IMPROVEMENTS IN THE MANUFACTURE OF GUN COTTON CARTRIDGES FOR CANNON AND SMALL ARMS
Year: 1865

page_text: LETTERS PATENT to Julian John Révy, of No. 28, Grosvenor Street,
Eaton Square, in the County of Middlesex, Civil Engineer, for the
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF GUN COTTON
CARTRIDGES FOR CANNON AND SMALL ARMS."
Sealed the 31st October 1865, and dated the 10th May 1865.
PROVISIONAL SPECIFICATION left by the said Julian John Révy at the
Office of the Commissioners of Patents, with his Petition, on the 10th
May 1865.
I, JULIAN JOHN REVY, of No. 28, Grosvenor Street, Eaton Square, in the
County of Middlesex, Civil Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF GUN COTTON CAR-
TRIDGES FOR CANNON AND SMALL ARMS," to be as follows:-
In manufacturing gun cotton cartridges it has before been proposed to
make the charge of gun cotton occupy a chamber or space greater than its
own bulk, and it has been found that when using gun cotton in the shape of
gun cotton yarn, or roving, or thread, or spun into braiding, or woven into
other desirable shape, or cotton muslin converted into gun cotton muslin, that
good results may be obtained by employing a charge of about th to th of
the weight of the ordinary gunpowder charge in a chamber of about the
capacity of that which gunpowder would occupy, the definite measure of the
chamber for the explosion of the gun cotton charge being secured by a stiff
centre composed of a tube of cardboard or wood, or being secured by other
suitable means, so as to prevent the gun cotton charge being compressed into
a smaller bulk, as is usual. I find that such charges give good results with a
density of charge of about 12 lbs..per cube foot, that is to say, the quantity of

page_text: of
gun cotton in the chamber of the gun in proportion to the chamber to be in
the same ratio as 12 lbs. of gun cotton are to one cube foot. Now, in addition
to causing the gun cotton to occupy a space greater than its bulk, I according
to my present Invention give to the gun cotton itself a greater individual
density than could heretofore be given to it by placing tension on the yarn or
braid, or other form of gun cotton employed, when winding it around the
cardboard or other centre. The individual density of the gun cotton charge,
that it to say, the density with which the threads of the gun cotton are pressed
against each other, or the density of the substance of the gun cotton itself,
I prefer to be about 25 lbs. per cube foot. Charges of less individual density
gun cotton layers will explode at a quicker rate, the hot gases of the first
combustion being more freely admitted to spread into the substance of the
charge. If the individual density as above given be much reduced irregu-
larities of explosions will result. A great variety of mechanical means may be
used to obtain the desired density of the substance of the gun cotton charge,
the loose gun cotton roving may be first spun into a dense twine, and then
wound round a bobbin by machinery; but when it is desired to have a
uniform density throughout the mass of the cartridge, I prefer to use the
lightly twisted roving without first spinning it into twine of great density. In
making the cartridge I press the loose roving by means of a roller upon the
bobbin with such pressure as will give the required density. Winding layer
upon layer in the above manner the fibres of the gun cotton are uniformly
spaced within the substance of the charge with the proper density. Such
cartridges insure a good and uniform effect for guns in general, but on
account of the comparatively small charge of gun cotton as to weight, being
only th to th of the weight of the ordinary gunpowder charge, the effect
obtained, measured by the initial velocity of projectile, is about 33 per cent.
under the effect of the full charge of gunpowder for which the gun has been
specially adapted. Such gun cotton charges exert about the same strain
upon the gun as the ordinary gunpowder charge. When the weight of gun
cotton in the above kind of cartridge is increased to rd of the weight of the
ordinary gunpowder charge, the effect of such cartridge in general is injurious
to both the gun and to the uniformity of shooting on account of the rapidity
and consequent violence with which such cartridge will explode in the
chamber of the gun.
To be able to burn a larger quantity of gun cotton in the barrel of the
gun without any injury to the gun or to the uniformity and accuracy of
shooting, I find that subdivision of the gun cotton cartridge into at least two
Separate charges is necessary; .it is, however, not sufficient to separate the gun

