The method of erection was as follows: An excavation was made on the
line of each post, 4 ft. deep and from 4 to 5 ft. square, depending on
whether it was for a single or reinforced post; 6 in. of concrete was
placed in the bottom, and on this were laid, at right angles to the
center of the trench, three 8 by 12-in. timbers varying in length with
the excavation from 3 to 4 ft. To these timbers was drifted one 12 by
12-in. timber of the same length as those in the bottom row, but at
right angles to them. Elevations were then taken on top of the 12 by
12-in. timber, and the bent was framed complete and of correct height.
The framing was done south of the line of the trestle and west of the
freight-house. The framed bents were picked up by a small two-boom
traveler carrying two double-drum, electric, hoisting engines, and run
forward into position. A hole had previously been made in the metal
gutter and canopy of the freight-house, by an experienced roofer, and
in the freight platform underneath, and, as soon as the bent had been
dropped into position, it was firmly drifted to the foot-blocks,
previously described, and the excavation made for them was filled with
concrete well rammed about the blocks and rounded off 6 in. above the
surface of the ground. Secure flashings, in two sections, were then made
about the posts to cover the holes made in the gutter and roof, the
bottom sections being firmly soldered to the roof or gutter, and the top
sections, which lapped over the bottom and cleared them 2 in. in all
directions, were firmly nailed to the posts and the joints leaded. This
arrangement allowed the bents to move slightly, and at the same time
made the roof and gutter water-tight. These bents were placed 16 ft. on
centers to correspond with the spacing of the doors of the freight shed.

Under the cross-overs near Eleventh Avenue, where the tracks had to
be supported in different positions on the caps, and could no longer
be kept over the posts, the caps were trussed and the posts were
reinforced, as shown on Bents "_J_," "_H_," and "_K_," Fig. 5.

[Illustration:
Fig. 5.
DETAIL OF BENTS FOR MATERIAL TRESTLE]

The trusses for the through bridge over the tracks were erected on
Sunday, April 16th. The two trusses, one 122 ft. and the other 165 ft. 8
in. from center to center of end posts, had been assembled and riveted,
lying flat on cribwork a few feet above the ground, south of the
permanent position and betwee