proceed to or from the station. From Fifth Avenue eastward to the
lowest point under the river, the grade was to be 1.5% on all lines.
Later, during construction, when excavating westward under 33d Street
from Fifth Avenue, the surface of the rock was broken through,
disclosing quicksand; within the next few days trial drill holes through
the tunnel roof at 32d Street and Fifth Avenue showed a thin cover with
quicksand above it. The conditions had been indicated in a general way
by borings made before construction was begun, but they proved to be
rather worse than anticipated. On the topographical map of Manhattan
Island, made by General Egbert L. Viele in 1865, is shown a watercourse
which had its source near what is now Broadway and 44th Street, flowing
thence along the west side and south end of Murray Hill, passing under
the present site of the Waldorf-Astoria Hotel, crossing 33d Street at
the point where the rock surface was broken through in the tunnel
excavation, as above stated, crossing 32d Street at its intersection
with Fifth Avenue, where trial drilling showed thin rock cover over the
tunnel excavation, passing thence eastward a short distance south of 32d
Street, which it recrossed near Third Avenue, and finally discharging
into the East River near 34th Street, and a little west of the present
First Avenue. The ancient creek apparently followed the course of a
valley in the rock, the valley having become filled to a considerable
depth with very fine quicksand. This concurrence of depressions in the
rock surface with the watercourse shown on Viele's map was noted in so
many places and the difficulties of construction were so serious at
these places, that a section of the map showing the old topography along
and adjacent to the station and tunnel lines is reproduced in Plate IX.

[Illustration: PLATE XI.--Long Island Shaft. Lines _A_ and _B_]

The unfavorable conditions developed at Fifth Avenue affected both the
construction of the tunnels and the maintenance of adjacent buildings.
It would be necessary to construct the tunnels in open cut for a large
part of the way westward, causing serious inconvenience to the public;
the buildings were mostly of the older class, founded in earth, but
there were several modern high buildings with foundations in the same
material; some of these had been built since the tunnels were planned.
In view of these added risks and the increased cost of construction, the
value of