IMPROVEMENTS IN SHELLS OR EXPLOSIVE PROJECTILES
Year: 1858

page_text: LETTERS PATENT to James Henderson, of Glasgow, in the County of
Lanark, North Britain, Engineer, for the Invention of "IMPROVEMENTS IN
SHELLS OR EXPLOSIVE PROJECTILES,"
Sealed the 21st May 1858, 'and dated the 24th February 1858.
PROVISIONAL SPECIFICATION left by the said James Henderson at the
Office of the Commissioners of Patents, with his Petition, on the 24th
"February 1858. .
I, JAMES HENDERSON, of Glasgow, in the County of Lanark; North Britain,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN SHELLS OR EXPLOSIVE PROJECTILES," to be as follows:-
This Invention relates to the arrangement and construction of explosive
shells in such a manner that their destructive effects shall be very greatly
increased in a very economical manner. A shell made according to this
Invention is duplex throughout, that is to say, it consists of both an outer and
an inner chamber, the two being accurately concentric. Both chambers are
cast in one piece at one operation; the internal shell is cast thin, and is used
solely as the chamber for the gunpowder or explosive agent to be used; it is
connected with the main external shell, which is of increased thickness, by
suitable arms or supporting pieces cast in to connect the outer surface of the
inner chamber with the inner surface of the external chamber. For the
purpose of charging the inner chamber and attaching the fuse, a commanica-
ting neck or throat piece is cast between the two shells, so that the inner

page_text: chamber is thus reached with great facility. The space between the two
chambers answers for the reception of bullets or loose missiles for increasing
the destructive effect of the shell. It is charged by an aperture on the
opposite side, both openings being closed by a screwed plug. In shells
arranged in this way the gunpowder is kept separate and clear from the other
ingredients .or details of the shell by the inner chamber, which is a most
effective separator, and the gunpowder being exploded right in the centre of
the mass, whilst a space is left between the actual exploding chamber and the
main shell, the result is that the explosion breaks up the shell on all sides, and
into a greatly increased number of pieces.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Henderson in the Great Seal Patent Office on the
19th August 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
HENDERSON, of Glasgow, in the County of Lanark, North Britain; Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of February, in the year of our
Lord One thousand eight hundred and fifty-eight, in the twenty-first year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said James Henderson, Her special license that I, the said James
Henderson, my executors, administrators, and assigns, or such others as I, the
said James Henderson, my executors, administrators, or 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 SHELLS OR EXPLOSIVE PROJECTILES," upon the condition
(amongst others) that I, the said James Henderson, 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 James Henderson, do hereby declare
the nature of my said Invention, and in what manner the same is to be

page_text: performed, to be particularly described and ascertained in and by the following.
statement, reference being had to the accompanying Drawings and to the
letters and figures marked thereon, that is to say:
My said Invention relates to the arrangement and construction of explosive.
shells in such a manner that their destructive effects shall be very greatly
increased in a very economical manner. A shell made according to this
Invention is duplex throughout, that is to say, it consists of both an outer and
an inner chamber, the two being accurately concentric. Both chambers are:
cast in one piece at one operation; the internal shell is cast thin, and is used
solely as the chamber for the gunpowder or explosive agent to be used; it is
connected with the main external shell, which is of increased thickness, by
suitable arms or supporting pieces cast in to connect the outer surface of the
inner chamber with the inner surface of the external chamber. For the
purpose of charging the inner chamber and attaching the fuse, a communi-
cating neck or throat piece is cast between the two shells, so that the inner
chamber is thus reached with great facility. The space between the two
chambers answers for the reception of bullets or loose missiles for increasing
the destructive effect of the shell. It is charged by an aperture on the opposite
side, both openings being closed by a screwed plug. In shells arranged in this
way, the gunpowder is kept separate and clear from the other ingredients or
details of the shell by the inner chamber, which is a most effective separator,
and the gunpowder being exploded right in the centre of the mass, whilst a
space is left between the actual exploding .chamber and the main shell, the
result is, that the explosion breaks up the shell on all sides and into a greatly
increased number of pieces.
And in order that my said Invention may be properly understood, I shall
now proceed to describe the explanatory Drawing which I have hereunto
appended, for the purpose of showing one modification under which my
improvements may be judiciously carried out in practice.
The Figure shown on the accompanying Drawing is a vertical section of one
modification of my improved shell or explosive projectile. In this modification
the shell is of a spherical figure, and is made of cast iron; the outer portion A
of the shell does not differ materially from shells of the ordinary kind, that is
to say, it is a hollow sphere of thick metal; within this hollow sphere is a
secondary shell B, forming a chamber to receive the exploding charge of
powder C. The inner spherical shell or powder chamber B is much thinner
in metal than the outer shell A, and it is cast in one piece with the outer shell.
The powder chamber B is arranged concentrically within the outer shell A,
and is connected thereto by means of the tubular passage D and the radial

