The Wilmington daily Republican. (Wilmington, Del.) 1890-1902, 1898-07-14
THE RIVER.
MINES.
Many Will Not be Blown Up
as the Explosion Will
Damage the Bed
of the River.

The work Of removing the mines In tho
Delaware river has not yet been commend
ed and 1t Is probable 1t will not until next
week. Although 1t has been said that the
mines will be blown up. the manner Of re-
Inoval will depend upon conditions.
They might bs raised without danger,
but to unload the turpedoss Of their charge
Of dynamite would involve risk. In explod.
Ing the mines the possibility Of injdring
the channel was consideration. While
the explosions would create holes they
might also create Jumps, which would les
sen tho depth In places. 1t Is likely instruc-
lions will be received to day from the
chief OF engineers relative to the removal
Of tho mines.
Valuable services were rendered in the
work Of laying the mines by tho Volunteer
Electrical Corps, organized for the pur-
pose. So thorough was the work done
execution should an enemy attempt to
force an entrance into the harbor. Over
ten thousand pounds of dynamite were
used in charging the torpedoes This de.
structive aggregation now commands tho
entrance to the harbor, and should 1t be
decided to get rid Of the mines by explod-
Ing them there will be thrilling upheaval
In the harbor.
Each mine ia charged with $50 pounds OF
dynamite and tho movement Of key on
tho electrical switchboard in the oase-
mates at the different forts would create
the necessary spark to explode the charge.
Any vsssel within forty feet Of the mine
would DO victim of this force, or II mono
were around huge column Of wutcr
would be thrown high in the mir As the
mines are anchored on the river bed by
their own weight the force exerted In all
directions by tho explosion would make
hole in the bed.
There are two folds Of mines, 80 that
should vessel Of the enemy escape one
she must encounter the other before en-
tering the harbor. These fields are in tho
vicinity OF Fort Delaware and control the
passage Of the main channel, which would
have to be used by n warship
There Are two classes of mines, one
known as judgment mines, which are fired
from the ca,einates, aud the other contact
mines, " hch can be set from the caseMates
to go on when struck by ship. The mines
are connected III groups Of three ut dis
tanco or 70 feet, SO that they can be ex-
ploded together to make sure Of the de-
structive work for which they are intended.
Let vessel OF tho enemy got in or near
this triangle and her destruction Is sure
III Judgment set fails to do the work tho
contact mines are counted upon to perform
1t. Both classes of mines are under con-
troll OF the operator in the cnseinate, and liz
au instant Gun be changed from one class
to the other.
Tho shell containing the charge OF dyna.
mite Is of heavy galvanized boiler iron and
Is shaped like mushroom. Its base Is
about three feet wide and the altitude in
the contre Is about two feet. A small stick
or Dynamite OF higher explosive nature
than the chargeis fixed SO that ian electric
spark sets it off, and in turn explode, II do.
tonating cap which explodcs the charge.
The completion Of the circuit which sends
INC death dealing current into the mine
Is done by simply moving key on the
switchboard. Wires leading to the mines
IRE thoroughly insulated ana inclosod in /,
heavy armonred cable to prevent injury If
struck by YES selA
An interesting feature Of the method in
which the mines are controlled Is the
means employed In locating II vessel and
IN exploding the right group of mines to
destroy her A base line has been cstab-
lished below Delaware City with an ex-
pert stationed ut either end and telephone
communication between them. Each is
provided with o chart of the mine fields
ana plat OF the shore line. When yes.
sol appears each man takes a sight with
the proper instruments and the result is
shown Oh the chart.
AS the vessel moves between two sta
tons the Intersection OF tho two points of
sight loca es her position. Other sights
are taken and he speed of the vessel noted
SO that the position OF the vessel, is shown
with mathematical accuracy. Reference
is then made to the chart of the mine fields
and tho group Of mines nearest to he YES.
sol is shown. An order to got ready to ex-
pioue the group goes over tho telephone to
the man Mt the switchboard, and at the
moment when the vessel is over or near
the groups the explosion occurs.