IMPROVEMENTS IN THE MANUFACTURE OF SHOT AND SHELLS FOR RIFLED ORDNANCE
Year: 1857

page_text: LETTERS PATENT to Charles Cowper, of No. 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, Patent Agent, for the
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF SHOT AND SHELLS
FOR RIFLED ORDNANCE."-A communication from J. M. Sigourney, of
Watertown, in the County of Jefferson, in the State of New York, in
the United States of North America.
Sealed the 24th July 1857, and dated the 25th March 1857.
PROVISIONAL SPECIFICATION left by the said Charles Cowper at the
Office of the Commissioners of Patents, with his Petition, on the 25th
March 1857.
İ, CHARLES COWPER, of No. 20, Southampton Buildings, Chancery Lane, in
the County of Middlesex, Patent Agent, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF SHOT AND SHELLS FOR
RIPLED ORDNANCE," to be as follows:-
The shot or shell is made of an elongated or cylindro-conical form, and it
is cast with two or more rings or projections of larger diameter than the bore of
the gun. These rings are afterwards turned so that they may fit the bore. The
shot is also cast with ribs, which are a little larger than are required to fit the
grooves in the gun, and these ribs are afterwards planed by a machine to the
proper size and twist. The body of the shot between the rings and between
the ribs is recessed, or cast somewhat smaller than the bore of the gun. By

page_text: this means a small amount of turning and planing is sufficient to fit the shot
very accurately to the gun. The parts of the shot which come into contact
with the gun being turned and planed, the gun is not so much worn or
abraded by the shot as when the rough surface of the cast iron is allowed to
come in contact with the gun.
The shells are made in a similar manner, and may be provided with a
percussion arrangement for exploding them on their striking an object. The
shot and shells are advantageously cast with the conical part downwards, or
with the axis in a vertical position, so that the metal may be well balanced
round the axis.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed:
by the said Charles Cowper in the Great Seal Patent Office on the
1st September 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
CowPER, of No. 20, Southampton. Buildings, Chancery Lane, in the County
of Middlesex, Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fifth day of March, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Charles Cowper, Her special licence that I, the said Charles Cowper,
my executors, administrators, and assigns, or such others as I, the said Charles
Cowper, 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 SHOT AND SHELLS FOR RIFLED ORDNANCE," communicated to me from J. M.
Sigourney, of Watertown, in the County of Jefferson, in the State of New
York, in the United States of North America, upon the condition (amongst
others) that I, the said Charles Cowper, 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.

page_text: NOW KNOW YE, that I, the said Charles Cowper, 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, reference being had to the accompanying Drawing, and to
the figures and letters marked thereon, that is to say :-
The shot or shell is made of an elongated or cylindro-conical form, and it
is cast with two or more rings or projections of larger diameter than the bore
of the gun. These rings are afterwards turned so that they may fit the bore..
The shot is also cast with ribs, which are a little larger than are required to
fit the grooves in the gun, and these ribs are afterwards planed by a machine
to the proper size and twist. The body of the shot between the rings and
between the ribs is recessed, or cast somewhat smaller than the bore of the
gun. By this means a small amount of turning and planing is sufficient to
fit tho shot very accurately to the gun. The parts of the shot which come
in contact with the gun being turned and planed, the gun is not so much
worn or abraded by the shot as when the rough surface of the cast iron is
allowed to come in contact with the gun. The shells are made in a similar
manner, and may be provided with a percussion arrangement for exploding
them on their striking an object. The shot and shells are advantageously
cast with the conical part downwards, or with the axis in a vertical position,
so that the metal may be well balanced round the axis.
Figure 1 of the accompanying Drawing is an clevation of the improved
shot or shell; Figure 2 is a cross section through the line w, x, in Figure 1 ;
Figure 3 is a section through the line y, z, in Figure 1.
Many modes have been tried to make the rifle principle practical in heavy
ordnance. Lead and other soft metals have been employed as ribs or pro-
jections to fit the grooves in the gun, to impart the rotary motion to the
projectile, but have been found not to answer, especially in heavy ordnance,
for the reason that the materials had not suflicient strength for the purpose,
and were besides liable to injury in handling.
Another agency has been used to get the rotary motion, viz. the reaction
of the atmosphere on spiral wings; but this mode has met with little or no
success. The great efficiency of the minié ball has suggested the adoption
of that principle in rifled ordnance, and various plans of applying that principle
have been tried; but this class of projectiles has a very serious objection,
which is great friction. In rifled ordnance the resistance to the projectile
in passing out of the gun is greater than with the ordinary round shot and
smooth bore, in consequence of the twist of the grooves. And it must be
obvious that, if in addition to this the shot or any part attached to it in

page_text: expanded by the blast of the powder, the strain on the gun and its liability
to burst must be greatly increased. The operation may be compared to that
of an ordinary blast" in 'rock,'and 'not only this 'but the wear of the gun
must be very considerable.
68
Another mode, which consists in casting ribs or projections on the ball or
shot, has been practised. This has the objection that it is impossible to cast
them with sufficient accuracy, and the scale on the casting being rough
creates friction and wear on the gun and grooves. The Lancaster gun and
projectile, and also polygonal guns, belong to the latter class. In the former,
as the bore of the gun and the section of the ball were oval, the grooving was
not sufficiently defined to insure that the ball would not wedge and split the gun.
Now, in rifled ordnance it is of the first importance to have the projectile to fit
the bore of the gun very accurately. This I secure by casting it with belts A, A,
of a greater diameter than the bore of the gun, so that they can be turned off
to the required diameter. In order to have the ribs B also to fit the grooves
accurately, they too are cast larger than the grooves, and are planed to the
required size. In order to finish the belts and ribs in this manner I recess
the cylindrical part of the shot or shell. That part of the shot between the
belts is of a diameter somewhat less than that of the bore of the gun, so that
it does not come in contact with it, and is not finished by turning or planing.
When the gun is rifled, the grooves are accurately spaced as the ribs are on the
ball. The latter are planed by a machine purposely made, which gives them
the same spiral or twist as the grooves, thus making a male and female screw.
By this shape I secure a constant diameter to the ball, and the minimum
of windage and the surfaces in friction are smoothly finished, so that the
wear is greatly reduced. This construction insures the rotary motion to the
projectile, and the continuance of the said motion depends mostly upon the
degree of twist given to the grooves in the gun. If this is sufficient, the
rotary motion will be kept up through the whole course of the flight of the
projectile The shot is of the ordinary cylindro-conical form, and may assume
various modifications in the shape of the point or the ribs, and may also vary
as to the number and size or breadth of the ribs and belts.
Shells are made of the same exterior form, with a percussion arrangement
communicating with the powder in the cavity in the shell, to explode it on
striking the object aimed at. In manufacturing these projectiles, it is preferred
to cast them with the cone downwards, in order that the metal may be as
uniformly balanced as possible around the axis of the projectile.
Having now described the' Invention, and in what manner the same is to
be performed, I wish it to be understood that what I claim is recessing the

page_text: cylindrical part of cylindro-conical shot and shells, in such a manner that
the contact of said shot and shells with the bore and grooves of the gun be
confined to the projecting ribs B and belts A, which belts and ribs are
finished by turning or planing, or similar means, to fit the bore and grooves
with precision, substantially as set forth.
In witness whereof, I, the said Charles Cowper, have hereunto set my
hand and seal, this First day of September, in the year of our Lord
One thousand eight hundred and fifty-seven.
CHARLES COWPER. (L.S.)