MENTS IN THE MANUFACTURE OF CAST STEEL
Year: 1857

page_text: LETTERS PATENT to Henry. Bessemer, of Queen Street Place, New
Cannon Street, in the City of London, for the Invention of "IMPROVE-
PROVISIONAL SPECIFICATION left by the said Henry Bessemer at the
FIČATI
Office of the Commissioners of Patents, with his Petition, on the 18th
September 1857
I HENRY BESSEMER of Queen Street Place, New Cannon Street in the
City of London do hereby declare the nature of the Invention for "IMPROVE
MENTS IN THE MANUFACTURE OF CAST STEEL" to be as follows.
These improvements consist in certain modifications of the apparatus and in
the processes to be employed in the manufacture of, cast steel direct from
molten crude iron by currents of air, used alone or in combination with other
gaseous or solid bodies and consists of
Firstly In melting the crude or pig iron in a cupola furnace with disul-
phurized or prepared coke anthracite coal, wood, or charcoal, in lieu of the
ordinary oven coke, as.heretofore used for that purpose.
Secondly. In separating the granular metal from the cinder which is thrown
out of the converting vessel during the "boil." by churning the solidified
cinder with iron balls in a suitable revolving vessel and at the same time
blowing a jet of air through the axes of the churn so as to remove the slag
29466-2.

page_text: which is reduced to powder during the process and whereby the metallic
parts will be separated for after use.
Thirdly In causing the air or gaseous or other matters used in the con-
verting process to enter the molten metal through a single tuyere situated at
or near the central and deepest part of the converting vessel such opening
serving also as a discharge apperture for the molten steel.
Fourthly In the use of highly heated crucibles or loam-lined vessels to
receive the molten steel from the converting vessel from which it is to be
conveyed and in some cases poured into moulds and thereby formed into
ingots or masses and in other cases it is to be poured into crucibles and kept
heated therein in suitable furnaces until it is in a more perfect state for
casting into ingots, or the fluid steel may be poured from the heated crucible or
vessel on to any suitable inclined surface placed over water and be shotted in
a similar manner to that already practised by me in running the fluid steel
direct from the converting vessel into water.
Fifthly In running or pouring the molten steel from the converting vessel
or from a heated crucible or vessel into moulds of such a shape as will form
masses of steel that will fit freely into the crucibles used for remelting and in
heating such masses by the spare heat of the remelting furnace or in a
suitable retort or other furnace previous to putting such masses into the
remelting crucibles.
Sixthly In crushing the hollow shots or products (formed by pouring
molten steel into water) by a stamp or by a pair of rolls placed horizontally or
otherwise and also in highly heating the broken shots in a suitable retort
or other furnace previous to charging the remelting crucibles with them.
Seventhly In coating or covering the surfaces of the broken steel shots
previous to the preliminary heating or remelting process.-The wash or
coating which I prefer consists of lime carbon manganeze and clay mixed
with water to the consistance of cream which is to be well mixed up with
the broken shots in sufficient quantity to coat or cover their surfaces.
Eighthly In annealing and heating cast-steel ingots in fire clay or iron
retorts instead of exposing them to the direct action of the fire as at present
practised.
Ninthly In improving the surfaces of rods, bars, and plates of cast steel by
first hammering or rolling the ingots to a certain extent and then grinding
the surface of them until all external defects disappear after which the tilting
or rolling is to be completed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Bessemer in the Great Seal Patent Office on the
18th March 1858. .
... .
TO ALL TO WHOM THESE PRESENTS SHALL COME I HENRY
BESSEMER of Queen Street Place New Cannon Street in the City of
London send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria by Her Letters
Patent bearing date the Eighteenth day of September 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 "IMPROVEMENTS IN THE
MANUFACTURE OF CAST 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 particu-
larly describe and ascertain the nature of the said Invention and in what
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;
These improvements consist in certain modifications of the apparatus and
in the processes to be employed in the manufacture of cast steel direct from
molten crude iron by currents of air used alone or in combination with other
gaseous or solid bodies and consists
Firstly In melting the crude or pig iron in a cupola furnace with desul-
phurized or prepared coke anthracite coal, wood or charcoal in lieu of the
ordinary oven coke as heretofore used for that purpose.
The ordinary description of coke manufactured in this country is found to
contain sulphur in such quantities as sensibly to deteriorate the finer qualities
of charcoal pig iron which are used in the manufacture of the best cast steel

