We could not expect precise dates from the natives of America, who had no real writings, and whose oldest traditions extended only to a few centuries before the arrival of the Spaniards. And yet, even among them, traces of a deluge are imagined to be found in their rude hieroglyphics. They have their Noah, or Deucalion, as well as the Indians, Babylonians, and Greeks[180]. The Negroes, the most degraded race among men, whose forms approach the nearest to the brutes, and whose intellect has not yet arrived at the institution of regular governments, or at any thing having the least appearance of systematic knowledge, have preserved no sort of annals or traditions. They cannot, therefore, afford us any information on the subject of our present researches, though all their characters clearly shew us that they have escaped from the great catastrophe, at another point than the Caucasian and Altaic races, from which they had perhaps been separated for a long time previous to the occurrence of that catastrophe. But if the ancients, it is argued, have left no history, their long existence as nations is not the less attested by the advances which they have made in astronomy, by observations whose date is easily determined, and even by monuments which still remain, and which themselves bear their dates. Thus, the length of the year, such as the Egyptians are supposed to have determined it, according to the heliacal rising of Sirius, proves correct for a period comprised between the year 3000 and the year 1000 before Christ, a period to which the traditions of their conquests and of the great prosperity of their empire also refer. This accuracy proves to what perfection they had carried their observations, and shews that they had for many ages applied themselves to such investigations. In order to determine the force of this argument, it is necessary that we should here enter upon some explanations. The solstice is the moment of the year at which the rise of the Nile commences, and that which the Egyptians must have observed with most attention. Having, at the beginning, made, from imperfect observations, a civil or sacred year of three hundred and sixty-five days complete, they would preserve it from superstitious motives, even after they had perceived that it did not agree with the natural or tropical year, and did not bring back the seasons to the same days[181]. However, it was this tropical year which it behoved them to mark for the purpose of directing them in their agricultural operations.