214 MOUNDS NEAR THE ESTUARY OF THE THAMES.
described, is more broken up, and not quite so easy to measure, but
it is certainly quite as long as the last. All the mounds of the limbs
consist, so far as I could discover, exclusively of the same dark grey
loamy clay as the marsh. None of them shewed any trace of level-
ling on the top; there is no evidence of the action of fire, no burnt
clay, no slag, no charcoal, no pottery. They consist simply of an
assemblage of steep-sided mounds of dark grey clay, rising abruptly,
at irregular horizontal intervals, out of the flat surface of the marsh.
Sections to any depth are not common, though small surface expo-
sures are found without difficulty. But one limb of the group
extends across the line where the railway runs; and one of the
mounds is cut through, and a small section is laid bare, in conse-
quence. A careful examination of this confirmed the view that the
mounds under notice consist simply of clay in no way distinguishable
from the clay of the marsh land around.
On the north-east side of the group last mentioned occur a few
smaller mounds that differ in no essential respect but that of size
from any of the others. These decline in elevation as they are fol-
lowed away from the main mass, so that in the direction indicated
the mounds die away into the marsh", which, beyond the point where
this occurs, maintains a uniform level as far as Sea Salter.
The mounds in Sheppey agree in all their general character with
those here described in detail. In both cases there is the same
curious combination of bosses of London Clay manifestly of natural
origin, with other mounds whose origin is more problematical. In
Sheppey, and probably in other localities where these mounds occur,
some, at least, of both kinds of mounds have been modified to suit
local requirements. In many cases this has clearly been done with
the object of taking advantage of the elevated position of these
mounds to adapt them as shelter for cattle during floods. Elsewhere
it is quite certain that some of them have been used for homesteads.
Indeed, I have myself stayed several days at a house in Sheppey built
upon one of the smaller of these mounds. Elsewhere some of these
may have been used for other purposes besides those here named.
Some, perhaps, because the kind of clay they consist of was found to
be suitable for the manufacture of a rude kind of pottery, and the
mounds, being above the level of the marsh, formed more convenient
sites for pottery works than the surface formed by the same kind of
clay at lower levels. The variable size of these mounds and their
sporadic distribution is, I think, against the view that they represent