Ellsworth American. [volume] (Ellsworth, Me.) 1855-current, 1898-06-01

The Big Seacoast Guns are not Aimed
by Gunners' Eyes.

by Gunners' Eyes.
Seacoast guns, the huge engines which
are intended, not to kill men directly but
to destroy ships of war, are not aimed
| by gunners' eyes, but by mathematical
formula and precise calculation. Indeed
there is nothing by which the eye could
sight modern coast defense gun for any
of the great ranges, as the weapon points
high up into the air and not at the OBJ
ject which is being attacked. This has
made it absolutely necessary to devise a
way of aiming which should be exact, and
the result has been that the high power
rihed steel gun OF day is the most ac
curate cannon ever used in warfare. Par
adoxically, as guns have increased their
ranges they have increased their accuracy
of fire.
The instrument that has replaced the
human eye to aim the seacoast guns is
called a range and position finder, and
its purpose is to tell exactly how far from
the cannon muzzle the ship to be attacked
is. To accomplish this one OF the most
peaceful professions, that of surveying,
has been pressed into service, and the
range of fire is ascertained by a method
based on the simple process of triangula-
ton.
Besides the range, however, the position
of the shi p must be known. Some forms
of range-tinders are designed SO that it is
necessary to have two of them at fair
distances from each other, using the dis
lance between them as the base of tri-
angle of which the ship is the apex.
Thus they tell at once both the range and
position of the enemy.
Others ascertain the range with one
movement and the position with another.
OF this class is the Lewis range finder,
which has been installed in the forts of
the United States. 1t is of the kind
known as depression range finder, and it,
too, calculates the distance by Triangular
ton The known part of the triangle is
furnished by the height of the instrument
above sea level. That gives the base of the
triangle, and the other two lines can be
| ascertained by the regular process familiar
to every mathematician. To ascertain the
position of the ship, the Lewis range
ated into degrees and minutes
The vast Importance of accurate range
and position finding in a modern engage
| ment is vast On its perfection may de-
pend the fate of cities and of countries.
| The best Notifications, the greatest of the
guns, the bravest of garrisons can do
nothing without it. a ship at sea is
ron arL "a bIy- :.
background by which it can be located
The smooth black barrel of the rife points
to the SKY and the man does not live who
can tell with his eye whether he elevation
is correct for ship that is at any consid-
cradle distance from shore. Neither is it
possible for the eye to tell within many
hundred yards how far away the ship is.
Thus, through necessity, was created the
eye of steel and glass that has no human
failings, that does not become nervous,
that cannot mistake, that registers auto
matically, where the object is as soon as it
looks at it.
The higher the finder can be placed
above the sea the more accurate is it in its
results. They can follow the progress of a
ship so fast that they can plot her posi-
ton exactly every ten seconds, SO that
she cannot get out of fire.
Each man at each range finder and each
man commanding gun has before him
chart on which is potted every entrance
to the harbor which he is defending On
it are marked channels and shoals and
every other condition which will affect
the course of an entering ship. The chart
is divided into squares, each square being
little larger than the area covered by
battleship. Each one of these squares is
numbered and as a ship is located the
telegraph in the range-fnding station an
nounces her position and her ''number SO
and so" to the men at the guns.
These men see nothing. They are hid
den behind earthworks, and they fire al
together by formula and rule. They do
not see the object at which they are firing.
An electric gong in the observers sta
ton clangs every ten seconds, and at its
sound the observer marks the position of
the attacking ship or ships on the chart.
1t is telegraphed at once to the battery, and
the man in command there glances at his
tdpie, "nlcn SHOWS MIN WHAT elevation ne
must give his gun to reach that particular
spot. The great gun is swung and sighted
(if that can be called "sighted'' deep in
| its gunpit of blue sky overhead. Then, at
the word of command to fire, it is raised
swiftly till it points over the parapet, fired
by electricity and lowered again before
the smoke has cleared away.
Dancnn kIino OF And1ro D.