IMPROVEMENTS IN THE CONSTRUCTION OF ORDNANCE, AND IN THE PROJECTILES TO BE USED THEREWI
Year: 1862

page_text: LETTERS PATENT to William Palliser, Captain of Her Majesty's 18th
Hussars, and Brigade Major of Cavalry, of the City of Dublin, for the
Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF ORDNANCE, AND IN
"
Sealed the 8th May 1863, and dated the 11th November 1862.
PROVISIONAL SPECIFICATION left by the said William Palliser at the
Office of the Commissioners of Patents, with his Petition, on the 11th
November 1862.
I, WILLIAM PALLISER, Captain of Her Majesty's 18th Hussars, and Brigade
Major of Cavalry, of the City of Dublin, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF ORDNANCE, AND IN
THE PROJECTILES TO BE USED THEREWITH," to be as follows:-
This Invention consists in various improvements in the construction of
ordnance and projectiles, the objects of which are to afford greater strength to
the guns, and more powerful and effective firing. It is well known that the
interior or bore of the gun has to sustain a far greater pressure from the
explosion of the powder than the parts more distant from the centre, and one
of my objects is therefore to form the interior of the gun of a stronger metal
than the exterior thereof. To effect this object I propose to cast a gun of
iron, and then to bore the same with a slightly tapering bore, whose diameter
is largest at the muzzle; where I cut a few threads of a screw; I then form a
tube of twisted wrought iron, the exterior of which is tapered to fit tightly into
the bore of the cast-iron body. This tube is to be of such thickness in
proportion to its calibre that the residuary strain borne by this tube shall bear

page_text: a ratio to the strain it transmits to the surrounding cast iron, we have
found most suitably proportional to their respective co-efficients of expansion
within the elastic limit. This ratio is also modified by the effects of heat on
the several metals, which have likewise been investigated. A groove or
channel is cut around the muzzle end of this tube, on which turns a swivel-nut
or screw-washer, the periphery of which is cut with a male screw, in order
that the tube may be accurately fixed home into the breech end of the piece,
and thus acquire a perfect contact throughout its entire length. A slot is cut
in the muzzle of the cast iron, to allow of the entrance of a guiding stud on
the outer tube, the object of which is to prevent the tube from turning in the
gun, and also to ensure the holes coming opposite each other, which receive
the vent plug. The vent or touch-hole of the gun is formed by boring through
the cast-iron body and the wrought-iron tube, but not into the bore, and
inserting a tubular pin therein, which is retained in position by means of a
screwed head turning in a thread cut in the cast iron; the lower extremity
of the tubular pin is provided with a copper ring, either inserted in the pin
or resting on the bottom of the perforation, in order to effect a more perfect
fitting or contact. A small orifice communicating with the bore. The breech
end of the wrought-iron tube is closed by means of a plug, the edges of which
are cut with a screw. When desired, in order to obtain greater strength of
the interior of the piece, another tube of wrought iron may be placed over
the first, and be similarly closed by a screw plug, so as to bear its own longi-
tudinal pressure.
In some cases a third tube or more tubes may also be
applied. Or the screws for each tube may be formed in one piece to fit the
several bores, and being cut to the same pitch of screw it is obvious that the
three tubes may be closed by one operation of the triple screw or plug; this
method would be applicable to breech-loaders, thus, if each step of the triple
screw were cut with three threads, three tubes would in a breech-loader be
closed by nine threads by three turns of the handle. If there were more than
three tubes, there would be a corresponding number of threaded steps on the
screw plug, and thus each tube would do its share of the longitudinal work.
The diameter of the screw portion or breech end of each tube is to be smaller
than the-diameter of the bore of the tube, in order that the extension due to
the longitudinal strain. may not occur in the screw threads. Or, in lieu of
plugs, screw caps may be adopted, either separately or containing a series of
variously-sized threads on the same principle as the plugs. A copper washer
may be applied in the breech, into which washer the screw or plug is to be
tightened up, so as to form a more perfect union or joint of the metals,
A groove or channel is cut around the surface of the washer, in order that the

