On the Field Testing of Methods the Egyptians May Have Used to Find Cardinal Directions

Abstract

The Egyptians were able to align their Fourth Dynasty monuments to cardinal directions with an accuracy of better than one degree. In the case of the Great Pyramid of Khufu, the casing is aligned to cardinal directions to better than four minutes of arc. Scholars have offered many theories which purport to explain how the Egyptians may have achieved such alignments, but only a few have been field tested. This article compiles test results on four of the proposed methods: the pole star method, the circumpolar star method, the simultaneous transit method, and the Indian circle method. The available evidence neither confirms nor refutes the hypothesis that the casings of the Fourth Dynasty pyramids were aligned using the simultaneous transit method. The other methods also have the requisite accuracy. On the other hand, there is reason to believe that the descending passageways at Dahshur were aligned using the pole star method.