nt to the tunnel company's
yard on the Passaic, at Harrison, N. J., and a small part to the
embankment in the Meadows Division. On account of the occasional closing
of the Passaic by ice, this involved the possibility of, and to some
extent resulted in, interruptions to the work of excavation. The
contract for the cross-town tunnels carried an option in favor of the
company to require the contractor for those tunnels to dispose of
materials at a stated price, and in the latter part of 1907, when the
excavation in these tunnels was being pushed rapidly, the railroad
company, unwilling to incur the responsibility for delays during the
winter, availed itself of this option. The disposal of materials was an
important part of the work, and will be dealt with more fully by the
Resident Engineers.

[Illustration: PLATE XIV.--Map and Profile, Cross-Town Tunnels]

At the time the contract was made with S. Pearson and Son, Incorporated,
it had not been determined whether mechanical ventilation would be
provided for the tunnels, and therefore the contract with that firm did
not include the final concrete lining at the shafts, above the inverts
of the tunnels. After the adoption of plans for mechanical ventilation,
in the latter part of 1908, the plans for lining the shafts with
concrete, including flues for conducting air to the tunnels, and
stairways for ingress and egress, were completed, and the work was
placed under contract; it will be described in detail by F. M. Green,
Assoc. M. Am. Soc. C. E.

At the east end of the work under the Pearson contract, the rising grade
of the tunnels brought them so near the surface of the ground that their
extension eastward could be carried out more readily in open cut than by
tunneling. The locations of the portals could be varied somewhat, and
they were built on rock which was found in rather narrow ridges at
convenient places. Tunnels _B_ and _D_ have a common portal; Tunnels _A_
and _C_ have separate ones, the portal for Tunnel _C_ being located
about 800 ft, west of the others as a result of its crossing over Tunnel
_B_, as already explained. Eastward from the portals, the track system
expands, in order to provide connections with the tracks of the Long
Island Railroad to and from Long Island City, with the New York
Connecting Railroad and New England lines, and with the storage and
cleaning yard known as the Sunnyside Yard extending to the west side of
Woodside Avenue, 2-3/4 miles e