masters of all this vast inheritance, they had not themselves the
ability to record the geographical knowledge thus acquired, and it
is to a Greek named Ptolemy, a professor of the great university
of Alexandria, to whom we owe our knowledge of how much the ancient
world knew of the earth. It will be convenient to determine this
first, and afterwards to sketch rapidly the course of historical
events which led to the knowledge which Ptolemy records.

In the Middle Ages, much of this knowledge, like all other, was
lost, and we shall have to record how knowledge was replaced by
imagination and theory. The true inheritors of Greek science during
that period were the Arabs, and the few additions to real geographical
knowledge at that time were due to them, except in so far as commercial
travellers and pilgrims brought a more intimate knowledge of Asia
to the West.

The discovery of America forms the beginning of a new period, both
in modern history and in modern geography. In the four hundred
years that have elapsed since then, more than twice as much of
the inhabited globe has become known to civilised man than in the
preceding four thousand years. The result is that, except for a few
patches of Africa, South America, and round the Poles, man knows
roughly what are the physical resources of the world he inhabits,
and, except for minor details, the history of geographical discovery
is practically at an end.

Besides its interest as a record of war and adventure, this history
gives the successive stages by which modern men have been made what
they are. The longest known countries and peoples have, on the whole,
had the deepest influence in the forming of the civilised character.