page_text: cotton charge into two charges of the same kind, in dividing the charge with
paper, pasteboard, wood, or any other suitable material, but the two separated
portions of the gun cotton cartridges containing the charge must also possess
different densities, and in general also different quantities. I find that
in subdividing the gun cotton cartridges into two distinct charges the outer
charge first to be ignited in the chamber of the gun to start the projectile
should be taken at about 3rd of the full gun cotton charge with an individual
density of charge of about 20 lbs. per cube foot, the second charge, which has
to explode during the motion of the projectile through the barrel of the gun,
to contain the remaining 3rds of the full gun cotton charge with a density of
about 40 lbs. per cube foot. The two, or it might be more, portions into
which the charge is divided are separated by a cylinder of carboard or other
suitable material, the portion of the charge which is around the exterior of the
cylinder being the portion to be first ignited.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Julian John Révy in the Great Seal Patent Office on the
10th November 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JULIAN
JOHN REVY, of No. 28, Grosvenor Street, Eaton Square, in the County of
Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of May, in the year of our Lord One
thousand eight hundred and sixty-five, in the twenty-eighth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Julian John Révy, Her special licence that I, the said Julian John Révy,
my executors, administrators, and assigns, or such others as I, the said
Julian John Révy, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times there-
after 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 GUN COTTON CARTRIDGES FOR CANNON AND SMALL ARMS,"
upon the condition (amongst others) that I, the said Julian John Révy, my
executors or administrators, by an instrument in writing under my, or their, or
one of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be per-
formed, and cause the same to be filed in the Great Seal Patent Office within

page_text: six calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Julian John Révy, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-
In manufacturing gun cotton cartridges it has before been proposed to
make the charge of gun cotton occupy a chamber or space greater than its
own bulk, and it has been found that when using gun cotton in the shape of
gun cotton yarn, or roving, or thread, or spun into braiding, or woven into
other desirable shape, or cotton muslin converted into gun cotton muslin, that
good results may be obtained by employing a charge of about th to
th of the weight of the ordinary gunpowder charge in a chamber of
about the capacity of that which gunpowder would occupy, the definite
measure of the chamber for the explosion of the gun cotton charge being
secured by a stiff centre composed of a tube of cardboard or wood, or being
secured by other suitable means, so as to prevent the gun cotton charge being
compressed into a smaller bulk, as is usual. I find that such charges give
good results with a density of charge of about 12 lbs. per cube foot, that is
to say, the quantity of gun cotton in the chamber of the
gun, in proportion to
the chamber, to be in the same ratio as 12 lbs. of gun cotton are to one cube
foot. Now, in addition to causing the gun cotton to occupy a space greater
than its bulk, I according to my present Invention give to the gun cotton
itself a greater individual density than could heretofore be given to it by
placing tension on the yarn or braid or other form of gun cotton employed
when winding it around the cardboard or other centre. The individual density
of the gun cotton charge, that is to say, the density with which the threads of
the gun cotton are pressed against each other, or the density of the substance
of the gun cotton itself, I prefer to be about 25 lbs. per cube foot, that is to
say, that one cubic foot of gun cotton of this density would weigh 25 lbs.
Charges of less individual density of gun cotton layers will explode at a quicker
rate, the hot gases of the first combustion being more freely admitted to spread
into the substance of the charge; if the individual density as above given be
much reduced irregularities of explosions will result.
In making the cartridge I press a loose roving of gun cotton as it is being
wound around the stiff central tube or bobbin by means of a roller upon this
central tube, with such pressure as will give the required density; the bobbin
is for this purpose mounted on a spindle, and by causing it to revolve the
roving, which is kept at as great a tension as it will bear, is wound around it,

page_text: and at the point where the roving is led on to the bobbin a roller presses the
roving against the bobbin and gives to it the requisite density. Winding layer
upon layer of the roving upon the bobbin in the above manner the fibres of
the gun cotton are uniformly spaced within the substance of the charge with
the proper density. Such cartridges insure a good and uniform effect for
guns in general, but on account of the comparatively small charge of gun
cotton as to weight, being only th to th of the weight of the ordinary
gunpowder charge, the effect obtained, measured by the initial velocity of
projectile, is about 33 per cent. under the effect of the full charge of gun-
powder for which the gun has been specially adapted. Such gun cotton
charges exert about the same strain upon the gun as the ordinary gunpowder
charge. When the weight of gun cotton in the above kind of cartridge
is increased to 3rd of the weight of the ordinary gunpowder charge the
effect of such cartridge in general is injurious to both the gun and to the
uniformity of shooting, on account of the rapidity and consequent violence
with which such cartridge will explode in the chamber of the gun. To be
able to burn a larger quantity of gun cotton in the barrel of the gun without
any injury to the gun or to the uniformity and accuracy of shooting, I find
that subdivision of the gun cotton cartridge into at least two separate charges
is necessary; it is, however, not sufficient to separate the gun cotton charge
into two charges of the same kind, in dividing the charge with paper, paste-
board, wood, or any other suitable material, but the two separated portions of
the gun cotton cartridges containing the charge must also possess different
densities, and in general also different quantities. I prefer in all cases to
separate the charges one from the other by a strong separating medium, in
order that the ignition of one portion of a charge may not affect the density
of the other portion or portions of a charge. I prefer to divide the charge
into two portions and to employ the separating medium in the form of a
cylinder, one portion of the charge being placed within the cylinder and the
other around its exterior. The exterior charge of cartridge I arrange to be
the one to be first ignited in the chamber of the gun for starting the projectile
and should generate the full pressure upon the base of the projectile necessary
to impart to it the desired velocity, but that pressure should never be so great
as to interfere with the shape of the separating medium containing the
remainder or core charge of the cartridge, which has to explode during the
motion of the projectile through the barrel of the gun.
When a core charge
of a high density is employed the cylinder is enabled to withstand a much
greater pressure on its exterior. The quantity of exterior charge should be
limited to the strength and resistance of the cylinder containing core charger

