144 The Mystery of the Heavens. [Ch.

we find. Again, at the commencement of the
third Sothiac cycle, in B.C. 1322, the archaic-
date would be later still, on the 29th or 30th
of August. And this appears to have been
adopted in the later times as the fixed archaic
date, without further variation in the Alex-
andrine Kalendar.

By a similar reference to the archaic date,
we may throw some light on the peculiar
sanctity attaching to certain days of the
month, for which it is otherwise difficult to
account. For instance, in the Kalendars of the
third Sothiac cycle, the fifteenth and the sixth
of the month appear to be particularly sacred ;
and in the Turin papyrus of the " Book of the
Dead " (the allusions in which would probably
not go back so far as the first cycle, but might
refer either to the second or third), command
is given no less than three times that the
most important festival of the year, the Birth-
day of Osiris, should be celebrated on the
fifteenth of the month. But the Birthday of