242 THE LIBRARY TABLE.
specially suitable for grass, and as once (when wheat was dear) having been
valuable for growing wheat, clover and beans. Mr. McConnell, however, thus
gives his own experience of it : —
" The greater part of the author's farm is situated on this clay, so that he
has learned from sorrowful experience what the nature of the soil is. Tiptree
Hall—farmed by the late Mr. Mechi—is also on this soil and is now a fruit
farm."
We are also informed that "the general contour of the land is alow
uneven, gentle undulating surface, the highest land not much over 400 ft. over
sea level, though some few hills in Essex reach 600 ft."
The present writer has never been able, aided by the new ordnance maps,
to detect any hills in Essex having a height of 500 ft. The highest ground
appears to be on the Chalk of the north-west corner.
Of the Lower Bagshot sands and gravels we learn that, though sometimes
too sandy or gravelly for fertility, yet while they have not the "body" of the
London Clay, they are more easily and satisfactorily worked. They cover but
a small area in Essex compared with the London Clay, on which they lie as
isolated patches at Brentwood, Rayleigh, Laindon Hills and elsewhere.
The Pliocene "Crag" of Eastern Essex is still more insignificant as a
maker of soil. It is the highest bed shown on a non-drift map except the
alluvium of the river marshes.
By far the most important of the drift beds is the Chalky Boulder Clay,
which probably occupies at least as much of the surface of Essex as all the
other beds combined, and a still larger proportion of that of Suffolk. Mr.
McConnell states that it covers about 3,000 square miles in the Eastern
Counties. He has about jo acres of it on his own farm, capping the
undulations of the London Clay, and finds that "it is the only arable land he
has that is fit for cultivation, the rest being London Clay." The Chalky
Boulder Clay appears to make good wheat land. He adds that "in the
course of ages a large part of the lime has been dissolved out of the surface
layer." This point makes the detection of Boulder Clay so doubtful when
only shallow sections are exposed. But it is satisfactory to learn that "there is
still sufficient left to supply the soil for plant needs ; while the existence of
marl pits shows that much of this marly clay was dug and spread on the
surface in the olden times ; in fact, if the subsoil is dug into almost anywhere,
beds and streaks of bluish-white marl are found in abundance."
It is interesting to learn that the sand and gravel of the Glacial Period,
which underlies the Chalky Boulder Clay, has generally a large admixture of
earthy matter in it, and forms a good loamy soil which compares favourably
with that of either the London Clay or the Boulder Clay, both in the
neighbourhood of Ongar and that of Chelmsford.
On the other hand, the patches of gravel coloured red on the drift maps,
which appear at High Beach, Laindon Hill, Rayleigh, and elsewhere in
southern Essex, and are considered to be of pre-Glacial age, are barren
gravels, "given over to gravel-pits and the growth of birch or copsewood."
Similarly barren are the Post-Glacial gravel patches, coloured orange.
As regards old river deposits, our author speaks highly of the loam or
brickearth in the neighbourhood of Southend and Rochford.