IMPROVEMENTS IN PROJECTILES FOR CANNON AND FIRE- ARMS
Year: 1853

page_text: LETTERS PATENT to William Hurt Sitwell, of Sydenham, in the
County of Kent, Esquire, for the Invention of "IMPROVEMENTS IN
Sealed the 20th October 1853, and dated the 28th April 1853.
PROVISIONAL SPECIFICATION left by the said William Hurt
Sitwell at the Office of the Commissioners of Patents, with his
Petition, on the 28th April 1853.
I, WILLIAM HURT SITWELL, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN PROJECTILES FOR CANNON AND FIRE-
ARMS" to be as follows:-
My Invention has for its object, firstly, the giving to a projectile or
fire-arm, when forced from any description of cannon, greater accuracy
of flight, by causing it to rotate on its axis by a peculiar construction
of the projectile itself. Secondly, the giving to a projectile fired from
any description of cannon or fire-arm, greater accuracy of flight and
increased length of range; also by a peculiar construction of the pro-
jectile itself, although it does not rotate on its axis as aforesaid.

page_text: 1 effect the above objects as follows:-I make my projectiles of an
elongated conical form, nearly similar to the improved balls now making
for rifled muskets. Firstly, through the axis of these projectiles I form
a circular passage or throat, through which, during the flight of the
projectile, the air passes; and I cause the same to rotate by placing in
the said passage or throat a small segment of a screw thread, which,
whether counter sunk as a female screw, or as a male screw raised,
upon the surface of the throat, or by the introduction into the throat
of a small portion of a spiral fan, compels the projectile to rotate on
its axis by the force of the air acting upon the said screw arrangement.
By this rotatory motion I attain improved accuracy of flight for my
projectile, as if it was fired from a rifled barrel; at the same time, by
the absence of resistance of the air on the point of the projectile, and
also by there being little or no vaccuum in its rear, the range of my
projectile is much increased. Secondly, I omit the screw arrangements
in the throat of my projectile, believing my Invention to have great
value even when the throat is plain. Over the throat of my projectile,
(whether it has a screw arrangement in it or not,) I place an iron or
other wad or button in the top of the chamber in rear of the projectile,
which button is slightly fastened to the projectile where the throat
terminates in said chamber. This wad or button protects the throat of
the projectile till the projectile is clear of the cannon or fire-arm; and
then becoming powerfully acted on by the air, the said button is forced
back, and disengaged from the projectile. I make my projectile with a
nearly similar chamber in its rear as the improved Woolwich ball for
rifled muskets, so that the force of the powder alone expands the pro-
jectile when made of any yielding metal, such as lead; but I make no
claim whatever to this portion of the construction, I merely adopt this
to my other objects.
The better to explain the nature of my Invention, and the modes
whereby I carry it out, I have attached to this Specification Drawings
No. 1, & 2. No. 1, shows a musket ball with one of my modes of im-
proved construction, with a screw arrangement; No. 2, the same with
a plain air passage; both show the wad or button covering the air
passage. But I do not confine myself to these exact details, provided
only that the general principle of my Invention be adhered to.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Hurt Sitwell in the Great Seal Patent
Office, on the 28th October 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
WILLIAM HURT SITWELL, of Sydenham, in the County of Kent, Esquire,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of April, in the year
of our Lord One thousand eight hundred and fifty-three, in the six-
teenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Hurt Sitwell, Her special
licence that I, the said William Hurt Sitwell, my executors, adminis-
trators, and assigns, or such others as I, the said William Hurt
Sitwell, 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 Inven-
tion for "AN IMPROVEMENT IN PROJECTILES FOR CANNON AND FIRE-ARMS,"
upon the condition (amongst others) that I, the said William Hurt
Sitwell, 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 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 Hurt Sitwell, 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 (that is to say):
My Invention consists in, and has for its object, firstly, the giving to
a projectile, when fired from any description of cannon or fire-arm,
greater accuracy of flight, by causing it to rotate on its axis by a
peculiar construction of the projectile itself. Secondly, the giving to
a projectile fired from any description of cannon or fire-arm greater

