RELATING TO ORDNANCE AS WELL AS FIRE-ARMS
Year: 1860

page_text: LETTERS PATENT to Edward Augustus Dana, of the State of Massa-
chusetts, of the United States of America, for an Invention "RELATING
TO ORDNANCE AS WELL AS FIRE-ARMS."-A communication from John P.
COMPLETE SPECIFICATION filed by the said Edward Augustus Dana.
at the Office of the Commissioners of Patents, with his Petition and
'Declaration, on the 22nd August 1860, pursuant to the 9th Section of
the Patent Law Amendment Act, 1852.
TO ALL PERSONS TO WHOM THESE PRESENTS SHALL COME, BE
IT KNOWN, that I, EDWARD AUGUSTUS DANA, of the State of Massachusetts,.
of the United States of America, am in possession of an Invention "RELATING
TO ORDNANCE AS WELL AS FIRE-ARMS," which Invention was communicated to.
me by John P. Schenkl, resident at Boston, in the said State of Massa-
chusetts; and I do hereby declare the nature of the said Invention, and
the manner in which it is to be performed, to be fully described in the
following Specification, and illustrated in the accompanying Drawings, that
is to say:-
The nature of the said Invention consists, first, in the combination of an
intercepting plug or leader, not only with an initial chamber formed in a gun
or fire-arm, and with respect to its bore, as herein-after described, but with a

page_text: projectile suitably adapted to such gun or fire-arm in the manner and to
operate substantially as herein-after explained.
Second, in certain methods of constructing such intercepting plug or
leader.
•
Third, in a cartridge as made of such an intercepting plug or leader, and
one or more charges of powder, applied to it, substantially as herein-after
described.
In the application of my Invention either to a gun or fire-arm, as the case
may be, such gun or fire-ȧrm should be constructed with what may be
termed an "initial chamber" or an "initial charge chamber," it being for the
reception of a small charge of powder separate from the main charge by which
the projectile is to be expelled from the gun, such small charge of powder
being intended not only to act against and start forward the intercepting plug
and the projectile, so as to overcome the inertia of the latter, but to fire and
explode the main charge. This initial charge chamber is to be arranged in
the breech and in range of the bore of the gun, the vent or priming hole or
passage being made to enter or open directly into the said initial charge
chamber. With such initial charge chamber I combine an intercepting plug
or leader, which running through the centre of the main cartridge shall at its
lower end (in or upon which is to be secured the small or initial powder
charge) be made to enter for a short distance; and fit tightly against the
interior walls of the initial chamber, so as when rammed home to intercept
all communication between the latter and the main bore of the barrel or piece,
while the other or outer end of such plug or leader is intended to act against
the center of the rearward surface of the projectile or sabot when the piece
is loaded; or such plug or leader may form a part of or be otherwise con-
nected with the projectile or the sabot, the small chamber aforesaid to be of
a capacity sufficient to receive a powder charge large enough to start the
projectile with the requisite velocity, and also to receive the entering portion
of the plug or leader. The bottom or breech of the piece inside immediately
surrounding the initial chamber may be chamfered or bevelled, so that the
plug or leader shall the more easily be entered therein in loading, and the
entering portion of the plug or leader may be slightly tapering, so as to more
easily enter and more tightly fit the chamber. The plug or leader should be
made of such a thickness and such material or materials as will secure a
perfect interception as aforesaid, and enable it without breaking or yielding
in its parts to receive and impart to the projectile the blow or force of the
explosion of the initial charge when the piece is fired; also when said plug
or leader is made of wood or any other non-metallic substance, or when it is

page_text: made of iron or any other hard metal, I am in favor of covering or surrounding
its lower or entering end with a cap or belt of lead or copper, or any other
metal or alloy which is sufficiently ductile to fit itself tightly within the walls
of the initial chamber when driven therein in loading. The lower end of
said plug or leader may be formed with a projecting rim for receiving in part
the initial cartridge, such rim being provided with perforations, through which
strings may be passed for the purpose of tying the initial charge firmly in its.
place. The initial plug or leader may be hollow from its lower or rear end
inward, and so as to contain within itself the initial charge, or a considerable
portion thereof, as shown in Figure 3 of the Drawings, in which case the plug.
or leader, or at least the portion of it thus chambered, must be made of some,
suitable metal, and with its walls and bottom of sufficient thickness and,
strength not to burst or improperly yield under the explosion of the initial.
charge. By adopting this method, the initial chamber in the breech of the
gun can be made proportionally smaller..
'
This Invention can be applied to an ordinary cannon, by forming in the.
center of the bottom or breech of the same, and in rear of and to open into
the bore, an initial chamber, and making: a new vent hole leading directly into
such chamber, the original vent hole being either previously or subsequently
securely plugged.
In the Drawings, Figure 1 is a sectional view of a piece of ordnance with.
this Invention applied thereto, A.being the main bore; B, the initial chamber;
ff, the chamfered or bevelled portion of the breech surrounding the chamber.
B; v, the vent hole leading into the chamber B; E; the plug or leader, with
its metallic cap c; c, containing or carrying the perforated rim a, a;. P, the
projectile; C, C, the main cartridge surrounding the plug E. Figure 2 is.a.
sectional view of the plug, or leader E, inserted axially through the main
cartridge C, C, and carrying the initial cartridge F; G, G, representing a disc
or sabot fixed on the outer end of the leader E, in order to keep the same
central in the piece. Figure 3 is a sectional view of a notched plug or
leader E, its lower or rear-part-a, a-a-being a suitable metallic cylinder for
holding the initial cartridge F.
The practical operation of my Invention in loading and firing the piece is
as follows:-The initial cartridge being secured to or in the entering end of
the plug or leader, and the latter being fixed in the center of the main
cartridge, the whole is to be rammed home from the muzzle, if it be a
muzzle-loading piece, until the entering end is forced sufficiently far into the
initial chamber to secure the requisite interception between that and the main
bore; and in case the projectile is not connected with the plug or leader, the

page_text: former is next rammed down, so as to stop against the exterior end of the plug
or leader; and in case the piece is a breech-loader, the initial cartridge and
entering end of the plug may be first inserted into the initial chamber in the
movable. breech before the latter is fixed in its place preparatory to the
discharge of the piece. The initial charge being ignited through the vent,.
must by the force of its explosion first break the interception: aforesaid, by
forcing the plug forward out of the initial chamber before the fire of the
initial charge can escape into and explode the main charge, and this initial
explosion communicating it's force: instantaneously through the plug or leader
to the projectile lying at its other end, serves to overcome the inertia of the
projectile, and put it in motion before the explosion of the main charge takes
place. The advantages thus secured over the common methods of loading
and firing ordnance and fire-arms are a great reduction of the strain on as
well as diminution of the recoil of the piece, and an increased velocity and
range to the projectile, in the two former particulars more especially,' making
my Invention of great value when applied to heavy ordnance and rifled
cannon.
"What I claim and desire to secure by Letters Patent is as follows:-
I claim the combination of an intercepting plug or leader with the initial
chamber, and a projectile suitably adapted to the gun or fire-arm, in the
männer and to operate substantially' as described.
I also claim the methods substantially as described of constructing the
intercepting plug or leader.
I.also claim a cartridge as made with an intercepting plug or leader, and
one or more charges of powder applied to it, substantially as herein-before
described.
In witness whereof, I, the said Edward Augustus Dana, have hereunto
set my hand and seal, this Second day of August 1860:
EDWARD AUGUSTUS DANA. '(L.S.)
EDWARD AUGUSTUS DANA. '(t.g.】