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neglect of superficial beds of every kind. For, on a coal field, for example, the
outcrops of the rocks of Carboniferous age, with the lines of fault crossing
them, are the fundamentally important things to be noted on the geological
map. To show, in addition, the superficial beds, would often be but to obscure
the most valuable information, as well as to retard the progress of the Survey.
And similar reasoning would apply more or less to formations directly under-
lying or overlying the Carboniferous series. The special needs of the miner
may be shown by the following illustration. In pre-geological days there was
a popular view in the Northumberland and Durham, and in the Yorkshire and
Derbyshire coalfields that there was "no coal under the limestone." This
was true of the Carboniferous Limestone on the west, but utterly untrue of
the Magnesian Limestone eastward. Other examples might be given, but the
supreme importance, in mining, of a knowledge of the geological structure of
a district hardly needs further illustration.
On the other hand, a knowledge of the geological structure of a country
has not the same importance to the farmer. Let us, for example, again take
two limestones, each of which occupies a considerable proportion of the
surface of England, the Carboniferous Limestone and the Chalk. We learn
from Mr. McConnell that the grass growing on the bare Carboniferous (or
Mountain) Limestone is exceptionally sweet and nutritious, fattening sheep in
a few months. The grass growing on the bare Chalk is also excellent for
sheep, as we all know from the reputation of the South Down breed. But it
would be obvious to any farmer that in each case the sheep fed on grass
growing on bare limestone, and he would need no knowledge of the
geological structure of the"respective districts or the comparative ages of the
limestones.
But though, regarding England as a whole, the claims of the miners for
geological information are manifestly greater and more fundamental than
those of the agriculturists, the counties of Norfolk, Suffolk and Essex have
unquestionably been under a special disadvantage in the postponement of
drift maps till the claims of the miners were satisfied. This becomes obvious
when drift maps and non-drift maps are compared with each other. A drift
map of Kent, when compared with a non-drift map, seems but to possess
some additional details. Drift maps of Norfolk, Suffolk and Essex, compared
with non-drift maps of those counties, look like maps of districts of utterly
different geological composition.
As regards the formations of Essex and their farming qualities, nothing is
said by Mr. McConnell of Chalk in connection with that county, though its
capabilities as seen elsewhere are noted. Chalk, however, occupies but a
very small proportion of the surface of Essex, being found only in the north-
west corner and between Purfleet and East Tilbury. And the lowest Tertiary
beds, the Thanet Sand and the Woolwich Series, occupy but very narrow
strips of country adjacent to those where the Chalk is seen. The next, in
ascending order, the Oldhaven Beds, cover but an insignificant area in Essex ;
but we learn that at Hassenbrook Farm, near Stanford-le-Hope, a small,
thin patch of this formation occurs, largely composed of rolled flint pebbles in
sand ; and that it is the best strawberry land in the district. The London Clay,
which comes next, forms a very large proportion of the surface in southern
and eastern Essex. As regards its character as a soil, it is described as being