preliminary surveys had been completed and the location and extent of
the Terminal track area had been fixed, in so far as the city blocks to
be occupied were concerned. This contemplated area, however, did not
include the portion between Ninth and Tenth Avenues, that being added
subsequently. The elevation of the track level had also been fixed by
the requirement in the agreement with the City that no part of the
permanent structure should approach within 19 ft. of the surface under
any avenue or under any street except within the Terminal area. The
nearest approach of the tracks to the surface is at a point 320 ft. east
of Eighth Avenue, where the top of the rail is 40 ft. below the 31st
Street curb line.


WASH-BORINGS.

The general plan of enclosing the area in retaining walls having been
adopted, wash-borings were taken, for the purpose of determining the
best location for the walls, the depth of rock, and the nature of the
material overlying it. These borings were made along both curb lines of
Seventh Avenue, the east curb line of Ninth Avenue, the north curb line
of 33d Street, and the south curb line of 31st Street. The borings, as a
rule, were taken at intervals of approximately 100 ft., some deviation
in these intervals being made in order to prevent injury to water, gas,
and sewer connections, and, if the elevation of the surface of the rock,
as determined by one of these borings, corresponded fairly well with
the borings on either side of it, no intermediate borings were taken.
When a discrepancy appeared, a boring was taken midway between the
two non-corresponding ones, and if the information obtained from the
intermediate boring failed to account for the discrepancy, others were
taken at the quarter points of the original 100-ft. interval.