The morning news. [volume] (Savannah, Ga.) 1887-1900, 1898-06-26

! gun gets less and contiues to decrease as
the projectile approaches the muzzle,
therefore the gun Is made stronger and
| heavier about the powder chamber than
at tho muzzle.
The foregoing will, perhaps suffice to
show that the modern high power gun is a
machine which is designed to all its fca-
| lures to perform lis special work, just as is
steam engine or lathe. If we regard that
work as penetrating armor plate, then the
gun is simply big machine for punching
holes, and if We know the thickness of
plate and how much power the punch (sAoD
must have to go through it, we can design
gun to project a shot with such force
that after that shot has traversed a GER
tain distance or range it will stu have
power enough to do the desired work
Thus for example, take our biggest gun,
the bore of which is Is inches in diameter
and which throws a projectiIe weighing
LOO pounds. With a velocity of 2100 feet
per second, this projectile will go through
eighteen inches OF solid face-hardened
armor-or about twenty-six inches of or
binary steel. But this is the speed at the
muzzle. At a distance of $500 yards from
, the muzzle its speed will have fallen Off to
1,S05 feet per second, and the shot will then
penetrate only fourteen inches of armor
So, to put the arithmetic in another way,
If we want to penetrate fourteen inches of
armor at $500 yards range, we can use
gun having a bore 10 inches in diameter
throwing a projectile weighing 100 pounds
with a velocity of 2,103 feet at the muzzle
OF course, to get this high speed, we have
to use great deal of powder-in fact, a
quantity weighing one-half as much as
the shot itself. or $50 pounds. To burn all
that powder and make it's gases act on
the projectile for a sufficient time to give
the latter the necessary high speed, we
have also got to make the bore very long
and thus the gun grows lean and thin and
lengthens out to forty feet.
So much though briefly for general
principles. Now how is the gun actually
produced?
Naturally, one would think that a tube.
open at one end and provided with vent
or touch hole, would serve all necessary
purposes. But while the steel of which
such a tube would be made might be
strong enough not to be torn apart by the
explosion, it is liable to stretch at press
ure not very much above that which the
powder exerts: and If it did happen to co
this then bursting might soon follow.
while the inside of the bore would be de-
formed, which would be fatal to accurate
shooting. Consequently, in order to coun-
teract this, the gun is made in several
parts, each separately constructed and nut
together; and such "bult-up'' gun. as
il is called. even If of the same dimen-
sions and material as one formed from a
single mass of metal, is much the strong ger
and safer of the two. So, i'm manufactur-
ing IL, there is made, first, a big ingot of
Steel which is squeezed and pounded and
annealed and tempered until the metal gets
so tough and strong that it will stand the
tremendous tensile strain of some 10000
pounds per square inch. This ingot which
is cylindrical, is then bored from end to
end, making 1t into a tube. Next, an
other ingot Is formed into a tube big
L. L,
tend over about two-fifths of it's length
That Is the Jacket. And II is put on hot.
so that when it cools it grips and com
presses the inner tube, which, therefore
cannot yield to the strain of the explosion
inside without first overcoming the Jack
cts compression. Outside of the Jacket
and also outside of the protruding portion
of the tube, are put succession of small
er jackets, or hoops, which also are shrunk
on: and, lastly, If the gun is TO be sup
ported on pivots projecting from its sides.
or, as they are termed, trunnions, the hoop
carrying them is added.
From what has already been said II will
be apparent that the thickness and weight
of these parts which are built up to make
the gun will depend upon the strain which
the gun has TO Withstand. This gun r. a
13-inch gun which is 40 feet long, the
greatest diameter at the breech Is over
four feet and its weight Is about 60 tons
All Of our great guns are now rifled-
that Is, the inner surface of the bore Is
spirally grooved, so that as the projectile
is driven out II Is made to revolve with
the result of obtaining greater range and
penetration and improved accuracy OF fire
The great feature In which our modern
guns differ from those with which the
civil war was fought Is that the charge
OF powder and shot is put into the open
rear end of the gun, and a door Is shut
behind 1t, instead of being put into the
front end, ana showed by long ramrod
to the bottom of the cavity ia the solid
metal In other words, modern guns are
all breech-loaders. With such long, lean
affairs as they, il would be very trouble
some either 60 climb out on them to put
In the charge and ram 1t home, or to run
them inside the ports from which thew
protrude so as to get at the muzzle in that
way. Besides II Is so much easter and
safer and quicker to open the end and
shove in first the shot and then the pow
der; and, moreover. IL you do not need
to get at the muzze the gun can be put
through a shield big enough to give con-
siderable protection to the crew.
but If you are going 70 put powder In