The Washington critic., 1889-04-19
pYNAMlrE GUNS TESTED.
interesting Experiments on the New
Cruiser yesuvius.

SAYS q special TO the Baltimore american
from Philadelphia. A series of interesting
experiments began at Cramps shipyard
this afternoon to test the rapidity OF
fire Of the guns Of the new dynamite cruiser
Vesuvus This is preliminary to the OIL
cial test by the Government, the date for
which will probably be set tonight, de
pending, OF course, upon the success OF the
preliminary experiments. The firing to-day
is done with empty Shells and at the start
was quite successful. To be accepted by
the Government each OF the three guns on
the vessel must be fired on an average once
In two minutes or five times minute, and
Captain Znlinski, the inventor, says he is
confident tn at the guns will do even better
than that when working smoothly.
He has devoted great deal OF time to .
the attainment OF perfection In these guns,
and thinks he has solved the problems In
volved. The principal OF these will be bet
ter understood when II is stated that the
guns on the Vesuyius are not movable, like
those mounted ashore or on large gunboats,
where the range OF the shell may be altered
at will by elevating or depressing the gun
independent OF any change In the pressure
OF the air, but are fixed In position, built
grees, and this elevation cannot be changed.
Therefore the range can only be altered by
controlling, to perfection, the amount OF
air that Is TO be admitted to the dynamite
guns, In which air, at high pressure, takes
the place of the gases produced by the ex-
plosion OF gunpowdcr.
To get the greatest possible range the
valve Is left open until the shell leaves the
gun; that is, the pressure upon the base OF
the shell is always one thousand pounds
per square inch, as IL moves along the bore.
II the valve Is closed when the shell has
moved through half the length OF the bore
that is, II only half gunful of air Is let
will gradually diminish, after the valve is
| closed, until II falls to five hundred pounds
| per square inch when the shell leaves the
muzzle The range will thus be shortened
certain amount that will be determined
| by experiment. The problem was, there
| fore, to so adjust the valve that the final
| pressure upon the shell would be made to
| vary by small differences of few pounds
| per square inch from one thousand pounds
| down to a pressure just sufficient to force
| the shell through the gun barrel. This
| problem Captain ZalinsN worked at a long
| time before solving, air at such a tremen-
| dous pressure having never before been
controlled. He has, therefore, received
| many congratulations upon his success.
| The guns Of the Vesuvius are three in
number, and are built into the deck side by
| side, pointing forward over the bow at an
| angle of IS degrees. They are 81 feet long,
and extend down nearly to the keel. Under
| meath the guns, and on both sides of the
keel, are twenty air storage reservoirs, each
Is feet long, Is Inches in diameter, and thick
! enough to resist pressure OF 1000 pounds
| per square inch, the air being raised to that
| pressure by powerful air pumps. In com
| munication with the storage reservoirs is
| the firing reservoir In which pressure Of
| 1000 pounds is constantly maintained.
| From the firing reservoir the air is admitted
to the gun barrel In the rear Of the shell,
and starts the latter on Its journey. The
valve that controls the admission of the air
involves the mechanical difficulties alluded
to above and its construction Is part OF the
secret of the invention.
The method Of operating the guns is very
interesting. The gun barrel is hinged at
the lower end, and section about twelve
feet long may be raised to join the rest Of
the barrel or lowered to horizontal posi-
tion for loading by means of hydraulic
ram. Forward Of this section of the gun
are two fve-barreled revolver cases, each
containing five shells. These revolver
cases turn on central spindle, working
exactly like the cases in which the cart
ridges Of an ordinary pocket revolver are
slowed. In loading, the lower section Of
the gun barrel is lowered to the horizontal
position by the hydraulic ram; the revolver
case Is turned until one Of It's barrels con-
tanning shell is exactly in line, and a n.y.
draulic rammer then pushes the she'll from
the revolver case into the breech-section OF
the gun, after which the hydraulic ram
again raises the lower section until It is in
line with the main portion OF the gun.
The captain, in the armored coming
tower, operates the firing lever which con-
trolls the firing valve and fires the gun at
will. An automatic attachment prevents
the gun being fired when the portion B is
avoiding self-destruction. The gun is a
smooth bore. To rifle 1t would increase the
strain on the gun and the projectile, and
increase, by the heat OF friction, the danger
Of premature explosion. Instead of rifling
the gun the shell is so constructed with
fanges at the base-acting the same as
feathers on an arrow-that II Is kept steady
point first. The shell is made OF thin brass
sheets, is about seven feet long and has a
conical point. There is heavy shell and
light shell. The former contains 500
pounds OF explosive gelatine with core of
dynamite. and the latter contains 200
Il pounds Of gelatine witha dynamite core.
The dynamite is used to explode the
gelatine, which is more powerful and lesi
sensitive than dynamite. The shell con
tains two fuses--one, an ordinary percus
sion fuse, will cause the shell to explode
, | Instantly In case II strikes the hull Of yes
sci above water; the second fuse will act
In case the shell strikes the water first
This is done by admitting salt water, which
closes an, electric circuit and ignites a trair
OF powder and illuminate The water will
, evidently be forced In when the she'll strikes
the surface. A little delay In the explo
sion is secured by the time necessary t
burn the powder train, aud this delay per
mits the shell to sink few feet, thus bring
ing it under ships bottom and blowing
her up like an ordinary torpedo. By thi
kmethod the dynamite shells are mad
, doubly destructive, and are expected I,
make the Vcsuvius one Of the most effec
tive vessels in the service OF the Govern
| ment.