ty.

South England is everywhere fertile, everywhere well watered, and
nowhere divided, as is the North, by long districts of bare country,
or of hills snowbound in winter, or of morass. Its forests, though
numerous, have never formed one continuous belt; even the largest of
them, the Forest of the Weald, between the downs of Surrey and Kent
and those of Sussex, was but twenty miles across--large enough to
nourish a string of hunting villages upon the north and the south
edges of it; but not large enough to isolate the Thames Valley from
the southern coast.

From the beginning of human activity in this island the whole length
of the river has been set with human settlements never far removed one
from the other; for the Thames ran through the heart of South England,
and wherever its banks were secure from recurrent floods it furnished
those who settled on them with three main things which every early
village requires: good water, defence, and communication.

The importance of the first lessens as men learn to dig wells and to
canalise springs; the two last, defence and communication, remain
attached to river settlements to a much later date, and are apparent
in all the history of the Thames.

The problem of communication under early conditions is serious. Even
in a high civilisation the maintenance of roads is of greater moment,
and imposes a greater burden, than most of the citizens who support it
know; but before the means or the knowledge exist to survey and to
harden roads, with their causeways over marshes and their bridges over
rivers, the supply of food in time of scarcity or of succour in time
of danger is never secure: a little narrow path kept up by nothing but
the continual passage of men and animals is all the channel a
community of men have for communicating with their neighbours by land.
And it must be remembered that upon such communication depend not only
the present existence, but the future development of the society,
which cannot proceed except by that fertilisation, as it were, which
comes from the mixture of varied experiences and of varied traditions:
every great change in history has necessarily been accompanied by some
new activity of travel.

Under the primitive conditions of which we speak a river of moderate
depth, not too rapid in its current and perennial in its supply, is
much the best means by which men may communicate. It will easily
carry, by the exertions of a couple of men, some h