page_text: When an excess of exterior charge is used the gases of its decomposition
compress the separating medium containing the remainder or "core charge
of the cartridge, and thereby disturb its density and mechanical construction,
which would cause irregularities and impair the uniformity of shooting. An
excess in the exterior charge may so much compress the core charge, and
thereby retards its decomposition, that it will be only partly consumed in the
barrel and the remainder blown out of the gun.
In the Drawings hereunto annexed I have shown Diagrams of three cart-
ridges constructed in the manner I prefer for carrying out my Invention.
At Figure 1 is shown, on an enlarged scale, a gun cotton cartridge suitable
for being used in a small-bore rifle; cartridges for other rifles may, however,.
be similarly constructed. Cartridges made as there shown will shoot well
both in the Enfield and small-bore guns, imparting a higher initial velocity to
the projectile than 75 grains of best rifle gunpowder. The dimensions and
quantities of No. 1 cartridge are,-
1. Exterior charge, 10 grains fine gun cotton thread braiding spun over the
charged cylinder by means of an ordinary braiding machine, 100 feet of such
gun cotton thread weighing 76 grains, using 12 bobbins each with three-fold
thread.
2. Interior or core charge 16 grains of hollow braiding made of similar
gun cotton thread. Density of core charge in relation to the space it occupies,
49.62 lbs. per cube foot. I prefer to employ braiding for the core charge so
that the requisite weight of charge may be readily obtained by cutting off a
regulated length of braid, but the requisite weight may be otherwise obtained.
3. Separating medium of both charges, a cylinder made of best and
strongest paper, the layers of which being glued together and of the following
dimensions: Bore of cylinder 0.26", outer diameter 0.365", length 2.00".
The cartridges are constructed in the following manner :-The cylinders for
separating the charges are cut off from tubes manufactured from layers of
strong paper coated with glue and wound around a mandril. On two opposite
sides of the mandril are rollers which are pressed towards it by springs, so
that whilst the layers of paper are being wound around the mandril they are
firmly pressed together by these rollers. After the cylinders have been
removed from the mandril they should be carefully dried, preserving their
cylindrical shape. Two small notches, such as are shewn at n, are afterwards
cut on opposite sides of one end of the cylinder, and the cylinder is afterwards
dipped into boiling wax for about two minutes to close occasional laminations
and also to protect the cylinder from the effects of damp; they should be stiff
and resisting and of uniform dimensions. The hollow braiding of 16 grains.

page_text: weight which is to form the core charge is next introduced into the cylinder,
and the cylinder, is placed into a recess in a die which it fits accurately. Two:
pistons or plungers then pass into the opposite ends of the cylinder and com-
press the braid within it to 1" length, so giving the core charge a density of
about 49 lbs. per cubic foot. The die is made in two halves so that the:
cylinders may readily be introduced into and removed from it. One end of.
the cylinder containing core charge is next plugged with a thin paper wadding,
over which about "layer of beeswax is placed so as to come flush with that
end of the cylinder; the other end has one or more notches n cut into its:
side to admit the flame of the exterior charge promptly to reach one end of.
the coro charge. The exterior of the cylinder is afterwards covered with the
braiding composing the exterior portion of the charge. For this purpose the
cylinders are in succession fed by hand into a circular braiding machine, by
which each cylinder is covered from end to end with braiding, and as soon as
one cylinder has been so covered the machine is allowed to continue working.
a short time before another cylinder is introduced into it. The covered
cylinders will thus be connected together by lengths of braiding which are.
afterwards cut through to separate the cylinders the one from the other; the
ends of the braiding are afterwards turned inwards into the ends of the
cylinder or are tied round to secure them.
The core charge of a cartridge made as above described ignites only at one
end near the bottom of the gun, and during the explosion works like a small
rocket, pushing both the projectile and the cylinder out of the gun.
Paper cylinders of good make uniformly split all along, and should not
break up nor show sign of compression, and the core charge should be con-
sumed within about 3rd length of the barrel.
The shooting of such cartridges if made by machinery is superior to best
rifle powder on account of cleanliness and uniformity of power of cartridge,
which is not impaired by damp, cold, or warm weather. A long exposure to
a damp place may temporarily interfere with the uniform performance of the
cartridge, but if only exposed to the open air it soon parts with the excess of
moisture and regains its former efficiency.
In some cases in place of forming the core charge solid as above described,
I form it as shewn in the sectional view, Figure 2, which shows a cartridge
especially adapted for the service Enfield rifle; by so forming a core charge a
more uniform pressure may be maintained upon the projectile during its
motion in the gun.
The motion of a projectile in the barrel of a gun being necessarily an
accelerated one, increasing from nil to about 1400 feet per second, the supply.

