The mountains on each side (of the Nile), which descend from the parts about Syene to the Egyptian Sea,[803] give this shape to the river tract of which I am speaking, and to the country. For in proportion as these mountains extend along that tract, or recede from each other, in the same degree is the river contracted or expanded, and they impart to the habitable country its variety of shape. But the country beyond the mountains is in a great measure uninhabited. 5. The ancients understood more by conjecture than otherwise, but persons in later times learnt by experience as eye-witnesses, that the Nile owes its rise to summer rains, which fall in great abundance in Upper Ethiopia, particularly in the most distant mountains. On the rains ceasing, the fulness of the river gradually subsides. This was particularly observed by those who navigated the Arabian Gulf on their way to the Cinnamon country, and by those who were sent out to hunt elephants, or for such other purposes as induced the Ptolemies, kings of Egypt, to despatch persons in that direction. These sovereigns had directed their attention to objects of this kind, particularly Ptolemy surnamed Philadelphus, who was a lover of science, and on account of bodily infirmities always in search of some new diversion and amusement. But the ancient kings paid little attention to such inquiries, although both they and the priests, with whom they passed the greater part of their lives, professed to be devoted to the study of philosophy. Their ignorance therefore is more surprising, both on this account and because Sesostris had traversed the whole of Ethiopia as far as the Cinnamon country, of which expedition monuments exist even to the present day, such as pillars and inscriptions. Cambyses also, when he was in possession of Egypt, had advanced with the Egyptians as far even as Meroë; and it is said that he gave this name both to the island and to the city, because his sister, or according to some writers his wife, Meroë died there. For this reason therefore he conferred the appellation on the island, and in honour of a woman. It is surprising how, with such opportunities of obtaining information, the history of these rains should not have been clearly known to persons living in those times, especially as the priests registered with the greatest diligence in the sacred books all extraordinary facts, and preserved records of everything which seemed to contribute to an increase of knowledge. And, if this had been the case, would it be necessary to inquire what is even still a question, what can possibly be the reason why rain falls in summer, and not in winter, in the most southerly parts of the country, but not in the Thebaïs, nor in the country about Syene? nor should we have to examine whether the rise of the water of the Nile is occasioned by rains, nor require such evidence for these facts as Poseidonius adduces. For he says, that Callisthenes asserts that the cause of the