IMPROVEMENTS IN ORDNANCE, AND VESSELS FOR CARRYING THE SAME
Year: 1869

page_text: LETTERS PATENT to Daniel Fitzgerald, of New York City, State of
New York, and County of New York, United States of America,
for the Invention of "IMPROVEMENTS IN ORDNANCE, AND VESSELS FOR
CARRYING THE SAME."
Sealed the 9th October 1869, and dated the 14th June 1869.
COMPLETE SPECIFICATION filed by the said Daniel Fitzgerald at
the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 14th June 1869, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DANIEL
FITZGERALD, of New York City, State of New York, and County of
New York, United States of America, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
ORDNANCE, AND VESSELS FOR CARRYING THE SAME," and have petitioned Her
Majesty to grant unto me, my executors, administrators, and assigns,
Her Royal Letters Patent for the same, and have made solemn Declara-
tion that I am the true and first Inventor thereof.

page_text: NOW KNOW YE, that I, the said Daniel Fitzgerald, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the said Invention, and
in what manner the same is to be performed, in and by the following
statement:-
The nature of my Invention consists in the construction and
arrangement of a vessel with one or more cannons or mortars which
will be partially submerged in water, and which can be made to throw
shells or balls of different calibre.
In order to enable others skilled in the art to which my Invention
appertains to make and use the same, I will now proceed to describe its
construction and operation, referring to the annexed Drawings which
form a part of this Specification, and in which Figure 1 is a side view
of the vessel; Figure 2 is a longitudinal vertical section of the same;
Figure 3 is a side view of a steel shaft, the use of which will be herein-
after fully set forth; Figure 4 is a front view of the guns in the stern
of the vessel; Figure 5 is a plan view of the same; Figure 6 is a plan
view of the vessel; and Figure 7 is a longitudinal vertical section of the
large cannon or mortar.
A represents a vessel of any suitable size and dimensions having a
hole or aperture in its bottom. In this aperture is placed a large
mortar B which is hung on trunnions having their bearings in the
sides of the vessel A. This mortar is so arranged that it can be turned
on its trunnions so as to be horizontal, perpendicular, or at any angle
desired, and when placed horizontally it will fill up and close the
aperture in the bottom of the vessel. Usually mortars or cannons of
very large calibre have to be very thick so as to withstand the immense
pressure from the inside, but if such a mortar or cannon were partially
submerged in water the pressure of the water on the outside would to a
great extent counteract the pressure from the inside, and hence the
mortar need not be of such great thickness. For this purpose. I place
the mortar B as above described, so that when it is to be fired at an
angle its breach, and in fact the greatest portion thereof, will be
submerged in water, and the water itself receive the greatest portion of
the concussion. I may not hang the mortar on trunnions but have it a
placed, stationary, at a certain angle if so desired. It will be seen that
in either case the vessel itself, so to say, becomes the gun carriage, and as
both the gun and the vessel are in the water the effect of the con-

page_text: cussion will be greatly lessened. Besides this advantage the mortar is
kept constantly cool, and as a consequence can be fired with greater
rapidity and for a longer period than is usually the case. To increase
this cooling effect of the water I may perforate the sides of the mortar
longitudinally, either partially, or clear through, forming a series of
passages a, a, in or through the metal as seen in Figure 2. Such
perforations will not as might be supposed impair the efficiency of the
gun, but on the contrary it increases its strength. If it is desired to
use smaller projectiles another cylinder C may be inserted in the
mortar B. This cylinder I cut with circular grooves its entire length,
or place hoops or rings around the same at suitable distances apart, and
provide it with a lip or flange b which extends over the upper edge of
the mortar B, the main portion of the cylinder projecting above the
same. Water is admitted between the mortar and the cylinder whereby
the strength of both these concentric cylinders is consolidated and
combined at the same time as it keeps the inner cylinder cool. In
Figure 7 I have represented the cylinder C with a series of concave
circular grooves or rings c, c, put around the outside of a cylinder d
which thus increases the strength of the gun as the strain has
And besides when the
a tendency to go off in two directions.
gun is immersed in water it will become cool a considerable distance
into the metal. I also provide a steel tube D which may be smooth
or rifled, and is inserted into the cylinder C, its rear end being
enlarged as seen in Figure 2 so as to form a chamber for the
powder. The tube D extends beyond the front end of the cylinder C,
and is at its mouth provided with an elastic steel ring E which rests
against the outer end of the cylinder C. The size of the mortar B,
cylinder C, and tube D should be such that when the mortar is placed
horizontally the mouth of the tube D shall be flush up against the end
of the vessel, that is against the inner front side of the cavity in which
the mortar is placed. Through the bow of the vessel is placed a steel
tube fin such a manner as to form a continuation of the tube D, so that
any projectile fired from the tube D will pass through the tube fand out
at the bow of the vessel. The tube f may be used alone as a gun,
which case I insert a shaft E (Figure 3) of steel or other suitable
material in the tube D, the front end of said shaft being even with the
mouth of the tube. In the inner end of the tube f is inserted a plug
or block E which forms the breach of the gun, and is supported by the
in