page_text: of the propelling 'gas from the core charge should also be increasing in a
similar ratio to maintain a uniform pressure.
The core of the gun cotton cartridge as represented in Diagram 1, will
supply the propelling gas at a uniform rate of speed, the core being of the
same density throughout, it will supply rather too fast at the commencement
and too slow at the end. An increasing supply of gas may be obtained from
the core charge by altering its mechanical construction, by giving the core
from its end first to be ignited a decreasing density so as to increase the
rapidity of explosion as the combustion proceeds to less dense parts of the
charge which are more freely penetrated by the blast of the explosion, but I
prefer to attain this object by proportionally increasing the burning surface of
the core as the explosion proceeds, in the manner shown in the Drawing,
Figure 2. The weight of gun cotton contained in a given length or division
of the core charge, and consequently the density of these divisions, is thus by
mechanical means made to vary from one end of the core to the other.
The dimensions and quantities of the cartridge shewn in this Figure are,-.
Bore of cylinder 0.31", outer diameter 0.45", length 1.75". The exterior
charge is made up of gun cotton braiding, 100 feet of the gun cotton thread:
weighing 76 grains, and using 24 bobbins, each with single thread; weight of
exterior charge 8 to 8 grains.
The cylinder containing core charge should be made similar to those of
No. 1 Diagram, and should be very hard and resisting, and should stand a.
pressure of 100 lbs. between two flat surfaces without altering in the least its
cylindrical shape or showing distress. The quality of the cylinder is essential
for the good performance of this cartridge. Such cylinders may be charged
with 5-fold solid gun cotton braid, such braid being produced by the braiding
machine in placing 5 successive layers of braiding one over the other, com-
mencing with 12 bobbins single thread and increasing the number of bobbins
as the additional layers are being made. 20 grains of such braid (about 2"
long) having been introduced into the cylinder it is next placed into the die
of the compressing machine, two steel pistons of 0.31" diameter compressing
the solid braid from both ends into the cylinder to 1:315 length, one of the
pistons having a conical pin projecting from its base 11" long and tapering
from a fine point to 0-16" at the base of the piston. After withdrawing the steel
pistons a conical hole m, Diagram 2, has been made into the gun cotton core
charge by the projection of the piston which a core charge of about 50 density
per cube foot will preserve; the other piston produces a flat surface on the.
core charge. The end with the hollow in the core is next plugged by first
inserting a wadding of paper, over which a layer of beeswax may be placed,

