CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF WROUGHT-IRON ORDNANCE
Year: 1855

page_text: PROVISIONAL SPECIFICATION left by Henry Partridge and John
Benjamin Broome at the Office of the Commissioners of Patents, with
their Petition, on the 18th January 1855.
We, HENRY PARTRIDGE and, JOHN BENJAMIN BROOME, of Birmingham, in
the County of Warwick, Gun Manufacturers, do hereby declare the nature
of our said Invention for "CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF
WROUGHT-IRON ORDNANCE" to be as follows, that is to say:-
We take two pieces of iron of the required weight and size, and having first
reduced them by hammering or otherwise into a semicircular form in their
transverse sections, but thicker at one end than at the other, and after being so
formed we reduce them to a welding heat, and having placed them together
on a suitable mandrel, which mandrel must be fixed in the front of a pair of
suitable rolls equal in their diameter, and of sufficient size in their circum-
ference that one revolution shall be equal in length to any cannon or ordnance
we may wish to make; around these rolls, and at right angles to their axis, are
grooves exactly opposite each other, of a semicircular form, so that the two coming
together presents a circular orifice, beginning with a size desirable or suitable
for the muzzle of the gun or cannon, and gradually increasing in size to the
breech with such rolls so formed, and the parallel mandrel which must be a
little smaller than the size of the bore of the intended cannon, fixed in such

page_text: a way that the front end of it shall just pass through the circle or hole formed
by the two grooves in the rolls; we take the two pieces of iron at a suitable
heat for welding together, as first described, and placed them on each side of
the mandrel, preferring to place them in such a manner that the two joints
may come vertically above and below the mandrel, so that the pressure from
the rolls may be applied in the best way for effecting a sound weld, and which
is done by setting the rolls in rapid motion by suitable gearing, which will
draw the two pieces of iron off the mandrel by their revolving action, and
deliver them on the other side formed into a perfect tube parellel in its bore,
but taper on the outside. This plan is similar to the one already adopted for
the manufacture of the barrels of small arms, but has never been applied to the
manufacture of cannon or ordnance, or the description of fire-arms mounted
or supported on trunnions; and we will further observe that such trunnions
may be suitably applied to such cannon after their formation, as herein-before
described, or they may be formed at the same time that we are forming. the
two pieces from which the cannon is to be made, forging the trunnions to as
near the form required in the finished gun as possible; and when we thus form
the trunnions, it may be necessary to observe that in the subsequent operations
it would be best that such pieces be laid on the top and bottom of the mandrel,
and that suitable cavities should be formed in the rolls to take in and form the
trunnions has they pass through, so that the thorough welding of the two
pieces at that part may be insured. The cannon or ordnance thus formed is to
be bored and finished in the usual way, and the breech to be applied by
screwing or otherwise.