AN IMPROVED PROJECTILE
Year: 1855

page_text: application for Letters Patent was not given within the time prescribed
by the Act.)
PROVISIONAL SPECIFICATION left by George Skelton at the Office
of the Commissioners of Patents, with his Petition, on the 13th
December 1855.
I, GEORGE SKELTON, of Lambeth, in the County of Surrey, Engineer, do
hereby declare the nature of the said Invention for "AN IMPROVED PROJECTILE
to be as follows (that is to say):-
My Invention, which has for its object to improve the form and construction
of projectiles, so that they may be fired from all descriptions of long range
smooth-bored guns, cannons, or mortars, without requiring any addition or
alteration to be made in them, consists of a conical or elongated cylindrical
cast-iron case or shell, with a convex or rounded base, and the upper or smaller
end made tapering, so as to decrease in size one-third of its entire length,
upon the periphery of which is formed a spiral groove or convoluted twist,
commencing at the lower side and extending round to within an inch and a
quarter of its full circumference. Within the top or smaller end of the projectile
is fitted and secured a brass tubular box or bush, and in the lower portion or
bottom of the said box or bush are formed three conical cavities or vent holes,
the base or opening of each conical orifice being within the body of the shell or
projectile, and next to the powder. Upon the top or inner surface of the lower

page_text: portion of the said box or bush the percussion cap or detonating powder is to
be placed; a plug or bolt is then screwed into the tubular cavity of the box or
bush, the upper portion of the said box or bush being tapped for the purpose
of receiving a corresponding thread upon the plug or bolt to prevent accident.
I next cause a pin to be inserted in the head of the said bolt or plug, so as to
rest upon the shoulder of the box or bush, and retain it in a permanent
position until the shell is required for use, when the pin must be withdrawn.
To exclude wet or moisture, a cast-iron cap is to be fitted over and screwed to
the box or bush, so as to enclose the several parts immediately in connection
with the explosive compounds, but which may also be removed before the
projectile is placed within the gun. In casting my improved projectile, it is
necessary that greater thickness and weight of metal may be preserved at the
top or striking end, so that the leading portion thereof may at all times be
rendered heavier than the body, even when filled or charged with the requisite
combustible materials. To increase the range and direct the flight of the
projectile when discharged, I cause the outside of the case or body of the shell
to be surrounded by a thick canvass, which serves as a wadding, and to give
a twist to the projectile in its passage, by confining the air and directing it
to act with greater force against the sides of the curvilinear groove on the
periphery of the shell.
I claim the constructing of shells or projectiles with a spiral groove or
convoluted twist upon the periphery of the case or shell, together with the
mode of forming the plug and bush for discharging the shell or projectile
by force.