IMPROVEMENTS IN THE EMBRASURES OF FORTIFICATIONS AND IN PROVISIONAL SPECIFICATION
Year: 1860

page_text: LETTERS PATENT to George William Hart, of 9, Stanley Terrace, Southsea,
in the Parish of Portsea, in the County of Hants, Engineer, for the
Invention of "IMPROVEMENTS IN THE EMBRASURES OF FORTIFICATIONS AND IN
PROVISIONAL SPECIFICATION left by the said George William Hart at
the Office of the Commissioners of Patents, with his Petition, on the
5th December 1860.
I, GEORGE WILLIAM HART, of 9, Stanley Terrace, Southsea, in the Parish
of Portsea, in the County of Hants, Engineer, do hereby declare the nature of
the Invention for "IMPROVEMENTS IN THE EMBRASURES OF FORTIFICATIONS AND IN
THE PORT-HOLES OF SHIPS OF WAB," to be as follows:-
This Invention has for its object improvements in the embrasures of forti-
fications and in the port-holes of ships of war. For these purposes, in con-
structing the embrasures of fortifications, in place of constructing the openings
in the form and of the dimensions heretofore necessary in order to work the
guns, the openings are made of a circular form, into each of which is intro-
duced either an entire sphere or such part of a sphere as will be sufficient for
the purpose, such sphere or part thereof being arranged to move freely within
the circular opening formed in the structure of the fortification in such manner
as to produce a ball-and-socket joint. Through the centre of the sphere is

page_text: formed a suitable opening for the purpose of running the fore part of the gun
into and firing it through the same, the passage through the sphere being
restricted to the size necessary for the passage of the fore part of the gun
through it, and the interior of the passage through the sphere will thus be
comparatively small as compared with an ordinary embrasure, in consequence
of the ball-and-socket joint admitting of the gun being pointed in varied
directions by the movement of the sphere within its socket. In some cases,
in the construction of embrasures and also of the port-holes of ships of war,
in lieu of the ball and socket I sometimes construct the embrasure or port-hole
in the shape of a cylinder, placed horizontally, in such way that whilst the gun
can be trained right and left through the aperture in the cylinder in the usual
manner, the cylinder, by being rotated, will admit of the gun being elevated or
depressed. Again, I use a disc or portions of a disc of sufficient thickness to
withstand shot, and this disc has an aperture through which the gun is fired,
and when the gun requires to be elevated or depressed the disc is rotated so
as to permit of such elevation or depression, and also when the gun is with-
drawn by rotation of the disc the port or embrasure can be entirely closed. I
sometimes attach to the part of the disc which revolves over the port or
embrasure a slide which moves between the sides or cheeks of the embrasure
or port, so that by the partial rotation of the disc this piece is moved so as to
permit of the gun being fired through an aperture in it when elevated or
depressed, or can be so placed as to totally close the port or embrasure. By
these means I obtain a revolving or sliding shutter to the port or embrasure,
which I put in motion by suitable mechanism.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George William Hart in the Great Seal Patent Office on
the 5th June 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
WILLIAM HART, of 9, Stanley Terrace, Southsea, in the Parish of Portsea, in
the County of Hants, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of December, in the year of our Lord. One,
thousand eight hundred and sixty, in the twenty-fourth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said George
William Hart, Her special licence that I, the said George William Hart, my
executors, administrators, and assigns, or such others as I, the said George

page_text: William Hart, 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 "IMPROVEMENTS IN THE
EMBRASURES OF FORTIFICATIONS AND IN THE PORT-HOLES OF SHIPS OF WAR," upon the
condition (amongst others) that I, the said George William Hart, my execu-
tors 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.
NOW KNOW YE, that I, the said George William Hart, 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:-
This Invention has for its object improvements in the embrasures of forti-
fications and in the port-holes of ships of war.
For these purposes, in con-
structing the embrasures of fortifications, in place of constructing the openings
in the form and of the dimensions heretofore necessary in order to work the
guns, the openings are made of a circular form, into each of which is intro-
duced either an entire sphere or such part of a sphere as will be sufficient for
the
purpose, such sphere or part thereof being arranged to move freely within
the circular opening formed in the structure of the fortification in such manner
as to produce a ball-and-socket joint. Through the centre of the sphere is
formed a suitable opening for the purpose of running the fore part of the gun
into and firing it through the same, the passage through the sphere being
restricted to the size necessary for the passage of the fore part of the gun.
through it, the interior of the passage through the sphere will thus be com-
paratively small as compared with an ordinary embrasure, in consequence of
the ball-and-socket joint admitting of the gun being pointed in varied direc-
tions by the movement of the sphere within its socket.
In carrying out this part of my Invention I apply a ball and socket in
constructing each embrasure of a fortification in a similar manner to that
described in the Specification of my former Patent, dated 22d October 1860
(No. 2576), and in doing so I construct the masonry so as to receive a
circular iron framing, such as is described in my said former Specification; in
which case the construction and arrangement of the ball or sphere will be the

