NOTICES OF OTHER SIMILAR REMAINS IN THE NEIGHBOURHOOD. 39
worthy of note that a piece of decayed "squared" timber is shown
still in place in the shell-marl, with which it is completely surrounded.
Just outside the lower dam a land-drain made a few years ago gave
a very large accumulation of bones at a depth of 6 to 7 feet.
In the alluvial deposit left by the artificial overflow, oyster-shells
may be frequently obtained; and in a land-drain made in this deposit
two human skeletons were found a few years ago.
About one mile south-east of Pleshey, at the confluence of two
small streams a dam is thrown across the valley. It is about 200
yards long and of proportionate height and thickness. It is called
"Dead Man's Bank," and is now clothed with oak and other trees.
No notice appears to have been made of this earth-work. A recent
additional breach has been made, and shows its structure to con-
sist of clay and gravel in equal layers. I found three oyster-shells here
after a hasty search. This dam would hardly have been made subse-
quent to the military earthworks in Pleshey village, as an important
part of its water supply was appropriated for artificial moats there.
About 11/2 miles south-west of Shalford village there exist;
another dam of considerable dimensions, which once held back a
lake of some four or five acres. The place is still called "Pond
Green," and it does not appear to have been very long ago drained.
The dam is here made of gravel and clay in equal layers. The
water-line all round the lake's basin is still visible, and all below it
is dark alluvial soil. One piece of Roman pottery was yielded by
a molehill in that basin. With this single exxeption all the lakes
appear to have been finally drained a very long time ago, as there is
a deposit of rainwash in them which obscures all traces of earlier
deposits.
Less than half a mile east of Black Notley village there is a dam
very similar to that at Pleshey, and of about the same dimensions.
It is also clothed with timber trees. The evidence of age is here
very apparent, the fields at each end of the dam being planed down
by natural denudation to a depth of at least 4 feet from the top of
the dam. It is worthy of remark that in all these cases the dams
seem to have suffered but little from natural weathering. I find,
however, from various authorities that artificial earthworks inclined
at a high angle, generally retain their sharpness and contour through
long periods of time. This is particularly characteristic of the
earthworks at Pleshey, some of which date at least from the Roman
occupation.