The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1884-10-05
UNDER FLOOD ROCK.
Preparations for What VIII Be the Greatest
Explosion Known in History.


Now York sun.
There are four miles Of tunnels in this NINE"
said Foreman Bernard Boyle, as he conducted
visitor down into the excavations under Flood
rock, which the government has undertaken to
bio" up as 1T blew up HGlletts reef short
distance 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 knife and
some Of it so hard that it has to be blown up.
The dip is at an angle of about sixty degrees,
which favors the entrance of water from the
river above US"
A dismal rain was pouring from the rock and
threatening to extnguish the oil lamp which the
explorer carried. On stepping through door
way he found himself in water up to the knees
of his high rubber boots. In the extreme north
east 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 cementing and in drilling test holes
in directions.
1--WE are working carefully now, guarding
against any further outbreak said Mr.. Boyle.
There is a million dollars worth of work at
stake here, and are exercising the greatest
caution. In case of sudden flood the miners
would escape through the door there and close
1t. Then the compressed air of this pipe would
be let loose and pressure of sixty pounds to
the square inch would prevent this section from
filling. The pumps are well able to take care of
the present leaks We might introduce the
compressed air into the seams there and stop it,
no doubt, but as we don't know the width of the
of cementing."
When shall you be ready for the great ex-
plosion?"
I'm about one year from this month. There
are only ninety men engaged here now although
we have had two hundred OF more in times past
Our present force can complete the work by the
time we are ready for the explosion. You would
be surprised at the number of men who apply
for work in such mine. You see, we keep a
uniform temperature here the year round. and
plenty of good fresh air. Some of the men have
been here from the start and we keep the old
hands as long possible No one has ever CON
tracted the eaisson disease here The men are
temperate and we never allow the use of liquor"
Next September you may see and hear of 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 1850, 600.
About 100 600 cubic yards of rock have already
been excavated Whatever We can carry out now
will not have to be fshed up by divers and
grapplers in the form of debris after the ex-
plOsion. Men are busy here night and
day. If you desire to count you will find
about 100000 two and threeinch holes drilled
for explosives already. The drills have to be
sharpened 1000 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 seventy feet deep just north
of Blackwells island, has served largely as our
dumping ground, The work requires drilling
blasting hauling hosting, dumping, pumping,
timbenng, transporting, 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 re-
quires 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 ventiate themselves. The
pumping operations are necessarily continuous
The average inflow from leakage at low tide is
$40 gallons per minute, but the last great leak,
which you noticed few minutes ago. has in
creased it TO over 1000 gallons.