158 The East Anglian Earthquake.
gravels forwarded by Mr. Shenstone were submitted to a
series of washings in the laboratory, and after the removal of
the clay a sand was at length separated from the larger
pebbles, and this, in general appearance as well as under the
microscope, closely resembled the specimen sent by Dr.
Wallace. It seems most probable, therefore, that the latter
was washed out of the gravel in the manner suggested, the
first specimen of " gravelly sand " referred to by Mr. Shen-
stone being the most likely source, as the loamy sand
obtained further from the place where the streamlets appeared
required much washing before the clay could be removed.
Canterbury.—Perhaps the most striking illustration of the
wide extent of the subterranean disturbance is furnished by
the fact that at the Canterbury Waterworks, on the morning
of the shock, two or three tanks had to be emptied, on
account of turbidity, before the water was sufficiently clear to
use. The water is drawn from Artesian borings about 600
feet deep, and is always bright and clear.63
Colchester Waterworks.—There are two wells here sunk into
the chalk to a depth of 420 feet and passing through the
following beds :—
53 From a report made by Mr. Sidney Harvey, F.C.S,, of Canterbury,
to a meeting of the East Kent Natural History Society. I am indebted
to Captain Gordon McDakin, of Canterbury, for calling my attention
to this circumstance.
54 From the Geological Survey Memoir, 48 S.W, Appendix I., by W. H.
Dalton, and information supplied by Mr. Charles Clegg, C.E., Surveyor
to the Borough.
55 From the proofs of Memoir, 48 N, containing supplementary Essex
well-sections ; kindly furnished by Mr. W. Whitaker.