New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1875-09-06
EAST RIVER IMPROVEMENTS.
PROGRESS OF TIE WORK AT UALLETrs PoiNF-PER-
PAIRING FOR THE FINAL EXPLOSION-THE REEF

PROGRESS OF TIE WORK AT UALLETT's PolNF-PHR-
PAIRING FOR THE FINAL EXPLosION--THE REEF
TO DE SHATTERED EARLY NEXT SUMMER.
The Government works at Iiallett's Point
have reached their last stage OF progress. but II will be
nine mont or more before the gre at explosion will take
place. The excavations were completed about two
months ago They undermine surface OF 2i4 acres, and
extend in headings and galleries 80 feet from land The
headings are the straight cuttings radiatng from the
sa they 10 in number at the SHAFT ana II in num-
Der at the outer edge Of the semcicc Tic galleries. 10
in number, arc OF circles connecting the headings
The cuttings OF both kinds regate 7,5i2f"et in length
they are from II 10 feet wide and from to 90 feet
high At their lowest Point they 80 feet below low
water They roof OF solid rock 10 feet thick be-
tween the mine and the water At the outer edge OF the
excavation the the river 20 feet deep AT low
tide.
At the inter section Of the headings and galleries col
unns or piers are left Standing by which Tie roof is
supported These number 172. The work ~ The final
demolition of the reef viii consist in breaking up these
uic, and shatto.ing TIE rocky roof Preparations fOl
this are now ia progress uO,rs are being bored BY
steam drills in the piers and roof into whc CHARGES or
nitro glyccIine will be put and all VIII be exploded at
the same instant There will he from 10 to 10 two and
tree-inch holes in each column; aud in the roof there
win be three-noh holes about i've feet apart. Tie
charges OF nitrG-e ycerne vii average from to 10
pounds and all viii DE connected ID gIsle hilcd VITA
the same explosive. The nltrosycaInc IN the pe beng
fired by lion battery, the charges viii he exploded
by conclusion. Ia clncHts haze been ltd under tie
direction Of Government officials in regard ~ this method
OF exploding the charges and The officers in command
have 10 doubts az 20 successful results At Mountain
View New-Jerscy 1000 charges fred m tais man
Dcr and Il said that il shown that there IS no limit
10 The number which may be exploded simultaneously.
The Gnal boring is less than hair completed and Will
occupy from two TO three months longer. 1t viii TAKE
TWO months longer to charge the holes with nibO-
glyoerine, and the officers win wait til weather
before firing tie mine. Nity lyccrne freezes al about
49, and is then practically nexosiye and safe to haB-
DIE The charges viii be Put in place during lie Winter.
AID will tbaw out during the early Summer Before cleo
city is applied the wiz be Jet III. This viii act
as Stamping and cause the explosion TO DC moe effect
i've Il is claimed that ~ only half The charges take fire
the work viii Do Thoroughly accom- sh;h IL IL h't
known exactly when tho maj ieihlt 70 brc,1 up ne
reef will made but the 30th OF june i TIE end of
IL arm, year and the appropriations ARE made only 10
HAT date it L. Thought that the explosion VIII take place
about that time
This work has ia progress six years since SG9-
but has been greatly Retarded and tie expense Srt aty
Increased by the usuciency Of the Ovtlnneh appO-
prGt.Uns Only 200 men can he enpU5 ed thTodghout
TIE year, willie 800 are required to WORK to Tie best al,
vantage. Once OF twice u force HAS pteh al on ana
worked uNtll tDe apIO.nlh IOF INC gtaT was TX
hasted hut il was found thai the best W0rnen goa EN-
plJyment elsewhere and could not be procured When
again required fol the past year the wOrk has been
cptinue1 with Oply tie nlnber of a5orcrs whom the
appropriation woull permit to continue II worn
Tie new work at Flood Rock has been IN progress
about tnrtO months. and shaft has Decu s'i.h about ~
c, IN the solid rock. The system VIII 10 pursurd
mere as at lalletls Point but the excavations Will be
much greater in extent tie rock stretches out ahout
400 feet directions from the snail No estimate
can be made OF the time II viii take 10 complete tlh
work as it depends chiefly Oh the appropriation made
by Congress Tue n0y1l Of the reef at Haliets POni
will Greatly reduce the dangers OF the Hell Gaze passage
and he permanent advantage to commerce oyDn before
the second enterprise Is brought to successful eonci