with the Nile, but, from the indication of the journey given by
him, it would seem more probable that it was the Niger, and that
the Nasamonians had visited Timbuctoo! Owing to this statement
of Herodotus, it was for long thought that the Upper Nile flowed
east and west.

After Herodotus, the date of whose history may be fixed at the
easily remembered number of 444 B.C., a large increase of 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