Besides the want of a fixed era, and the insufficient knowledge of the ancient period, and of the alien monarchy—besides the motives of national vanity, there was another remarkable circumstance connected with the priests of Egypt which was calculated to lead them far away from historical truth. The Egyptians measured time by a solar year of 360 days, divided into twelve months of thirty days. It was early observed that this year did not correspond to the sun's orbit; and therefore five additional days were added. The decisive event of the Egyptian year was the inundation. The Nile began to rise at the time of the summer solstice, and was coincident with the rising of the Dog-star (Sothis), the brightest star in the Egyptian sky. The Dog-star proclaimed the approach of the inundation and the new fertilization of the soil, and by proclaiming caused it. Thus to the Egyptians this star Sothis was "the Lady of the Beginning." The rising of the star denoted the new year; which therefore must have begun on the 20th July, the first of Thoth in the Egyptian calendar. But since, in the Egyptian year, a quarter of a day was wanting, in spite of the additional five years, to make up the true astronomical year, the beginning of every fourth year must have been a day in advance of the true year, and the seasons, of which the Egyptians made three of four months each, the months, and the festivals anticipated more and more the true time of the year. This advance could not have escaped the priests; they must soon have observed that a period of 1,461 Egyptian years must elapse in order to allow the Egyptian year to coincide with astronomical time. For in 1,460 Egyptian years the additional quarter of a day in the astronomical year would amount to 365 whole days—i.e. to an Egyptian year; and at the end of this year the beginning of the next was again coincident with the rising of the Dog-star, as seen from Lower Egypt, and the commencement of the inundation. Thus in a period of 1,461 years the year was again brought to its true beginning.[28] Since the fruitfulness and life of the Egyptian land depended on the inundation, and the inundation began with the rising of the Dog-star, the history of Egypt must also have begun with a similar rising. If after 1,461 Egyptian years the rising of the Dog-star again coincided with the beginning of the civic year, the priests would regard this restoration of the natural order as the completion of a great cycle of events. The Dog-star brought the inundation, and with it the fruits and life of Egypt. It was the awakener of life. It must therefore have brought life to the world also; time must have begun with the rising of Sirius. Porphyrius tells us that to the Egyptians the rising of the Dog-star was the beginning of the world.[29] Hence the periods of the world must proceed according to a number of periods fixed by the Dog-star. It seems that the priests comprised the whole duration of the world in twenty-five Sothis periods, i.e. in 36,525 Egyptian years. Regarded in this light, the Sothis periods of the priests of Egypt must lead to a cyclic treatment of their history, to which also the want of any definite era was forcing them, while the antiquity and number of the lists of kings offered abundant material for it. The history of Egypt must comprise a definite number of Sothis periods. It was known that in the fourteenth century B.C. such a period ended, and a new one commenced; the difficulty was to fill up two or three periods anterior to this. Before the Sothis period of the kings, the gods had ruled over Egypt, to whom, therefore, a number of Sothis cycles, naturally more extensive than those given to the rule of men, was allotted. Thus the priests of Thebes were able to tell Herodotus that, from the time when the Twelve Gods ruled over Egypt, down to the days of King Amosis, 17,000 years had passed; that from Menes, down to Sethos, 341 kings ruled in succession over Egypt, and that in this space of time the sun had four times risen in an unusual way—it had twice risen where it then set, and had twice set where it then rose; and nothing in Egypt had been changed by this, either in the gifts of the earth or the river, in sickness or in mortality.[30] This change of the rising and setting of the sun is nothing more than the symbolical astrology of the priests, who must have expressed the completion of the movable solar year by the opposite quarters of the sky; and it means no more than that two Sothis periods had elapsed between Menes and Sethos; but to Herodotus the statement as given naturally appeared quite incredible.[31] What the priests told Herodotus, Manetho, following far older authorities, had already fixed in a systematic form before Diodorus found that the gods ruled 18,000 years, and the human kings had begun to reign 4,700 years before his arrival in Egypt. To the gods and demigods Manetho allows twelve Sothis periods, i.e. 17,520 Julian years. Then follows the history of the men, the beginning of which Manetho places in the commencement of that period of the Dog-star which begins with the year 5702 B.C. From this point the series of kings runs through three complete Sothis periods down to Menephta; in the fourth period Manetho closed the lists of his thirty dynasties with the last native ruler in 340 B.C., the 984th year of the fourth Sothis period of the human kings. Thus it would be possible to make the scheme clear on which the priests of Egypt dealt with the history of their land, and the lists of Manetho would then lay claim to complete historical credibility for the ancient periods in isolated items, though certainly not in their combination as a whole.
With this result before us the only course open is to seek for external evidence, and attempt to ascertain the antiquity of the civilisation of Egypt independently of the priests and their traditions. The first fixed point in Egyptian chronology is given by the campaign of Pharaoh Sisak against Judah and Jerusalem. Sisak caused a sketch of his enterprise to be delineated on the wall of a structure erected by him in the temple at Karnak. According to Manetho's list, Sisak (Sesonchis), the first ruler of his twenty-second dynasty, begins his reign in the year 934 B.C.[32] But the chronology of the Hebrews, which from the establishment of the monarchy downwards coincides within a few insignificant variations with the Assyrian records, proves that Sisak must have been king in the first half of the tenth century B.C. The campaign against Judah falls in the middle of this century. From Sisak to the expulsion of the Hyksos there was an interval of at least 500 years, as we may maintain approximately from the names of kings and their reigns recorded on monuments. If therefore we accept the excerpt from Manetho's history given in Josephus (and that excerpt was made precisely for this period, and has come down to us in the best shape), and allow 511 years for the reign of the Hyksos, we arrive at the year 2000 B.C. as the end of the old monarchy. From this monarchy numerous monuments have come down to us belonging to the Amenemha, and Sesurtesen, the twelfth dynasty of Manetho; and again to the time preceding these princes belong the greatest monuments in Egypt, the pyramids of Memphis, which, according to Manetho's list, are the work of the fourth dynasty. These pyramids therefore may have been built about the year 2500 B.C. The plan and execution of these monuments presuppose a very long practice in the treatment and preparation of materials; the size, permanence, and solidity of the construction were impossible without great experience in the use of stone; and their massive form requires an acquaintance with the principles of architecture which can only be obtained in the course of centuries. And independently of the advanced state of architecture exhibited by these monuments at the first sight, their erection is a proof of a condition of social and civic life far removed from primitive tribal communities. So long as tribes few in number and isolated from each other possessed the valley of the Nile, under the rule of their tribal chiefs, such structures were impossible. They presuppose a settled population, accustomed to work, and skilled in it. And more than this. The whole population could not any longer be occupied in agricultural work; there must have been a considerable amount of superfluous labour, living upon the productions obtained from the earth by others. Such structures required the united force of many thousands, the continued efforts of long years. And as the use of complex machinery for moving and raising the heavy materials was unknown to the Egyptians, and remained unknown, as we see from the monuments, a still greater force of men and beasts of draught were necessary to move such huge squares and blocks by means of a simple lever and rollers. Finally, the combination and continued employment of such forces presupposes that society has