THE IMPROVEMENT OF PROJECTILES USED WITH FIRE-ARMS
Year: 1857

page_text: LETTERS PATENT to Milivoï Petrovitch, Lieutenant-Colonel of Artillery,
of Belgrade, in the Principality of Servia, for an Invention for "THE
IMPROVEMENT OF PROJECTILES USED WITH FIRE-ARMS."
Sealed the 27th November 1857, and dated the 27th May 1857.
PROVISIONAL SPECIFICATION left by the said Milivoï Petrovitch at
the Office of the Commissioners of Patents, with his Petition, on the
27th May 1857.
I, MILIVOÏ PETROVITCH, Lieutenant-Colonel of Artillery, of Belgrade, in the
Principality of Servia, do hereby declare the nature of the said Invention for
"THE IMPROVEMENT OF PROJECTILES USED WITH FIRE-ARMS," to be as follows:-
This Invention is based, first, upon the principle that gases act with equal
force in all directions; and, secondly, upon the method of forcing the projec-
tiles into the barrels of fire-arms by the combined and simultaneous action of
expansion and compression of gases. It is well known that the forcing of
projectiles into the barrels of fire-arms does not depend either upon the volume
of gas used as the propulsive force or on the form or capacity of the concavity
upon which the gas acts, but upon the tension of the gases and the surface
upon which they act. To create this propulsive force it is sufficient to make
in the rear end of the projectile a small annular recess or concavity, suffi-
ciently deep to present surface enough for the gases to act upon. Now,
repeated experiments have shewn that the degree of propulsion or expansion

page_text: is the same, whether made with a projectile having a reduced annular con-
cavity, as above stated, or with a concavity without any solid part in the centre
thereof. By removing the aforesaid solid part, the volume of the gases which
enters the hollow part thus formed may be increased by these means, but there
will be no increase in their tenison or expansive power, nor of the surface
of the sides of the projectile.
Taking as a basis this. theory of the action of gases, I propose by these
improvements to combine the dilation of the sides of the projectile with their
compression by the action of the gases thereon; and this I effect by making
deep grooves around the outside of the cylindrical or largest part of the pro-
jectile and a concavity in the end thereof, and it is the combination of these
two elements of constructing projectiles which constitutes these improvements.
SPECIFICATION in pursuance of the conditions of the Letters Patent, fileḍ
by the said Milivoï Petrovitch in the Great Seal Patent Office on the
27th November 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MILIVOï
PETROVITCH, Lieutenant-Colonel of Artillery, of Belgrade, in the Principality
of Servia, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of May, 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 Milivoi Petrovitch, Her special licence that I, the said Milivoi
Petrovitch, my executors, administrators, and assigns, or such others as I,
the said Milivoi Petrovitch, 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 "THE
IMPROVEMENT OF PROJECTILES USED WITH FIRE-ARMS," upon the condition (amongst
others) that I, the said Milivoi Petrovitch, 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 Milivoi Petrovitch, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following.
statement thereof, that is to say:-
The system of projectiles constituting my Invention, and herein-after par-
ticularly described and shewn in the annexed Drawings, is based upon the
principle that gases act with equal force in all directions; also upon an
improved method of forcing projectiles into the barrels of fire-arms by the.
combined and simultaneous action of expansion and compression of the gases.
resulting from the explosion of the gunpowder.
In order to explain my said Invention as completely as possible, I now pro-
ceed to describe the best means I am acquainted with for carrying the same
into practical effect, and have attached to these Presents a Drawing illus-
trative of my improved method of forming projectiles.
Figure 1 is a longitudinal section of one of my improved projectiles, shewing
the same made with an annular concavity at A, A, and the solid portion M in
the centre thereof.
.
Figure 2 is a longitudinal section of another of my improved projectiles,
shewing the same made with surfaces at A, B, for the compression of the gases
to operate upon; C, C, a concavity reserved for expansion; L, K, deep
grooves; ✗, area of the circle of concavity; N,
direction of inertia : D,
direction of compression; G, direction of expansion.
Figure 3 is a modification of the grooves, which in this projectile are
intended to diminish as they approach the point thereof. V, V, is a recess or
step formed in the interior of the cavity.
Figure 4 represents a somewhat similar projectile to that last mentioned,
but differing therefrom by having a cavity R formed therein; the solid part
exhibited at the other Figures being entirely removed at this last-mentioned
Figure.
I would first remark, that practice has determined that the forcing of pro-
jectiles into the barrels of fire-arms does not depend either on the volume of
gas, nor on the form or capacity of the concavity upon which the gas acts, but
wholly on the tension of the gases and the extent of surface upon which they..
act.
To create this propulsive force I make in the projectile a small annular con-
cavity of sufficient depth (see Figure 1, A, A,) to present surface enough for
the gases to act upon, and repeated trials have shewn that the degree of pro-..

