nerating plant might almost have been omitted
from this period, as the first compressor did not begin running until
February, 1905. Previous to that time, the power for drilling, pumping,
driving, sheeting, etc., was steam furnished by the boilers which
subsequently drove the compressors, these being brought on the ground
and fired as occasion required.

Train-Disposal Period, Beginning May 22d, 1905.

At the beginning of this period there had been excavated 242,800 cu. yd.
of earth and 22,800 cu. yd. of rock, of the total excavation of 803,500
cu. yd. of earth and 804,000 cu. yd. of rock included in the principal
contract, leaving to be excavated under that contract 560,000 cu. yd. of
earth and 781,200 cu. yd. of rock, and an additional contract had been
let to the New York Contracting Company for the terminal power station,
which increased the earth by 16,500 and the rock by 15,500 cu. yd.
During the year following, contracts for the east and west portions and
the sub-structures were let, which brought the total to be excavated,
after the beginning of the train-disposal period, up to 681,000 cu. yd.
of earth and 1,494,000 cu. yd. of rock.

The central plant, transportation plant, and dock plant were used
indiscriminately on all these contracts, and, as no separation can be
made which will hold good for any appreciable length of time, the plant
in those classes will be stated in total. The retaining-wall and pit
plant here given include that used on the principal contract and
terminal power station only. The power-generating plant given under
the horse-and-truck period was doubled at the beginning of the
train-disposal period, but it was still insufficient for the work then
under contract, and the additional contracts necessitated a greater
increase. The location had also to be changed to permit the excavation
of the rock under Ninth Avenue. The old stone church fronting on 34th
Street, between Seventh and Eighth Avenues, a building 68 ft. wide and
92 ft. long, made a roomy and very acceptable compressor-house. The
wooden floors and galleries were removed, and good concrete foundations
were put in, on which to set the plant; the walls, which were cracked in
several places, were trussed apart and prevented from moving outward by
cables passed about the pilasters between the windows.

The boilers were erected south of the church, an ash-pit being first
built, the full width of it, with the floor on a level with the