The Portland daily press. [volume] (Portland, Me.) 1862-1921, 1884-10-07
UNDER FLOOD ROCK.
Preparations for What Will Re the Great
est Explosion Known in History,
New York SUM-

(New York SUM-
There are four miles OF tunnels In GIiis mine,
said Foreman Bernard Boyle as he conducted
visitor down into the excavations under
Flood Rock, which the Government has un-
dertaken to blow up as it blew up Hallett's
Reef, short distance above 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 sons of it SO hard that it has to be
blown up. The dip is at an angle of about
6O0, which favors the entrance of water from
the river above u.s."
A dismal rain was pouring from the rock
and threatened to extinguish the oil lamp
which the explorer carried. On stepping
through doorway he found himself in water
up to the knees of his high rubber boots In
the extreme northeast corner OF the mine q
roar was heard. and soon the water was seen
rushing down through wide seam. num-
Der OF laborers were busily engaged in ce-
menting and in drilling test holes in new di-
rections''
We are working carefully now, guarding
against any further outbreak" said Mr.. Boyle
"There is million dollars worth of work at
stake here, and we are exercising the greatest
caution. In case of sudden flood the miners
1t. Then the compressed air of this pipe would
be let loose and a 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 oriice farther back we prefer the
slower process of cementing."
when shall you be ready for the great ex-
plosion?"
tsTp ohont oua raa. f~o,,, +h;a r,.n4I rrh.o
are only ninety men engaged here now, al
though we have had 2C0 or more in times
past. Our present force can complete the
work by the time we are ready for the explo-
sion. You would be surprised at the number
OF men who apply for work In such mine
You see, we keep 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 as
possible. No one has ever contracted the
and we never allow the use of liquor.
Next September you may see and hear the
largest explosion known to history. ALI of
those holes you see there. with plugs in them,
will be filled with explosives, which will cost
$36O,CN. About 100000 cubic yards of rock
have already been excavated. Whatever we
can carry out now will not have to be fished
up by divers and grapplers in the form of de-
bris after the explosion. Men are busy here
night and day. II you desire to count you
WILL Anu IOOsOuO bWU Huu Gur66-luCu
holes, drilled for explosives already.
The drills have to be sharpened 10000 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 Blackwell's
Island, has served largely as our dumping
ground. The work requires drilling, blasting,
hauling, hosting, dnmping, pumping, timber.
ing, transr orting, surveying, sounding and
many other things Every hole has to be drill
other hole. We try to keep twenty feet and
upward of rock for a re of, which requires an
accurate knowledge Of the depth OF water
above 1t. Ventilation is kept up by a fan
twelve feet in diameter, driven by an engine.
The large galleries ventilat3 themselves. The
pumping operations are necessarily continu-
GUS. The average inflow from leakage at low
tide is TAO gallons per minute, but the last
great leak, which you noticed few minutes
ago, has increased it to over thousand gal