IMPROVEMENTS IN THE MANUFACTURE OF ORDNANCE
Year: 1855

page_text: LETTERS PATENT to Henry Bessemer, of Queen Street Place, New
Cannon Street, in the City of London, Engineer, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF ORDNANCE."
Sealed the 18th December 1855, and dated the 18th June 1855.
PROVISIONAL SPECIFICATION left by the said Henry Bessemer at the
Office of the Commissioners of Patents, with his Petition, on the 18th
June 1855.
I, HENRY BESSEMER, of Queen Street Place, New Cannon Street, in the
City of London, Engineer, do hereby declare the nature of the Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF ORDNANCE" to be as follows:-
When ordnance is cast in gun metal or iron, it is found to wear out so
rapidly when in use as to prove of serious inconvenience in siege or like opera-
tions. The object, therefore, of the present Invention is to give greater
durability and strength to various kinds of ordnance, by founding or casting the
said pieces of ordnance in molten steel of the desired form, the trunnions,
handles, or other required projecting parts being formed thereon in the mould.
as in the founding of ordnance in iron or gun metal as at present practised,
and whereby all forging or shaping by the hammer is entirely avoided; the
moulds I prefer to form in dry loam, as at present practised in the founding
of iron or gun metal. The great cohesive force of cast steel, as compared with
iron or
gun metal, while it gives greater strength and adds to the safety of the
piece of ordnance, also admits of a diminution in its weight; at the same time

page_text: the superior hardness of steel will cause it to suffer much less from the action
of the shot on its interior surface than is the case with ordnance cast in softer
metals. When the founding of the piece of ordnance is effected, and it is
judged that the metal has quite solidified, the mould and the casting within it
is to be removed to a convenient place, where the whole should be covered up
with sand, so as to allow the casting to cool slowly, whereby it will become
sufficiently soft,to be bored out; or in, lieu of this, the casting may be removed
from the mould and be placed in a suitable annealing oven, where a red heat
may be maintained for any desired length of time, so as to obtain the greatest
degree of toughness in the metal. If air is pretty freely admitted to the
oven, an oxidation and partial decarbonization of the exterior portions of the
casting will take place. This decarbonization may be carried on if desired
until the exterior portions of the piece of ordnance is reduced to nearly
the soft and tough condition of wrought iron, while the interior portions
thereof will still retain the qualities of steel. This decarbonization may
be facilitated by embedding the casting in oxide of iron, manganese, or iron
ore; when the annealing is effected to the desired extent, the casting may
be bored out in the usual way. The piece of ordnance may either be cast
solid and afterwards be bored out; or a suitable core may be inserted in the
mould, so as to form the-large cylindrical cavity or bore by the process of
founding, and which may be afterwards perfected by a boring tool.
The steel for the purposes of this Invention may be melted in crucibles, as
at present practised in the manufacture of cast steel, the contents of several
crucibles being poured simultaneously into the mould; but I prefer the mode of
melting steel and running the same through gutters into the mould, as described
in the Provisional Specification of a Patent for "Improvements in the Manu-
facture of Cast Steel and Mixtures of Steel and Cast Iron," bearing even date
herewith
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Bessemer in the Great Seal Patent Office on the 3
18th December 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
BESSEMER, of Queen Street Place, New Cannon Street, in the City of London,
Engineer, seud greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters 3
Patent, bearing date the Eighteenth day of June, in the year of our Lord
One thousand eight hundred and fifty-five, in. the eighteenth year of Her

page_text: 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 ORDNANCE," upon the condition (amongst others) that I,
the said Henry Bessemer, by an instrument in writing under my hand and
seal, should particularly describe and ascertain the nature of the said Inven-
tion, 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
performed, to be particularly described and ascertained in and by the following
statement thereof (that is to say):
When ordnance is cast in gun metal or iron, it is found to wear out so
rapidly when in use as to prove of serious inconvenience in siege or like
operations. The object, therefore, of the present Invention is to give greater
durability and strength to various kinds of ordnance, by founding or casting the
said pieces of ordnance in molten steel of the desired form, the trunnions,
handles, or other required projecting parts being formed thereon in the mould,
as in the founding of ordnance in iron or gun metal as at present practised,
and whereby all forging or shaping by the hammer is entirely avoided. The
moulds I prefer to form in dry loam, as at present practised in the founding of
iron or gun metal. In making the moulds for founding ordnance in steel, care
should be taken that all matters capable of producing gases be excluded from
the sand or loam used for that purpose, because the great heat of fluid steel
acting on such substances would endanger the soundness of the casting, by the
bubbling up of such gaseous products through the metal. The more fully to
avoid such an accident, I find it. preferable to put the mould into a drying
stove, and to raise its temperature to a low red heat, previous to pouring in
the steel; the high temperature of the mould will at the same time prevent
the too sudden chilling of the metal. The handles, trunnions, and other pro-
jecting parts, as well as the general configuration of the piece of ordnance, is
thus given by the act of founding, and whereby I obtain a homogenous mass
of metal, in contradistinction to the plan heretofore practised of shaping a piece

