a whole year, and so the movable year and the fixed year fell together
again. It is this Sothic period which Manetho has employed in his
account of Egyptian history. Besides his history, Manetho has left us a
work on astrology, called _Apotelesmatica_, or Events, a work of which
there seems no reason to doubt the genuineness.

It is a poem in hexameter verse, in good Greek, addressed to King
Ptolemy, in which he calls, not only upon Apollo and the Muse, but, like
a true Egyptian, upon Hermes, from whose darkly worded writings he had
gained his knowledge. He says that the king's greatness might have been
foretold from the places of Mars and the Sun at the time of his birth,
and that his marriage with his sister Arsinoe arose from the places of
Venus and Saturn at the same time. But while we smile at this being said
as the result of astronomical calculations, we must remember that for
centuries afterwards, almost in our own time, the science of judicial
astrology was made a branch of astronomy, and that the fault lay rather
in the age than in the man; and we have the pain of thinking that,
while many of the valuable writings by Manetho are lost, the copiers and
readers of manuscripts have carefully saved for us this nearly worthless
poem on astrology.

Petosiris was another writer on astrology and astronomy who was highly
praised by his friend Manetho; and his calculations on the distances
of the sun and planets are quoted by Pliny. His works are lost; but his
name calls for our notice, as he must have been a native Egyptian, and
a priest. Like Manetho, he also wrote on the calculation of nativities;
and the later Greek astrologers, when what they had foretold did not
come to pass, were wont to lay the blame on Petosiris. The priests were
believed to possess these and other supernatural powers; and to help
their claims to be believed many of them practised ventriloquism.

Timosthenes, the admiral under Philadelphus, must not be forgotten in
this list of authors; for though his verses to Apollo were little worth
notice, his voyages of discovery, and his work in ten books on harbours,
placed him in the first rank among geographers. Colotes, a pupil and
follower of Epicurus, dedicated to Philadelphus a work of which the very
title proves the nature of his philosophy, and how soon the rules of his
master had fitted themselves to the habits of the sensualist. Its
title was "That it is impossible even to support life according