2 NOTES ON AN ALLUVIAL DEPOSIT IN THE CANN VALLEY,
of the Mollusca. Mr. Clark gave his observations on the subject in
a paper, an abstract of which afterwards appeared in the "Natural
History Journal" (York: vol. iii., February, 1879, p. 3). Further
observation, however, has enabled me to correct a few statements
made therein.
The spot in question lies on the right bank of the Cann (a tributary
of the Chelmer), in the parish of Chignal St. James, 31/2 miles north-
west of Chelmsford, and 51/2 miles from the brook's source. Its exact
position on the one-inch ordnance geological map (1.N.E.) is a quarter
of an inch W.S.W. of the church. (Six-inch map, Essex XLIII.;
25 inch, Essex XLIII. 14.) The river is a small one, running
quickly over a pebbly bottom ; it is very subject to floods in winter,
but often very low (though never dry), in rainless summers. It is fed
from the Boulder-clay district of High Easter, &c., to the N.W. The
valley consists of a strip of meadow-land, usually about 100 yards
wide, the sides sloping gently up to a height of from 30 to 50 feet.
The deposit, or rather collection of deposits, lies adjoining the brook,
and its surface is 8 or 9 feet above the usual level of the stream. At
the present time it is seldom, if ever, flooded, and the rabbits, per-
ceiving this, have taken great advantage of the soft dry upper stratum
to excavate many burrows in it—indeed, it was their working which
first caused me to notice the deposit, in June, 1876.
The field in which this deposit lies is known as the "Hop-garden,"
from the fact that hops were formerly grown in it.3 Until about
thirty years ago, this meadow was little better than a bog, and when
under cultivation it was laid out in high baulks, on which the hops
were grown, with ditches between. At that time large pipes were
laid, as shown on the ground-plan (Fig. 1), by a celebrated profes-
sional drainer; and the feat was considered so wonderful in the early
days of pipe-draining, that it is said many persons came to see it done.
The outlet at A still runs freely with extremely clear cold water, and
with but very little variation, summer or winter. The other outlet at B
became blocked some years ago by the root-fibres of an ash tree,
growing about twenty yards off. These, entering between the joints
of the pipes, completely filled them, so that a bog began to form.
When, in 1879, we opened the pipe, the water ran very strongly for many
hours, and has run steadily ever since. The putting-in of these pipes
lowered, by 3 or 4 feet, the water in the well at Boynton Hall, which
3 But not, it is almost certain, for the last 100 years ; I believe that there is now only a single
hop-ground left in Essex—that at Sible Hedingham.