IMPROVE- MENTS IN WORKING GUNS, AND IN MATTERS RELATING THERETO
Year: 1863

page_text: PROVISIONAL SPECIFICATION left by Henry Duncan Preston Cunning-
ham at the Office of the Commissioners of Patents, with his Petition,
on the 8th July 1863.
I, HENRY DUNCAN PRESTON CUNNINGHAM, of Bury, in the County of Hants,
Esquire, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN WORKING GUNS, AND IN MATTERS RELATING THERETO," to be as
follows:-
This Invention consists of improvements in working guns, and in matters
relating thereto, applicable. to guns on board. ships and in batteries on shore.
As regards loading muzzle-loading guns, my Invention consists in mounting
the gun on a carriage of such construction as hereafter explained, that the
gun shall be capable of being turned round, so that when it runs in it shall
point in-board, or along the deck or battery, thus greatly facilitating the
operation of working, sponging, loading, and ramming, and also affording
protection to the gunner working the gun. The carriage is divided horizontally
into two parts, the upper part is fitted to revolve on an axis fixed to the lower
part. This Invention also refers to provisions for closing or partially closing
the aperture of the porthole, to prevent as much as possible the admission
of missiles and projectiles; for this purpose I fit in the port three or more or
less slabs of iron or other metal or material to slide up and down in grooves
on each side of the port. The depths of the slabs are so adjusted as when raised
in their respective grooves or extended, they shall close up the aperture of the port
after the manner of jalousie blinds, so that when the gun is run in for loading,

page_text: the aperture of the port shall be closed against the admission of projectiles or
missiles. The slabs can also be so adjusted as to close up those parts of the
port not occupied by the gun when run out. For instance, if the gun be
horizontal for point blank firing, one of the slabs may be raised to the top of
the port and the other two allowed to remain at the bottom, a space is thus
left in the centre of the port for the gun to protrude through. Or should the
muzzle of the gun be elevated, all the slabs may remain at the lower part of
the port, the outer slabs being slightly raised according to the angle of the gun;
or again, should the muzzle of the gun be depressed, all the slabs would be
raised to the upper part of the port. I propose to raise and otherwise work
the slabs by the assistance of counterpoises, which may consist of, say, similar
slabs fitted in a frame corresponding nearly to the shape and size of the port,
which frame is situated, say, in the rear of the gun. Ropes or chains will be
led over suitable pullies from the slabs in the port to the slabs in the frame,
so that by raising or otherwise the slabs in the frame a corresponding move-
ment will be effected in the slabs in the port; thus, the adjustment of the
sereen can be easily and rapidly effected. I do not, however, confine myself
to this particular method of raising the slabs as ether mechanical arrange-
ments may be adopted. I also fit the carriage for the trunnion axis of the
gun to be raised or lowered to increase the powers of elevation and
depression.