The total length of the bridge between the faces of the abut-
ments is 150 ft., divided into three openings, two of 37 ft. 6 in.,
and one of 75 ft. The total width is 30 ft., divided into a car-
riage way 21 ft. wide, and two footpaths 4 ft. 6 in. each.
The river bed and the strata below are of the kind usual in
the fen country about Peterborough. After piercing through
6 or 8 ft. of mud, peat, and clay, a harder stratum of clay and
sea-shells forming a friable rock is reached, and below this,




Examples of Bridges. 153

again, there is rock firm enough for a foundation. Each abut-
ment is supported on wooden piles driven down to the rock, and
is made of concrete with a face of masonry.
The river piers are formed by sink-
ing cast iron cylinders 5 ft. diameter
and I in, thick, made in lengths of
7 ft., to a depth of about 14 ft. into
the river bed, the average total
height from the bottom edge of the
cylinder to the under side of main
girder being 22 ft. 6 in. The flanges
of the cylinders were faced in the
lathe, and ajoint of red lead between
each flange was sufficient to make a water-tight connection.
