and Crete, apart from the fact that they do not stand in tidal water,
have no navigable rivers. Iceland, standing in a tidal sea, too far
north indeed for successful commerce, but not too far north for the
growth of a civilisation, is at a similar disadvantage. Great Britain
and Ireland alone--Great Britain south of the Scottish Mountains, that
is--enjoy this peculiar advantage; and there are few things more
instructive when one is engaged upon the history of England than to
take a map and mark upon it the head of each navigable piece of water
and the head of its tideway, for when this has been done all England,
with the exception of the Welsh Hills and the Pennines, seems to be
penetrated by the influence of the sea.

The conditions which give a river this great historic importance, the
fundamental character, therefore, which has lent to the Thames its
meaning in English history, is twofold: a river affords a permanent
means of travel, and a river also forms an obstacle and a boundary.
Men are known to have agglomerated in the beginning of society in two
ways: as nomadic hordes and as fixed inhabitants of settlements.

There has arisen a profitless discussion as to which of these two
phases came first. No evidence can possibly exist upon either side,
but one may take it that with the first traditions and records, as at
the present time, the two systems existed side by side, and that
either was determined by geographical conditions. A river is an
advantage to both groups, but to the second it is of more consequence
than to the first; and in South England, if we go back to the origins
of our history, it is in fixed settlements that we find the first
evidence of man. With every year of research the extreme antiquity of
our inhabited sites becomes more apparent. And indeed the geographical
nature of Southern England should make us certain of the antiquity of