Savannah morning news. [volume] (Savannah) 1868-1887, 1884-10-12

Preparations for What VIII Be the
Greatest Explosion Known in His

Greatest Explosion Known in His
tory.
Eeto York Tri6uns.
''Tbere are four miles of tunnels in this
mine," said Foreman Bernard Boyle, as
he conducted a visitor down into the ex-
cavations near Flood rock, which the
government has undertaken to blow up
as it blew up Hallett's reef, short dis
lance above it, in He'll Gate. This is all
gneiss rock" the guide continued. "Some
of it is so soft that it can be cut with a
knife, and some of it so hard that it has
to be blown up. The dip is at an angle of
about 90 degrees, which faVOrs the en-
trance OF water from the river above us.O
A dismal rain was pouring from the rock
and threatening TO eXtinguish the oil
lamp which the explorer carried. On
stepping through a doorway he found him
self in water up to the knees of his high
rubber boots. In the extreme northeast
corner of the mine a roar was heard. and
soon the water was seen rushing down
through a wide seam. A number of
labOrers were busily engaged in cement
ing and in drilling test holes in new direc-
tiOns.
eve are working carefully now. guard
ing against any further outbreak said
Mr.. Boyle. 'sThere is 100000 worth of
work at stake here, and we are exercising
the greatest caution. In case of a sudden
uuDu luE ulluETS NOulu escape
the door there and close it. Then the
compressed air of this pipe would be let
loose, and a pressure of sixty pounds TO
the square inch would prevent this sec
ton from filling. The pumps are well
able to take care of the present leaks. We
might introduce the compressed air into
the seams and stop it, no doubt; but as
we don't know the width of the orifice
further back, we prefer the slower pro-
cess of cementIng."
"When shall you be ready for the great
explosiOnY'
''In about one year from this month.
There are only so men engaged here now,
although we have had 200 or more in
times past. Our present force can COM
plete the work by the time we are ready
for the explosion. You would DE surprised
at the number of men who apply for work
in such mine. You see we keep a uni
form temperature here the year around,
and plenty of coed fresh air. Some of the
men have been here from the start, and
we keep the old hands as long as possible.
No one has ever contracted the caissOn
disease here. The men are temperate,
and we never allow the use of liquor.
Next September you may see anu hear
the largest explosion known to history.
All of these holes you see there with plugs
in them will be filled with explosives
which will cost 100000. About 100000
cubic yards of rock have already been Elk.
cavated. Whatever we can carry out
now will not have to be fished up by div
ers and grapplers in the form of debris,
after the explosion. Men are busy here
night and day. If you desire to count,
you will find about 250, 900 two and three
inch holes drilled for explosives already.
The drills have to be sha-pened $4,000
times per year in the shops overhead.
The rock, after being mined, has to be
hOisted, carried away to deep water and
dumped. A hole 20 feet deep, just north of
BlackwelPs Island, has served large
ly as our dumping ground. The work re-
quires drilling, blasting, hauling, hoist
ing, dumping, pumping, timbering, trans
porting, surveying, sounding and many
other things. Every hole has to be drilled
with mathematical precision to meet
some other hole. We try to keep twenty
feet and upward of rock for a roof, which
requires an accurate knowledge of the
depth of water above it. Ventilation is
kept up by fan twelve feet in diameter,
driven by an engine. The large galleries
ventilate themselves. The pumping OPP
eratiOns are necessarily cautious. The
average inflow from leakage at low tide
is 74O gallons per minute, but the last
great leak, which you noticed a few
minutes ago, has increased it to over
600 pallOnsO