The Abbeville press and banner. [volume] (Abbeville, S.C.) 1869-1924, 1894-10-03

fraction of second. The difficulties
encountered in accomplishing this have
not been overcome. The department
has already expended $50, 900 upon ex-
periments with these guns without any
decided improvement. Without en-
tering further, at this time, into the
merits of the system, the bureau rec
ommends that further experiments
be deferred until after the installation
at Sandy Hook of the ffteen-inch
guns now in course of construction for
the War Department. In these guns
the company promises to overcome
the difficulties which exist in those of
the Vesuvius. ... e..
Next to the interest that attaches to
this establishment of the effectiveness
of dynamite as an ammunition, prob
ably as interesting lesson Of the re-
cent tests is to be drawn from the use
of compressed air in the guns. The
officers say that for many reasons it
would be impossible to use powder.
Perhaps the most important is that it
would detonate so sensitive an explo.
sive as dynamite. The 36, 900 pounds
pressure to the superficial inch, which
is about the average force Of powder,
would cause the projectile to explode
before it left the gun. Another ne
cessity which renders the use Of pow.
der impossible is the Importance of
keeping the gun cool Powder would
heat it to such an extent that the dy.
namite would explode. As It's, the
pneumatic gun is made cooler by every
introduction OF compressed air. If
powder we're used the she'll of the pro-
jectile would have to be very much
heavier than It is now, and there
would be less space for the explosive.
The largest projectile now weighs ll20
pounds, and about forty-fve per cent.
of this weight is in the explosive,
which in these large projectiles weighs
500 pounds.
The projectile must, moreover, be
expelled at uniform rate. The first
shock of the explosion of powder, di-
minishing until its force ceases, would
cause the r'roiectile to explode, while
an explosion is prevented by the un-
varying pressure of compressed air,
which maintains the same rate about
1000 to the inch-throughout the gun.
Another reason given by the company
for the use of compressed air is that
the force OF powder is likely to be
variable. 1t is not always uniform,
and for that reason greater accuracy
is obtained by the use of compressed
air, which they say they can be GER
tain will always produce an exact re.
suit. In addition to these ad-
vantages, as the company regards
them, there is, of course, no dirt or
smoke or necessity for scrubbing out
the gun after it has been used.
The idea of using compressed air as'
substitute for powder is said to have
originated with Toledo mechanic
named Meffort, who had made study
of explosives. The pneumatic gun Of
to-day is said to have developed from
an idea suggested to Meffort by ar
rangement of piece of gas pipe and
roughly made dynamite torpedo. He
succeeded in throwing his projectile
by means of ON Impoverished mortar,
but could not mako it explode more
than once or twice IN half dozen ef-
forts. This was due to the fact that
his fuses were not adequate. Since
that time Mefort's idea has been i'm
proved upon from time to time until
the present gun was devised, and
members OF the company say that the
latest tests have suggested possible
improvements in the details of the
gun.
The gun and carriage weigh in the
aggregate ffty-two tons, but tho gun
can be moved by the turn of wheel
or aimed in any direction. A tele-
scope stands by The gun, aud through
this the gunner places ais elm. The
gun is moved by electricity. The
compressed air is conveyed from the
engine rooms by means Of pipes to
wrought iron and steel reservoirs,
which are in chambers under The gun