IMPROVEMENTS IN CANNON AND OTHER FIRE-ARMS
Year: 1862

page_text: LETTERS PATENT to Benjamin Franklin Cowan, of Memphis, State of
Tennessee, America, but now residing at the Victoria Hotel, Euston
Square, in the County of Middlesex, Gentleman, for the Invention of
"IMPROVEMENTS IN CANNON AND OTHER FIRE-ARMS."
PROVISIONAL SPECIFICATION left by the said Benjamin Franklin Cowan
at the Office of the Commissioners of Patents, with his Petition, on the
4th September 1862.
I, BENJAMIN FRANKLIN COWAN, of Memphis, State of Tennessee, America,
but now residing at the Victoria Hotel, Euston Square, in the County of
Middlesex, Gentleman, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN CANNON AND OTHER FIRE-ARMS," to be as follows:-
I use a loading chamber which I call a thimble, because it has the general
shape of a thimble, being a hollow tube open at one end, that towards the
muzzle of the gun, and closed at the other end, that towards the breach of the
gun, and presenting to the contained charge a concave, dome-like or spherical
internal surface. The sides of this thimble taper slightly towards its open end,
and there are slits in its sides parallel to its length, and therefore to the axis
of the gun, so that the gases generated by the explosion of the powder slightly
expand the thimble, and cause a proportionate amount of friction against the
sides of the gun surrounding the thimble, which friction must be overconie
before the thimble can be stirred backwards, so that I employ the expansive
force of the ignited charge to counteract its own tendency to blow off the

page_text: breach, and this employment of the power of the exploded charge by means of
such a slit thimble is the first part of my Invention. The thimble may be also
secured in its place when the gun is loaded by any of the means ordinarily
employed in other breech-loaders. The charge may be exploded in any of
the usual ways, but a second part of my Invention consists of the nipple or 5
other conductor of the spark to the powder being so placed or so arranged
that the charge is ignited at its front portion instead of its rear, so that no
portion of the charge can be blown out of the gun without being ignited.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Benjamin Franklin Cowan in the Great Seal Patent Office
on the 18th February 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BENJAMIN
FRANKLIN COWAN, of Memphis, State of Tennessee, America, but now residing
at the Victoria Hotel, Euston Square, in the County of Middlesex, Gentle-
man, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourth day of September, 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 Benjamin Franklin Cowan, Her special licence, that I, the said
Benjamin Franklin Cowan, my executors, administrators, and assigns, or such
others as I, the said Benjamin Franklin Cowan, 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 CANNON AND OTHER FIRE-ARMS," upon the
condition (amongst others) that I, the said Benjamin Franklin Cowan, 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 Benjamin Franklin Cowan, do hereby
declare the nature of my said Invention, and in what manner the same is

page_text: to be performed, to be particularly described and ascertained in and by the
following statement :-
I employ a loading chamber or cartridge case which I call a thimble,
because it has the general shape of a thimble. This thimble is a hollow
metallic or other suitable tube open at one end, that towards the muzzle of the
gun, and closed at the other end, that towards the breech of the gun.
In the accompanying Drawing I have shewn a section of a shape I have
found serviceable, but provided the thimble is made adequately strong, the
particular shape of its internal surface at the breech end is not material. The
sides of this thimble taper slightly towards the open end. There are two
or more slits in the sides of the thimble running from its open end towards
the breech end, but stopping at a suitable distance from the breech end, so as
not materially to diminish the strength of the breech end. These slits of
course make the sides of the thimble more or less flexible, so that the bore of
the thimble towards its open end can be expanded by an internal or contracted
by an external force. This thimble contains the whole of the charge of powder
or other explosive material, and may contain also, as may be found convenient,
the whole or the rear portion of the projectile or shot. When the explo-
sion takes place, the gases thereby generated expand the thimble, and cause a
proportionate amount of frictional pressure against the breech chamber, that
is, the inner surface of the sides of the gun surrounding the thimble, so that I
thus employ the expansive force of the ignited charge to counteract its tendency
backwards. I further secure the thimble in its place by some suitable external
application. In the Drawing I have shewn one which is suitable for large
guns. The charge may be exploded in any of the usual ways, but I prefer
the central forward ignition, and a thimble so arranged may be applied to any
of the existing breech-loading small arms which are fitted for central ignition.
For the purpose of obtaining such ignition I employ the second part of my
Invention which consists in the nipple or other conductor of the spark to the
powder being so placed or so arranged that the charge is ignited at the centre
of its front portion. When so ignited the expansion of the thimble is obtained
most rapidly, and no portion of the charge can be blown out of the gun with-
out being ignited, while the fouling is also left in the thimble, and removed
with it.
Figure 1 of the accompanying Drawings is a longitudinal section of a breech-
loading cannon loaded by means of my expanding thimble; Figure 2 is a
similar section of the expanding thimble by itself. The same letters denoto
the same parts in each Figure.
A is the breech end of the thimble; B is the elongated nibble, which is

page_text: screwed back through the conical base of the thimble; C, C, the vent; D, D,
are the longitudinal slits in the thimble; E, E, the tapering sides of the
thimble; F is a handle hinged at G, G, which may be employed for the pur-
pose of facilitating the withdrawal of the thimble from the piece; H, I, is a
wrought-iron yoke, hinged on to the trunnions I, I, with counterbalancing
weights J, J, to facilitate the raising and lowering of the yoke by means of
the handle K, for the purpose of inserting and removing the thimble. Through
the handle runs a mandril L, attached to a spiral spring in such a way as to
work back from and up against the nipple. The piece is discharged by with-
drawing the mandril as far as requisite, and then releasing it, on which it is
forced forwards by the spiral spring so as to strike and explode the cap. If it
is desired, by adding on to the mandril a stud working into a slot in the
handle, the piece can be placed either at half or full cock. N, N, is the main
body of the gun; and O, O, its bore.
Having now described the nature of my said Invention, and in what manner
the same is to be performed, I declare that I claim,―
First, the employment by means of a slit thimble or cartridge case of the
expansive force of the gases generated by the ignition of the charge, to produce
a frictional pressure between the outside of the thimble or cartridge case and
the inside of the barrel or breech chamber, for the purpose of counteracting
the backward tendency of the thimble produced by the backward pressure of
the same gases.
Secondly, the specified application of the igniting spark at the central fore
part of the charge, and this part of my Invention is applicable both for
breech-loaders and muzzle-loaders.
In witness whereof, I, the said Benjamin Franklin Cowan, have hereunto
hand and seal, this Second day of February, in the year of our
Lord One thousand eight hundred and sixty-three.
set my
Witness,
WILLIAM SHAEN,
BENJAMIN FRANKLIN COWAN. (L.S.)
8, Bedford Row, W.C.