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 east of the East River. (Plate XV.) The
yard and approaches are designed to avoid grade crossings by opposing
trains. The various general features of the yard and tunnel approaches,
bridge crossings, and street closings, have been described in sufficient
detail by General Raymond in the introductory paper.

[Illustration: PLATE XV.--Plan and Profile of Lines _A_ and _B_, and
Sunnyside Yards]

For convenience in placing the work under contract, a line was drawn 10
ft. west of Thomson Avenue, dividing the work east of that embraced in