we find that at Zimbabwe means had been provided
for ascertaining the time of the summer solstice, and
that the side of the temple which faced the rising sun
at this period of the year was adorned with a decoration
symbolical of fertility.
But the temples at Zimbabwe seem also to have
served a more directly practical purpose than that of
mere worship of the powers of nature, and while regulating
the festivals held in honour of natural powers,
to have provided the means of observing the passage
of the seasons and of fixing the limits of a tropical
year, and thus providing the elements of a calendar.
The duration of a day is clearty marked by an
apparent revolution of the sun, and from the most
remote antiquity a month has been equivalent to the
length of a lunation; but there is no equally obvious
astronomical phenomenon to enable the length of the
year to be fixed 8 and although the difference between
summer and winter is very apparent in most climates,
there is nothing which very obviously defines the
l im i t s of these seasons, and the periods of spring and
autumn are even less marked. But the dates of all
festivals in solar worship would have some relation
to the seasons; and, besides, the times for agricultural
and many other operations would require to be fixed,
and it would thus be doubly necessary to find means
of marking the progress of the year. By most ancient
peoples twelve lunations were considered to be equal
to a tropical year, but it was soon discovered that
this was not so, for the several months did not long
coincide with their appropriate seasons, and so the