14
The Presidential Address.
the peaty pine forests of Denmark, bringing with them cows,
sheep, pigs and goats, wheat, barley, flax and perhaps pulse,
and even fruit trees.7 Our first enquiry must be what was the
state of vegetation in Essex at this commencement of
agriculture. We may take it that, drainage, fen reclamation
and tillage excepted, the surface soils of our county were then
as they are now, i.e. (with the exception of two small areas
of Chalk down, in the south and in the north-west) clays of
Eocene or Glacial age, stiff loams or gravels, having an
undulating surface, but only a slight general slope, covered
the whole area, abounding in marsh and streams and
surrounded on two sides by the gravels and peats of the
Thames flats, then probably frequently inundated, and by
the muddy levels of our eastern coast, which has probably
altered much in outline and but little in vegetation.
The astronomical causes that produced the Glacial Epoch
were no longer in operation; but the climate may then have
been slightly colder than now, and the rainfall was in all
probability greater, as evidenced to some extent by the more
general and more rapid growth of peat. Undoubtedly, from
that day to this, man by clearing forest, by draining land,
and by embanking rivers and the sea, has exerted a most
important influence upon both the moisture in the air and
that in the soil.8
7 See Greenwell and Rolleston, 'British Barrows.'
8 "It is certain that the island when it fell under the Roman power
was little better in most places than a cold and watery desert. Accord-
ing to all the accounts of the early travellers, the sky was stormy and
obscured by continual rain, the air chilly even in summer, and the sun
during the finest weather had little power to disperse the steaming mists.
The trees gathered and condensed the rain ; the crops grew rankly, but
ripened slowly, for the ground and the atmosphere were alike overloaded
with moisture." Elton, op. cit., p. 223. "In Mauritius, once the
sanatorium of India, the climate has undoubtedly deteriorated, as the
air has become drier from the removal of the forests, and the springs
are drying up......Humboldt mentions that the water supply of
Venezuela had decreased, from the clearing of some of the forests;
whilst some of the West Indian Islands, in spite of a tropical rainfall,
have been reduced to arid sandy wastes. South Africa has suffered
much in climate from the destruction of forests, the rainfall having
become somewhat less and very irregular."—"The Science and Teaching
of Forestry,'' 'Journal of Forestry,' vol. vi.