IMPROVEMENTS IN THE CONSTRUCTION AND MANUFACTURE OF ORDNANCE
Year: 1855

page_text: LETTERS PATENT to Henry Bessemer, of Queen Street Place, New Cannon
Street, in the County of Middlesex, for the Invention of "IMPROVEMENTS
IN THE CONSTRUCTION AND MANUFACTURE OF ORDNANCE."
Sealed the 17th April 1855, and dated the 10th January 1855.
PROVISIONAL SPECIFICATION left by the said Henry Bessemer at
the Office of the Commissioners of Patents, with his Petition, on the
10th January 1855.
I, HENRY BESSEMER, of Queen Street Place, New Cannon Street, in the
County of Middlesex, Engineer, do hereby declare the nature of the Invention
for "IMPROVEMENTS IN THE CONSTRUCTION AND MANUFACTURE OF ORDNANCE" to be
as follows:-
The Invention consists in manufacturing ordnance by casting the same of a
mixture of steel and iron in suitable moulds, provided with iron core bars for
the purpose of chilling the metal; or the ordnance may be cast solid and be
bored out as usual; in either case the metal should be prepared in a manner
more particularly described in a Patent bearing even date herewith. The
superior hardness of this compound and its great cohesive force renders it
particularly suitable for the manufacture of ordnance, and will admit of a

page_text: great diminution in the weight of the piece; and to diminish the recoil of
light ordnance of this description, part of the elastic vapours, resulting from
the explosion of the powder, is allowed to escape at apertures made near the
muzzles.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry, Bessemer in the Great Seal Patent Office on the
10th July 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
BESSEMER, of Queen Street Place, New Cannon Street, in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of January, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth 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 CON-
STRUCTION. AND 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 Invention, and in what manner the same was to be performed, and
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.
cause
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 lessening the recoil of ordnance of various
"kinds, and in obtaining greater strength in their structure. For the purpose
"of lessening the recoil, part of the elastic vapours, resulting from the explosion
of the powder, is allowed to escape from the piece by suitable apertures
made near the muzzle thereof, prior to the discharge of the projectile, and

page_text: "
may be made at right angles to the bore of the piece, or nearly so, in which
case a diminution of the recoil will take place, in consequence of the
"diminished pressure of the elastic matters contained in the piece at the time
"when the projectile is leaving it."
In order that this and other modifications of my said Invention may be
fully understood, I have hereunto annexed a Sheet of Drawings; in which,
Figure 1 is a longitudinal section of a piece of ordnance; and Figure 2, a cross
section of the same, on the line A, B, of Figure 1; in which Figures, a and b
represent two apertures bored in the sides of the gun for the escape of the
elastic vapours, which will commence to rush out with great force so soon as
the projectile g arrives in the position shewn in Figure 1, and will continue to do
so until the projectile has passed out of the muzzle; the pressure of the clastic
vapours will thus be considerably diminished during the movement of the
projectile from the apertures a and b to the muzzle. I therefore prefer to
increase the length of the piece of ordnance about half as much as the
distance between the apertures a and b and the muzzle, and thus compensate
for the diminished pressure of the elastic vapours, which would otherwise
act less powerfully on the projectile.
A piece of ordnance when in the act of projecting a missile may be considered
as a close vessel containing elastic vapours under great pressure, and which
pressure acts on both sides of such vessel with equal force, and thus the vessel
will be in a state of equilibrium; but if an aperture be made, as at a, Figure 1,
on one side of such vessel, the elastic vapours will have less surface to press.
upon on that side, and consequently the additional surface on the side opposite
to the aperture a will be acted upon so forcibly as to move the vessel sideways;
and in an opposite direction to the issuing gases, and would thus produce a
sideway recoil of the piece of ordnance. This principle of reaction is exemplified
in the emissive steam engine, and in Parker's mill. But, however, if a corre-
sponding aperture be made, as at b, Figure 1, a still larger escape of elastic
vapours will take place; but as the two forces are equal, and will act in opposite
directions, they will so far neutralize each other as to prevent any lateral
movement whatever in the piece of ordnance. It will, nevertheless, be under-
stood that these two forces, each of which are of themselves sufficiently powerful
to move the piece of ordnance sideways, are not additions to the force generated.
by the explosion of the powder, but are forces which must be deducted from
the force with which the gun will recoil endwise, and which reduction of force
will lessen the recoil of any piece of ordnance having lateral emission apertures,
as described. . In some cases it may be found preferable to place the emission
apertures at an anglé, so as. to project the vapors away from the gunners, and

