The times. [volume] (Richmond, Va.) 1890-1903, 1898-05-15

IN three parts. TO an observer WHO can
be permitted a glimpse underneath the
surface Of the water the observatioh
mine consists OF three balls. one three
feet below the water. another eight ieet
below the water and the third lying
on the bed OF the ocean These three
are Joined by a cable. The top one Is
the observatory. This consists Of
globe with two points upon 10. On be-
ing touched these points sink into the
globe and complete circuit. This CIR
cifif communicates with a station on the
shore. As the points are driven INTO the
TOP globe a bell Is rung IN the station
and the engineer IN charge realizes tnat
n shin IS passing over the mine. He
looks out TO see II II be a friend or foe.
If IL Is n foe he touches button ana
completes the circuit which discharges
a mine. The explosive lies In the mid
die bulb or the one which is about eight
feet below the upper bulb.
I'm case friendly ship has passed over
the little observatory bulb the engineer
does not touch the button and no explo-
sion takes place. These are extremely
safe mines and are inexpensive. They
can be planted in any harbor without
danger 20 merchant ships.
The big ground mine is the one upon
which we rely for coast defence. This
mine consists OF very large bulb or
high explosive II lies on or near the
bottom OF q the ocean directly in the
channel over which the ships pass. IL
ie connected with the shore by two cir
cults These circuits pass into stations
which are widely separate. They olten
lie on opposite sides Of the river so tnat
the officers IN charge Of the station
which controls the submarine mine are
separated by a broad expanse Of water.
In order to explode one Of these ground
mines there must be simultaneous ac-
ton on the part Of the engineers In their
stations on opposite sides Of the river.
They must both act at once or the mine
will not explode. The manner In when
this IS done can best be explained by an
illustration.
Engineer A. on the west side OF the
river IS seated Ia a little room. He rs
provided with a telescope which sights
the harbor. Engineer b, Is on the otner
side of the river lie Is seated IN
small room and IS also provided with a
telescope which overlooks the sea. Both
engineers are connected by electric cir
cuit with the submarine mine which lies
in the middle of the harbor. Inc tele-
s.copos are remarkable ones that are
made by Government electricians IN the
Government electrical works. They have
no other work 10 do than TO assist IN the
explosion Of the mine.
When a hostile ship IS sighted both
engineers turn their telescopes upon II.
AS IL draws near both OF them keep II
in sight, swinging the telescope as the
chin apDroaches When 40 gets direct
lv over the mine the telescopes are To-
cussed simultaneously upon II and the
mechanism of the telescopes Is so ar
ranged that they complete the circuit
of explosion and the mine goes of. This
is done witrout any touch Of the button
and without any effort whatever upon
the part Of the engineer. He has only
TO center his telescope upon the snip
and 10 watch Il as ii slowly comes up
the barber.
When the explosion takes place, the
ship IS supposed 10 be blown into atoms
and the work Of the engineer is done
until such time as another mine can
be laid
This very elaborate mechanism was
provided IN order 20 save valuable
Ground mines from being destroyed pre-
m9turely. These mines, in their me
chanism and construction. cost the Gov
eminent 5000 each and were they to be
prematurely destroyed il would be a
great loss 10 the Government.
Ii was feared that in the excitement
Of sighting a warship the engineer might
touch the button by accident or might
make a mistake in the location of the
ship therefore tire twin telescopes, each
with their automatic circuits were ar
ranged on opposite ports. and with great
success. This has not been tried upon n
warship as yet, but its experiments have
been so highly satisfactory that there
IS no doubt Of its successful working
at the critical moment.