The Dawson news. (Dawson, Ga.) 1889-current, 1898-11-02
FLAWS IN BIG GUNS.
INTERNAL DAMAGE CAUSED BY
SUCCESSIVE DISCHARGES.

The "Erosive ActiOa OF Indamed
Gases Causes the First Serious In
Jury-How the ProjectiIe Helps TO
Kill the Gun.
The larger cannon the more extern
sive are the injuries it receives with
each successive discharge All damage
done to a gun is internal The separate
action of the powder and the projectile
damages the piece every time it is aimed
and fred. Obviously the amount of the
damage depends upon the material and
workmanship of the gun. Men who
make big guns describe the harm done
their pets with many intricate and puz-
cling terms of scientific turn In one
case a gun is damaged because the part
of the bore which contains the powder
is enlarged. This happens when the
metal is compressed, and it is more dan
gerous and more plainly seen if the
gunners have been using wads between
their explosive and their projecti!e
Then, again, cavities are produced by
the melting away Of part Of the metal
by the heat of combustion Of the charge
Cracks come from the tearing aaunder
of the PARTICLES Of the metal al the sur
face of the bore When it is first made,
a crack Of this particular kind is barely
peroeptible, but it increases 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 because, as guns now are, this
part is not SO well supported as the
others.
Edward S. Farrow, U. S. A, is au-
thority on damage to guns, although,
like all others who have studied the
question, he does not agree with very
many authorities on all the points to
consider in the life of cannon. He con-
tends that furrowing or scoring produced
by the erOsive action of inflamed gases
is the great disease which attacks the
very big guns first. This particular in
jury Is most apparent where the current
OF the gas is most rapid or at the inte-
rlor OTitiCe Of the vent and on the sur
face of the bore, directly over the seat
of the projectile. This scoring begins
very early III the life of a very large
gun, but it is conceded that it does not
become very important until the piece
has been discharged considerably. Lieu
tenant Farrow describes this scoring as
resembling the bark of an aged elm tree,
the metal being eaten away into irregu-
lar burrows and ridges In extreme
cases, however, scoring has not killed
the gun, although in some cases it has
acted ike a wedge and split the bore at
the place attacked.
Where the action Of the proieotile has
ruined the gun the damage has been
done around the projectile and in front
of it. The elasticity of the metal and
the crowding 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
it 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 motion is to raise and de-
press 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
gunners wrap the shell in cloth or pa
per or else shift the base of the mass
TO be hurled. This last process is CON
sidered the best and is done by reduo-
ing the diameter Of the cartridge and
adding to its length. Projectile injury
is also caused by burrows or scratches
made by rough shells or case shot.
S%all ~. fTo qg, =. .oGts, too, break away very