page_text: to prevent the ignition of the core from this end of the cartridge; the charged
cylinder is next covered with gun cotton braiding as above described. The
cartridge baving been introduced into the barrel of the gun with the end C
foremost it may be fired with an ordinary percussion cap, taking care that the
flame of the cap will reach the exterior charge, which will explode with great
rapidity and produce the necessary pressure to start the projectile and expand
its base into the grooving of the rifle. The explosion of the exterior charge
simultaneously ignites the end C of the core charge, from which during the
comparatively slow motion of the projectile from rest a supply of
gas is obtained
proportional to the surface of the section of the core charge. As the explosion
proceeds, and the projectile attains higher velocity, the flame will reach the
end of the hollow in the core charge, and it will suddenly spread over the new
area of the hollow of core charge. The supply of gas will now be considerably
increased, and as the explosion proceeds and. the hollow of the core charge
becomes larger as its sides burn away, a continually increased supply of gas
will be obtained, which at a certain density just meets the increasing velocity
of projectile. An increase or decrease in the length of the hollow of the
core charge is distinctly felt in the performance of the cartridge. If the
hollow or tubular part of the core would reach right through from end to end
the
gun cotton cartridge would become violent and the shooting wild.
The performance of the gun cotton cartridge, Diagram 2, is superior to the
service gunpowder charge, both for accuracy of shooting and for velocity of
projectile. At an elevation at which the service gunpowder charge of 75
grains shoots 500 yards range, the above cartridge will at precisely the same
elevation shoot to 550 yards. Reducing the length of tubular part of core
by 0-3" or increasing the thickness of the solid part of the core from 0.1"
to 0.4", the velocity of the projectile is reduced to that of the service gun-
powder charge, at the same time the shooting is not so uniform as with 0.1"
solid core; if a reduction in the velocity of the projectile should be desirable,
the quantity of the core charge should be reduced, but maintaining the same
mechanical construction of cartridge. The core charge of these cartridges
does not explode simultaneously but progressively. Six grains exterior charge
with 0.1" solid core will give good shooting, and about the same velocity as
the service gunpowder charge 75 grains, whilst the same exterior charge
with a similar core, but of 0.4", solid length, will give inferior shooting, and
the velocity of projectile will be considerably under that of the service gun-
powder charge, although the whole of the core charge is consumed in the gun,'
but its consumption is too slow, and the supply of propelling gas too late to be
effective on the projectile. All gun cotton cartridges should be made by

page_text: machinery to insure their uniformity of construction, and care should be taken
that the flame of the fulminate used for igniting charge will reach the exterior
gun cotton charge; it is also essential to insure good and uniform ignition of
charge, that the fulminate does not derange the mechanical construction of
cartridge.
At Diagram No. 3, is represented a gun cotton cartridge for fowling guns
charged into a breech-loading case of No. 12 gauge; the dimensions and
quantities of the cartridge are, bore of cylinder 0-375", outer diameter 0.500",
length 0.94"; such cylinder should stand a pressure of 40 lbs. between two
flat surfaces without altering cylindrical shape the core charge is made up of
20 grains of 7-fold gun cotton braiding and compressed into 0-7" length, the
density of core charge being 63.86 lbs. per cubic foot. The core is ignited
from both ends, and to insure such ignition promptly both ends of the cylinder
are notched. Weight of exterior charge 4 grains of fine gun cotton muslin.
It is essential for the good performance of this cartridge to prevent the escape
of the fine gases generated by the combustion of the exterior charge which
will easily penetrate common felt wadding. The wadding used next the gun
cotton cartridge should be the ordinary felt wadding boiled in wax for about
45 minutes, until the wadding is soaked through and through; such wadding
will become hard, and will be impermeable to the blast of the explosion and
prevent the blast from reaching the pellets in the barrel, which would cause
irregularities of shooting. Next the bard waxed wadding another soft one
should be used, and the remainder of the charge made up as usual, taking care
that the case does not become enlarged when the hard wadding is introduced,
which is easily prevented by slipping a metal tube over the case when charging
case. In place of the waxed felt, a thin metal disc may be used with a soft
wadding. The breech-loading cases into which gun cotton cartridges are
charged should be of denser material than those used for gunpowder, to prevent
the escape of the fine gun cotton gas through the casing, which may be soaked
in wax; for this purpose the cases should well fit the breech of the gun,
which will prevent their splitting or breaking, and care should be taken that
the fulminate of the cap will not derange the mechanical construction of the
cartridge; the fulminate ought only to produce a flame sufficient to ignite the
exterior charge of the cartridge. The above principles of construction of gun
cotton cartridges also hold good for cannon; the relative proportions of quantities
and dimensions of cartridge should meet the size and construction of such
cannon, and the object and construction of projectile. **
Having thus described the nature of my Invention and the best means with
which I am acquainted for carrying the same into effect, I would state that in

page_text: all cases I prefer to employ gun cotton manufactured from cotton fibre, but
gun cotton manufactured from other vegetable fibre may be employed,
especially for the core charges of the cartridges last described; I would also
have it understood, that I do not confine myself to the details or to the exact
proportions above given, but that what I claim is,―
First, in the manufacture of cartridges, such as herein first described, the
giving to the charge of gun cotton a greater density than heretofore, by
pressing the gun cotton charge around a cylinder by rollers, as described.
Second, the dividing the charges of gun cotton cartridges into two or more
portions of differing densities.
Third, the separating the two or more portions into which the charge of a
gun cotton cartridge may be divided by a strong resisting medium, as above
described.
In witness whereof, I, the said Julian John Révy, have hereunto
set my hand and seal, this Tenth day of November, in the year
of our Lord One thousand eight hundred and sixty-five.
J. J. REVY. (L.S.)