page_text: same as formerly described. I however prefer, in place of that arrangement,
to support the sphere or ball on the interior, and to have the ball or sphere
smooth on the exterior surface, simply surrounded by a suitable frame with a
circular opening to receive the ball or sphere. Figure 1 shows a vertical
section of this arrangement; A is a turn-table moving on the upright axis B ;
on the turn-table is a standard C, which is forked at its upper part for the gun
to pass between it. The two horns of the fork have suitable bearings formed
thereon to receive two internal necks or axes D. By this arrangement the
axes D will be directly over the axis B of the turn-table, and at right angles
thereto, hence the ball or sphere can be turned by the pointing of the gun on
its horizontal axes, and also on the vertical axis B.
In some cases, in the construction of embrasures, and also of the port-holes
of ships of war, in lieu of the ball and socket I construct the embrasure or
port-hole in the shape of a cylinder placed horizontally in such way that
whilst the gun can be trained right and left through the aperture in the
cylinder in the usual manner, the cylinder, by being rotated, will admit of the
gun being elevated or depressed. In carrying out this part of my Invention
I mount a cylinder in the embrasure or port-hole in the shield of a gun, which
is arranged to rotate with its carriage about a centre. In Figure 2, A is a
section of a hollow cylinder, with a passage through it for the passage of the
fore part of a gun. This cylinder has short necks or axes at its ends which
turn in suitable bearings carried by the framing of the shield B, which is
mounted on the turn-table C, which turns about the pivot or central axis D,
and the turn-table is facilitated in its movement by circular tracks or rails E, E,
on which the wheels F of the turn-table run. This arrangement is suitable
for land and floating fortifications, and for the deck guns of gun-boats and
other vessels. Again, I use a disc or portions of a disc of sufficient thickness
to withstand shot, and this disc has an apperture through which the gun is
fired; and when the gun requires to be elevated or depressed the disc is
rotated so as to permit of such elevation or depression, and also when the
is withdrawn, by rotation of the disc, the port or embrasure can be entirely
closed. I sometimes attach to the part of the disc which revolves over the
port or embrasure a slide, which moves between the sides or cheeks of the
embrasure or port, so that by the partial rotation of the disc this piece is
moved so as to permit of the gun being fired through an aperture in it when
elevated or depressed, or can be so placed as to totally close the port or
embrasure. By these means I obtain a revolving or sliding shutter to the
port or embrasure, which I put in motion by suitable mechanism. In place
of the ball and socket, or the cylinder arrangements above described, I some-
gun

page_text: times employ an arrangement of shutters or sliding shields; such an arrange-
ment is shown at Figure 3. A, A, A, A, is the port or embrasure; B, the
cannon; C, C, the shield or shutter which turns on the pivot D, having a
counterpoise at one end, and a slot through it for the passage of the muzzle of
the gun at C'; the end of the cover or shield C, which closes the port, carries
another piece E, which may be of any suitable shape, and is suspended at F
to the piece C, and has an apperture to allow of the gun B being protruded and
fired. The piece C, C, by moving on its axis D, allows of the elevation and
depression of the gun, and the piece E moves from side to side of the port so
as to allow of the gun being trained right and left. Figure 4 is a section of the
same arrangement, the same parts bearing the same letters; Figure 5 is a
modification of the arrangement last, described; the piece E is suspended at
F, and rests at once over the port instead of overlapping the piece C as before;
the vertical adjustment is obtained by the motion of the piece C on its centre
D, and the horizontal adjustment by the motion of the piece E on its pivot F.
In witness whereof, I, the said George William Hart, have hereunto set
my hand and seal, this First day of June, in the year of our Lord One
thousand eight hundred and sixty-one.
GEO. W. HART. (L.S.)