146 THE ESSEX FIELD CLUB
were used for the storage of food supplies in those early times when life and pro-
perty were equally insecure, and our land was frequently invaded by foreign
hordes. They were ancient in the time of Henry IV., and are mentioned and
figured by Camden, Blaeu, and others, some 300 years ago ; and at that time were
considered of extreme antiquity. A copy of Camden's woodcut, 1610, roughly
represents the plan of those at Tilbury, and appeared, with other views and
coloured plans, in the Report of the Denehole Exploration.
The men were early on the ground on the Friday, but the day was largely
occupied in erecting shears and tackle, and clearing out the shaft of one of the
pits, marked No. 3 on the plan, which had been nearly choked by dead branches
of trees, brushwood, and rubbish, during the thinning which has recently been
made in the wood, the "roughs" from Grays and the neighbouring docks appar-
ently finding special delight in casting down even tree trunks and branches into
the shafts, and thus causing great trouble to the explorers an i damage to the pits.
In consequence of this senseless damage very considerable difficulty was experi-
enced in entering "No. 3 pit," and when at last, by removal of rubbish and
faggots, Mr. Shipman, Junr., and Mr. Cole were enabled to crawl down by the side
of the timber obstructions into the pit itself, the destruction caused was only too
apparent. During the explorations in 1884, the conical mound of earth in this
pit had been removed, and the pit cleared (see Report, etc., Essex Naturalist
i., pp. 335-36).' Now we found a heap of debris, mainly lumps of chalk, and fag-
gots, reaching quite to the opening of the shaft, and evidence of serious and even
dangerous damage to the roof of the pit. A diagram (fig. 2) will make this
clearer. The symmetry of the pit is completely destroyed, and the whole of the
mass of chalk between a and b broken down. Mr. Holmes suggested that the
destruction occurred in some such way as this : "The throwing down of the tree
trunks, which had damaged the Thanet-sand part of the shaft to some extent,
must have knocked away many masses of chalk, and have suggested to some
playful idiots who descended either by this or some other shaft the entire removal
of the mass of chalk between a and b by the use of the tree trunks as battering
rams. It is probable that the hole, about 3 feet by 2 feet, between 0 and c, was
the result of the concussions attending the destruction of the pillar of chalk
between a and b. It shows how easily similar holes elsewhere may have been
formed centuries after the disuse of the pits." It may be that the vibration
caused by the forcible descent of the tree trunks may have caused the whole
damage—the wilful battering down of the chalk by intruders in the pit would
have been a very dangerous piece of mischief. The directors fear that No. 3 pit
will not be a safe one to descend in the future. Captain Whitmore saw the damage
that had been done, and expressed his intention of checking the descents of unau-
thorised persons in the future, and if possible of securing the open pits against
wilful injury by fencing them in. Mr. Cole and Mr. Holmes were pleased to
find that the other pits had not been damaged, and were in much the same con-
dition as when left at the termination of the explorations in 1887. It was very
satisfactory to observe that the Thanet Sand everywhere stood well, and was
unchanged, even in the shaft of "No. II"pit, where the chalk is very much
shattered and full of cracks. And the unchanged state of the chalk in that and
some other pits suggests that in places where the chalk seems to have flaked
away considerably (as in the tunnel between Nos. 3 and 2 pits) the result may be
1 A diagram and section of this pit (one of the best examples known) will be found on Plate
I., vol. iii. of Trans, Essex Field Club.