The Grand Haven news. [volume] (Grand Haven, Mich.) 1858-18??, 1864-03-02
GREAT GUNS.

fully test the practical value of guns Of
immense caliber. A twenty-inch gun
was recently cast in Pittsburg rs an ex-
pertinent, and we here record the results,
although we should, with a far higher
degree of satisfaction, give place to some
account of three-hundred- FOUNDER which
could throw shot five miles, and do it
without bursting at the sixth or seventh
round. Better devote the knowledge of
ordnance and the force of exploding gun
powder we possess to the construction of
comparatively small but efficient weap-
on, than to waste it on these huge bonn
bards which can not. except by mere
chance, be made available against IRON
clad ships.
II has been generally known for some
months that preparations were making at
the Fort Pitt Works for the casting of
monster columbiad gun of twenty inches
caliber. These preparations were compile
ted on the 4th inst, and the gun cast, an
unparalleled feat in the manufacture of
iron. The furnaces in which the iron of
this gun was melted contained the enor-
nous amount of forty tons each, and
nearly this quantity was melted on the
occasion. The construction of the pat
terms alone, of the flask aud gun, occupied
many weeks. The core barrel used in
the manufacture of all guns of Rodman's
patent, is a long-huted cylinder of iron,
semicircular at one end and closed at the
other by cap, through which pipe en-
ters and passes nearly to the bottom of
the cylinder. Through this pipe stream
of water is conducted 10 the bottom of
the barrel during the process of casting,
and rising around it 10 within a few inches
of the top, is carried off by waste pipe.
This barrel is rather smaller in diameter
than the rough bore of the gun, and is
prepared for the casting by wrapping it
with layer of hard cord, which is then
coated with peculiar refractory compost
ton. This casting of the barrel "vents
the metal--that is, affords an exit TO the
gases generated during the casting, which
pass along the hutings of the barrel and
burn fiercely at the top; the bnrrel, when
coated, is also subjected to the drying ov-
en-, before being lifted into the mold. The
centerng of the core in the mold is a
task Of extreme delicacy, but with con-
slant practice, the employees in the Works
have become so expert as to insure almost
perfect accuracy. The barrel is support
ed at the upper end by massive tripod,
lifting its head some two feet above the
upper edge of the flask, and enabling the
workmen to observe the rise of metal in
the mold. During the operation of cast
ING constant stream Of water pours
through the barrel, keeping down It's tom
perature, and cooling the gun from the in
terror.
THE CASTING.
The labor of many weeks Of prepara-
ton closed on the Sd inst. The flask was
lifted into the pit, closed and luted, and
the core barrel fixed in its place. The
three furnaces were charged, one with
thirty-nine tons, aud each of the others
with twenty three and half tons of met
al, chiefly Bloomfield, and worth $65 per
ton, at the furnace. One of the smaller
furnaces in the old foundry was also
charged with twelve tons Of metal rs n
reserve in case of accident. From each
of the four furnaces lines of open troughs
of cast-iron, known rs "runners," led to
the "pool" or reservoir beside the pit,
from which two shorter lines connected
with the mold. In moldrs, two long
cylindrical bars are laid beside the pattern,
forming, when the flask is closed, a circu-
lar opening on each side of the mold,
leading 10 the bottom, and connected with
the mold by openings all the way to tho
top, breaking the fall Of the flood of met
al before reaching the gun bottom. With
each of these openings or "gates is con-
nected one Of tho runners from the pool.
The furnaces were fired at an early hour
on Thursday morning, 4th inst, and eve
rything working most admirably the
charges we're reduced before twelve o'clock.
At twenty minutes past twelve the fur
naces were tapped, and three fiery streams
of metal poured into the pool and thence
into the mold.
The reduction of the metal had been so
successfully performed that no difference
was perceptible in the character Of tho
iron flowing from the several furnaces
The filling of the mold proceeded with
the Same success, and at quarter to one
twenty minutes after the furnaces
were tapped, the mold was filed and they
were stopped of--l7O,ooo lbs. of meta
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