The sun. [volume] (New York [N.Y.]) 1833-1916, 1897-06-26
BROADWAY WON'T SLUMP.
SOMEBODY SAW 4 RACE TESTER.
DAT AND THOUGHT IT MIG I.

The Crack Was Caused by Excavations Be1Pg
Made in the Quicksnnds mt Broadway ana
Exchange Place for n Big BuiidinE-Coas
tractor Giiligan Says There Is No Danger.
Down in Broadway, where the old Exchange
Court building stood, and running clear through
TO New street and below Exchange place for
125 feet, workmcn are sinking a foundation for
a great office building for John Jacob Astor, and
the work being done is one of the most slippery
and treacherous of the many quicksands which
lie hidden between rock and loan on the lower
part of Manhattan Island. The sand. when 10
is dry, looks as il it might have resulted from
the disintegration Of brownstone. 1t has no
grit, but is an almost impalpablc powder, and
in this is mixed plentifully fine sparkling bits
of mica. The admiXture of mica with fine sand
is considered by engineers to make the worst
kind of a quicksand because OF the mica's be-
ing so slippery. This quality of mica is so pro-
nounccd that lubricants arc made of it, mixed
Somewhere about fifty feet below the level of
New street and considerably, further below
rock, but because of the quicksand no attempt
Is being made TO 30 To the rock. directly with
the foundations for the new building: Instead
through the quicksand TO the rock or TO a hard
pan which caps it, and the columns of thu build
ing. will stand upon rock and brick caps TO DO
Even the driving Of the piling is n delicate
operation, for the tall, narrow Tower building
stands next door and must be kept from being
undermined, and broadway overs high above
the bottom of the excavation where the men
are ut work. Within the lines of the street lies
n big water pipe, sewers, gas pipes, electrical
subways. and the cable road conduit. and lie
the walls and the snoring which props up that
side of the big hole were to give way IL would
make II great miN.up, besides endangcring
many lives and much property.
Some one discovered IA zig.Zng crack between
some of the paving stones in Broadway oppo-
site the excavation yesterday and became
alarmed. I. y. Gnlligan N son are the con-
tractors who are sinking the foundations. They
said yesterday that there was no way 10 pre-
vent the moving Of the soil when work was
being done in quicksands and piles were being
driven, but that there was no danger OF broad
way s~luIuplng into the hole. The old walls Of
the sidewalk vaults are still standing, and these
are shorcd up by, big timbcrs. The footing of
the wall is, upheld by n closr line of sheet piling
walton. The tidcwatcr line is only about four
the tops of the piles. which are to support tho
building are to be eight feet lower down than
| this. In order to sink the piles and then build
upon them their masonry caps, square Golfer
dams Of sheet piling are being made about the
size of each of the Seventy.two piers which
will support the building. The quicksand Is
reached In these cOfferdams at about the tide
water level, and although the piling of tho
COiirriamb goes down deep, the sand will oole
up from six inches TO n foot in Il single night
when left. The new building will he eleven
stories tall on broadway and twelve stories on
New street, and viii cover n plot l25 feet on
/ broadway, 1894 feet on New street, and 1851
feet on Exchange plnrc.