name Sothis. It chances that, as viewed from about the region of
Heliopolis, the sun at the time of the summer solstice occupies
an apparent position in the heavens close to the dog-star. Now,
as is well known, the Egyptians, seeing divinity back of almost
every phenomenon of nature, very naturally paid particular
reverence to so obviously influential a personage as the sun-god.
In particular they thought it fitting to do homage to him just as
he was starting out on his tour of Egypt in the morning; and that
they might know the precise moment of his coming, the Egyptian
astronomer priests, perched on the hill-tops near their temples,
were wont to scan the eastern horizon with reference to some star
which had been observed to precede the solar luminary. Of course
the precession of the equinoxes, due to that axial wobble in
which our clumsy earth indulges, would change the apparent
position of the fixed stars in reference to the sun, so that the
same star could not do service as heliacal messenger
indefinitely; but, on the other hand, these changes are so slow
that observations by many generations of astronomers would be
required to detect the shifting. It is believed by Lockyer,
though the evidence is not quite demonstrative, that the
astronomical observations of the Egyptians date back to a period
when Sothis, the dog-star, was not in close association with the
sun on the morning of the summer solstice. Yet, according to the
calculations of Biot, the heliacal rising of Sothis at the
solstice was noted as early as the year 3285 B.C., and it is
certain that this star continued throughout subsequent centuries
to keep this position of peculiar prestige. Hence it was that
Sothis came to be associated with Isis, one of the most important
divinities of Egypt, and that the day in which Sothis was first
visible in the morning sky marked the beginning of the new year;