page_text: shaft E. A vent hole i is then also provided. In the stern of the
vessel are made two cylindrical openings in which are inserted two
guns F, F. These guns are made thicker or provided with rings or
bands around the mouth and breach of such size as to fit exactly in the
cylindrical openings in the vessel, while the guns have at their centre
a chamber or space around them which is filled with water through an
aperture in the upper side of the vessel. The guns F, F, may also have
grooves as seen in Figure 5 for the same purpose as above described for
the cylinder C. Around the mouths of the guns F, F, is placed a
block G which connects the two guns together, and being secured to
the stern of the vessel holds the guns securely in position. It will be
understood that I may use as many guns or cylinders one inside the
other as may be desired having water or other fluid between them and
not confine myself to the specific number above mentioned. It is well
known that heavy guns which must be of great thickness are very liable
to crack and burst; but by combining a series of guns one inside of
the other, and the interstices filled with water I get all the advantages
of a solid gun of the combined thickness without the danger of bursting
as the water tends to consolidate and combine all the thicknesses, and
at the same time keep it cool. Safety valves are of course placed at
convenient points as well as inlet and outlet tubes, so that any steam
that might possibly be generated may escape, and so that the water can
be drawn off and replenished again. Another advantage of making a
heavy gun in this manner, so to say, in sections is that it can be far
easier transported that if it was in one solid piece. The gun which I
have represented in Figure 7 having a series of conical or concave rings
may be used without water, and these rings may be of almost any shape
desired, the more conical the better, and answer all the purposes of a
solid gun of the same thickness with the additional advantage of there
being no danger of bursting, as the expansion of the metal tube has free
room to go off without any injury to the outer circumference, while the
rings make the gun just as strong as if it were perfectly solid. These
guns may then also be used as field pieces or be placed in some
stationary battery, in which latter case I may also surround it by water
if so desired. When the gun is placed horizontally in the vessel the
breach should come directly against the rear side of the cavity in which
the gun is placed, thus taking off all effects of the concussion from the
trunnions. When the gun is placed at an angle and consequently

page_text: concussion relieving the trunnions. The gun or tube f in the bow of the
vessel is surrounded by a series of rings m, m, made of steel or other
suitable material. These rings are made in kind of zig-zag shape, as
shown in Figure 1, and slipped over the gun and fastened together in
any suitable manner, forming a part of the vessel, and may be of any
diameter desired so as to form in fact a gun of enormous thickness.
The rings m, m, being of the peculiar shape above mentioned will allow
for any expansion of the gun itself without any danger of breaking or
bursting.
Having thus fully described my Invention what I claim as new and
desire to secure by Letters Patent is,-
1st. Surrounding a cannon or mortar by water while it is being
discharged, substantially as and for the purposes herein set forth.
2nd. The mortar B hung on trunnions or stationary in the bottom.
of the vessel A. so as to be partially submerged in water while it is
being discharged, substantially as and for the purposes herein set
forth.
3rd. In combination with the mortar B I claim the cylinder C
constructed as described, and the space between the two filled with
water, substantially as and for the purposes herein set forth.
4th. A gun constructed as described of a series of concentric
cylinders placed one inside the other, and the interstices filled with
water or other fluid, thereby consolidating and combining their strength,
substantially as and for the purposes herein set forth.
5th. In combination with the mortar B and one or more cylinders C
I claim the tube D constructed as described, either rifled or smooth,
substantially as and for the purposes herein set forth.
6th. In combination with the mortar B one or more cylinders C and
tube D I claim the gun f through the bow of the vessel, substantially as
and for the purposes herein set forth.
7th. A gun surrounded by a series of conical or zig-zag shaped rings,
substantially as and for the purposes herein set forth.
8th. The arrangement within a vessel of suitable construction of the

page_text: mortar B one or more cylinders C, tube D, bow gun f, and stern guns F, F,
all constructed as described and for the purposes set forth.
In testimony that I claim the foregoing I have hereunto set my
hand and seal, this Third day of May, in the year of our Lord
One thousand eight hundred and sixty-nine at Washington, in the
District of Columbia, United States of America.
Witnesses,
DANIEL FITZGERALD. (L.S.)
CHARLES MADISON ALEXANDER.
JAMES MADISON MASON.