Los Angeles herald., 1909-10-13

the orulnary steel-Jacketed gun at
twenty yards. Congress was impressed
with his claims, and voted him a pile
of money to build a ten-inc.. gun 1t
was tried beside the Crozier wire
wound, and the experts decided in fevor
of the latter.
It was claimed for the Brown gun
that it could hurl a six-hundred pound
projectile fifty-nine miles, and that If
siXteen-inch model were built, it
would have a firing range of one hun
dred miles. Even with the ffty-nine-
mile firing range Of the ten-inch gun.
the paper description of it showed that
the shells would reach a maximum
height of eighteen miles above the
earth during their flight travelling
seventy-one miles. 1t was explained
that the energy with which the proiec-
tile was hurled from the gun would
be equal to the lifting of sixty large
freight locomotives ten feet in a sin
gle second. With such a gun 1t would
be possible to lombard New York or
Boston, and to throw shells into Phil
adelphla from the waters off Atlantic
City.
More interesting, perhaps, than the
mere making of the big guns is the
manner of testing them and ascertain
ing their true values. We hear much
about the muzzle speed of a cannon
pan, and wonder how it can be accu-
rately told. An instrument called the
chronograph supplies this information.
There are two targets connected with
the chronograph by electric current
AS the projectile passes through the
hrst target it releases a weight from
an electro magnet, which in falling re-
cords the time the projectile passes the
hfst target Another released weight
marks the time of passing the second
target, and the difference shows the
time of passing the known distance.
10 measure the pressure in gun fire two
methods are used The one places n
piece of brass in a steel case. A piston
IS connected with this piece of brass,
and the pressure produced by the ex-
plosion, acting on the piston, COM
presses the brass, which is afterward
taken out and the degree of com
preston determined. This gives the
basis for the calculation of pressure.
Inc other method is to measure the
distance of the guns recoil and com
pute the pressure from that data,
A testing machine has been installed
by the government at the arsenal at
Watertown, Mass, which can register
the breaking point Of metals IN tn tbe
enormous capacity of 100000 pounds.
All metals that go into big guns must
ne tested, and the date of their build
ing as accurately prepared as if it were
the making of prescription contain
ing dozen deadly poisons. One two
thousandth of an inch is as wide Of
the mark as the average shrinkable
surface can vary from exactitude,
and If piece of work gets more than
one-hundreth of an inch away from
the exact in length it is rejected.
Perhaps the most interesting piece of
ordinance construction from the Law
mans point of view is the Whitehead
torpedo, now the worlds standard.
David Bushnell of Connecticut may be
said to have been the father of tor
pedoes, as well as of submarine boats.
In 1776 ne perfected a little one-man
submarine, with which he attacked the
British man-of-war Eagle, then lying
in New York harbor. He had a tor
pedo which he attempted to screw
fast to the bottom of the warship, but
failed because he struck iron. Failing
to attach 1t, he dropped the torpedo in
the harbor where it exploded at the
very minute he had planned for it to
go off If attached to the man Of war.
The Whitehead torpedo is a descend
ant Of BushnelPs idea. It's motive
power Is furnished by compressed air,
stored in tank within the torpedo, at
a pressure of about 110 pounds to the
square inch. In chamber back OF the
compressed air tank is the mechanism
LOA iSS uldllllS the u6plH at which the
torpedo shall glide along in the water.
There is a piston which is held in
balanced position by the pressure of
the springs on the one side and of the
water on the other. When the torpedo
goes too deep the water pressure drives
the piston out of the normal position,
thus forcing the submerged rudders
upward and pointing the nose of the
torpedo upward in the same propor-
tiOn When II patG tOn fha
face the springs force the piston to
the other extreme and the torpedo is
guided downward. This would keep 1t
gliding first upward and then down
ward, so a pendulum is introduced
which perfects the depth determining
apparatus.
In the tail of the torpedo there is
little gyroscope. If the torpedo at
tempts to turn either to the left
or the right the gyroscope, true to it's
own law of motion, adheres to it's own
straight line, and in so doing opens
little valve in a small steering en-
gine which moves the vertical rudders
in such a manner as to bring the tor
pedo back to its course. This gyro-
scope is the driver which guides the
steed of death on it's errand of de-
struction. There is also a sea valve in
the torpedo, and If 1t misses its mark
1t is automatically sent to the bottom
Of the sea.
Tomorrow-ChiIdren on the Stage.