It must be borne in mind that it is not merely a question of stately piles such as Karnak and the Parthenon in populous centres, but of the humblest dolmen or stone circle, in scattered agricultural communities, which was as certainly used for orientation purposes, that is, for recording the lapse of time at night or return of some season important to the tiller of the soil. The advent of the season thus determined could be announced to outlying districts by fire signals at night.
I have already pointed out that any temple, dolmen or cromlech oriented to a sunrise or sunset at any dates between the solstices will receive the sunlight twice a year.
If the temple is pointed nearly solstitially the two dates at which the sun appears in it will be near the solstice; similarly, for a temple pointed nearly equinoctially the dates will be near the equinox; but if the ancients wished to divide the ninety-one days’ interval between the solstice and equinox, a convenient method of doing this would be to observe the sun at the half-time interval, such that the same temple would serve on both occasions. This could be done by orienting the temple to the sun’s place on the horizon when it had the declination 16° 20′ on its upward and downward journey, or, in other words, was, in days, half-way between the equinox and solstice. Thus, for the 45 days (91 days 2) from March 22, we have in—
| March | 9 |
| April | 30 |
| May | 6 |
| 45 |
What, then, are the non-equinoctial, non-solstitial days of the year when the sun has this declination?
They are, in the sun’s journey from the vernal equinox to the summer solstice and back again,
| May 6 and August 8 | Sun’s decl. N. 16° 20′. |
Similarly, for the journey to the winter solstice and return we have
| November 8 and February 4 | Sun’s decl. S. 16° 20′. |
We get, then, a year symmetrical with the astronomical year, which can be indicated with it as in [Fig. 7]; a year roughly halving the intervals between the chief dates of the astronomical year.