high, spanning and connecting the two shafts. One machine was
provided for each shaft, and where their tracks crossed 33d Street they
were separated sufficiently to permit the machines to pass each other.
At this point, and covering the street, a large platform was provided,
on which the trucks were loaded and unloaded (Fig. 2, Plate LVIII), and
from which they descended by an incline on First Avenue leading south to
32d Street. The platform also covered practically all the yard at the
South Shaft and materially increased the available working area. The
telphers were built by the Dodge Cold Storage Company, and were operated
by a 75-h.p. General Electric motor for hoisting and a 15-h.p. Northern
Electric Company motor for propulsion. Their rated lifting capacity was
10,000 lb. at a speed of 200 ft. per min.

The carpenter shop and machine-shop, both of which served the entire
work, were conveniently located in small buildings on the loading
platform. In the former the saws were each run independently by small
electric motors suspended under the platform. The heavy forms and form
carriages used in lining the tunnels with concrete were fabricated and
stored on the platform outside. The machine-shop lathes, etc., were all
belted to one shaft driven by an 8-h.p. General Electric motor. Above
the machine-shop was a locker-room and below it on the street level was
the main blacksmith shop for the work. Subsidiary blacksmith shops were
located at each of the other shafts. The storeroom and additional
locker-rooms were located above the power-plant in the North Shaft yard,
and isolated from the other structures was a small oil-house. Additional
storage space was provided by the contractor on 32d Street just west of
First Avenue by renting three old buildings and the yards in the rear of
them and of the Railroad Company's cement warehouse adjacent. Here
electric conduits, pipe, castings, and other heavy and bulky supplies
were stored.

During excavation the headings were supplied with forced ventilation
through 12-in. and 14-in. No. 16, spiral-riveted, asphalted pressure
pipes, canvas extensions being used beyond the ends of the pipes. A No.
4 American Blower, located at the top of each shaft and driven by a
15-h.p. General Electric motor, supplied the air.

[Illustration: PLATE LVIII, FIG. 1.--VIEW OF FIRST AVENUE PLANT.]

[Illustration: PLATE LVIII, FIG. 2.--TELPHER STRUCTURE AND LOADING
PLATFORM, FIRST AVENUE SHAFT.]

[