page_text: explosion of the powder may act thereon, and enlarge the periphery of the
washer, to ensure a tighter joint. The diameters of the screw plugs in all:
cases are therefore to be less than the bore of the respective tubes in which
they are inserted, excepting that of the inner tube. In small pieces of
ordnance I prefer to cut three grooves or riflings in the interior tube; these
tubes, are to be cut in the form of spirals, increasing. towards the muzzle."
I incline the bearing surface of the grooves at an angle of thirty degrees with.
the normal, and thus the bearing edges of the grooves will form parts' of the
sides of an equilateral triangle or triangles described in the gun.
The projectiles are furnished with copper or other soft strong metal studs or
buttons to enter and fit the grooves of the rifling. In cases where three
grooves are only used, the three copper plugs are in the same circular plane,*
at equidistant points on the surface of the projectile; and a ring or band of
lead is to occupy the surface of the projectile in rear of the copper studs, in
order to enlarge the diameter of the projectile, and form a soft and effective
bearing surface to travel through the bore of the piece, the iron projectile
itself never coming into contact with the metal of the gun. This shot will be
used for accurate practice at long ranges, but the lead may be dispensed with
for rough work, the projectile being adapted for small guns.
In large guns. I prefer to cut six grooves of a similar character; these
grooves are equidistant, and when six are cut, three alternate grooves reach
further towards the breech than the others for the following reason:-When
six copper studs are applied, the remaining three are to be of a larger size, and:
to be placed further towards the rear end of the projectile, and at equidistant
points between the former studs. The rifling is to be enlarged accordingly.,
Thus it is obvious that when a heavy projectile furnished with six studs is.
discharged it becomes steadied in its passage up the gun. A channel is, formed:
round the rear end or circumference of the projectile, into which the edge of
the leaden ring may be turned down in order that the force of the explosion!
may tend to tighten and press down upon the lead, and so avoid ripping it off
the projectile. Another slight bevil is undercut in the iron in front of the
leaden band, in order that the lead may be turned down to avoid its being
blown off from the front. The cast-iron rear end of the projectile is enlarged
so that only a small portion of the pressure of the powder can come around it,
and
press upon the lead. The surface of the lead may have corresponding
spiral projections to suit the rifling.
With regard to the mode of manufacturing the guns according to the
principle of my Invention, I should propose in some cases to cast the outer
portion or body of the gun on to the tube or tubes, which would afterwards

page_text: have another tube inserted into them. When casting upon a tube I propose
in some cases to form the tube with projections thereon, in order that the tube
may bear some portion of the longitudinal strain. This tube will be formed
with the fibres of the iron running longitudinally; the inner ones will be
twisted. In some cases I propose, when using extra tubes to place them on
in sections or divisions, in lieu of a complete tube; and I propose àlso, when
desired, to place some iron rings over the tubes at the breech end for extra
strength. The power of a gun's resistance to tangential strains is diminished
by the cross strain placed at the same time on the metal by the longitudinal
work. The inner tubes will be entirely relieved from the latter strain, since
they will. abut against the cast-iron breech of the gun. I do not limit myself
to the application of twisted wrought-iron tubes to cast-iron ordnance, as
I propose to apply them to gun metal or other ordnance.
When using three tubes, I propose in some cases to make the outer tube
of soft German steel, as the power of resistance of this metal within the
elastic limit is double that of wrought iron, and its extensibility within this
limit is almost as great.
In very large guns I propose that the innermost tube shall be made of the
softest and most ductile wrought iron, such as Bradley's L charcoal iron, the
next to be of a stronger and harsher nature, and the third, for some distance
from the chamber, of German steel. These tubes should merely fit each
other accurately, and the whole tube should be fired with a charge equal to
any that the gun when completed will have to withstand. The tube will
during this proof abut against some substance to prevent the breech blowing
off. The bore of the inner tube will then be found to be very slightly enlarged,
and is then to be rebored up to the proper size, rifled, and the whole placed in
the gun. The tubes will be found to have become immoveably fixed in each
other, and thus a useful strain will be placed on each. This strain or set in
the inner tube will never be increased by an equal charge, even were the tube
not placed in the gun.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of November, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-sixth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Palliser, Her special licence that I, the said William Palliser,
my executors, administrators, and assigns, or such others as I, the said
William Palliser, 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 "IMPROVE-
MENTS IN THE CONSTRUCTION OF ORDNANCE, AND IN THE PROJECTILES TO BE USED
THEREWITH," upon the condition (amongst others) that I, the said William
Palliser, 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 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 William Palliser, do hereby declare
the nature of my 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:-
My general principle for the construction of ordnance consists in forming
the barrel of concentric tubes of different metals, or of the same metal
differently treated, so that as nearly as possible, owing to their respective
ranges of elasticity, when one tube is on the point of yielding all the tubes
may be on the point of yielding.. It thus differs essentially from the method
hitherto prevalent of equalizing strains on concentric tubes by placing an
initial or permanent strain on the exterior ones. Since the power of any
substance to resist an impulsive strain is measured by the product of the
resistance it offers while stretching into the distance through which it can
stretch, and since the interior surface of a gun stretches most; it will follow
that an extensible substance at the interior of a gun will offer the greatest
resistance to the impulsive pressure of the discharge, while it will evoke the
greatest amount of assistance from the exterior portions of the gun; I there-
fore make the interior of the barrel of a tube of the most ductile wrought iron
coiled round a mandril, so that the grain or fibres of the iron may run circum-
ferentially or spirally. The next tube I construct in the same manner, but

