Evening star. [volume] (Washington, D.C.) 1854-1972, 1911-07-23

finitesimal fraction Of a second to make
good-sized portion OF the plate yielt
to the first force Of the blow. more -
than a sharp point with its limited area
of contact. ana while the plate is 80
yielding. the point OF the projectiis
pierces Its own cap and drives itself un-
impaired into the relaxing fbers of tho
steel. effecting penetration through tho
hardened surface and the underlying
tougher metal before the mass OF tho
plate can recover and unite in hating
the shot.
Where the face Of the armor plate a
ened steel. as Is the case with some SORT,
of armor plate, the unprotected point OF
the projectile can do more damage than
If II were capped. In this case. the softer
frontal surface of the armor serves ~
steady and to protect the sharp point OF
the shot at the instant of attack so that
II secures an initial entrance into Tie
harder underlying steel before this ma
terial can split or deform the proiectiles
point This is fact not commonly
known.
Another one of the astonishing things
10 be seen at Indian Head is the work
ing OF the ingenious percussion fuse by
which the time of bursting OF the shell
Is regulated that II will occur after
the shot has penetrated an enemy's de-
tense The problem involved is that In
making the fuse safe enough so that tha
Shell in handling may be dropped by accI-
dent thirty or forty feet without invit-
ing an explosion, and Yet be sensitive
enough to act with precision and at the
proper time II II hit an obstruction dur
ing flight from the gun.
The shell must not only travel a certain
distance. but II must spin about its long
axis enough times to cause the little
guard ring to open by centrifugal action
and make clear the path Of the weight or
hammer which detonateS the explosive
primer. At Indian Head thousands OF
these fuses are tested before they are
permitted to be placed in the loaded pro-
Jectles and stored away I'm the shell
rooms Of our fighting ships.
Precision and perfection are the watch
words at the naval proving ground. OF
course. these cannot be obtained without
some hazard and a good deal of expense.
Every time a test is made OF q plate OF
thick arInor the outlay is probably not
far from $4,000. This. of course includes
the cost of the test plate. its transporta-
ton to Indian Head and the expense OF
the powder and projectiles used in the at
tack. A single test round of a twelve
inch gun firing an armor- piercing shell
means an expenditure of 500: but IL Is
only in this way that the naval author
ties can make sure OF their fighting tools
and predict their performance In the
hour of strife
The need of exactness and great care
in the fashioning OF our guns and IN the
making Of our powder and project!es Is
because our rifles are designed fer long
ranges. and any error in sighting or any
tendency Of the shot to swerve from the
true course would be multiplied by every
yard of its journey, and at modern fight
ing distances probably would fail to hit
the biggest battleship on that account.
The wearing away Of the rifiing Of a gen
impairs its accuracy of fire, and vari-
alton of only twenty-five thousandths OF
an inch In the rotating band on q shot.
the soft copper collar. which squeezed
into the grooves Of the gun, has been
found enough to vary the propulsive pow
der pressure quite three tons In the case
Of a six-inch shell, modifying accordingly
the velocity and the range of the shot
If projectile in being loaded into
gun is not placed exactly at the right
point change of position Of only a few
tenths Of an inch will sometimes serious
ly reduce the shells impetus and fits
power to do damage.
At 10000. 1900 and 1900 yards even
a dreadnought is not much of a target
viewed through a telescope sight. and
the gun pointer cannot hope reasonably
to do more than hit her anywhere, some
published nonsense to the contrary. But
he knows, that as his toools are fashioned
for him with added care and greater pre-
cision the chance of his hitting and hit
ting hard Is correspondingly Increased.
Therefore the big guns Of our battle
ships are fabricated with a nicely in
which a hairs breadth Is an important
dimension even though their ultimate
mission is to deal a ponderous blow
amounting to many thousands OF tons.
The naval proving ground brings us face
to face with some of the things that may
be expected in the next great naval bat
tie. and there one can see what Is being
done by our ordnance experts and our
makers Of armor and projectiles.
The navy is now hiding its light under
a bushel. but II has, of course. secrets OF
stunning potentialities which will be re-
yealed only when our national dignity
and the glory of our flag are at stake