The morning news. [volume] (Savannah, Ga.) 1887-1900, 1898-06-26

the gun and only shut a door behind It.
what is to prevent the tremendous force of
the eXploSion-strong enough to drive that
huge shot through twenty-six inches Of
stecl-from blowing the door open and
killing everybody in rear of the gum"
A vast deal of ingenuity has been ex-
pended In devising various ways and means
of answering that question. and 10 refer
to even 1.-THE of them In detail would be
impossible here. Still. we can easily get
a general idea of how the thing Is done Ev-
cry one knows what a screw stopper is
a pug with screw threads on It which Is
screwed into a hole on the inner wall of
which corresponding screw threads are cut.
This is very strong and excellent means
of closing the opening, but not useful, as
it stands, for shutting the breech of a gun;
because among other reasons, K would
take too long TO screw In such large and
heavy metal plug as would be needed
rms dlfficulty is, however, met by cutting
away parts Of the screw threads in both
gun and plug, 50 as to make longitudinal
scores IN both from which no threads pro-
trude. Now when the plug or block is
put into the gun. the threaded parts of the
pug slide easily intod the longSbudinalz
scores in the gun; but as soon as the plug
Is turned on its axis then its screw
threads all meet the screw threads In the
gun and engage with them; so that all the
threads on the plug engage with all the
threads in the gun simultaneously. and not
successfully, as would be the case n the
plug were gradually screwed into the eun
or course the plug or breech block In the
sIeat guns IS a very heavy mass of steol
which requires machinery and sometimes
engines to manipulate it, But ali Of the
mechansms push in the plug and then
turn 1t In proper way to make the screw.
threads catch, or else turn il in Tho re-
verse direction 10 release the screw threads
and then pun it out, sometimes landing "
upon a swinging tray so that ii can ns
swung to one side and out OF the wav
while the shot and powder are being mn,
into the gun N1'
or course, 1t may seem that gas undo,
SUCH tremendous pressure as exists In fna
gun would force it's way through the mi
hutest crevices in the breech and so do
harm; but this Is stopped by The "aoa
check, which Is a steel mushroom with
It's stem passing rearward through the
pIeech-block and having under ats head a
steel-coVered pad OF asbestos and grease
which being enormously compressed by
me explosion expands very tightly and
hlls up the bore
The firing of the gun Is a very simple
operation. A hole is made through Inc
stem OF the mushroom gas check and into
tnat Is PUT primer provided with fulmI-
nate which is exploded when the hammer
OF the spring lock strikes it; or els. an,
electric device IS inserted which is iRnitef
Dy pressing bottom 10 close the circuit.
me flame shoots through the vent-hola
ana SO reaches the powder in the guns.
We have now built our gun. Il has got
TO be supported so that It can be directed
TO throw its shot exactly where that mis-
sic VIII DO the enemy the most harm and
incidentally ourselves the most good The
great guns OF the navy, which go to make
up what is called the main battery on a
man-ofwar, are by no means light affairs
The smallest have bores four inches IN o.
ameter, and the largest thirteen inches
and their weights range from a ton and a
half to sixty tons. The four-inch. five
inch, six-inch and eight-inch guns are gen
orally placed In broadeide The 1O-incb
12-inch and 13-inoh guns are turret guns,
The broadside guns are mounted on carr
riages The turret guns are arranged In
the turrets which are rotated by power
full engines, so that the guns are thus
trained to bear on any point of the hori-
zon. ~
There are many kinds of gun carriages
or mount, but generally described there Is |
usually lower so-called slide mounted on
very heavy rollers, which rest on circular
tracks on the deck. The carriage proper
rests on the slide and receives the gun
trunnions or side pivots which are SO
placed that the gun Is fairly balanced. The
parts of the slide on which the gun car
gun Is fired and its recoil, or kick. lends
to move II onward, Il has 10 run up llE
Furthermore the gun carriage Is fastened
to a piston, which fits In a cylinder of ely-
cerine and water The firing IS something
like a syringe only instead Of the piston
forcing the water out through little noz-
zle, there is a small score on the inside
wall OF the cylinder which lets the piston,
as 1t moves, dispiace but a small amount
of water from one side of It TO the other.
This greatly retards the motion of the piss
ton and hence of the gun. After the gun
has got through its kick it Is arranged to
slide back to proper position by its own
weight.
This hydraulic control Is a great advant-
age. The gun jumps IN 50 llttle that It h
not even necessary 10 tell the men 10 get
out Of the way, which used 20 cause loss
of valuable time when one wanted 70 fire
the instant a good view OF the target was
got through the sights. The old-fashon-
ed guns were mounted on ordinary wheel
ed carriages. and help by piece of heavy
rope, fastened at It's ends 10 the side Of
the ship. When they were fired they
jumped In carriage and all for about six