Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1898-11-22
FLAWS In BIG GUNS.

+ LA ND LIN DlU uONO.
INTERNAL DAMAGE CAUSED BY Sue
cesSvE DISCHARGES
The "Eroaive Action sf 1naaaed
Gnsea~ Causes the First Serious In
iury-How the Projectile Helps Go
KIN the Gun.
The larger q cannon the more exten-
sive are the injuries 1t receives with
each successive discharge. All damage
done to gun is internal. The separate
action of the powder and the projectile
damages the piece every time IL 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.
zling terms of Q 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 II the
gunners have been using wads between
their explosive and their projectile,
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 asunder
Of the PARTICLES Of the metal at the sur.
face Of the bore, When it is first made.
crack Of this particular kind is barely
perceptible, but 1t increases each time
the gun is fired. Gradually it extends
completely through the side OF the
piece The crack usually begins mt the
junction OF the chamber with the bore.
simply because. as guns now are. this
part 10 not 80 well supported as the
others
Edward 8. Farrow. u. S. A.. is au
thority on damage 10 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 infamed 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.
rior oriiics Of the vent and on the sur,
face OF the bore. directly over the seat
Of the projectile This scoring begins
very early in the life Of very large
gun. but IL in conceded that il does not
become very important until the piece
has been discharged considerably Lieu.
tenant Farrow describes this scoring rs
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 killsi
the gun, although in some cases IL has
acted like wedge and split the bore at
the place attacked
Where the action OF the projectile has
ruined the gun the damage has been
done arouud the projectile and in front
Of it The elasticity Of the metal and
the crowding up Of portions Of 1t ir
front Of the shot cause rebounding
process. The projectile. carried forward
BY the force VI the charge. strikes
against the upper part Of the bore; then
il is sent against the bottom and again
bounds TO the top. and 10 on until IL
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 aud is done by reduc.
ing the diameter Of the cartridge and
adding to its length. Projectile injury
is also caused by furrows or scratches
made by rough shells or case shot
Small Fragments too, break away very
often from the shclls and give the bore
grinding aud cutting process. produc.
tive Of great damage.
Enlargement Of thu muxzle is another
serious injury produced by the projec.
tile 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 vertical
direction.
Some men who ought to know say
that 100 shots is the life Of very big
gun-a l2 or IL inch weapon. Others
place the number Of shots at 400 or 500
As matter of fact, IL 10 all guesswork-
The great Krupp gun shown at the
Worlds fair and conceded 10 be perfect
-or supposed to be so-bas been dis
charged less than ten times. and 1t II
now believed to have reached its limit
On the other haud, the big guns Of the
American battleships have passed the
time allotted them by wise men who
know guns and apparently are as good
as when tested. How soon they may
yield, however, is not in the books.
Lieutenant Farrow says that o very
large gun should not be expected to
stand more than 400 or 500 shots before
it will be necessary to open new vent
closing the old one at its interior orifice.
When the gun dies-bursts-the lines
II fracture are photographed. Speci.
mems of the metal are saved. Tets are
made and conclusions drawn. And Un-
Gle 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 tha wise ones say they
should. Chicago Times Herald.
His Idea Of yeoriag.
At country cricket match in Lanark'
shire local farmers boy was appoint
ed scorer, his duties being carefully ex.
plained to him The first inning was
not very productive of runs and soon