The times., 1898-07-11
THE SPEED OF BULLETS.
Small Ones Become Hot From the
Velocity.

Velocity.
New York July 10.-Mention is often
made during these days of the great
speed of projectiles fired from modern
guns. The velocity ranges from 1,5C0
to 5000 feet per second. 1t is comput-
ed that the average velocity OF the
larger guns on the cruiser New YORK is
2,100 feet per second. To the uninitiated
the way in which this is found out
should be of interest, says the Chicago
Times Herald.
In the first place it may be stated that
one cannot time a projectile as one
would a horse Some of them can De
seen as they rush through the ar. 1t
is a favorite amusement during the
battery drill with the old seacoast guns
at West Point 10 stand behind and
slightly above the guns and watch the
projectile from the moment it leaves
the muzzle until it strikes the target
painted on old Gro Nest mountain,
about mile away. Spectators with
good eyesight can also see the shell
fired from the largest mortar rise TO the
highest point of its course, and then
descend with rush upon the mountain
top, mile and half away, where
it bursts into many pieces.
1t is reported that during the recent
bombardment of Santiago the shells Of
the cruiser New Orleans could be fol-
lowed by the eye. This was largely
due 10 the use of smokeless powder,
which permitted clear vision.
IN.
with greater velocity, ii is imposs. BILE
to see them during flight But whether
they can be seen or not, Ii is quite out
OF the question to time them as one
would a race, bv simply using the eye
and d step watch! The least hesIta lion
in pushing the spring would maze a
difference of hundreds of feet in the
distance travelled. Errors such as these
would make the results of no pracucal
value.
Our small arm shoots bullet only
one-third ef an inch in di.meter, whicn
! travels 2,6UU feet in a second. or a mile
| in three. II goes so fast that il be-
comes hot to the touch, due to the
! resistance of the air which it pushes
| aside. Strange 10 say, the heated bull
| let Will cauteriZe the wound of its own
| making, and few of the wounded
| in our war with Spain will bleed TO
| death unless struck IN vital spot
/ The projectile has, besides the for
| ward velocity, a rotational velocity
| which is given TO it by the rifiing OF
| the gun. Otherwise. since its length
| is much greater than its diameter. ii
would soon begin to turn on end. The
| rifiing prevents this by causing the
! bullet TO bore path through the air
| and the higher the forward velocity
/ the higher. too, must be the rotational
| This turning over and over would de-
| stroy the range and the accuracy OF
the gun.
! The determination of the forward We.
/ locity is now made with extreme ac-
| curacy. The knowledge OF it is of the
! utmost Importance to military science
! Various methods have been adopted fol-
its determination within the gun, as
well as at various points of the traiec-
! tory.
The following method is the one
adopted by all nations for finding the
velocity of projectile at any point OF
| its path after leaving the muzZie OF
| the gun. II is so simple that brie1
explanation Of it will make it intelh
Two screens, SO closely strung witt
gible to all.
copper wire that a projectiIe in pass
ing thrugh must break one or more
of the strands, are placed fifty yards
| apart. The wire on each screen is con.
nected with a battery which sends E
| current through it, and two instru.
ments, one called a disjunctor, the Other
the chronograph. Although both cr
| cults pass through these Instruments
yet they are kept distinct and sepa.
rate.
The chronograph answers the pur
pose of a stop watch of greatest accu
racy. Two bars are held up by eIec
trio magnets; the currents flowing il
one magnet also flow through it's re
spective screen, while the current of tn,
other passes through the second screen
The disjunctor is an instrument which
is used to break both circuits at tn,
same instant As soon as this is don
the bars fall since the electromagnetic
cease to act when there is no curren
| flowing through them. The bar eon
nected with the first screen falls upol
a. small platform. which releases
wedge-shaped piece of metal Thi
strikes the bar connected with the sec
ond screen. leaving wedge-shape,
slit in it as line of reference durin,
the experiments.
This being done, the currents ar
established again and the rods place,
once more under the influence of tn
electro magnets. Let a 32-inch riff
whose muzzle velocity is TO be found b
placed in front Of the first screen
The gun is aimed, fired, and it's projec
tile passes quicker than the roar O
the discharge through the first screer
breaking some of the wires; in anoth
er instant it is through the secon
screen destroying it's electric currenr
and at last finds a resting place i
some distant sand pile.
The break in each circuit is communj