
pillars by the screw nuts Q. By this arrangement it will be seen that the
upper half of the moulds may be removed by raising the set screws L
sufficiently high to allow the ends of the upper halves of each mould to pass
over the rim K2, and thus slide out end wise from beneath the rings M; after
the removal of the upper half of the moulds, the cast ingots may in like
manner be lifted up and removed. In the Drawing I have represented eight
moulds arranged around the centre of the disc, and thus an octagonal space
or cavity is there formed, into which I place a hollow fire brick R, having as
many lateral openings as there are moulds around it; an opening is also made
on its upper side, into which is poured the fluid metal at the time of casting,
so that the centrifugal force generated by the rotation of the metal when
received in the hollow receptacle thus formed, will cause the metal to be driven
off from the centre of motion, and passing through the lateral openings will
accumulate in each mould, and be there subjected to considerable pressure,
and produce sounder ingots than would otherwise be obtained; it will be obvious
that in lieu of the fire brick before described, the central cavity may be
moulded in sand, loam, or other suitable substance, but I prefer to use the
hollow fire brick and to heat the same to redness in a suitable oven; and to
employ it in the apparatus while in the heated state.
In the manufacture of cast steel as herein-before practised, the molten steel
is poured with great care into the mould,a small round stream being preferred
by the workman; however carefully this operation is performed, it frequently
happens that enough agitation of the metal is produced to disengage therefrom

page_text: carbonic oxide or other gaseous matter, and thereby produce an unsound
bubbly ingot. When casting ingots of steel without the application of cen-
trifugal force, I prefer to disengage as much as possible of the carbonic oxide
or other gaseous matter previous to the formation of the ingot, for which
purpose I place over the mould an iron vessel lined with loam or other slow
conductor of heat, or I use a red-hot fire-clay vessel of such an internal form,
that when a stream of molten iron or steel is poured therein from a height, that
the stream may fall on a projecting part of the interior of such vessel, and
be scattered or divided into numerous globules, which collect in the lower part
of such vessel, and pass through it into the mould; the metal will thus be
lowered in temperature, and will disengage large quantities of carbonic oxide
or other gaseous matter; when employing this mode of forming ingots, I prefer
to direct a stream of carburetted hydrogen or other gas into the said vessel,
in order to prevent the oxydation of the numerous globules of molten metal
formed therein.
Having described my said Invention, and the manner in which the severa!
parts or modifications thereof may be carried into practical operation, I desire
it to be understood that I do not confine myself to the precise details herein
given, provided that the peculiar character of my Invention be retained.
In witness whereof, 1, the said Henry Bessemer, have hereunto set my
hand and seal, this Fifth day of May, in the year of our Lord One
thousand eight hundred and fifty-eight.
Witness,
W
MILLS,
HENRY BESSEMER. (L.S.)
12, Cursitor Street, Chancey Lane.