New-York tribune., 1901-07-07

building are having a great deal OF trouble in
following the advice given in the Scriptures
to found all worthy structures on rock The
rock at this particular point on Manhattan
Island is covered with many feet Of sand. and
quicksand at that. At depth of twelve feet
water begins to rush into any excavations
which may be made. Rock bottom is not found
until a depth of fifty feet has been reached.
The men who planned the new building knew
this and decided that four floors below the
street level could be used TO advantage for the
machinery of the building the vaults and
rooms for employees. Having decided upon this
arrangement the architects left the problem OF
carrying it out in the hands Of John +. q Rourkc.
an engineer and foundation contractor. He found
that it would be necessary to depart from
dinary methods of constructing foundations
and decided to build continuous concrete dam
around the entire site. 1t is said that such
foundation dam has never been built before. The
dam Will be fifty feet deep eight feet wide and
will rest on the solid bed rock making a reser-
Yor that will be proof against water and sand.
For the building of this continuous dam cais-
sons are now being sunk on the boundaries of
the site. These cassons oblong in shape and
measure thirty feet long, eight feet wide and
fifty feet deep. They built of wood and
iron and weighted down with from fifty to
hundred tons of cement or pig iron. Fifteen men
Work IN a chafIltef at the bottom OF etth CaiS-
Compressed air is supplied from machines
on the surface in sufficient quantities to keep
back the sand and water which would other
wise fill the chamber. AS the aborers dig
away the earth it is taken to the surface in
buckets. The weight Of the iron and concrete
on top of the caissons keeps pushing them down
When they finally rest upon the rock bottom
the work of building the dam begin.
A number of circular cassons being
driven in various parts of the site They are
from six to nine feet in diameter, and in them
will rest the steel columns which will help sup
port the building AS these are in place
and the outer foundation dam is built the cross
beams of steel will be put in place. Then ex-
cavatng will begin. If these crossbeams were
not placed first, the outer wall dam would
be pushed in by the weight Of the surrounding
buildings. The excavation will be carried on a
floor at a time. and crossbeams will be placed
every twelve or fifteen feet. By the time the
eXcavating is ended the foundation viii be prac-
tically completed.
The men who work in caissons follow n
dangerous calling. Only the strongest men can
stand the increased pressure of the compressed
air which is necessary to keep the sand and
water out of the chamber. The men have to
pass physical examination before they are al
lowed to go into the chamber. John f. O. Rourke
the contractor, carries accident and life insur-
for all of the men employed on this work
He makes a personal inspection of the chambers
almost every day, and such care has been taken
that there have been fatalities among his
caisSon workers The contractors personal
popularity among his is said to be the
reason for his never suffering from strikes
Casson workers have name for the peculiar
disease from which they occasionally suffer
They call il the bends" because those who are
afflicted are twisted out of shape and some
times bent double by the terrible pain. The
bends is usually preceded by bleeding at the