Artemidorus says, that the navigation up the river is 28 schœni, which amount to 840 stadia, reckoning the schœnus at 30 stadia. When we ourselves sailed up the river, schœni of different measures were used at different places in giving the distances, so that sometimes the received schœnus was a measure of 40 stadia and even more. That the measure of the schœnus was unsettled among the Egyptians, Artemidorus himself shows in a subsequent place. In reckoning the distance from Memphis to Thebaïs, he says that each schœnus consists of 120 stadia, and from the Thebaïs to Syene of 60 stadia. In sailing up from Pelusium to the same vertex of the Delta, is a distance, he says, of 25 schœni, or 750 stadia, and he employs the same measure.
On setting out from Pelusium, the first canal met with is that which fills the lakes, “near the marshes,” as they are called. There are two of these lakes, situated upon the left hand of the great stream above Pelusium in Arabia. He mentions other lakes also, and canals in the same parts beyond the Delta.
The Sethroïte Nome extends along one of the two lakes. He reckons this as one of the ten nomes in the Delta. There are two other canals, which discharge themselves into the same lakes.
The canal was first cut by Sesostris before the Trojan times, but according to other writers, by the son of[844] Psammitichus, who only began the work, and afterwards died; lastly, Darius the First succeeded to the completion of the undertaking, but he desisted from continuing the work, when it was nearly finished, influenced by an erroneous opinion that the level of the Red Sea was higher than Egypt, and that if the whole of the intervening isthmus were cut through, the country would be overflowed by the sea. The Ptolemaïc kings however did cut through it, and placed locks upon the canal,[845] so that they sailed, when they pleased, without obstruction into the outer sea, and back again [into the canal].
We have spoken of the surfaces of bodies of water in the first part of this work.[846]