page_text: it therefore becomes important that in the remelting of charcoal-made pig iron
that such iron should be brought as little as possible in contact with sulphur
or with any vapour or compound thereof I therefore employ in the remelting
furnace coke that has been desulphurized by any known process capable of
effecting that object. But where anthracite coal free or for the most part free
from sulphur can be readily obtained it may also be used with advantage in
lieu of ordinary coke in the remelting of charcoal-made pig iron. But in all
cases where the cost of charcoal or dried wood is not too high I use one or
both of them in preference to any other kind of fuel making in that case the
cupola furnace much higher than those in general use with coke in order
that the charge of iron may not sink down to the bottom of the furnace before
it has time to pass into the fluid state. The time required to bring a charge
of iron into a fluid state in any furnace will more or less depend on the size
of the pieces of metal put into the furnace and the amount of injury it may
receive from the impurities of the fuel employed must also in part depend on
the time during which the metal is exposed to its action I therefore prefer
before putting the crude metal into the melting furnace to reduce it to small
lumps or fragments in any convenient way or to have the crude metal made
into feathered shots by running it from the blast furnace into hot water in a
manner well understood. In the remelting of pig iron lime is sometimes
added in its dry or natural state to the charge of iron in the melting furnace
but when small fragments or shots are to be remelted I prefer to mix
powdered lime with water and to pour the semi-fluid mixture on to and mix it
with the small pieces or shots of iron previous to putting them into the
remelting furnace whereby the surface of the pieces of iron will be more or
less coated therewith and be protected from the influence of the gaseous
matters present in the furnace. It will also be obvious that in the remelting
of pig or crude iron for the purpose of being afterwards converted into steel
by the forcing of air or other gaseous matters therein that not only lime may
be used in the remelting of such iron in the manner described but that any
substance or flux or any oxide or metallic substance that is known to improve
or purify iron or has before been used or has been proposed to be used or
added to or mixed with iron for the purpose of improving its quality or
purifying or alloying the iron in other processes of melting or making iron
or steel may also be employed in the remelting of iron for the purposes of the
present Invention but the use of any of which substances fluxes metals or
oxides and the shotting or reducing of the pig iron to small fragments to
facilitate the melting thereof and the coating thereof with lime are not
claimed by me as forming any part of the Invention desired to be secured by

page_text: these Letters Patent although they may in some cases be benencially used
therewith.
..
My Invention consists Secondly. In seperating the granular metal from the
cinder which is thrown out of the converting vessel during the boil" by
churning the solidified cinder with iron balls in a suitable revolving vessel and
at the same time blowing a jet of air through the axes of the churn so as to
remove the slag which is reduced to powder during the process and whereby
the metallic parts will be separated for after use.
The improvement included under this head of my Invention may be
carried into practical operation by employing a cast-iron churn or drum
mounted on horizontal axes to one of which is attached a spur wheel or
driving drum for the purpose of imparting a rotary motion to the churn the
interior of the churn has several longitudinal ribs running the whole length of
it and projecting for a few inches inwards in the direction of the axis of the
cylinder and having. their angles. rounded off so that the matters under
operation in the cylinder may roll over them without too much obstruction a
blast pipe from a blowing fan or other air-forcing apparatus is fitted freely into
one axis of the churn while the other axis (which is also hollow) is open to
the external air, on one side of the churn a door is formed for the admission
and egress of the materials and it is so made to close and fasten that the
materials are thereby retained in the churn until it is desired to remove them.
By means of this door I introduce the slags or scoria which is thrown out of
the converting vessel during the "boil" I also put into the churn a sufficient
quantity of iron balls or other lumps or pieces of iron to act upon crush and
reduce the spongy slags and disengage therefrom the granules of metal which
they contain the blast of air may be continued throughout the churning
operation so that the small particles of powdered scoria may be all blown out
by the blast of air and the metal only remain in the churn at the close of the
operation. The grains of metal thus obtained may be put into the converting
vessel along with any other scrap metal intended to form part of the charge
of steel or they may be re-melted in a cupola furnace with the crude pig
iron.
My Invention also consists Thirdly In causing the air or gaseous or other
matters used in the converting process to enter the molten metal through à
single tuyere situated at or near the central and deepest part of the converting
vessel such opening serving also as a discharge aperture for the molten
steel.
And in order that the mode by which I prefer to carry into practical
operation this part of my said Invention may be fully understood I have