page_text: stays or arms E. It is within the annular space, thus formed between the
inner surface of the shell A and the outer surface of the powder chamber B.
that the balls F or other missiles are placed. This annular space is charged.
with balls or other missiles by means of a tubular passage cast in the metal of
the outer shell A; this tubular passage has an internal screw cut therein, to
which is fitted a screw plug G. After the annular space between the shells,
has been filled with balls or other missiles, the plug G is screwed tightly into
the tubular passage in the outer shell, so as to secure effectually the contents
of the same.
The tubular passage D serves as a channel or duct whereby the
inner chamber B may be readily charged with gunpowder, fulminating powder,
or other explosive compound, as shown at C. The charge of powder is poured
through the tubular passage D, which is then stopped with a screw plug H;
this plug is bored longitudinally; the aperture I is, however, not carried
through the lower end of the plug. A small orifice J is made through the
metal of the plug H, in a lateral direction or at right angles to the longi-
tudinal orifice, which forms a chamber to receive the igniting fuse K. A short
length of fuse or slow match K is inserted in the longitudinal chamber I of
the plug when the shell is fired from a gun; the fuse is lighted by the
explosion of the powder, and it continues burning during the flight of the
projectile through the air. When the ignited match burns down as far as the
lateral aperture J, the fire passes through it and ignites the charge of powder C
confined within the inner shell. The particular means used for igniting the
bursting charge forms, however, no part of my Invention, the foregoing mode
is therefore only given by way of illustrating one way of effecting the object,
namely, that of firing the charge in the chamber B with certainty and within
a given time. The bursting of the charge may be regulated to take place
within a certain time after the shell leaves the gun by adjusting the length of
the fuse so as to burn so many seconds after it is ignited. In this arrange-
ment of an explosive projectile, the bursting charge of powder being confined
within an inner chamber, and not allowed to get scattered among the balls F,
its destructive effect is greatly increased. Moreover, the elastic force of the
ignited charge is exerted from a central point and in all directions alike,
resulting in the more complete and entire destruction of the outer shell A, and
the more forcible scattering of the missiles F. This mode of arranging or
manufacturing duplex or concentric shells may also be applied to cylindro-
convidal shaped shells or other forms used for obtaining increased accuracy in
the flight of the shell.
Having now described and particularly ascertained the nature of my said
Invention and the manner in which the same is or may be used or carried

page_text: into effect, I may observe, in conclusion, that I do not confine or restrict myself
to the precise details or arrangements which I have had occasion to describe
or refer to, as many variations may be made therefrom without deviating from
the principles or main features of my Invention; but what I consider to be
novel and original, and therefore claim as the Invention secured to me by the
herein-before in part recited Letters Patent is,-
First, the general arrangement and construction of shells or hollow explosive
projectiles, as herein-before described.
Second, the system or mode of casting or constructing shells or explosive
projectiles with an inner chamber or space to receive the bursting charge of
powder, as herein-before described.
Third, the system or mode of arranging and constructing shells or explosive
projectiles in which the bursting charge of powder or other explosive compound
is collected in a mass and retained in the centre of the projectile, so that the
disruptive force is exerted from the centre of the shell and in all directions
alike, as herein-before described.
Fourth, the system or mode of arranging and constructing shells or explosive
projectiles in which the balls or other loose missiles are arranged round a
central mass or core of powder or other explosive material, as herein-before
described.
In witness whereof, I, the said James Henderson, have hereunto set my
hand and seal, this Sixteenth day of August, One thousand eight
hundred and fifty-eight.
JAMES HENDERSON.
L.S.)