page_text: of steel by the hammer, so as ultimately to form it into a gun, by which mode
of operating it is extremely difficult (if possible) to obtain an equal amount of
condensation of the metal at all parts thereof, while the handles or trunnions
cannot be formed thereon, as in the process of founding. The great cohesive
force of cast steel, as compared with iron or gun metal, while it gives greater
strength and adds to the safety of the piece of ordnance, also admits of a
diminution in its weight; at the same time the superior hardness of steel will
cause it to suffer much less from the action of the shot on its interior surface
than is the case with ordnance cast in softer metals. When the founding of
the piece of ordnance is effected, and it is judged that the metal has quite
solidified, the mould and the casting within it is to be removed to a convenient
place, where the whole should be covered up with sand so as to allow the casting
to cool slowly, whereby it will become sufficiently soft to be bored out; or in
lieu of this, the casting may be removed from the mould, and be placed in a
suitable annealing oven, where a red heat may be maintained for any desired
length of time, so as to obtain the greatest degree of toughness in the metal.
If air is pretty freely admitted to the oven, an oxidation and partial decar-
bonization of the exterior portions of the casting will take place. This
decarbonization may be carried on if desired until the exterior portions of the
piece of ordnance is reduced to nearly the soft and tough condition of wrought
iron, while the interior portions thereof will still retain the qualities of steel.
This decarbonization may be facilitated by embedding the casting in oxide of
iron, manganese, or iron ore. When the annealing is effected to the desired
extent, the casting may be bored out in the usual way. If it be desired to carry
on the decarbonization of the steel to a considerable extent, it will be found
preferable to remove the oxide of iron ore or other matters after twenty-four
or thirty. hours' application of heat, as they will have lost so much of their
power of absorbing the carbon of the steel as would, in consequence, render
the operation extremely slow. A fresh supply of the oxydised materials should
be therefore substituted, and the decarbonization allowed to proceed until the
desired quality is obtained, when the fires of the annealing oven may be allowed
to die out and the oven to cool slowly. The piece of ordnance may either be
cast solid and afterwards be bored out, or a suitable core may be inserted in
the mould, so as to form the large cylindrical cavity or bore by the process of
founding, and which may be afterwards perfected by a boring tool.
The steel for the purposes of this Invention may be melted in crucibles, as
at present practised in the manufacture of cast steel, the contents of several
crucibles being poured simultaneously into the mould; but I prefer the mode
of melting steel and running the same through gutters into the mould, as

page_text: described in the Provisional Specification of a Patent for "Improvements in
the Manufacture of Cast Steel and Mixtures of Steel and Cast Iron," bearing
even date herewith; and by means of which Invention the process of founding
ordnance will be facilitated by the simultaneous discharge of the molten steel
from several large crucibles, as set forth in the Specification of the said Patent,
and filed on the same day with this present Specification.
Having thus described my said Invention, and the manner in which the
same is to be performed, I declare that what I claim as my Invention is,―
Firstly, the founding or casting of ordnance in molten steel, such pieces
of ordnance having formed thereon trunnions, handles, or other necessary pro-
jecting parts, so as to give the general shape and configuration to the piece
of ordnance by the process of founding.
Secondly, I claim founding ordnance in molten steel in loam or sand
moulds, as described.
Lastly, I claim the partial decarbonization of steel ordnance, as herein
described..
In witness whereof, I, the said Henry Bessemer, have hereunto set my
hand and seal, this Fifteenth day of December, in the year of our
Lord One thousand eight hundred and fifty-five.
Witness,
JNO. ALCOCK.
HENRY BESSEMER. (L.S.)