The weekly pioneer and Democrat. [volume] (Saint Paul, Minn. Territory) 1855-1865, 1864-02-26
THE CORE

is long, hollow, cast-iron, futed barrel,
hung vertically precisely in the centre of
the mould It is exteriorly cOated-firs
by a coil of three-e;ghths inch rope, closely
wrapped, and mile in length; and, Sec
ondly, with luting of stiff clay, which is
put on to separate the cast-irOn of the bar
rcl from the molten iron of the gun. The
rope is used to keep the clay out of the
grooves, and. by presenting a rough sur
face, toprevent it slipping off. The grooves
allow the gas (mainly hydrogen, formed
by the contact of the melted metal and the
clay, to escape freely at the upper end into
the air. where it burns with quite large
flame. After the coatings are on, the core
is likewise baked hard in an oven. Its out
side diameter is nineteen inches, one inch
less than the finished diameter of the lore,
thus allowing half an inch all round for the
completion of the latter.
The core barrel is kept cool by means of
stream of cold water circulating through
out its whole length. A small pipe extend
ing almost to the bottom of the core is
traversed by the water, which, rising, fills
the barrel, and passes off at the top. Dur
ing the casting the flow of water was sixty
gallons per minute.
THE FURNACES.
Three large reverberatOry or air fur
naces are used. Two are of the capacity
of twenty-five tons each. The third, of
the capacity of forty tons, is believed to
be the largest in the world. 1t was built
expressly to accommodate the 20-inch. 1t
was charged with thirty-nine tons, and
each of the smaller furnaces was charged
with twenty-three and halt. From these
furnaces the iron is conducted through
iron troughs, lined with clay, into a COM
mon pool near the pit Thence it is con-
Quoted by two troughs into the gates of
the mould These gates are two OPEN
ings, three inches in diameter, extending
all the way down the mould outside the
matrix of the gun. They communicate
with the gun proper by means OF smaller
gates, cut through at intervals of fifteen
inches, all the way up. The iron is thus
conducted first into the bottom of the
mould, and then through the sidegates,
respectively, up to the top, as the metal
rises in the mould The difference between
the reverberatory and the cupola furnace
is that in the former the fuel and iron are
separated, and there is natural draft
through large slack. In the latter the
fuel and iron are together, and the DRAFTS
made by blast
One of the most deeply interesting sights
of the kind that ever took place was to be
seen on Thursday noon. The west end of
the Fort Pitt foundry wHs thronged with
workmen and visitors. Including all,
about three hundred people were present.
Among these were the members of the
Ordnance Board, which consisted OF Major
Dyer, Major Rodnian and Captain Benet
Major Rodman is in command of the
Watertown arsenal; Major Dyer is in COM
mand of the Springfield arsenal, and Capt.
Benet is Inspector of cannon and projec-
tiles, and was, until very lately, inspector
of ordnance and gunnery at West Point.
He is now stationed at New York.
Among the visitors present were the
Marquis de Bassecourt, colonel in the
Italian army General Copeland; Major
General Brooks; Professor Parker, Of
Cambridge; Captain Berrian, q. S. N,
and resident inspector of ordnance; Capt.
Edie; Lieut.. Rockwell, of the ordnance
of the army; Capt. Aulick, U. S. n,
assistant chief of the Bureau of Ordnance;
Hon. A. W. LoOmis, of Pittsburg, and
others.
The furnaces were fired at five o'clock
A. NJ; the metal was melted by eleven
O'Clock Whilst the iron was running in
the mould, it was constantly stirred by
men with long poles of oak. The object
of this was to relieve it of the gas often
formed in gun-irons, and which, if not re-
moved, creates globnlar cavities in the
mass of the gun, and thereby destroys
its uniformity. The casting commenced
at twenty-four minutes after twelve.
Eighteen bushels Of coal were allowed to
each ton of iron to make the fusion. Fur
mace number FIVE was first opened, and
then furnaces number six and four. The
scene was most animated and very excit-
ing. The liquid iron, traversing the sturdy
runners, glared and sparkled with daz-
zling intensity. Along the black line OF
the runners, corruscations and fiery spray
shot out into the air. The sparks flew up
by millions, and, tying themselves into
dazzling knots, twisted and exploded.
The mould was surrounded by an eager
crowd; the cranes were lined with work.
men; four men were busy with long, mar
row pudding sticks, collecting the scum
and scori@ which gathered ca the surface
of the liquid iron. Small quantities of
iron were thrown into the pit from time
to time, in order to light the gas which
escaped from the sand through the small
yent-holes in the flask. As the rods with
which this process was effected struck the
sides of the mold, shower of fire-fakes
descended into the cavity, and shot out
scintillations upon the assembled crowd
The gas escaping from within the iron
pipe surrounding the core-barrel was in a