Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1898-08-29

The larger cannon the more extern.
tive are the injuries II receives with
each successive discharge, says the
Chicago Times Herald" All damage
done to gun is Internal The separate
action Of the powder and the projectile
damages the piece every time It II
aimed and fired Obviously, the
amount Of the damage depends upon
the material and workmanship Of the
gun. Men who make big guns de-
scribe the harm done their pets with
many intricate and puxxling terms OF
a scientific turn. In one case a gun ID
damaged because the portion Of the
bore WHICH contains the powder is en-
Urged. This happens when the metal
Is compressed. and 1t Is more danger
Gus and more plainly seen il the gum
Eers have been using wads between
their explosive and their projectile
Then again. cavities are produced by
the melting away Of portion Of the
metal by the heat OF combustion OF the
charge. Cracks ceme from the tearing
asunder Of the particles OF the metal
at the surface OF the bore. When It Is
first made a crack Of this particular
lind is barely perceptible. but it in
treases each time the gun Is fired.
Gradually it extends completely
through the side Of the piece. The
crack usually begins at the junction Of
the chamber with the bore. simply be-
cause, as guns now are. this portion is
rot SO well supported as the others
Edward s. Farrow. U. S. A., late as
s slant Instructor at West Point, is au-
thority on damage to guns. although.
Ike all others agrees with very many
authorities on all the points to con-
slider in the life of cannon. He con-
tends that furrowing or scoring pro-
fuced by the erOsive action of in
| famed gases is the great disease which
attacks the very big guns first. This
particular injury is most apparent
where the current of the gas is most
apid, or at the interior orifice of the
vent, and on the surface OF the bore,
directly over the seat OF the projectile.
This scoring begins very early in the
life OF a very large gun, but it is con-
ceded that it does not become very i'm
rortant until the piece has been dis
harged considerably. Lieutenant Far
row describes this scoring as re-
sembling the bark OF an aged elm tree.
the metal being eaten away into irreg-
ular burrows and ridges. In extreme
cases. however. scoring has not killed
The gun, although in some cases 1t has
acted like a wedge and split the bore
at the place attacked
| Where the action of the protectile has
ruined the gun the damage has been done
around the projectile and in front of IL.
The elasticity of the metal and the
orowding up of portions Of it In front of
the shot cause a rebounding process.
The projectile, carried forward by the
force of the charge, strikes against the
upper part of the bore. Then 1t is sent
against the bottom and again bounds to
the top. and so on until it emerges from
the piece. The. effect of this bounding
raotiOn Is TO raise and depress the gun in
its trunnion holes The accuracy of fire
Is diminished and of course the gun is
| unfit for service. Bronze guns are the
worst sufferers in this way Mortars-
short and dumpy-are not affected To
stop the bounding of the projectile gun
ners wrap the shell in cloth or paper, or
else shift the base of the mass tosf,bes
hurled. This last process is considered
the best and is done by reducing the
diameter of the cartridge and adding to
It's length. Projectile injury is also
caused by burrows or scratches made by
rough shells or case shot. Small frag-
uents. too, break away very often from
the shells and give the bore a grinding
and cutting process, productive of great
damage.
Enlargement of the muzzle is another
serious injury produced by the projectile.
This is caused by process which seems
unavoidable. AS the shell leaves the
piece it strikes against one portion of
the bore. The resistance at the mouth
being less than at any other point. the
metal naturally yields and the muzzle of
the cannon is elongated in a vertical di-
rection.
80 shots is the life of very big gun-a
twelve or thirteen-inch weapon. Others
place the number of shots at 400 or 500.
AS a matter of fact, it is all guess-work.
The great Krupp gun shown at the
Worlds Fair and conceded to be perfect
or supposed to be sO-has been discharged
less than ten times, and it Is now be-
lieved to have reached It's limit. On the
other hand. the big guns OF the Ameri-
can battleships have passed the time al
lOtted them by wise men who know guns.
and apparently are as good as when test
ed. How soon they may yield. however.
is not in the books. Lieutenant Farrow
says that very large gun should not be
expected to stand more than 400 or 500
shots before it will be necessary to open
a new vent. closing the old one at it's in
terror orifice. When the gun dies
bursts-the lines of fracture are photo
graphed. Specimens of the metal are
saved. Tests are made and conclusions
drawn. And Uncle Sam has figured out
so many things in this same connection
that his guns nowadays are conceded to
be better than those of any other maker.
They live longer than the wise ones say
they should.