Evening star. [volume] (Washington, D.C.) 1854-1972, 1898-03-07
SUBMARINE MINES.
How They Are Controlled by the Use
of Electricity.

From Electricity.
Electricity as a means of controlling the
engines of war plays an important part.
This is especially the case with submarine
mines and torpedoes, which are kept under
thorough control and made to act at the
pioper time through the influence of the
electric current. Submarine mines have
been extensively used in modern warfare,
notably during the civil war in this coun-
try and during the Frarco-Prussian con-
Eict. The last decade, however, has seen
extensive improvements in the method of
firing mines due to the rapid development
of electricity.
Probably the simplest form of mine and
the one most extensively used until cleo
tricity came into general use, was that
Known as the contact mine, which consist
ed of an iron case containing an explosive
attached to a cable, the latter having its
Il wer extremity fastened to an anchor Of
sc me sort The iron case was provided
with a number of firing pins, any one of
which being brought in contact with the
hull of ship fired percussion cap and
exploded the charge. AS will readily be
seen, these contact mines are not in any
way under control and were equally dan
gerous to friend and foe. With a view to
remedying this evil, what is known the
electro-contact mine was invented. In this
device the firing pins on the case contain
percussion cap when brought in contact
with an object, act as a switch oy closing
one opening in electric circuit. Another
switch is located in this same circuit at a
station on shore, so that in order to fire
the mine it is necessary to close the land
switch at the same time that one of the
pins has been driven in by the hull of a
vessel. If this is not done no explosion
takes place. which enables friendly vessels
to pass in and out without fear of acct
Gentally running foul of mine and being
blown up, would be the case with the
ordinary form of contact mine.
Numerous electrical inventions have been
patented from time to time for controlling
and firing submarine mines. One of these
inventions consists in an ingenious
rangement for holding mine down near
enable friendly vessels to pass it in
safety. The device consists in a loop fas-
tened to the anchor and to point on the
cable near the mine In hollow opening
in this loop small charge of an explosive
is placed, which can be fired from the
shore by means of spark from an electric
battery. In bursting, the loop is destroyed
and the mine Immediately rises the full
length of it's cable and to within few
feet of the surface. The mine itself may
then be fired from the shore in the ordi-
nary manner.
In deep water, or where a strong cur
rent exists, recourse is had to what is
known as ground mines. These consist of
large charges of gun cotton or other high
means of mushroom anchors. Mines of
this character being too far below the sur
face to be fired by coming in contact with
the hulls of vessels, arrangement has to
be made to ascertain exactly when a ves-
sci is over a mine in order to know when
to fire IT, This is accomplished by a very
simple method. although an extremely in
genious one. An electric circuit extends
from the mine to two stations on land at
no great distance from one another At
each of these stations break occurs in
the electric circuit. and in order to explode
the mine both of these breaks must he
closed simultaneously. A telescope is
mounted at each station on a pivot, which
permits of It's being swung in Il horizontal
direction c-s - --~ --nd that whap point
ed at the mine 1t closes the circuit a. mat
station. Thus all that is necessary to do
is TO keep both telescopes pointed at an
enemy's vessel as 1t advances, and when
the latter passes over the mine both
switches will be closed, the circuit conn
pleted and the mine exploded.
Innunerable other devices have been
brought out, in which electricity invaria.
ply plays an important part. for carrying
or warfare Of this nature. What Is known
as the observation mine, an improvement
over the electro-contact mine, is one Of
these. In a mine Of this character the ar
ing mechanism and the. explosive are in
two distinct and separate receptacles,