The sun., 1898-06-19
FIRING OF BIG GUNS
Affects the Body and the Chemical
and Physical Changes Brought
About in So Doing.

and Physical Changes Brought
About in So Doing.
Not one man in ten thousand has a
clear idea OF just what happens when a
big cannon is fired. The physical mani
festations are numerous. Even pro-
fessors of chemistry and physics are
stumped when they want to differentiate
all the gases set loose and the peculiar
effects they induce. The puff of whitish
smoke, the flash of fire, the dim image
of the flying projectile, the roar and the
recoi are ali familiar, but back OF these
is complex mass of phenomena most
bewidering to the mind OF any but an
artillery expert.
First, the cubes, discs, hexagons or ir-
regular Jumps Of powder are chemically
transformed into powerful, expanding
gas the instant firing takes place. Then
there are innumerable by-prodncts that
even chemists do not understand.
The explosion of gunpowder is divided
into three distinct Stages, called the gnl-
ton, Inflammation and combustion. The
ignition is the setting on fire of the first
grain, while the inflammation is the
Spreading of the fame over the surface OF
the powder from the point OF ignition.
Combustion Is the burning up OF each
grain. The value OF gunpowder is due
to the fact that when subjected to suf-
ticient heat it becomes gas which ex-
pands with frightful rapidity. The So
called explosion that takes place when a
match is touched to gunpowder is merely
a chemical change, during which there
is a sudden evolution OF gases from the
original solid.
It has been calculated that ordinary
gunpowder on exploding expands about
nine thousand times, or fills space this
much larger as a gas than when in a
solid form. When this chemical change
takes place in closed vessel the expan.
sion may be made to do work like that
of forcing a projectile along the bore OF
the great gun or test-tube in the line ol
least resistance.
The hardest work gunner is called
upon to do is to stand the tremendous
shock. The forces exerted by these gases
in expanding seem to radiate in all al
directions from the cannon, as ripples
are caused by dropping a pebble in
pool of still water. As matter OF TACT
It has been discovered that these lines Of
forces are exceedingly complicated at
fairs and play very queer pranks about
the cannon. As result few people know
lust which is the safest or the most dan
gerous position for gunner to take be-
side his gun. In the case OF the great
thirteen-inch guns on our monitors.
position back Of the gun is much easie
than one nearer the muzzle.
In addition to this force there is al
immense pressure exerted on the sides o
the cannon, SO that another distinc
series of shocks also radiates outward
from the barrel Of the gun. These lines
of force are influenced, besides, by the
rec Ill of the gun, which tends to make
the lines curve outward and intensifie!
the shock. These are in turn more o.
less compensated by the forces OF the all
opposing them as it rushes into TN
mouth OF the cannon when the projectile
leaves it. As result OF all these forces
the atmosphere is, of course, violentl.
disturbed. Although no projectil'
strikes the gunner, who must stand by
il will be seen that the air is full o
missiles in the form of invisible lines Q
force or vibrations which lombard, as i
we're, every part of the gunner's body a
the same time.
An examination and analysis OF tin
, effect produced upon the human system
and the mind by the firing of cannon
is most engrossing. Men general.
accounted courageous tremble violently il
their knees; others feel na,lseated; som
have severe headaches; few have ha.t
their eardrums split or the action OF thel
heart affected.
Take the vital organ, the heart, first
In the space between the right aurlcl
and ventricle are set of fine, thread
= like cords called the tendincae. TIN
= conclusion makes them tremble lik
timbers in building when there is al
p earthquake. In a weak man, the cham
Der of the heart is left open for an in
slant; the opening and closing spring
lose their control; the heart shakes; pos
sibIy the chordae tendineae are snapped
contraction or dilation of the crgal
ens,,es and in some instances death fol
lows.
Deafress induced by an explosion ma,
be traced to the sudden pressure npol
the inner DflllNe vi plle cttl ll.t viz Wv
mendous vibration set up. The thin
transparent, fairly bright membrane
called the dr'lm of the ear is burst, ike
piece nf tissue paper held taut and forci
blv blown upon. Sounds are conveyed
by the beating Of tiny malet upon thi
anvil. II the beating is too rapid ant
l. too fo,cbIe, the membranes may be rup
tured. a temporary disturbance of tht
mind occurs and the sufferer becomes
dizzy.
When the knees tyemble it is due tt
the nervous shock produced in the
cerehelltm All the nerves and muscles
art. thrown into atomic contractions ant
plaxations and the knees appear to give
WY.
Nausea j. also caused by the physio
l. gicrl change that takes place in th(
rain. There is pressure OF blood there
md the stomach, responding, tries t'
mpty itself.