A SUPPOSED NEOLITHIC SETTLEMENT. 125
the Skitts Hill Brick Works, in which the words "Clay Pit"
appear twice. In this field the nature of the material, the shape
of the ground, and the appearance ot London Clay at intervals
along the slope, suggested that its surface was mainly occupied
by terraces of old river deposits. Then, crossing Duggers'
Lane, we came to the excavations in the alluvium—the most
recent of the river-deposits. To a distance of some twenty or
thirty yards from the river Brain the alluvium on its western
bank had been carted away to a depth of 6 or 7 feet, the original
surface of the flat being shown by its level on the eastern bank
of the stream. The alluvial flat of the Brain hereabouts is of no
great breadth, and there are no signs of the former existence of a
lake ; but primitive "Moated Granges" may often have been con-
structed on an alluvial marsh with the aid of piles, and by the
formation of an additional short channel, which would allow the
habitations to be surrounded by water.
Of Mr. Kenworthy's discoveries in this alluvial flat there is
no need to say anything here. It may, however, be useful to
add, for the sake of comparison, the following brief account of
some excavations in the alluvium of the river Cam, between
Audley End and Saffron Walden, quoted in the Geological Survey
Memoir on Sheet 47 (pp. 72--73). The original account was given
by the late G. E. Roberts, in the Anthropological Review, vol. ii.,
pp. 41--43 (1864).
"In the course of railway works between Audley End and Saffron
Walden, it became necessary to divert the course of the river Cam into a part
of the meadow land bounding the stream, which was traditionally known as
'the old river bed.' A cutting, about 20 feet deep, through this, necessitated
for the foundation of a wide and large culvert to give passage to the river
through the railway embankment, disclosed the following section :—
Near the bottom of this "peat," and at a depth from the surface of 16 ft.,
an astonishing quantity of Mammalian bones were found. . . . Out of the
excavation—an area of not more than 20 ft. by 60ft.—two cartloads of "large
bones" were taken away,
The peat is, more properly, a blackish clay, with numerous fragments of
wood and a few logs of considerable size bedded in it. It is everywhere full
of fluviatile shells, of species common in the district, and contains many
naturally-formed chips and flakes of flint and a few rolled pebbles.