f knowledge
was obtained of the western part of Asia by the two expeditions of
Xenophon and of Alexander, which brought the familiar knowledge of
the Greeks as far as India. But besides these military expeditions
we have still extant several log-books of mariners, which might
have added considerably to Greek geography. One of these tells
the tale of an expedition of the Carthaginian admiral named Hanno,
down the western coast of Africa, as far as Sierra Leone, a voyage
which was not afterwards undertaken for sixteen hundred years.
Hanno brought back from this voyage hairy skins, which, he stated,
belonged to men and women whom he had captured, and who were known
to the natives by the name of Gorillas. Another log-book is that
of a Greek named Scylax, who gives the sailing distances between
nearly all ports on the Mediterranean and Black Seas, and the number
of days required to pass from one to another. From this it would seem
that a Greek merchant vessel could manage on the average fifty miles
a day. Besides this, one of Alexander's admirals, named Nearchus,
learned to carry his ships from the mouth of the Indus to the Arabian
Gulf. Later on, a Greek sailor, Hippalus, found out that by using
the monsoons at the appropriate times, he could sail direct from
Arabia to India without laboriously coasting along the shores of
Persia and Beluchistan, and in consequence the Greeks gave his
name to the monsoon. For information about India itself, the Greeks
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