232 REPORT ON THE DENEHOLE EXPLORATION
the further development of No. 12 by the removal of most of
the chalk which now separates its chambers, would eventually
produce a pit having its roof supported by three nearly central
pillars, situated near the present points of junction of the chambers.
It is somewhat singular that neither in No. 12, nor in any other of
the Hangman's Wood deneholes, have we met with a pit in its last
stage of development, that in which most of the partition between
each chamber has been removed, only enough chalk being left
towards their present entrances to serve as pillars for the support
of the roof. In the similar groups of deneholes at Stankey, and
Cavey Spring, Bexley, pillars are found where the dimensions are
much less than those common at Hangman's Wood. The first
pillars made were always on each side of the opening at the base
of the shaft, a six-chambered denehole eventually becoming six-
pillared. In the example given (Fig. 3) of one of the Cavey Spring
pits, two pillars have already been formed, and others are in process
of formation; in the Stankey pit (Fig. 4) one pillar only has been
formed, the second being nearly completed. In both cases the
lateral expansion is much less than that of the Hangman's Wood
pits, a fact which the identity of the scale used (40 ft. to an inch)
snakes very obvious.
We may now start from No. 3 by the northerly tunnel, and visit
Nos. 9, 10, 11, 5, 6, 14 and 15. As No. 9 is a shaft-closed pit, we
had no knowledge of the positions of its chambers, and could only
direct our tunnel towards its shaft. On entering No. 9 we discovered
that a rat hole connected the two pits a few feet to the right of our
tunnel and about the centre of the ends of the two contiguous
chambers, the thickness of the partition at the rat-hole being about