New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1885-10-01
juror could be obtained new panel ordered for
READY TO BLOW UP FLOOD ROCK.
EXPECTED EFFECTS OF THE EXPLOSION
FOUR FEET LESS OF WATER RIGHT AFTER IT
CLEARING THE DEBRIS AWAY.

FOUR FEET LESS OF WATER RIGHT AFTER IT
CLEARING THE DEBRIS AWAY.
To passengers on the big sound steamers that
carefully pick their way through the whrling cur
rents of Hell Gate every night and morning, there
Is little change noticeable in the works on Flood
Rock. The same skeleton OF smoky Oily timber
raises its angular framework against the back
ground of the charity hotels on Wards Island; the
same endless stream OF dirty water tiOws from the
trcless pumps and the same solitary workman
stands on the dump and gazes at the passing
steamer But down under that desolate island ana
ont under the foamng current. many men, and
machinery almost human in Its perfection have been
deviDg away through miles and miles OF rock,
leay ing behind them legacy OF dynamite that III
fraction OF n second viii make the work OF years
visible Lieutenant Derby, who has had Immediate
charge of the work, the elimination of which will
occur within q week, was found by TRIBUNE re.
porter yesterday, in the midst OF sawdust and
dynamite overseeing the preparation Of the last of
the explosives which are to knock the bottom from
under Flood Rock .
ing of the coming explosion in regard 70 tho state
of affairs Immediately after the firing People seem
TO think that the whole thing will cave in and
there will be twentysx feet CT water all about here
from that moment on. The truth is that there Will
be on an average four feet less water at every point
than there is at present. 1t was the old idea to
under the bottom, let 1t fall In and lie there With
the Improvement of dredging apparatus We find II
to thoroughly distribute the explosives. The OK
plOsion then breaks the rock up into pieces which
can be handled. In this case expect TO hit the
whole bed of rock right up from its resting place;
There will then be n of broken stone that will
lie four feet higher than the solid rock at present
This will be picked mp by dredges ana dropped III
the deep hole north OF Blackwelrs Isl and, where
tons aud tons of rock have been dumped and there
is still seventy feet OF water In year or So If the
work is not checked, it will all he cleaned mp and
there will be twcnty-SN feet OF water where fIood
Rock now is
Will not the report he much louder than that
when Hallet's reef was blown up = asked tic re-
Yes, probably, because part of the rock ont of
water while the other was entirely submarine. The
pcccs will ly also but not beyond thousand feet.
No one will be allowed to come within radius OF
that length, and we shall explode the mine from
point on the Astoria shore beyond that limit.sNo
injurious effects expected. but 1t Is always well
TO be on the safe side IL would be much letter for
1 man t. take down his French pier glass and lay it
on he floor dozen times, than to have 1t shaken
wv .WRat viii be the effect on the current, p
"Thc immediate effect will be to make them worse
than at present. After the linGments OF rock are
proved They will still be strong and TO
certain extent conflicting, but not 50 much SO as at
present. The removal of the rock viii be begun
Immediately after the explosion. we have about
$50 900 on hand for that purpose
" How does this compare in size with previous
"WeiI il wIlI bc four or five times larger than
that at lIallcts Reef, and that was far ahead Of
ans thing else of the kind"
The original estimate for the wort OF improving
Hell Gate channel was 50. 1870, 100. Up 10 the
present tmc!ahout -, 800 900 has been expended
The work on Flood Rock alone amounts 10 q round
million. The total cost of removing thc broken
cock after the explosion is estimated Mt SGuo,0OQ
The dynamite cartridges. the preparation OF which
has been Lieutenant Dcrbys special care for several
months are innocent looking cylinders. eight inches
m circumference aud several feet long. They con
IAN an explosive cOmuOund known n rack-a-rock
aud some pure dynamite of the No. grade. They
will he exploded in part directly By an electric
current. aud partly by con russion. The holes IN
which they are placed point upward at an angle OF
forty-Gye degrees and are nine feet deep. A. the
initial explosion occurs ut the mouth OF the hole
the tendency will be TO drive the cartridges still
dcrper into the rock. The subtcgrancan and sub
marine commotlon that will be produced by the
simultaneous liberation OF the enormous force
chained up in several hundred thousand pounds OF
These HIGH explosives can scarcely be conceived
even bS tho most able bodied ina siuItion.