ANCIENT EGYPTIAN GEODESY - PART III
Based on excavations in 1865, Mahmoud Bey determined that the streets of ancient Alexandria ran 24° north of due east, with cross streets running at right angles 24° east of due south. The three most significant Egyptian locales for Alexander the Great were Siwa, Luxor and the site he chose for Alexandria. The azimuth of the great circle route from Alexandria to Luxor is 156°. This is 24° east of due south, aligned with the axis of the streets of ancient Alexandria. The azimuth from Alexandria to Siwa is 245°. This is 25° south of due west, within one degree of the alignment of the streets of ancient Alexandria as reported by Mahmoud Bey.
The distance from Alexandria to Luxor is just under 410 miles. The distance from Alexandria to Siwa is 300 miles. The distance from Siwa to Luxor is 500 miles. Thus, the triangle formed by the great circle vectors from Alexandria to Luxor and Siwa, and the vector from Luxor to Siwa, very nearly form a perfect pythagorean 3-4-5 right triangle, with the right angle in very nearly perfect alignment with the right angled axis of the streets of ancient Alexandria.