Some explorers are of opinion that these illustrations do not represent boats, but fortifications, or stockades of some sort. If we relied only on the rude representations painted on the vases, the question might be a moot one. It has, however, been definitely set at rest by Professor Flinders Petrie, who, in the year 1899, brought back from Egypt very large drawings of the same character, taken, not from vases, but from the tombs themselves. The drawings clearly show that the objects are boats, and that they were apparently very shallow and flat-bottomed. It is considered probable that they were employed in over-sea trade as well as for Nile traffic; for, in the same tombs were found specimens of pottery of foreign manufacture, some of which have been traced to Bosnia. [Illustration: FIG. 3.--Egyptian boat of the time of the third dynasty.] The most ancient mention of a ship in the world's history is to be found in the name of the eighth king of Egypt after Mena, the founder of the royal race. This king, who was at the head of the second dynasty, was called Betou (Boethos in Greek), which word signifies the "prow of a ship." Nineteen kings intervened between him and Khufu (Cheops), the builder of the Great Pyramid at Ghizeh. The date of this pyramid is given by various authorities as from about 4235 to 3500 B.C. As the knowledge of Egyptology increases the date is set further and further back, and the late Mariette Pasha, who was one of the greatest authorities on the subject, fixed it at 4235 B.C. About five centuries intervened between the reign of Betou and the date of the Great Pyramid. Hence we can infer that ships were known to the Egyptians of the dynasties sixty-seven centuries ago. Fortunately, however, we are not obliged to rely on inferences drawn from the name of an individual; we actually possess pictures of vessels which, there is every reason to believe, were built before the date of the Great Pyramid.