The Fulton County news. [volume] (McConnellsburg, Pa.) 1899-current, 1901-12-19
TESTING THE BIG GUNS
MINUTE OBSERVATIONS MADE AT
THE p7ovNc.SRoUNDs.


cy of two Magnets, a steel Rod, and
"A Knife -Biade-A Metbodicai Operation
The Government ordnance proving
ground at Sandy Hook is busy and
thunderlngly noisy place just at this
season of the year, and every week
thousands of dollars worth of armor
plate, projectiles and powder are util-
lied in demonstrating that this coun-
try possesses the best guns. the best
steel armor, and the most efficient ex-
plosives in the world. 1t seems al
most wanton waste of material to
heave ponderous steel shell or armor-
piercing projectile, which is the prod
uct of the finest machinery, against n
steel plate which has required the work
OF many men and years Of experiment
ing to bring 1t to its perfection and
submit 1t to demolition.
But Governments are proverbially
prodigal when it comes to testing these
offensive and defensive weapons, their
substitutes for "wooden walls" 1t
would indeed be niggardly TO count
the cost of even half dozen armor
plates, several hundred pounds of pow
der. and a dozen or more steel shot
and weigh it against the millions rep
resented in a battle-ship, to say moth
ing of the lives of four hundred men
and the dignity of the nations flag.
Time was when the testing of gun
was, viewed in present lights, slipshod
unsatisfactory sort Of process. Much
tol~ tn1 .
had demonstrated It's ability to hold
together during the strain of dis
charge. There were few Of the nice
ties" Of a gun test. But now the prov
Ing. Of gun Is as careful and method
lcal an operation as the testing of q
watch. Not only must it hold to-
gether, but it must demonstrate its in
tention to hold together under rapid
and continuous use, it must show itself
capable of giving the projcctles a high
velocity, a comparatively fiat trajec-
tory and he as good n gun afterward as
it was when it left the lathe and the
pit.
Velocity is the thing, for that means
range and penetration. The seacoast
defense guns, which stand to guard
the country against the invasion of a
naval force, are designed to hurl shells
fllleG with high explosives against an
enemy's ships, to penetrate their ar
NOR or vulnerable parts, and, through
delayed action Of the shell fuse, to
blow them "out Of the water"
SO. after a gun has behaved properly
with powder. the test for velocity is
imposed, and this brings into use an
instrument which performs its task
with an accuracy which is simply as
founding. 1t is used to measure the
velocity of the projectile and is called
n chronograph. 1t depends upon the
fundamental law of gravtatlon. and is
at once simple and complicated. The
principal IS certainly simple.
In general way the chronograph
consists of a powerful magnet, a steel
rod, and knife blade. These three
parts, with others naturally related to
them, are mounted in structure set
at cons. erable distance from the en-
placement from which the gun is to
be tested is mounted. This Is to OBJ
vlate jarring when the piece is dis
charged. At the top of the machine is
the powerful magnet which, when the
current is closed holds the rod sus-
! pended as an armature. The rod hangs
over an aperture in the base of the
instrument, and at one edge OF this
opening Il knife blade is placed and
held back against n spring by another
! electro magnet. The brick foundation
upon which the instrument is built
goes many feet into the ground in Or
der that the greatest stability may be
obtained.
To return to the gun, two square
frames are erected on the line OF fire,
the first one hundred yards from the
muz2le of the gun, and the frames
exactly one hundred yards apart. Back
and forth across these frames is a net
work of wires, rather cross weaving
OF one wire, which runs from the
frame to the instrument in the distant
house, and is connected with the cleo
tro magnet which holds the slender
steel rod. The second screen is like
Nilt save llul ltS Mllt W
the second electro magnet, the one
holding back the knife blade at the
base Of the chronograph.
Then, with the current on. the rod
suspended, the knife blade restrained
against the spring, the gun is fired
The projectile pierces the first screen
the wire is broken, the current is
opened, the magnet Is demagnetized
instantly and the rod drops. The pro-
jectile speeds across the hundred-yard
space, and plerces the second screen,
breaking its wires and breaking the
electric current. This releases the
knife blade. past which the rod must
fall, and, energized by the spring. the
blade flies forward and strikes the rod.
making Il minute nick upon it. BY
this time the projectile has flown into
the great sand butt and buried itself
and the nicked steel rod has dropped
into sand-filled receptacle. The ve-
loclty has been denoted by the utiliza-
ton of a simple law.
1t Is known that falling body fails
sixteen and one-half feet the first
second. thirty-three feet the second,
and so on in this ratio until it reaches
earth. Applying this principle to the
rod, 1t is known that the foot was ex-
actly at the level of the blade, so that