page_text: hereunto annexed a Sheet of Drawings on which Figure 1 represents the
converting vessel in elevation-Figure 2 is a vertical section through the
centre thereof Figure 3 a horizontal section taken through the lower
chamber a and Figure 4 is another horizontal section taken through the
upper chamber g. The vessel is formed of boiler plates rivetted in the usual
manner, and may be lined with fire-bricks moulded of a suitable form, or any
refractory substances such as "ganister" road drift &c. may be rammed
around a suitable core placed in the iron vessel after the manner of lining up
furnaces with such materials as already practised but I prefer to line the
vessel by forming the fire-resisting material into one two or three pieces only
so as to have as few joints as may be and all of which joints I prefer to have
above the line to which the metal rises in the vessel but with whatever
materials the vessel may be lined I prefer to form the lower part of its
interior of the shape represented in the Drawings, or of a shape affording
practically the advantages it possesses over the flat or cylindrical bottoms
heretofore used. Into the central part of the bottom of the chamber a I
insert a tuyere 6 which is held in its place by ramming in loam tightly
around it, the external end of the tuyere is made conical to receive the end
of the blast pipe c as will be better seen by reference to Figure 6 which is a
vertical section of a fire-clay tuyere on a larger scale and Figure 7 is also a
plan of the same. The molten crude iron may be run into the vessel through
an opening made in the side thereof as shown at d Figure 2 and may be
allowed to rise to about the height shown in the Drawings and indicated by
the letter e the opening f communicates with the upper chamber 9 from
which the flame and scoria are allowed to escape by the openings h. h. The
upper part of the iron vessel has a stout hoop i rivitted to it and is provided
with lugs through which pass four rods j by means of which the vessel is
suspended to two cast-iron girders m which run parallel with each other and
which may receive support from the walls of the building or otherwise. The
lower part of the iron vessel is connected to the upper part by means of
flanges and bolts / so that the whole apparatus may be supported at any
convenient height above the floor of the building.
In the manufacture of steel by forcing atmospheric air therein it is
important that every portion of the metal should be acted on as equally as
possible throughout the whole time of the process and also that when the
metal arrives at the desired state of decarbonization that the process should at
that point be suddenly arrested in order that it may not be carried too far and
the metal be thereby made softer or milder than may be desired.. In order to
effect these objects I employ the apparatus herein lastly described and by

page_text: forcing in the air from the lowest part of the vessel I prevent any portion of
the lower stratum of metal from remaining there without undergoing the full
amount of refining. The powerful jet formed by introducing all the air by one
aperture and its ascent vertically through the fluid metal tends to form return
currents of metal downwards by the sides of the vessel and thus to produce
such a complete mixture of the metal as to insure an equal or nearly equal
action on all parts thereof while the tendency, which jets of air when
introduced at the sides of the vessel have to act unequally on the metal
occupying the centre of the vessel is entirely avoided. If it should be desired
to still further diffuse the air through the fluid metal the tuyere may be made
in the manner represented in Figures 8 and 9 in which the jet is divided into
four parts or into any desired number of parts so that with one tuyere only at
the bottom of the vessel several smaller currents of air may be forced upward
through the fluid metal.
In the manufacture of cast steel by means of air forced into fluid crude
iron it has been found that the steel so obtained undergoes a change in
quality during the discharge thereof from the converting vessel in those cases
where the air is continued to be forced into a vessel during the period of such
discharge and whereby those portions that last leave the vessel are softer or
approach nearer to the quality of iron than those portions that first, escape
from the tapping hole, and further. that if the unstopping of the tapping hole
is not quickly effected that the metal during such period of delay also under-
goes a like change in quality. Hence in the production of steel of any desired
temper or degree of hardness it is desirable that the workman should be
enabled to commence the discharge of the metal from the vessel at any
desired moment of time, and also that the decarbonization of the metal should
cease at the same instant in order that every portion of the metal should be
of the same quality or degree of hardness. It is in order to secure these
advantages that the following arrangements are made viz-The pipe n
which conveys air steam or any gaseous or other matters, which are. to be
forced into the fluid metal is provided with a cock p the key or plug of which:
is hollow and terminates in a branch or curved blast pipe c as will be best
seen by reference to Figure 5 which shews the arrangement in plan and on a
larger scale the other end of the key or plug has coiled around it a spiral>
spring which passes through a flange formed on the elongation of the plug
while the other end of the spring abuts against a studs which is fixed to the
cock and whereby the plug of the cock is made to turn suddenly round when.
required into the position indicated by dots at c* Figure 2. When the tuyere.
6. is secured in its proper position the pipe c may be forced round until its:

