THE KANSAS CITY BRIDGE. Th

an elevation of 94 ; the sheet piles were driven down as the work proceeded,
and the water kept out by a steam-pump.

Three pile-drivers were then mounted over the pit, and the bearing piles
of the foundation driven ; these were 90 in number, and their average penetra-
tion was a little more than 30 feet. The drivers were at first worked by horse-
power, but this was found unprofitably slow, and two of them were afterwards
worked by steam. This done, the pit was again pumped out on the 16th of
December, and the excavation carried a foot and a-half lower. The sand was
dug away from the outside of the sheet piling for eight or ten feet, to relieve the
pressure, but it was found difficult to excavate much faster than it flowed in on
the inside’; the water also came in in such quantities that the two centrifugal
pumps were required to keep it down. The piles were then cut off with axes
and the heads worked smooth ; they were capped with flattened sycamore
sticks, on which a second course of timber was laid, which was planked with
four inch oak plank, finishing at an elevation of 94.7. On this the masonry of
the pier was begun on the 3d of January, 1868. The pier was built up at
once, the pit around it being filled with riprap.

PIER No. 7.

As early as February, 1867, an excavation was made in the side of the
bank, at the site of this pier, and in this the foundation piles were driven at
once. They were 73 in number, and their average penetration 27 feet ; their
driving occupied about a month, from the 27th of February to the 27th of
March. The excavation was then resumed around the piles, but after a week’s
work the men were driven out of the pit by the rising water of the April flood.
The water continued too high for the work to be resumed till after the summer
floods ; when it fell in August no trace of the foundation could be seen, the
piles having been completely covered by the deposit of sand. The pier was
therefore located anew, an excavation made at the site, and the buried piles
dug out, in nowise injured by their premature inhumation. A rough enclosure
of sheet piling was driven, and the excavation continued below ; the water came
in rapidly, working its way through the porous soil, and making the excavation