page_text: accuracy of flight and increased length of range; also by a peculiar
construction of the projectile itself, although it does not rotate on its
axis. And I effect the above objects in the following manner and by
the following means, that is to say:-I make my projectiles of a
truncated cylinder cone-headed form, and somewhat similar to the
improved balls now making at Woolwich for the rifled muskets.
Through the centre of these projectiles, and in the direction of their
length, I form a circular passage or throat, of either of the forms
exhibited by the Drawing at Figures 1, 2, 3. I do not, however,
intend to limit or confine myself to the precise forms there exhibited,
but have only given them as examples of the means by which said
my
Invention may be carried into practical effect. And I employ the said
passage or throat for two purposes; first, to get rid of the vacuum
at the rear of the projectile; and secondly, to assist in keeping the
projectile in its proper course during its flight after it leaves the cannon
or fire-arm from which it is discharged, by reason of the atmospheric
air being compelled to pass through the said passage or throat. And I
cause said projectile to rotate on its axis at right angles to and during
its line of flight by rifling the same, which I effect by introducing into
said air passage or throat a small segment of a screw thread or helical-
shaped projection. Or the sam result may be obtained by forming a
helical-shaped groove or recess, similar to the thread of a female screw,
in the interior of the aforesaid air passage or throat, or any other
similar form of screw, helix, spiral, or rifled arrangement or contrivance
by which the rotation of the projectile on its axis can be effected, by
the pressure of the air acting thereon as it passes through said air pas-
sage or throat. And by thus imparting rotatory motion to the projectile,
I am enabled to attain greater accuracy of flight thereof than is the
case with projectiles as hitherto constructed. And further, by the absence
of resistance of the air upon the point of the projectile, and also by
causing a current of air to pass through said projectile, I destroy or
prevent, entirely or nearly so, the formation of a vacuum in the rear of
the projectile, and thus increase the range thereof very considerably.
And in order to explain my said Invention as completely as possible,
I now proceed to describe the best means I am acquainted with for

page_text: carrying my said Invention into practical effect, reference being had to
the illustrative Drawing hereunto annexed, and to the numerical figures
and letters of reference marked thereon respectively as follows:-
DESCRIPTION OF THE DRAWING.
Figure 1, exhibits a transverse and vertical section of a musket ball,
or other "small arm" projectile, constructed according to my said
Invention. Figure 2, shews a musket ball or projectile with a plain
passage through the same, and without the screw arrangement before
mentioned and exhibited at Figure 1. Figure 3, shews another form
of construction of musket ball, or other "small arm" projectile, same
being formed with what I call an expanding throat, rifled or formed
with a screw or helical-shaped groove or projection, similar to that
before mentioned and represented at Figure 1. Figure 4, shows
another form of construction of musket ball, or other "small arm"
projectile, in which the throat thereof is formed, rifled and of a
different form to that lastly above mentioned and exhibited at Figure 3.
Figures 5, 6, 7, exhibit wads to be used in combination with the
before mentioned projectile, for the purpose of covering and tem-
porarily closing the aperture in the rear of the projectile whilst the
powder is acting thereon. Figure 8, is a transverse and vertical
section, and Figure 9, is an outside view of a projectile for cannon,
shewing the rifled air passage or throat and windage ring thereof.
Figure 10, is an elevation, and Figure 11, an edge view of a plain wad
to be used in combination with the lastly above mentioned projectile.
Figure 12, is an elevation, and Figure 13, an edge view of a wad, con-
structed with a plaited ring of oakum or or other material, for the pur-
pose herein-after stated; and Figure 14, is a transverse and vertical
section of a war-rocket, constructed with an air passage or throat accord-
ing to my said Invention. At each of the foregoing figures, I employ
similar letters of reference to denote corresponding parts, in so far as
such parts appear or can be seen at each of the Figures respectively.
At Figure 1, A, marks the point or front end of the projectile B, the
rear end thereof, in which a recess b, is formed; C, an air passage
or throat formed with a helical projecting piece c, the pitch of which

