attributed to the Greek astronomers. But, like
Hipparchus, they made faults of calculation in consequence of the defects
of their instruments.[98]

It was the same with the moon. They succeeded in determining its mean daily
movements, and when they had established a period of two hundred and
twenty-three lunations, they contrived to foretell its eclipses. Eclipses
of the sun presented greater difficulties, and the Chaldaeans were content
with noting their occurrence. They were acquainted with the solar year of
three hundred and sixty-five days and a quarter; they used it in their
astronomical calculations; but their religious and civil year was one
composed of twelve lunar months, alternately full and short, that is, of
twenty-nine and thirty days respectively. The lunar and solar years were
brought into agreement by an intercalary cycle of eight years.[99]

The assertion of the philosopher Simplicius has been called in question for
very plausible reasons. Simplicius declares, upon the faith of Porphyrius,
that Callisthenes sent from Babylon to his uncle Aristotle, a copy of
Chaldaean observations dating back as far as 1903 years before the entry of
Alexander into Mesopotamia, that is, to more than twenty-two centuries
before our era.[100]

However this may be, all ancient writers are agreed in admitting that the
Chaldaeans had begun to observe and record astronomical phenomena long
before the Egyptians;[101] moreover the remains of those clay tablets have
been found in various parts of Chaldaea and Assyria upon which, as Pliny
tells us upon the authority of the Greek astronomer Epigenes, the Chaldaeans
had inscribed and preserved the astronomical observations of seven hundred
and eighty thousand years.[102] We need not dwell upon the enormity of this
figure; it matters little whether it is due to the mistakes of a copyist or
to the vanity of the Chaldaeans, and the too ready credulity of the Greeks;
the important point is the existence of the astronomical tablets, and
those Epigenes himself saw. The library of Assurbanipal at Nineveh included
catalogues of stellary and planetary observations, among others the times
of Venus, Jupiter and Mars, and the phases of the moon, for every day in
the month.[103] Tablets have also been recently discovered giving the
arrangement of the stars in the sky for each season and explaining the rule
to be followed in the insertion of the intercalary months. Finally, a
fragment of an Assy