56 On Deneholes,
adjacent unopened one—as suggested to me by our Secretary
—would probably be the means of decisively settling the
question of their age and use.
As the Charlton and Blackheath Deneholes must have
been, judging from the greater difficulties attending their
construction, of later date than those of Bexley and Grays,
it may on similar grounds be considered probable that small
and shallow pits in the chalk alone, such as Nos. 7, 8, and 9
in Mr. Spurrell's plate, are the oldest of all. Mr. Spurrell
mentions one at Crayford, thirty-six feet six inches deep,
which was examined. Part of the flint forming the floor had
been taken up and piled in a heap on one side of the cave.
The heap at the base of the shaft showed many flint flakes
and scrapers ; above these was primitive pottery, and above
that Roman pottery. But though this primitive pit was thus
shown to have originated in the Stone Ages, the age of the
deeper ones still remains to be ascertained, and will, I trust,
yield itself to the explorations of the Essex Field Club. And
our investigations at Grays will have the advantage resulting
from the fact that the primary purpose of pits solely in the
chalk can never be so satisfactorily established as that of pits
sunk through fifty or sixty feet of Thanet sand, where there
is plenty of bare chalk within a mile. It seems probable
that experience may have shown Thanet sand to be a
better material for shafts than chalk. Mr. Spurrell describes
some caves in the chalk near Rochester, and remarks;—
"The shafts have been much enlarged by the action of
frost, which detaches large blocks of chalk"—:a serious
consideration in the case of caves intended for permanent
stores and refuges, though immaterial as regards temporary
flint-workings.
That these Deneholes are very ancient—that they certainly
date from a time when the art of building can scarcely be
said to have existed in this island, and when invisibility
formed the best security against the sudden attacks of an
enemy—seems, to me, evident. And their position, as
regards those at Bexley and Grays, at Blackheath and
Charlton, points to the conclusion that the enemy feared