But while, in the case of the sun, we have to deal with a change of something like 1° in seven thousand years; we have to face in the case of the stars a maximum change of something like 47° in a period of thirteen thousand years. The change of declination must be accompanied by a change of amplitude, and therefore by a change in the direction of the temples. [Illustration: GROUND PLAN OF EDFÛ.] Hence, when we get a temple of known date, with an amplitude which has been accurately measured, we can determine from that amplitude the exact declination of the body the temple was intended to observe, supposing, of course, that the temple was oriented upon any astronomical considerations at all. If the declination of the body turns out to be 23° 30′ or less, the temple may have been, in all probability was, a solar one; if the declination is greater it cannot have had anything to do with the sun directly. [Illustration: GROUND PLAN OF THE TEMPLE OF HATHOR AT DENDERAH.] [Illustration: PLAN OF THE TEMPLE OF SETI AT ABYDOS.] This being so, it will be understood why in an inquiry of this kind it is obviously desirable to begin with a region in which the number of temples is considerable. Such a condition we have in the region near Thebes; and the directions of the axes of the different temples--that is, the orientation of each of them, or, in other words, the amplitude of the direction in which each temple points--have all been tabulated. Chief among these we have the large temple of Karnak, showing that the amplitude of its orientation is 26° north of west, and the temple of Mut, showing that its orientation is 72½° north of east. There is a temple at right angles to the temple at Karnak, and again another with an amplitude of 63° south of west, and so on. [Illustration: PLAN OF THE TEMPLE OF RAMSES II. IN THE MEMNONIA AT THEBES (FROM LEPSIUS) SHOWING THE PYLON AT THE OPEN END AND THE SANCTUARY AT THE CLOSED ONE.] It may be stated generally that at Karnak itself, not to go farther afield, there are two well-marked series of temples which cannot, for the reason given, be solar, since one series faces a few degrees from the north, and the other a few degrees from the south. There are similar temples scattered all along the Nile valley.