The Londonderry sifter. (South Londonderry, Vt.) 1883-19??, 1898-05-27

The Latest Device for Throwing Shells
Loaded With High Explosives.
The newest type of dynamite gun
consists of two tubes placed directly
one above the other, whereas in the
old type there are three tubes placed
side by side in the same horizontal
plane. The elimination of the third
tube means a great saving in the
weight of the gun and at the same time
it is claimed it's effectiveness is in
creased. 1t is said that the gun can
be fired at least five times in two min
utes.
OF the two tubes the upper is several
feet the longer and is smooth bore. 1t
receives the projectile, and the mater
ial used in it's construction is either
brass or steel, the latter being prefer
able. Within the lower tube there is
an inner tube in which the blank cart
ridge containing seven ounces Of
smokeless powder is placed. The in
ner tube opens into the lower tube,
which in turn opens into the upper
tube through port Immediately be-
hind the projectile. When the pro.
jectile is placed in the upper tube and
the blank cartridge in the lower, the
breeches are closed and the gun is
ready for firing. The pulling of the
lanyard explodes the smokeless pow
der, which congresses the air in the
tube, and this, passing into the upper
tube through the port, exerts there a
pressure of 5000 pounds to the square
inch. This pressure expels the pro-
jectile. The air forms cushion that
protects from shock the walls of the
shell, and, it is claimed, obviates the
danger which would follow from the
conclusion of the powder were it ex-
ploded directly behind the projectile.
The entire length of the projectile
used is thirty-four inches. This in
cludes a tail piece about ten inches in
length and fitted with vane set at an
angle that insures slow rotation. The
| body of the shell is brass cylinder
having a conical head containing
| fuse. The main body of the shell con-
tains usually charge of explosive
gelatine, although guncotton or any
other explosive may be used. The
ignition is effected by means of me-
chanical fuse, and it is SO arranged
that the explosion can follow immed-
lately upon impact or may be delayed
| for as much as six seconds thereafter.
/ When the shell strikes the water or
| any other object, small steel ball,
acting as hammer, is driven forward
by the sudden retardation of the flight
of the she'll and strikes one or more
percussion caps, causing a defamation.
This ignites tube of powder commu-
nicating with the illuminate of mer.
curry, and so explodes successfully the
guncotton and the main explosive. The
fuse embodies a device which renders
the shell inactive until it has travelled
at least 300 feet from the gun This
device is very ingenious. There is
attached to the head of the fuse a lit
tie vane or windmill, which is fastened
to threaded rod running back into
the head of the fuse far enough to
press on the small steel ball mention
ed, and hold it in place. AS the pro-
jectile passes through the air the
blades revolve, and, in revolving, I'M
screw the threaded rod, and thus re-
lease the small steel ball, which is now
ready to run forward and explode the
primers.
In connection with the firing of the
gun there is neither smoke nor noise.
1t cannot be heard at the distance of
one-half mile, nor can any smoke be
seen. Thus it would be nearly i'm
possible for sharpshooters or rapid-fire
gunners to locate the gun.