Here we may conclude our reference to the stars which, in the latitude of Egypt, do not rise and set—or, rather, did not rise and set at the epochs of time we have been considering.
CHAPTER XV.
TEMPLES DIRECTED TO THE STARS.
I have now to pass from the circumpolar stars to those which both rise and set. The difference between the two groups—those that do not rise and set and those which do—was fully recognised by the Egyptians, and many references are made to the fact in the inscriptions.
In a previous chapter I have given reasons to show that some of the earliest solar temples in Egypt were not oriented to the solstice.
The temple of Amen-Rā at Karnak, however, and others elsewhere were built in such a manner that at sunset at the summer solstice—that is, on the longest day in the year—the sunlight entered the temple and penetrated along the axis to the sanctuary. I also pointed out that a temple oriented in this manner truly to a solstice was a scientific instrument of very high precision, as by it the length of the year could be determined with the greatest possible accuracy, provided only that the observations were continued through a sufficient period of time.
All the temples in Egypt, however, are not oriented in such a way that the sunlight can enter them at this or any other time of the year. They are not therefore solar temples, and they cannot have had this use. The critical amplitude for a temple built at Thebes so that sunlight can enter it at sunrise or sunset is about 26° north and south of east and west, so that any temples facing more northerly or southerly are precluded from having the sunlight enter them at any time in the year.
It is imperative to be perfectly definite and clear on the question of the amplitudes above 26° at Thebes. I repeat, therefore, that any amplitude within 26° means that up to that point the sun at sunrise or sunset could be observed some day or days of the year—once only in the year if the amplitude is exactly at the maximum, twice if the maximum is not reached. But in the case of these temples with greater amplitudes than 26°, it is quite clear that they can have had nothing to do with the sun.
This being so, we have the problem presented to us whether or not temples were built so that starlight might fall along their axes in exactly the same way that the sunlight could fall along the axes of the solar temples when the sun was rising in the morning or setting in the evening.
It is abundantly clear that temples with a greater amplitude than 26° were oriented to stars if they were oriented at all by astronomical considerations. How can this question be studied? What means of investigation are at our disposal?