page_text: of a harsher and less extensible iron, which, however, offers more resistance
within its limits of elasticity than the metal of the interior tube; over these
I place a tube of coiled sheer steel or of steel that can be welded, and
increase the strength of this tube by tempering it at a medium heat in oil.
This mode of treatment greatly narrows the limits of elasticity of the steel,
but it increases its modulus of elasticity, i. e., its powers of resistance within
this limit to a very high degree. Thus, should two or more concentric tubes
of steel be employed, the inmost tube would not be tempered, the next would
be tempered at a low heat, and the next at a higher heat, and so on up to
about a straw color. Also, should a single thick tube of steel be employed,
the whole tube would be tempered to about a straw color. A red-hot iron
cylinder would then be placed inside in order to reduce the temper in such a
manner that the original temper should remain on the outer part of the tube,
and from thence be gradually reduced until it was completely removed at the
interior surface. I consider that a barrel constructed on the above men-
tioned. principles, and of a thickness equal to the radius of the bore, will be
amply strong enough to resist the tangential strains of the discharge of a gun
of any size. These combinations of strength would only be required for a
certain distance from the breech end of the barrel; I therefore, for the sake
of economy, make the fore part of the barrel of a thick single-coiled tube or
solid forging.
For ordinary guns, up to a seven-inch or hundred-pounder rifled gun, such
a combination of strength would not be requisite, for a coiled wrought-iron
tube of a thickness equal to one-third the diameter of the bore is far stronger
than any cast-iron gun, whatsoever its thickness of metal, of the same calibre,
since, however thick a homogeneous gun, more than half the tangential strain
placed upon it by the internal fluid pressure of the discharge is borne by the
metal at the interior of the gun to the depth of one-third the calibre, also
more than one-third of the total pressure is borne by the interior metal to the
depth of one-sixth the calibre. For these guns, a single coiled tube or a com-
pound tube composed of two wrought-iron coiled tubes of a thickness equal
to about the radius of the bore would be amply strong.
I have ascertained by experiment that a wrought-iron tube formed of what
is termed a solid forging, or formed so that the grain runs longitudinally, is
useless for the purpose of adding strength to a cast-iron gun, since its resist-
ance to an impulsive internal pressure does not exceed that of cast iron
itself; I thus make my barrel or tube strong enough of itself to support the
tangential strains of the gun. A gun, however, requires longitudinal strength,
weight, exterior form, such as trunnions, &c., and for these purposes I employ

page_text: cast iron, as it is cheapest and easiest of manufacture. The principle
enunciated at the commencement will be satisfied as nearly as possible with
a single coiled wrought-iron tube in. a cast-iron gun. when the thickness of
the tube is about equal to the radius of the bore, since, owing to the
ranges of
their respective limits of rupture, it will be found that even with this thick-
ness of tube the strain transmitted to the cast iron would generally produce
rupture before the wrought iron yielded. For smooth-bored round shot guns,
up to a 9-inch or one hundred-pounder, a thickness of one-third the calibre
will be found ample for the coiled internal tube.
The next part of my Invention relates to the method of closing the breech
end of the barrel, and of guns generally. I make the barrel thicker at the
breech end, and run a female screw thread into it, so that the distance from
the bottom of the screw thread to the exterior of the barrel should be at
least equal to the thickness of the remainder of the tube. I then screw in.a
plug. I further make the metal of the tube slightly overlap the face of the
breech plug all round it, and thus prevent any escape of gas, much on the
principle of Bramah's collar. When two or more, concentric tubes are .em-
ployed, I close each of them by a separate plug, as already described, with the
exception of the metal of the tube overlapping the face, which will only be done
to the interior plug. Each plug is made to bear up or press against the plug
in front, and thus each tube performs its own share of the longitudinal work.
I may connect the several plugs by means of a pin screwed through them all,
and thus prevent any chance of any of the tubes slipping forward.
.
The last part of my Invention relates to projectiles and rifling; these I
make cylindro-conoidal in form, whether for use in smooth-bored or rifled
guns, and make them smaller in the cylindrical part than the bore of the gun,
in order to allow for windage and easy loading. In order to prevent the
ballotage or jumping about in the bore consequent on this windage, I have
two rows of studs, one on the front and the other on the rear of the cylindrical
part of the shot; these studs project very slightly from the surface of the shot,
and thus make an easy accurate fit to the bore of the gun. These studs may
be formed of copper, gun metal, zinc, or other alloy, screwed or countersunk
into the shot, or they may be merely bumps or swellings cast on the shot itself,
and turned down accurately afterwards. For use from smooth-bored guns, I
throw the centre of gravity in these shot forward by casting them hollow in the
rear, as described in my Provisional Specification of 20th July 1854, No. 1597,
and I may or may not have undercut flanges on the surface, in order. that the
resistance; of the air may impart a spinning motion to the shot..
With regard to rifled 'guns, I propose to have three grooves formed in such a