page_text: orifice is in communication with the orifice of the tuyere the catch will then
be brought over the stud z which projects from a short arm formed on one
side of the key or plug of the cock, so that the spring will not be able to move
the plug of the cock so long as the catch is kept in contact with the stud.
In this position of the apparatus the forcing of the air or other matters into
the vessel may be effected and whenever it is judged that the metal has
arrived at the desired degree of decarbonization the workman will pull
the ring 9 which is attached by a wire to the catch t and thus withdraw it
from the stud the spring being thus released will rapidly force round the
plug of the cock and thus withdraw the blast pipe from the orifice of the
tuyere and simultaneously shut off the communication with the reservoir of
compressed air steam or other matters. A rapid discharge of the fluid steel
will immediately follow the withdrawal of the blast pipe through the orifice by
which the air was before admitted while the shutting off of the air will
prevent any portion of the charge of metal from being further acted upon by
the air or other matters used for its decarbonization.
In this apparatus it will be necessary to force the air through the tuyere
previous to letting the crude metal enter to vessel in order to prevent its flow
into the blast pipe it is therefore preferable to admit the metal as rapidly as
possible so that all parts thereof may be as equally acted on as may be but if
the tuyere be made with a closed end as represented in section at Figure 10,
or with a stopper & fitted to it as shown in section at Figure 11 the whole of
the crude metal may be run into the vessel before the blast is turned on and
then by introducing a rod through a suitable opening in the blast pipe the
closed top of the tuyere may be forced open or the stopper removed therefrom
by a sharp blow on the end of the rod when the blast will suddenly enter the
whole body of metal and thus more clearly define the time of commencing the
process.
The converting vessel herein described is shown as suspended in a fixed
position from girders placed above it for that purpose. But it will be under-
stood that vessels of the general form and construction of that represented in
the annexed Drawings and provided with a single tuyere at the lower párt
thereof may also be made to move on axes placed either at or near their
centre of gravity or at any part where a spout or orifice is formed so that the
metal may be poured therefrom quietly from its upper surface after the
manner of pouring fluids from spouted vessels and which mode of pouring out
may be effected by forming a suitable spout at one side of the vessel or by
removing the upper part of the vessel and pouring from the lower one as from
an open ladle or crucible. If either of these plans of pouring out be preferred.

