IMPROVEMENTS IN PROJECTILES FOR ORDNANCE AND FIRE- ARMS
Year: 1861

page_text: PROVISIONAL SPECIFICATION left by William Edward Newton at the
Office of the Commissioners of Patents, with his Petition, on the 12th
February 1861.-A communication from abroad by Silas T. Burbanks,
of the City and County of Providence, in the State of Rhode Island,
United States of America.
I, WILLIAM EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane,
in the County of Middlesex, Civil Engineer, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN PROJECTILES FOR ORDNANCE AND FIRE-
ARMS," to be as follows:-
The object of this Invention is to obtain a rotary motion of projectiles, with-
out the use of rifle grooves in the bore of the piece of ordnance or fire-arm
from which they are projected, and to enable them to be projected without lateral
deviation from the smooth bored pieces in common use, and to this end this
Invention consists in the construction of the externally cylindrical rear portion
of the projectile with oblique sided cavities, of the peculiar form herein-after
specified, surrounding a conical core, whereby it is caused in its flight to have a
rotary motion on its axis imparted to it by the pressure of the atmosphere
against the sides of the said cavities. The general form of the projectile is
cylindro-conoidal, and in the front of the cylindrical portion is made a groove
for the reception of a packing of fibrous substance saturated with grease, or of
soft metal or any other suitable material. The cavities whose form constitutes
the principal feature of the Invention may be three or more in number, ac-

page_text: cording to the size of the projectile. These cavities have both sides oblique
in the same direction with respect to the axis of the projectile, but in different
degrees, the less oblique sides, which may be called the working sides, facing
toward the front of the projectile, and presenting plane surfaces, and the more
oblique sides facing toward the rear of the projectile, and having a spirally
formed surface. These cavities are open at the rear end of the projectile and
are of increasing depth from front to rear, and the bottoms are in other respects
of such form that they may be considered as portions of a conical core, the
solid metal portions left between the cavities may be considered as fins pro-
jecting from the conical core, the outer faces of such fins forming portions of
the periphery of a cylinder of a diameter equal to the full diameter of the
projectile. The front end of the cavities may be either flat and square with
the axis of the projectile, or concave so as to meet the sides and bottom with
gradual curves. The plane working sides are tangential to the core at the
rear end of the projectile, but gradually approach a radial relation to the core
towards the fronts of the cavities. The spiral sides are radial to the conical
core at the rear end of the projectile, but gradually approach a tangential
relation to the said core toward the fronts of the cavities. The degree of the
obliquity of the working sides to the axis may be varied, but it is preferable
to give the sides such a degree of obliquity as would give one revolution
in about ten feet of length. An elongated projectile made with cavities in
its rear in the manner described, will, when fired from a gun of smooth
bore have a rotary motion about its axis, caused by the pressure of the air
against the working sides as the air rushes against them, to fill the vacuum
produced in the cavities by the flight of the projectile, while the steadiness of
the motion of the projectile is greatly aided by the constant and equable
pressure of the air upon those portions of the central conical cone which
constitutes the bottoms of the cavities. The conical core is also a support to
the partitions or fins between the cavities, and prevents them from being
broken off by the pressure of the gas at the moment the projectile leaves the
gun, or by centrifugal force during the flight of the projectile.