The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1896-01-13
NEW WEAPONS OF DEFENSE.
Dynamite Guns Capable of Throwing
PrOjectfIes Three Miles.

Washington Special to New York Tribune
An interesting report on the work of i'm
proving the countrys coast defense has
been received at the War Department. 1t
pneumatic dynamite guns of forty calibres
length now in position at Fort Winfield
Scott, Cal. They were contracted for by
the government some time ago. The trial
board now reports that they are in place;
that they have been tested. and that the
country Is the possessor Of three additional
important weapons of defense. AS a result
or the trial the guns will be accepted by
the War Department. and as soon as a sup
lenses Of the harbor of San Francisco will
be much stronger The experiments with
the guns began early in December and con-
tinued for number of days, as the weather
permitted. In the course Of the test eleven
projectiles, three charged with five hundred
pounds OF explosive gelatine, and eight
charged with one hundred pounds of the
same, and fifteen dummy projectiles of full
calibre and weight were fired. The pro-
jectiles were fired seward. The explosion
impact with the water, threw up a column
about three hundred feet high and the
acknowledgement shells threw up col
The official report says that the test for
the capacity of the compressors of the guns
able of supplying air in sufficient quantity
Tor firing continuously forty-five rounds an
hour at extreme range Forty-four rounds
minutes. At the beginning of the test the
pressure per square inch in each gun
Loo pounds, and in the storage reservoirs
ZOO pounds. Through the first part of the
test the compressors had difficulty in
keeping this pressure in the reservoirs, the
engines running under eighty-seven pounds
OF steam. The last twenty rounds were
fired at minute intervals. and no effort was
made TO keep up the storage pressure; ii
only fell to 1,7S0 pounds at the ffty-fourth
shot Using one gun, twenty rounds-air
shots-were fired in seven and a half min
utes, the pressure i'm the storage tanks fall
ing from i.1s9 to 1,2So pounds, the engines
steam. That the loss of air was sufficient
to produce extreme range was shown in
the accuracy test, in which one gun, No. g.
with the same loss of air, produced range
of over 5000 yards.
The traversing and elevating of the gun
is sde for the of he wopR
by hand IL required. The flight of the eight
inch subcaliber shell charged with one hum
full caliber fifteen inch shells charged with
five hundred pounds of gelatine we're I'M
steady in flight. They had gyrating mo-
about the line of flight, the head in a
small circle. Members of the board found
1T difficult to observe whether these shells
always struck the water point first. There
was no failure. however to fire the fuse
and explode the shell. The fuses used were
mechanical and were set for instantaneous
two seconds. Those set for action on inn
pact worked desired. Two shells were
fired with fuses set for two seconds delay.
One of these fell at such range that the
length of delay could not be obtained.
though a delay was observed. The other
fell at short range and a delay of exactly
two seconds was noticed. The valve mech
anism of the gun and all the working parts
of the system acted In a most satisfactory
manner. throughout the experiments
test for rapdity of firing and loading. Four
shells charged with one hundred pounds of
explosives were used to ietermine accura-
"a or n "a 1S
for range, fight, etc. Shells charged with
one hundred 10 five hundred pounds Of ex-
mum distance attained with the r Suni irA
pound shells was 500 yards (about three
miles,, and with the five-hundred-pound
test for accuracy which the limited supply
Of projectiles permitted was made with four
shells charged with one hundred pounds OF
of 5.03l yards, near dispersion in range
OF twenty-three yards, and an extreme dis
The Oh n seseffy bos sbe usng the f ne
pact as the line Of fire the mean deviation
from that line was sixteen yards, the ex-
two N,'' yards to the left. and the extreme lat
eral diversion was flfty-two yards. A sum-
mary of the shots fired shows that IS per
of $50 by ninety feet A range of 5000 yards
and rectangle of twenty-one by 156 feet
would have contained AL the hits
Two shells with one hundred pounds OF
explosive were fired from different guns on
different days at hillside about 300 yards
distant from the guns The shells struck
sixty-one feet apart 1t is of interest, the
report says, TO know that the craters
formed in the soft red rock by the explosion
of the shells were bowl-shaped, % feet in
diameter and 4 feet In depth in one case,
and 80 feet in diameter and feet in depth
in the other These shells were provided
with impact fuses. All shells fired for i'm
pact showed satisfactory action of the
fuses. In the test for rapidity OF loading
and firing five dummies. representing shells
containing 500 pounds of gelatine, were fired
in minutes and % seconds. the longest in
terval between shots being two minutes.
The time OF maneuvering the guns by cleo
trio power from extreme depression to ex-
treme elevation and the reverse varied be-
tween nine and thirteen seconds. The time
required for traversing through $50 degrees
by power varied between forty-one seconds
and one minute and thirty-eight seconds.
BY hand one gun was traversed by the
crew in eleven minutes twelve seconds. and
elevated from zero to thirty-five degrees in
forty-seven seconds. and back in A seconds.
The particular gun tested for this purpose
was the most difficult of the three TO ira
verse. Consequently the other two can be
maneuvred more rapidly. although the time
is reg n satisfactory