MOUNDS NEAR THE ESTUARY OF THE THAMES. 211
tion. Professor Hughes, who examined these mounds in connection
with the Geological Survey of that part of Kent, came to the con-
clusion that, like the larger mounds above referred to, they represent
projecting bosses of London Clay, due to the very irregular denuda-
tion effected by the salting streams cutting down through alluvium
older (and higher lying) than the alluvium of the present marsh. He
discusses their origin in the Geological Survey Memoir on the
"Geology of the London Basin," page 291 (published in 1869).
Soon after the appearance of the Memoir referred to, Mr. H. Stopes2
gave an account of his investigation of some similar mounds on the
Essex side. He carefully guarded himself against any definite con-
clusion regarding their origin ; but the view that the Essex mounds
he describes are artificial seems to me to be clearly implied by his
remarks. Later, the Rev. J. C. Atkinson, of Danby-in-Cleveland,
examined these same Essex mounds, and came to the conclusion
that they represent vestiges of old salt works, like some similar
mounds met with under much the same physical conditions in
Yorkshire. Various other views have been from time to time
advanced by divers observers regarding the nature of these proble-
matical mounds, the majority being in favour of the view that they
are not due to the action of natural causes, but are wholly, or
mainly, artificial in character. The mounds in Sheppey specially
under notice have, therefore, been variously referred to look-out
stations (speculatoria); to the sites of the pottery works of some
primitive people ; to the homesteads of seafaring man in early times,
to standing-places for the protection of cattle when the marsh was
flooded; and, lastly, to the "tips" where the mud has been put when
the numerous ditches that intersect the marsh have been dug out.
There is much to be said in favour of each and every one of these
views, especially when the area examined does not extend beyond
one locality. And there is almost as much to be said against any
one of these views when a wider survey of the question is taken.
Mounds similar to those at Sheppey occur at the mouth of the
Humber (Clement Reid); near the mouth of the Tees (Geo. Barrow
and T. V. Holmes); near Redcar (Rev. J. C. Atkinson); and on
the west coast of England, near the estuary of the Mersey. Doubt-
less, were the question looked into, similar mounds would be dis-
covered in connection with the fluvio-marine alluvia of other parts of
the kingdom.
Archaeological Journal,'' xxxvi. pp. 369-72, and Essex Naturalist, i., pp. 96-105.
M 2