The Cook County herald. [volume] (Grand Marais, Minn.) 1893-1909, 1898-12-03
HOW BIG GUNS AAE MADE.
Assembling tho Huge ForEings at the
.5.35s KID Washington Gun Foundry. lS Il

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Washington Gun Foundry.
b The guns are made of what Is called
forged steel. This steel is made by
private firms, principally at the famous
Bethlehem works in Pennsylvania, and
is sent to the gun-foundry in the shape
OF large tubes, and in other shapes
called jackets and hoops. These steel
pieces, after being finished, are put to-
gether and made into guns. The jack
ct of a gun is about half the length OF
the tube, and itself is really a large
tube. The inner tube, when it arrives,
Is put into a lathe, and has the hole
bored out to nearly the size It will be
when finished then it is turned down
inside for about half its length from
the rear or breech end to its proper
size. "Tsurned down" means that the
metal is cut off with a steel cutter. The
Jacket also is bored out smoothly and
the hole carefully measured. The dia-
meter of this hole, or bore, in the jack
ct is a little smaller (some hundredths
of an inch) than the outside of the
tube after being turned down. Over
head in the shop are big cranes, which
travel back and forth on tracks, and
which can easily lift and carry heavy
weights. The largest crane is called
weight even greater. Near the center
OF the gun-shop is large pit in which
there are furnaces. After the tube has
been bored out and turned down out
side, it is carried by crane and lower
ed into the pit near the furnaces, so
breech end being up in the air. The
jacket is also lifted and lowered into
a furnace and heated. This furnace
has top, or cover, which lifts off, and
which is put on after the jacket has
been lowered into it. Hot air is forced
into this furnace, which heats the jack
ct till it expands so that the size Of its
bore becomes greater In diameter than
the size Of the tube it is to inclose
When all Is ready, the cover is lifted
from the furnace, the crane hooks on
to the jacket, lifts it out of the fur
mace, and swings it over the tube. The
jacket Is then quickly measured, and
carefully lowered over the tube, which
is standing on it's end. A stream Of
cold water is then admitted into the
lower end of the tube: This water ris-
es nearly to the top Of the tube, and
helps to cool both tube and Jacket, now
fitted together. AS the Jacket cools it
shrinks to its proper Size, and SO
squeezes and holds the tube tight with
in. When both are cold, the partly
made gun is lifted out of the pit, put
into another lathe, and turned down
outside so as to be ready to have the
hoops put on These hoops, which have
been bored out to the proper size, are
heated and shrunk on over the gun
just as the jacket was shrunk on over
the tube. The whole gun is made, or
built up in this manner. After all the
hoops are on, the gun is bored out
again to final size, put into rifing
machine, and ri1ed; that is, it has
grooves cut inside of the bore through
out it's length. These grooves COM
mence at the muzzle, and gradually
curve till they reach the end of the
bore. They are cut by what is called
o rifling-bar, which is long shaft
with cutters at one end. The gun re-
mains steady, while the bar enters in
to the gun at the muzzle, and turns at
the same time, thus cutting what are
called spiral grooves throughout the
length of the bore of the gun. This
rifling is done so as to give the shot or
she'll, when the gun is fired, twirling
or rotary motion, which prevents it
from tumbling end over end, and caus-
es it to keep pointed in the right direc-
ton. The shot or shell (projectile) is
long, and has a copper band fitted on
it's rear end. When the gun is fired,
this copper band, being softer than the
steel of the gun, enters into the grooves
is turned by them, and gives the pro-
jectile a spinning motion during its
flight.