power-house which had been erected at that point. The contents of the
blacksmith shop remained the same as for the first period. The equipment
of the machine shop was increased by one 18-ton trip-hammer operated by
air and one bolt-cutting machine, size 1 in. to 1½ in. The carpenter
shop remained the same except that the electric motor was replaced by a
25-h.p. single-cylinder air motor; there was added to the repair shop a
drill shop containing: Four forges with compressed air blowers, four
anvils, two Ajax 20-ft. drill sharpeners, and one oil blower forge.

_2._--_Retaining-Wall Plant._

The retaining-wall plant was identical with that described for the first
period, with the addition of two Ransome 1-cu. yd., concrete mixers,
with vertical engines mounted on the same frame, using compressed air.

_3._--_Pit-Excavating Plant._

The pit-excavating plant included that listed for the first period and,
in addition, the following:

One Vulcan, 30-ton, steam shovel, with 1-cu. yd. dipper and a vertical
boiler.

One Ohio, 30-ton, steam shovel, with 1-cu. yd. dipper and a vertical
boiler.

Four guy derricks (50 to 80-ft. masts and 45 to 60-ft. booms),
operated by Lambert 7 by 10-in. engines, with two drums and swinging
gear, mounted with 25-h.p. vertical boilers, but driven by
compressed air.