Walker Lake bulletin. (Hawthorne, Nev.) 1883-1926, 1902-04-18
LOADING THE GREAT PINCH RIFLE PREPARATORY TO SHOT

records the time when the shot breaks
it. Then as the projectlle pierces frame
after frame along the range they, too,
telegraph the exact instant to waiting
instruments.
But even the practically instanta-
neous record made by an electric re-
corder Is not swift enough in itself.
Electricity has to be helped with In
genious means The wires that are
scattered along the range do not lead to
an instrument that makes n record on
paper That would be far too slow.
They lead to the queer apparatus OF
polished steel, able to record inconceiy-
able fractions of seconds. 1t is known
as the Sieber velocimeter. Its notice
able feature is chunky, beautifully
polished cylinder of steel few inches
long. 1t has one sharply pointed end,
BY this end, which is magnetic, 1t just
hangs to an upper supporting arm.
When the shot breaks the first wire,
it, in turn, breaks the electromagnetic
that holds the steel bar, and down it
falls 1t has only a few inches to drop.
Yet before it falls that short distance
the projectile has smashed through
framework after framework. As the
successive wires break, successive cir
cults are broken, and tiny, sharp
gravers shoot out from the sides of the
instrument and strike that falling bar.
Each graver marks it, and by the time
the shot has struck its mark the little
steel cylinder just about reaches the
end of its drop. Now, knowing to the
thousandth part of a second how fast
it dropped, the ordnance expert can
calculate the swiftness of the proJectile
by measuring the distance between the
marks scratched on the cylinder by the
gravers.
To measure the recoil another sim
pie method is used. One end of a long.
thin strip of steel, with its face smoked
to a uniform blackness, is fastened to
the carriage of the gun. Near the muz-
zle end of the cannon is an apparatus
with a tuning fork so arranged that a
spur on one of its jaws just touches
the face of the blackened face of the
steel band. When all is ready for firing
this tuning fork is set to vibrating by
an electrical instrument that makes it
vibrate exactly 1000 times second
without varying a single vibration.
When the cannon is discharged the re-
coil naturally jerks the steel band back
ward, and the little spur on the fork
marks long waving line on the steel.
The band is dipped in solution that
fixes the record so it will not rub off
Sometimes gun will undergo tests
for year or more, each shot being
carefully recorded and little history
being written about it before the Gov
eminent gets final report on it. Many
a cannon has had enough to fill n big
book written about it in successive re-
ports of tests and then been rejected.
If gun gets the so. K" mark from
Sandy Hook it is a good one. Foreign
Governments realize that more keenly
than do the people of the United States
Foreign military men consider the
proving grounds on Sandy Hook as one
of the most authoritative Government
departments in the world. and its re-
ports are at a premium in every war
office on the globe.
If type of gun doesn't develop a
feverlsh pulse before its test is ended
and If it Is accepted finally more guns
of the same pattern are ordered. An
army officer superintends every step of
their manufacture and sees that each is
made exactly like the gun that was
tested As each is finished it is sent TO
Sandy Hook to he proved" Five shots
are fired from it under service condi-
tons, and If it acts correctly it is sent
on to coast fertilization. Not a single
gun is mounted to-day in a fort unless
1t has been through the hands of the
proving ground officers.