Drawn by Faucher-Gudin, from a sketch by Peiser.

It was a question in ancient times whether they or the Egyptians had
been the first to carry their investigations into the infinite depths
of celestial space: when it came to be a question as to which of the two
peoples had made the greater progress in this branch of knowledge, all
hesitation vanished, and the pre-eminence was accorded by the ancients
to the priests of Babylon rather than to those of Heliopolis and
Memphis.*

* Clement of Alexandria, Lucien, Diogenes Laertius, Macrobius, attribute
the origin of astronomy to the Egyptians, and Diodorus Sioulus asserts
that they were the teachers of the Babylonians; Josephus maintains, on
the contrary, that the Egyptians were the pupils of the Chaldaeans.

[Illustration: 340.jpg ASTRONOMICAL TABLE]

The Chaldaeans had conducted astronomical observations from remote
antiquity.* Callisthenes collected and sent to his uncle Aristotle a
number of these observations, of which the oldest had been made nineteen
hundred and three years before his time--that is, about the middle of
the twenty-third century before our era: he could have transcribed
many of a still earlier date if the archives of Babylon had been fully
accessible to him.

* Epigenes asserts that their observations extended back to
720,000 years before the time of Alexander, while Berossus
and Critodemus limit their antiquity to 490,000 years, which
was further reduced to 473,000 years by Diodorus, to 470,000
by Cicero, and to 270,000 by Hipparchus.

The Chaldaean priests had been accustomed from an early date to record on
their clay tablets the aspect of the heavens and the changes which took
place in them night after night, the appearance of the constellations,
their comparative brilliancy, the precise moments of their rising and
setting and culmination, together with the more or less rapid movements
of the planets, and their motions towards or from one another. To their
unaided eyes, sharpened by practice and favoured by the transparency
of the air, many stars were visible, as to the Egyptians, which we can
perceive only by the aid of the telescope. These thousands of brilliant
bodies, scattered apparently at random over the face of the sky, moved,
however, with perfect regularity, and the period between their departure
from and their return to the same point in the heavens was determined
at an early date: their position could be