The Portland daily press., 1862-10-28

TESTING A MONSTER GUN The first 15-
inch Monitor gun, finished at the Fort Pitt
Works, Pittsburg, Pa, has been proved at the
proving grounds, Walls Station, on the Penn
syvana railroad The 11-inch and 9-inch ma
Wy guns are taken out on the ordinary plat
form cars, and run out on the switch beneath
stout overhead railway" by means of which
they are transferred, when swung upby screws
to the proper position for firing the regular
proof of ten service charges.
In order to sustain the enormous weight of
the l5-inch guns. it has been necessary 10 re-
build the entire frame in the most substantial
manner, and set up triangle of massive pro-
portions. This triangle is fornedby the franz
ing together Of two sets of massive timbers in
the shape of triangles, upon the apex of which
massive cross tImbers rest on semi-circular
bearings.
From this cross-timber depend the heavy
rods by which the gun is supported-two en-
circling the trunnion, and the other pair, much
lighter, embracing the breech. and supporting
its preponderant weight. Notwithstanding
the enormous weight to be handled, and the
incompleteness of some of the arrangements,
the gun was mounted under the active super
vision of Mr.. Joseph Kay, and ready for firing
before o'clock.
The first three loads to be fired were proof
charges, composed of fifty pounds of Rodman's
mammoth grained powder and shells of three
hundred and fifteen pounds. As the firing
of such an enormous load is very severe test,
the utmost anxiety was felt as the landyard
was pulled and the gun discharged. The
port which followed was by no means as heavy
as might have been expected.
The shell struck the ground short distance
in front of the muzzle, glanced up slightly,
and passing through an immense pile of dirt in
the bullock pen" buried itself in the hill be-
yond. The free manner in which the gun is
suspended permits of the greatest latitude of
motion, and the recoil was tremendous, in the
second round breaking defective breach rod,
and bringing the trial for the day to sum
mary conclusion.
The damage will be repaired, and the firing,
after another proof charge continued for some
time with service charge of thirty pounds of
powder aud shell weighing three hundred
and thirty pounds. The firing is conducted
under the supervision of Capt. Berrien of the
navy, and Mr.. Lee of the works. The charges
already fired are a sufficient test of the endu-
rance of the gun.
The model of these guns differs considerably
from that of the regular 8 and 11-inch Dahl
grens, and still more from the model of the
lo-inch columbiads, or Rodman guns. As the
iron tnrrets in which they will be mounted
furnish but cramped fighting quarters-being
generally of twenty-five feet in diameter-the
guns are made very short in proportion to
their calibre, being some two feet shorter than
the Rodman 15-nch. They are not turned
from muzzle to breach, as all other guns now
are, but from line some seven or eight inches
behind the trunnions TO the muzZle, leaving
the breach huge unfinished mass.
The arrangements of the breach for operat-
ing tackle also differs from the regular navy
pattern, having no horizontal opening for re-
cevlng the hawser, and in its place a simple
seinicircular projection. some seven inches in
diameter and the same in thickness. The
trunnions are much shorter than those of the
regular navy guns, being adapted to an iron
carriage. The "water-circuating core" now
adopted in casting the columbads has also
been adopted to the 15-inch monitor guns, all
other navy guns being cast solid. OF these
guns half dozen at least will be required in
a few weeks to arm the Monitors in course of
completion.