page_text: also to provide more fully for the escape of the gaseous matters from the pieces
of ordnance, by making numerous openings around it. A piece of ordnance so
constructed is shewn in plan at Figure 3; Figure 4 being a longitudinal section,
and Figure 5 a cross section of the same, taken on the line C, D, of Figure 3.
c, c, c, are the apertures for the emission of the elastic gases, there being two
rows of them, the holes in one row being opposite the spaces in the other, as
shewn by dots in Figure 5. Instead, however, of making the emission
apertures at a slight angle, as herein lastly described, "these openings may be
"inade almost parallel with the bore of the piece, and in a direction pointing
"to the breach end thereof, so that the reactive force of the vapours issuing
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gun
from these apertures may act in a contrary direction to that in which the
recoils, and thereby tend still further to diminish its backward motion. In
this case I form on the outside of the piece hollow chambers or guards,
which deflect the issuing gases, and give them the same direction as the
"other portions which are emitted from the muzzle."
"
In order that this modification may be fully understood, I have shewn a side
view thereof at Figure 6, taken at, right angles to the longitudinal section
thercof, shewn in Figure 7; a cross section is also shewn at Figure 8, taken
on the line E, F, of Figure 7. e, e, are openings or passages formed in the
bore of the gun, at right angles to it; these passages are angular, the parts e**
being, almost parallel with the bore of the gun. f. f, are hollow chambers or
guards, for the purpose of deflecting the emitted gases, and thereby preventing
any injury to the gunners by the emission of gases from their own gun.
It will be readily understood that in this modification of my Invention the
recoil of the piece of ordnance will be diminished, partly from the diminished
volume of gases under pressure escaping from the muzzle of the gun, and
partly from the reactive force exerted by the emission of the gases from the
orifices being in an opposite direction to that in which the recoil takes
place.
"When applying this improvement to guns already constructed, holes may
"be made in them at right angles to the bore, and inclined channels may be
made to communicate with them, and a ring or hoop of wrought iron
be forced over the holes first named; the issuing gases will then take the
"direction of the inclined channels, and by the reactive force of the gases
lessen the recoil of the piece; a guard plate may be fixed near the trunnions,
whereby the emitted gases will be deflected."
This mode of altering guns already constructed so as to lessen the recoil
thereof is shewn on the annexed Sheet of Drawings; where Figure 9 is a side
view, taken at right angles to the longitudinal section, shown in Figure 10-

page_text: and Figure 11 is a cross section on the line G, H, of Figure 10.' is a wrought-
iron hoop, bored out to fit accurately the conical exterior of the gun, the
muzzle being reduced in size to admit of the hoop h being passed over it;
the dotted lines shew the original shape of the muzzle. n, n, are holes made in
the sides of the gun, into which wide but shallow channels's, s, are made. The
hoop h is made red hot, and then driven on to the gun, so that the shrinking
of it while cooling will bind it very tightly to the gun; the hoop passes over
the openings n, n, and partly over the channels s, s, as shown by dots, and
thus the elastic gases in escaping are made to take a direction nearly parallel
with the bore of the gun, and in a direction opposite to that which they would
have taken if issuing from the muzzle. In some cases, however, it may be
preferable to make a number of smaller holes in the gun, in a similar manner
to that represented in Figures 3, 4, and 5, the direction of the emission
apertures being either at right angles to the bore of the gun; or inclined
towards the breech or muzzle end of it.
"
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"My Invention" also ", consists in manufacturing ordnance by casting the
same of a mixture of steel and iron in suitable moulds, provided with iron
core bars for the purpose of chilling the metal; or the ordnance may be cast
"solid, and be bored out as usual; in either case the metal should be prepared
"in a manner more particularly described in a Patent bearing even date
herewith. The superior hardness of this compound and its great cohesive
"force renders it particularly suitable for the manufacture of ordnance, and
"will admit of a great diminution in the weight of the piece, so that the mode
"herein firstly described of diminishing the recoil will be found of great
"service when applied to light ordnace of this description."
Although I have herein-before mentioned that ordnance may be cast with
an iron core bar, which would add greatly to the hardness of the interior, I
nevertheless prefer to found them solid, and afterwards bore them out; and in
order that the metal may be made tough, I put the piece of ordnance after it
is cast into an annealing oven, and there keep it at a red heat for about
twenty-four hours, more or less, according to the weight of the piece, after
which time the oven is allowed to cool gradually. The way in which the steel
and iron may be melted and combined for the purposes of this Invention is as
follows:-I construct a reverberatory furnace with a hollow chamber or basin,
into which the cast or pig iron is first placed, and is there exposed to a powerful
heat, which will have the effect of melting it, and causing it to run down into
the lowest part of the basin. The steel should in the meantime receive a pre-
liminary heating in a suitable oven or heated chamber; it is then quickly
transferred to the reverberatory furnace, and plunged into the melted iron,

page_text: which will much facilitate the fusion of it, and at the same time protect the
steel so introduced from the action of the atmosphere and vapours of the
furnace; the iron itself should also be covered by flux or vitreous matters.
The quantity of steel added to the iron may differ considerably;. I have found
one-third part steel and, two-third parts cold blast Welch pig iron give very
strong and sound castings; but if it is desired to cast the piece of ordnance
very light, and at the same time very strong, I prefer to add a much larger
quantity of steel, in some cases amounting to four-fifths of the whole, or even
morc. The combination of the steel and iron may be also effected in other ways,
a mode or modes of doing which is fully described in the Specification of a Patent
granted to me for "Improvements in the Manufacture of Iron and Steel,"
dated the Tenth day of January, One thousand eight hundred and fifty-five.
Having thus described my said Invention, and the manner in which the
same is to be carried into effect, I would state that I do not confine myself to
the precise details here given, so long as the peculiar character of any part of
my. Invention be retained; but what I do claim is,―
First; the manufacture of ordnance with outlets or passages to lessen the
recoil, as herein described.
And, secondly, I claim the manufacture of pieces of ordnance by casting or
founding the same with a compound metal, composed of cast or pig iron and
steel, run into suitable moulds...
⚫. In witness whereof, I, the said Henry Bessemer, have hereunto set my
hand and seal, this Ninth day of July, in the year of our Lord One
thousand eight hundred and fifty-five.
Witness;
.B. GOBEY,
4, Old Square, Lincoln's Inn..
HENRY BESSEMER. (L.S.)