The Republican. [volume] (Oakland, Md.) 1877-current, 1889-11-16
BORING A BIG GUN.

Interesting Processes in the Manufacture
of Breech Loading Cannon.
At last the cannon is turned down.
and is ready to be bored inside. In
this operation it must be bored so
straight and true that the boring tool,
entering at the exact center of the
small end of the cannon, will come out
precisely at the center of the large end,
seventeen feet away. Those of you
who have tried to bore a straight hole
lengthwise through even a short bit OF
wood will know that this work requires
not little skill and care
When any of you boys have job of
boring to do at your work bench, you
make fast the article to be bored and
turn the boring tool. 1t is just the 9TH
err way in boring a cannon. The bor-
ing tool, or ''bit." is held firm and mo-
tionless, while the great mass of steel
to be bored turns around. This plan
is found TO insure steadiness of the
"bit." 1t would be almost impossible
to make this bit firm and solid enough
TO do Its difficult work, and yet free to
turn around in the cannon. So if you
had been at the side of this gun-lathe
when the work was begun you would
have seen that the bit was motionless
except for a slow advance into the
gun.
The bit attends strictly to business,
and steadily bores its way through the
steel. Most of you have been to the
country and have seen pig roofing"
in the ground. Imagine then, the pig
to be standing still and the ground to
be slowly passing under the pigs
snout and being rooted" and you will
have case much like that of the bit
and the cannon. In fact. the boring
tool is called ''hog-nosed" bit, and it
roots up that cannon as if it enjoyed
the operation. No long. graceful curls
come from this boring, but small, crisp
shavings that are removed as fast as
they accumulate in order that the Dor
ing tools work shall not be interfered
with. The bit is going into the steel al
the rate of three-eighths of an inch for
every turn of the cannon, and it is
making a round hole almost large
enough for a boy to put his head in
five and three-quarteri inches in diameter.
AS the round hole grows deeper, the
heavy bar, on which the bit is fastened,
advances into the cannon steadily,
mova6 nv, n ,,,po how Of ubaals opd eo,o,y.
that form part of the lathe.
l must not lose sight of the shavings,
the little ones that come from the in
side, and the long, spirally twisted ones
that are turned from the outside of the
cannon. A military-looking man,
standing near the lathe. does not lose
sight of these shavings or trimmings,
either. This mans business is to care
fully inspect the borings and trim.
mings. That is what he is paid to do.
Uncle Sam pays him, and he expects
him to earn his salary. The cannon is
being made for Uucle Sam. and he in
tends to find out all its qualities.
whether good or bad. So the man eyes
the borings carefully. Now, if with q
plane, or your knife-blade. you will cut
Il thin shaving from a bit of wood. il
will show any little flaw existing in the
wood from which it was sliced. The
tiniest knot-hole or crack will show in
the shaving much more plainly than in
the wood itself. So it is with cannon's
shaving. 1t is dreadful tell-tale, and
the fault-inding man beside the gun
knows this perfectly well. He exam.
ines the spiral turning. or the little
piece of boring, and finds no evidence
of a flaw or crack. The long spiral
strip is as smooth as glass and as
glossy as your sisters curls.
Into the solid steel the hog-nosed Bit
roots its way until it Is in SO far that
little electric light must bear it com
pany, to show the workmen how mat.
ters are progressing in the heart of the
cannon. After eighteen days of steady
boring. the bit lets daylight into the
bore of the cannon by emerging at the
other (or larger) end, seventeen fee
away.-G. F. Miller, in St. Nicholas.