ABSTRACT
As Pliny himself said, such calculations had been recorded over a long period of time in Mesopotamia, but not during these remote periods of prehistoric myth. The great totals of years are merely postulated datings designed to cover the phases of human development envisaged by the Sumerians as having elapsed after the creation of the world. The use of other means of calculating long periods of time by means such as 'precession' has been suggested by some writers, but has not as yet proved to have been used by the Egyptians. Precession is caused by the conical motion of the earth's axis, which traces a circle on the heavens and is directed to different Pole stars through many millennia as the visible sky changes. The Sothic cycle therefore remains the most probable method used by the Egyptians for back-dating historical events, and especially phases of prehistory.