page_text: pulsion or expansion is the same, whether the experiment be made with a
projectile having a reduced concavity, as at Figure 1, A, A, or with the
concavity without the solid part reserved in the centre, as in Figure 4, R.
By cutting away this solid part the volume of the gases precipitated into
the hollow part may be increased, but there will be no increase in the tension
or expanding power, nor of the surface of the sides of the projectile. Taking
as a basis this theory of the action of gases, I have combined the dilatation of
the sides of the projectile with their compression by the action of the gases.
For example:-In Figure 2 the gases act with the same force upon the
hinder surfaces A, B, as upon those of the concavity C, C. The arrows G and
D indicate this action. The arrow N shews the inertia diametrically opposing
the force, the direction of which is shewn the arrow D, perpendicularly or
obliquely, according to the angle of the sides shewn by the arrow. G. From
this combination it results that if the sides of the projectile as high up as the
concavity extends are divided by deep grooves, see Figure 2, letters K, L, both
compression and expansion will operate simultaneously in forcing the projectile
forward. As a basis of proportion I take the area of the circle of the pro-
jectile, and giving to the sides A, B, Figure 1, more surface than to the area
of the circle X, separated from the sides by the concavity, I thus compel the
gases to act with greater power on the sides A, B, than on the circle X; con-
sequently the pressure being greater on the surface A, B, than on X, the
tearing or rending of the projectile becomes impossible, and renders the
projectile for the purposes of transport as solid as the massive ball.
The form and arrangement of the grooves can be varied, increased, or
diminished in number or depth, sometimes by gradually decreasing the latter
as they approach the top or point of the ball, or otherwise. The concave parts
may also be varied by being more or less reduced, or by being made perfectly
concave, as at Figure 4; also a recess or step may be formed in the cavity, as
at Figure 3, V, V.
All these arrangements I have found produce excellent results in firing, in
consequence of their being based upon the principle of simultaneous com
pression and expansion. My improved projectiles possess a decided superiority
over all those hitherto made with concavities, as well as over all the solid ones
forced and expanded by manual means, whilst they fulfil all the conditions and
requirements of a first-rate military ball.
My improved projectiles are simple in their construction, easy to cast, and
applicable in all circumstances of warfare,
A fire-arm is loaded with this ball in the same way as with a spherical ball;
it has nothing attached to it to complicate its manufacture, neither is it put up

page_text: into cartridges. It can be fired with any charge of powder without tearing or
rending, contrary to other balls having a cavity. By my improvements, the
greater the charge of powder the greater the compression, and consequently
increased solidity. My improved projectiles are equally resisting at any solid
base, and their weight is nearly the same, an important condition where great
range and precision are required. By my improved method of making pro-
jectiles they are not able to get out of shape by being carried about or in
loading or firing, and they possess the same advantages whatever may be the
calibre of the arm they may be used with.
Having now described the nature and object of my said Invention, I
claim,-
First, the union of two elements hitherto only used separately in the manu-
facture of projectiles, namely, deep grooves and cavities..
Secondly, the forcing of projectiles into the barrel of a fire-arm by simul-
taneous compression and expansion produced by the action of the gases only,
thus giving to balls capable of expansion the solidity and strength of a massive
solid ball, without any other agent or accessory than the said gases.
In witness whereof, I, the said Milivoi Petrovitch, have hereunto set my
hand and seal, this Nineteenth day of November, in the year of our
Lord One thousand eight hundred and fifty-seven.
Witness,
JOHN PIDDINGTON,
Patent Agent, Brussels.
MILIVOI PETROVITCH. (L.S.)