262 REPORT ON THE DENEHOLE EXPLORATION
Method of Sinking Chalk Wells.—Where the chalk is near the
surface, as is the case where it is merely covered by the Clay-with-
Flints, etc., the depth of the well rarely exceeds 15 to 20 ft.—as before
remarked—the diameter of the shaft being 4 ft. 6 in. Clay-with-
flints, however, occurs very irregularly over the chalk, sometimes in
deep pipes or "bags," as they are locally termed, and sometimes only
as a mere skin. Hence the term "thin-skinned" soils. Trial holes
Fig. 10.—Section and Plan of Chalk-Well, Seen and Measured at Sevenacres,
Three-and-a-half Miles N. of Newbury.—C L F, clay with flints; C K F, chalk with
flints ; A P, point where galleries meet; G, gallery; Q, quoins or piers ; A, angles ; K, part of
quoins cut away; L, landing; D, dell; S, shaft. Shaft 20ft. deep. At the bottom, three
"angles" (A) were driven, each being about 3 ft. wide and 9 ft. long. The men then worked
right and left, each man ascending as steep a slope as he could work on for perhaps 7 ft.
Then a short level was formed, and after that upward work was resumed till the headings
were united, a circular gallery being thus formed, communicating with the shaft by means
of the headings. When all the chalk required has been extracted, the quoins (Q) will be cut
away as far as safety will allow, and the workings will fall in after a time, forming a dell or
slight hollow at the surface.—From a drawing by F. J. Bennett and H. A. Cole.
are dug, and the wells sunk, as far as possible, at the spots where the
chalk is only just covered (see Fig. 10). When the required depth has
been reached, what is termed "angling" commences, i.e., headings are