page_text: 'manner; that were the bore of the gun laid out flat they would become arcs
of a circle, whose radius would be fixed by the length of the bore of the gun
and the final angle of rifling required. For a short distance towards the
muzzle the rifling would be straight lines, which would be tangents to the
curves, and thus inclined at the required' angle. The shot will have three
copper or gun metal studs screwed into it nearly round the centre of gravity;
.the rifled grooves will only extend down the bore of the gun to such a distance
as that their lower ends may coincide with the position of the studs upon the
shot when it is home. The gun will thus be a smooth bore for the space
occupied by the powder, the wad, and half the length of the projectile. I
'may adopt two rows each of three studs in order to obtain a double bearing.
The studs of the front row will be made smaller than those in the rear, which
are made to fit the grooves; thus. the reverse edges of the grooves are common
tangents to the studs when the shot is home, and the driving edges become
tangents when the shot reaches the straight rifling towards the muzzle. For
firing at iron plates I form the shot of wrought iron; I then make a ring of
coiled shear steel; this I weld on and round to the fore part of the shot, and
'afterwards temper it at a straw color. This ring will cut through the iron
plate, and also prevent the wrought-iron shot from bursting out at the fore
part, and thus prevent an alteration of figure of the shot.
I shall now proceed to describe how I propose to apply the general prin-
ciples of construction, which form the first part of my Invention, to particular
cases. First, with regard to cast-iron guns already made, I propose to bore
them up: until their thickness of metal at the breech end be about equal to
the radius of this new bore. I then make the bore slightly taper, larger
towards the muzzle, and insert the tube or tubes previously described, whose
exterior surface is tapered correspondingly. A hollow screw nut or washer
round the muzzle of the tube screws into the cast-iron gun, drives the tube
home, and retains it in its place; or I may accomplish this by means of a
.screw plug passing through the breech end of the cast iron into the tube.
Secondly, I may bore out the cast-iron gun towards the breech end somewhat
in the form of a soda water bottle; the tube will fit the bore towards the
muzzle, but will be too small towards the breech end. I then heat the cast-
iron gun to about 1000° Fahr., and pour in gun metal or other suitable alloy
through an aperture, which may afterwards contain the vent peg. This metal
will fill up the space round the tube at the breech, and prevent it from
'shifting. Thirdly, in constructing guns, I may cast the guns over the tube or
barrel; this will be raised to about 1000° Fahr. when put into the mould.
The cast iron will be poured into the mould at the bottom; it will run in at

page_text: a tangent to the inner circumference of the mould, thus the metal will flow
round and round the tube as it rises. Since wrought iron has an excess. of
expansion when heated over cast iron, the metal at the inner surface of the cast
iron will when cold be loose round the tube; it will, however, in its turn be com-
pressed by the contractions of the surrounding cast iron, and thus made to bind
round the wrought-iron tube. Were the tube not heated, the pressure on the
cast iron would be excessive, and it would split under the increased strain of
the discharge; and, furthermore, the metal at the interior surface would
become chilled, and thus have its extensibility destroyed, and become brittle.
Moreover, heating the tube obviates all danger of the metal blowing, and
causes it to lie most perfectly round the tube. The gun complete would now
be fine-bored and finished, or an interior tube may be inserted, in the manner
already described. In casting simple cast-iron guns for the reception of tubes,
I should prefer casting them hollow over a core.
I claim the "Improvements in the Construction, and in the Projectiles to
be used therewith," substantially according to the principles I have herein
specified.
In witness whereof, I, the said William Palliser, have hereunto set my
hand and seal, this Eleventh day of May, One thousand eight hundred
and sixty-three.
WILLIAM PALLISER. (L.s.)
Witness,
ALEX³. PRINCE,
Agent for Patents,
4, Trafalgar Square,
Charing Cross.