were, for a long time, dependent upon the account of Megasthenes,
an ambassador sent by Seleucus, one of Alexander's generals, to
the Indian king of the Punjab.

While knowledge was thus gained of the East, additional information
was obtained about the north of Europe by the travels of one PYTHEAS,
a native of Marseilles, who flourished about the time of Alexander
the Great (333 B.C.), and he is especially interesting to us as
having been the first civilised person who can be identified as
having visited Britain. He seems to have coasted along the Bay
of Biscay, to have spent some time in England,--which he reckoned
as 40,000 stadia (4000 miles) in circumference,--and he appears
also to have coasted along Belgium and Holland, as far as the mouth
of the Elbe. Pytheas is, however, chiefly known in the history
of geography as having referred to the island of Thule, which he
described as the most northerly point of the inhabited earth, beyond
which the sea became thickened, and of a jelly-like consistency. He
does not profess to have visited Thule, and his account probably
refers to the existence of drift ice near the Shetlands.

All this new information was gathered together, and made accessible
to the Greek reading world, by ERATOSTHENES, librarian of Alexandria
(240-196 B.C.), who was practically the founder of scientific geography.
He was the first to attempt any accurate measurement of the size of
the earth, and of its inhabited portion. By his time the scientific
men of Greece had become quite aware of the fact that the earth
was a globe, though they considered that it was fixed in space
at the centre of the universe. Guesses had even been made at the
size of this globe, Aristotle fixing its circumference at 400,000
stadia (or 40,000 miles), but Eratosthenes attempted a more accurate