ragms instead of sheet iron as it was more easily maintained in a
vertical position. The general arrangement of the diaphragms is shown on
Fig. 4, Plate LII. The results obtained by using diaphragms have been quite
satisfactory, and cracks approximately straight and vertical have usually
appeared opposite the diaphragms soon after the forms were removed.
Diaphragms were used on all the remaining walls, with the exception of
those between Stations 187 + 07 and 188 + 83 on the north side, where the
rock was of poor character and bad slides had occurred. Between these
points, in order to strengthen the wall, twisted steel rods, 1 in. square,
were placed longitudinally, 6 in. in from the face of the wall and 2 ft.
apart vertically, between Elevations 295 and 335.

[Illustration: PLATE LII, FIG. 1.--GIRDERS UNDER 9TH AVENUE ELEVATED
RAILROAD.]

[Illustration: PLATE LII, FIG. 2.--TW 100. P.T. & T.R.R. Co. Terminal
Station West. Showing excavation of completion of South abutment 9th Ave.
and method of Supporting Elevated Railway Column 488. July 21, 09.]

[Illustration: PLATE LII, FIG. 3.--TW 31. P.T. & T.R.R. Co. Terminal
Station West. View showing excavation 9th and 10th Avenues South of 32nd
St. looking West from Sta. 184. Aug. 17, 07.]

[Illustration: PLATE LII, FIG. 4.--TW 101. P.T. & T.R.R. Co. Terminal
Station West. Inside of concrete form for lower-face wall, showing drains,
tie rods, diaphragms and methods employed for tying in the form in addition
to braces outside. July 21, 09.]

_Tenth Avenue Portal._--The design of the Tenth Avenue Portal is shown on
Fig. 9. The stone selected came from the Millstone Granite Company's
Quarries, Millstone Point, Conn., and is a close-grained granite. Fig. 2,
Plate LI, shows the completed portal.

Practically all the stone cutting was done at the quarry, but certain
stones in each course were sent long and were cut on the ground, in order
to make proper closures. Drains were left behind the portal around the back
of each arch, leading down to the bottom, and through the concrete base at
each side of the portal and in the central core-wall; all these drains have
been discharging water.

_Power-House._--The old church at No. 236 West 34th Street, between Seventh
and Eighth Avenues, was turned over to the New York Contracting
Company-Pennsylvania Terminal for a power-house to supply compressed air
for use on the Terminal Station work between Seventh and Ninth Avenues and
the wor