page_text: to running the metal from the tuyere I fit a cylindrical tube to the blast pipe
large enough to contain a fire-clay or other stopper by means of which the
tuyere may be suddenly stopped whenever the process is completed, this con-
trivance will be better understood by reference to Figure 12 where v is the
fire-clay tuyere wo is the cylindrical piece attached to the blast pipe y and x is
the stopper which is suddenly forced upwards by means of the rod which pro-
jects downwards from. it for that purpose when this is done the metal will
run down to and solidify around the joint of the stopper and make it perfectly
tight the metal may then be retained in the heated vessel for some time
previous to pouring it into moulds, and although I have herein described how
the tuyeres may be made with solid ends or stoppers and how the converting
vessel may be made moveable on an axis and also how the tuyeres may be
stopped with a plug after the converting process is effected I nevertheless
desire it to be understood that I lay no claim thereto under the present
Letters Patent.
My Invention consists Fourthly in the use of highly-heated crucibles or loam-
lined vessels to receive the molten steel from the converting vessel from which
it is to be conveyed and in some cases poured into moulds and thereby formed
into ingots or masses and in other cases it is to be poured into crucibles and
kept heated therein in suitable furnaces until it is in a more perfect state for
casting into ingots or the fluid steel may be poured from the heated crucible or
vessel on to any suitable inclined surface placed over water and be shotted
in a similar manner to that already practised by me in running the fluid steel
direct from the converting vessel into water. In the production of cast steel
direct from crude iron by forcing air therein it frequently happens that the
steel acquires in the converting vessel a temperature higher than is desirable
for casting into ingots and after its discharge from the vessel it is sometimes
found still to be in a state of ebullition, it is therefore found desirable in such
cases to run the steel from the converting vessel into a heated fire-clay
crucible or into an iron vessel or ladle lined with loam or other -refractory
substance and highly heated in order that the excess of heat may be gradually
dissipated and the metal becomes quiet after the disengagement of carbonic
oxide or other gaseous matters previous to pouring the steel into the ingot
moulds or in lieu of this mode of casting while the steel still retains the heat
it has acquired in the converting process the steel may be conveyed in the
said heated vessels or crucibles to a furnace or furnaces of any suitable con-
struction in which fire-clay crucibles are kept heated in readiness to receive it
and in which it may be kept in a highly-heated state for any desired length of
time or until all ebullition or disengagement of gaseous matters has ceased

page_text: before pouring it into ingot moulds or forming other articles therewith. The
kind of furnace employed for reheating or retaining the heat of the steel is un-
important provided that it is capable of keeping the steel in a perfectly
molten condition if small crucibles are preferred for retaining the heat of the
steel then the ordinary steel melting furnace may be used to advantage the
same construction of furnace may also be used when the crucibles are required
to contain several times the ordinary steelmaker's charge but when the quan-
tity of steel to be kept fluid is very large I then prefer to use a furnace and
crucibles of the form and construction commonly employed in this country
by manufacturers of plate glass in which furnace the crucibles or casting
pots are heated and from which they are removed at the time of casting.
This process of reheating and purifying steel made in vessels without fuel
affords great facility for altering or modifying the quality of the steel by the
admixture therewith of other kinds of steel or by the admixture therewith or
by the addition thereto of carbon alone or of a mixture of carbon and
manganese or by the use of carburet or carbide of manganese in any desired
proportions and also of mixing therewith any fluxes or metallic substances
that have heretofore been used or have been proposed to be used in the
manufacture of steel the use of which substances is not new and are conse-
quently not claimed by me under these Letters Patent.
My Invention also consists Fifthly. In running or pouring the molten steel
from the converting vessel or from a heated crucible or vessel into moulds of
such a shape as will form masses of steel that will fit freely into the crucibles
used for remelting and in heating such masses by the spare heat of the
remelting furnace or in a suitable retort or other furnace previous to putting
such masses into the remelting crucibles.
When crude iron is converted into steel in any locality in which it is not
desirable to complete the manufacture and in other cases where the remelting
of the steel is desirable I cast or form the fluid metal into such a shape ns
will enable the founder to get as large a charge as possible into the crucible,
I therefore prefer to make cylindrical or conical masses of steel as near to
the shape of the interior of the crucible as may be or to make two or more
pieces of such shape as will fit readily into it when it is intended to remelt
such masses of steel where they are formed I put them into the remelting
crucibles while they still retain a large amount of the heat they had acquired
in the converting process but when this cannot be conveniently effected I
prefer to beat the masses of steel in a chamber formed between the steel-
maker's melting furnace and the chimney and through which chamber the
heat escaping from the furnace employed in melting a charge of steel may be

