cataclysm is proved both by the regularity with which they are deposited, and by the fact that the materials of one river-system are never found mingled with those of another. For example, the gravel-beds of the Somme Valley are entirely composed of débris from the chalk and Tertiary strata occupying that area. But within a very few miles of the head-waters of the Somme comes the valley of the Oise. This latter valley contains the remains of other and older strata, none of which have ever found their way into the Somme Valley, as would certainly have been the case if any great and sudden inundation had ever swept over the surface of the whole country.
From such considerations as these, and many others that might be brought forward, prehistoric archæologists are united in the opinion that the St. Acheul axes found in these Quaternary deposits, and in certain caverns, accompanying the bones of the same fossil animals, are relics of the earliest phase of man's existence yet discovered. Of course, the few are excepted who maintain the belief in the Tertiary man. Such implements have been searched for and found in many countries, but there was still one unfortunate hiatus in the line of argument. It was objected, if such evidence of the great antiquity of man has been discovered in so many different regions, Why is it not to be found in Egypt, the oldest country of which we have direct historical knowledge? This question several have attempted to answer, but hitherto they have failed of complete success. This was owing to the nature of the case, and the peculiarities of the country. Most travelers spend the winter months in their dahabeeahs, ascending and descending the Nile, and have little leisure for long and patient researches; while the distinguished scholars who have resided for long periods in the country have been exclusively occupied with studying its numerous historical monuments, and no one of them has had any special acquaintance with or interest in the prehistoric question. It is true that M. Adrien Arcelin and Sir John Lubbock, and also Dr. Haury with M. Lenormant, who all made the usual Nile trip, have published articles on the subject, some of them figuring in plates certain worked flints discovered by them in Egypt. But they did not succeed in satisfying prehistoric students that they had actually discovered evidence of the Palæolithic age in that country. That they had indeed found worked flints there, could not be questioned by any one who has had competent experience in the subject, though even this has been denied by the distinguished Egyptologist, Lepsius. Some have even supposed that such objects may have been used by the poorer classes within the historic period, of which the paintings and sculptures in the tombs give us such vivid glimpses. The opening of an hotel at Luxor, in Upper Egypt, the site of ancient "hundred-gated" Thebes, in the winter of 1878, gave me an opportunity of carefully studying the question on the spot. I remained seven weeks and searched the region thoroughly in various directions, so far as was possible in journeys of one day's length. The