page_text: may be either quick, as denoted by the red lines, or slow, as represented
by the black lines at c. D, is a wad or button of lead, iron, or hard
leather, or card or other material, the face whereof is placed against
the seat of the projectile to which it is temporarily fixed. The effect
of a projectile thus constructed, when placed within a rifle or other
fire-arm, is as follows:-The powder which is in the rear of the pro-
jectile, upon its being exploded, will exert its force against the wad or
button D, and rear end of the projectile, until the said projectile leaves
the barrel or bore of the rifle or other fire-arm, after which time the
pressure from the powder will cease to be exerted upon the wad or
button; and as the projectile passes through the air, the wad will be
removed from the orifice by reason of the pressure of the air thereon
as it enters into the air passage or throat in its endeavour to pass
through the same. At the same time the inclined plane, or helical-shaped
projection, groove, or channel, in the throat of the said projectile, offer-
ing resistance to the passage of the air, will have the effect of imparting
rotatory motion to the projectile upon its axis, and thereby improve the
accuracy of its flight. And I would here remark that, although I
consider the causing of a projectile to rotate upon its axis to be a
great improvement in the projectile, still, however, I do not intend to
limit or confine myself to the constructing of projectiles, rifled or with
inclined planes, or a helical shaped projection or projections, grooves or
recesses, in the air passage or throat thereof, as, by constructing pro-
jectiles with a plain hole only through, the same will be found a great
improvement in the flight thereof, when compared with other projectiles
as hitherto constructed, and formed without a hole through the same.
And as regards the modified forms of the projectiles exhibited at
Figures 2, 3, and 4, the difference consists simply in making the air passage
or throat C, expanded or larger at one part than another. And as regards
the projectile for cannon exhibited at Figures 8, 8, and 9, 9*, it
differs in its construction from those above described in the following
respects; that is to say, instead of making the outer surface thereof
plain as at Figures 1, 2, 3, 4, I form a groove or recess d, around
and about the same, near the rear end of the projectile, as at Figures 8,
and 9, and into this recess I place a ring e, of oakum or other material

page_text: in a bevilled neck as shewn in the Drawing, which I call a "windage
ring," and employ for the purpose of enabling this part of the pro-
jectile to fit and adapt itself closely to the bore of the cannon. In other
respects the construction of this projectile is similar to those herein-
before mentioned and described, excepting that, instead of making the
wad or button as before described, it may in practice be found desirable,
and more economical in the construction of large projectiles, to employ
a plaited oakum ring placed in a groove or recess, formed around the
edge of the wad or button as exhibited at Figure 13; said ring
should be made sufficiently large in diameter to fit into the conical-
shaped recess b, so that when pressure is exerted upon the wad or
button by the explosive force of the powder, the oakum ring will be
forcibly pressed or squeezed into the conical recess, and thereby form
an air-tight joint or covering over the end of the air passage or throat.
And in constructing large projectiles for cannon, I cast them of iron in
a mould of suitable shape, in a somewhat similar manner to that
usually practised; and in constructing small projectiles for muskets and
such like small fire-arms, I cast or otherwise press them out of lead, in
a mould of suitable shape, in a somewhat similar manner to that
usually practised. And as regards the war rocket exhibited at Figure 14,
the construction thereof according to my said Invention is as follows;
that is to say, in the same manner as war rockets are at present con-
structed, only having the difference of a metal cylindrical tube intro-
duced in the centre to form the air throat, and the stick to have a
forked end as in Figure 14, where it joins the rockets, to allow of the
fire from the interior cone of the rocket to escape, with the usual effect
for the projection of the rocket which it now has.
Having now described the nature of my said Invention, and in what
manner the same is to be and may be performed, I declare my
Invention of "An Improvement in Projectiles for Cannon and Fire-
arms," to consist in, and I claim, firstly, the forming such said projectiles
with an air passage, throat, or opening through the centre thereof, and
in the direction of their length, with or without a wad or button,
whereby I am enabled to steady them in their flight, and to give to
them greater range. Secondly, I claim the constructing of such said

page_text: projectiles with an air passage or throat through the centre thereof,
with or without a wad or button, and the rifling of such said air passage
or throat, by constructing the same with a segment of a screw or
screws, or threads of a screw, or helical or spiral shaped projection or
recess, fixed to or formed in or upon said air passage.
Thirdly and lastly, I claim the constructing of war rockets and
projectiles generally, by forming an air passage or throat through the
centre thereof, with or without a wad or button, whether such said air
passage or throat be formed rifled or not, or with or without a segment
of a screw or screws, or threads of a screw, or helical or spiral shaped
projection or recess, in or upon the same, as herein-before particularly
described, set forth, and represented by the illustrative Drawing here-
unto annexed, and for the purposes set forth.
In witness whereof, I, the said William Hurt Sitwell, have here-
unto set my hand and seal, this Twenty-eighth day of October,
in the year of our Lord One thousand eight hundred and fifty-
three.
Witness, ALEX. PRINCE,
Patent Agent,
4, Trafalgar Square.
W. H. SITWELL. (L.S.)