On the Sand-Pit at High Ongar, Essex. 85
Beds in conjunction with the older formations in the same
delineation, I accompanied it by a copy of the Ordnance ten
miles to the inch Index-map coloured (in MS.) geologically,
on which I inserted by careful reduction from the one inch to
the mile sheets the contours of all the arcs which were the
subject of the paper on the River-valleys of the East of
England in the Phil. Mag., and with that minuteness and
care which the scale of that map allowed, and in which they
consequently strike the eye more clearly than in the litho-
graphed map to the last-mentioned paper. This manuscript
map I presented in 1866 to the Library of the Geological
Society, where it can be seen on application to the Librarian.
Wickham Bishop, Essex. Fig. 1.—Mr. Dalton's representation with
assumed fault. Fig. 2.—Suggested correction by sinuosity in the fold.
c. Glacial Gravel; d. London Clay ; e. Reading Beds; f. Thanet Beds ;
g. Chalk.
I have added, in manuscript, to the plate of my paper on
River-valleys of the east of England placed in the Club's
library, a copy of the section at page 25 of the Geological
Survey Memoir for sheet 12,10 which crosses one of the Isle
of Wight arcs, and shows the flexure there; and have indi-
cated the direction of it on the map by the line marked
"A—B" there. I have also added a copy of the section in a
chalk-pit N. of Barkway, on the Royston escarpment brow
10 'The Geology of South Berkshire and North Hampshire. Illustrating
Sheet 12.' By H. W. Bristow and W. Whitaker. London, Geological
Survey.