El Paso daily herald. (El Paso, Tex.) 1881-1901, 1898-08-08
The Diseases of Bio Guns.

| Chicago Times Herald.
| The larger a cannon the more extern
sive are the injuries il receives with
| each successive discharge. All dam
age done to a gun is internal. The
separate action of the powder and the
| time it is aimed and fired. Obviously
the amount of the damage depends up
on the material and workmanship of
| the gun. Men who make big guns
describe the harm done their pets
| with many intricate and puzzling terms
OF q scientific turn. In one case q gun
| Is damaged because the part of the
bore which contains the powder is en-
larged. This happens when the metal
Is compressed, and it is more dan
gerous and more plainly seen if the
gunuers have been using wads between
their explosive and their projectile.
Then, again, cavities are produced by
the melting away of part of the mt
tai by the heat of combustion of the
charge. Cracks come from the tearing
asunder OF the particles of the metal at
the surface of the bore. When it is
first made q crack of this particular
kind is barely perceptiole, but it in
creases each time the gun is fred
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 rs the others.
Edward S. Farrow, u. S. A. late as
sistant instructor at West Point, 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 a cannon. He
contends that furrowing or scoring
produced by the erOsive action or 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
rapid 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 very large gun, but it is con-
ceded tn at 1t does not become very i'm
portant until the piece has been dis
charged considerably. Lieutenant
Farrow describes this scoring as re-
sembling the bark of An aged elm tree,
the metal being eaten away into ire
gular burrows and ridges. Ins extreme
cases, however, scoring has not killed
the gun, although in some cases it has
acted like wedge and split the bore
at the place attacked.
Where the action of the projectile
been done around the proiectile and in
front of it. The elasticity of the metal
and the crowding up of portions OF it
in front of the shot cause d rebounding
process. The projectile, carried for
ward 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 until
it energies from the piece. The effect
ia tn
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 guDners
wrap the shell in cloth or paper, or
else shift the base of the mass to be
hurled. This last process is considered
the best, and is done by reducing the
diameter of the cartridge and adding
to its length. Proiectile injury is also
caused by burrows or scratches made
by rough shells or case shot. Small
fragments, too, break away very often
from the shells and give the bore a
grinding and cutting process, produc-
tive of great damage.
Enlargement of the muZzle is anoth-
err serious injury produced by the pro-
jectile. This is caused by process
which seems unavoidable. AS the shell
leaves the piece it strikes against one
portion of the bore. The esistance at
the mouth being less than at .,ny other
point, the metal naturally yields and
the muzzle of the canon Is elon gated in
a vertical direction.
Some men who ought to know say
that Il hundred and fifty shots is the
life of very big gun-a u or ] 3 inch
weapon. Others place the mum Der of
shots at four hundred or five hu udred.
As matter of fact, it is all guess work.
The great Krupp gun shown at the
Worlds Fair and conceded to be per-
tect-or supposed to be so-has been
discharged less than ten times, a nd it
is now believed to have reache its
limit. On the other hand, the big
guns OF the American battle chips
have passed the time allotted theI ID by