e,
160 ft., at the house line, each area tapering gradually to the width
of the standard three-track tunnel at the east ends, noted above in 33d
and 32d Streets. Additional track room for four tail-tracks is gained by
the construction of two double-track tunnels under Ninth Avenue at 33d
Street, their center lines being parallel to the street and 45.5 and
84.5 ft. distant, respectively, from the north house line. An additional
width of 24.5 ft. is occupied on the north from 277.5 ft. to 543.5 ft.
west of the west line of Seventh Avenue, where the buildings on the
north side of 33d Street have been torn down and the enclosing wall set
back in anticipation of a future outlet to 34th Street; and on the
south, from 459 ft. to 597 ft. west of the west line of Seventh Avenue a
rectangular offset of 124 ft. encloses the area occupied by the Service
Building. The total area above outlined is the space occupied at track
level, and amounts to 28 acres, of which the portion west of the east
house line of Ninth Avenue and south of a line 107.3 ft. south of the
south line of 33d Street is a part of the North River Division, and was
constructed under the direction of the engineers of that Division; the
fan-shaped areas east of the west house line of Seventh Avenue were
constructed under the direction of the Chief Engineer of Electric
Traction and Terminal Station Construction.

[Illustration:
Plate LIII.
Pennsylvania Station, New York City: Plan Showing Area at Track Level]

In June, 1903, when the writer's connection with the work began, the
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