page_text: made to pass and thereby heat the said masses of steel and thus economise
both the time and fuel expended in the remelting thereof.
My Invention also consists Sixthly. In crushing the hollow shots or products
(formed by pouring molten steel into water) by a stamp or by a pair of
rolls placed horizontally or otherwise, and also in highly heating the broken
shots in a suitable retort or other furnace previous to charging the remelt-
ing crucibles with them.
It has been found that shots produced by allowing a shower of globules of
molten steel as it issues from the converting vessel to fall into water are for
the most part hollow and filled with water, it is therefore desirable that they
should be broken previous to putting them into the remelting crucibles both
for the purpose of causing them to occupy less space in the crucible and also
to separate the water more readily therefrom. I prefer to use crushing rolls
mounted in a horizontal frame and surmounted by a hopper to receive the.
shots, this kind of apparatus which is in use for numerous purposes will be
found most convenient as the extreme brittleness of the thin hardened steel
spherules admits of their being crushed most readily.
My Invention consists Seventhly. In coating or covering the surfaces of the
broken steel shots previous to the preliminary heating or remelting process.
The wash or coating which I prefer consists of lime carbon manganese and
clay mixed with water to the consistence of cream which is to be well mixed
up with the broken shots in sufficient quantity to coat or cover their surfaces.
The proportions in which the substances herein lastly mentioned are to be
used must in all cases depend more or less on the quantity of the steel shots
employed but in general it will be found that from one to three ounces of oxide
of manganese and from two to four ounces of charcoal mixed with from five
to ten ounces of lime and an equal quantity of clay will be sufficient for forty
lbs. of sheel shots. these materials should be well ground together and mixed
with water to the consistence of cream and be then well 'mixed with the small
fragments of steel so as to coat or cover their surfaces as completely. as
possible after which the steel may be heated prior to putting it into the re-
melting crucibles or it may be at once put therein and brought to a state of
fusion and be cast into ingots or other articles of cast steel.
My Invention also consists Eighthly. In annealing and heating cast-steel.
ingots in fire clay or iron retorts instead of exposing them to the direct action
of the fire as at presented practised.
The object of this part of my. Invention is to obtain a thorough annealing of
such steel ingots as are cast in chills or iron moulds in order that the particles
of metal which have undergone sudden contractions in consequence of the

page_text: rapid solidification of the fluid steel may re-arrange themselves under the
influence of a more. equal and longer continued heat than can be readily ob-
tained in the fires now employed for that purpose while the ingot is at the
same time defended from oxydation and from the effects of the mineral fuel
employed in such furnaces. For this purpose I prefer to use iron retorts or
square tubes of sizes little more than sufficient. to put in the ingots freely
they may be arranged nearly close to each other side by side and in several
tiers one above another so that a furnace may hold a considerable number at
one time and thus allow each ingot to be a longer time under the influence
of the heat without delaying the workmen or wasting the fuel. The "hearth
now generally employed may still be used by merely fixing the retorts in the
front and back walls in the same position that the ingots generally occupy
when being heated therein.
"
My Invention consists. Ninthly. In improving the surfaces of rods bars and
plates of cast steel by first hammering or rolling the ingots to a certain extent
and then grinding the surface of them until all external defects disappear
after which the tilting or rolling is to be completed.
In the manufacture of steel direct from crude or cast iron it frequently
happens that the ingots have a number of small blow holes on their surfaces
which become oxydized in the heating of the ingot and consequently do not
close up but on the contrary they become elongated as the hammering or
rolling of the bar proceeds and eventually they present the appearance of a
crack or flaw extending along the bar for a considerable distance the continued
extension of the metal fails to remove such external defects which thus aug-
ment in proportion as the bar becomes extended and have eventually to be
removed by the file or the grindstone from a vast number of small articles. To
prevent so much useless labour I first proceed to roll or hammer the ingot
until it is reduced to about one half its original thickness this hammering
brings all external defects up to the surface the bar is then to be ground on
a large stone until all appearance of bubbles or flaws disappear after which
it may be tilted or rolled to any desired size and when finished its surface
will be found to be more perfect than ordinary steel which is always more or
less subject to the defect arising from surface air holes and which defects arise
from accidents or causes totally irrespective of the quality of the metal in
other respects.
Having described the means by which the several parts which constitute
my present Invention are 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 general character of any of the several parts of my Invention

page_text: be retained and I would remark that the above improvements are applicable
when manufacturing steel to be used as such as well also when manufacturing
steel to be converted into iron by continuing the process for a longer time.
In witness whereof I the said Henry Bessemer have hereunto set my
hand and seal this Seventeenth day of March in the year of our
Lord One thousand eight hundred and fifty-eight.
Witness
B. GOBEY
24 Southampton Buildings
Chancery Lane.
HENRY BESSEMER. (L.s.)