Hence comes the assertion that before the time of Menes the whole country between the sea and Lake Mœris was a marsh. Such a statement is intelligible only if we remember that, when Herodotos sailed up the Nile, its banks were inundated on either side. Had he seen the country south of Memphis as the modern traveller sees it when the water is subsiding and green fields begin to line the course of the river, he could never have entertained the belief. But all distinction between the Delta and the rest of Egypt was hidden from him by the waters of the inundation. That he should have made the Fayyûm the limit of the marsh is indeed natural; it was the limit of his exploration of Upper Egypt, and consequently he did not know that from Memphis southward to Edfu the valley of the Nile presents the same features.
The strange error he twice commits in imagining that there were vaults under the pyramid of Kheops in an island formed by a canal which the builder had introduced from the Nile is due to the same cause. Doubtless his dragoman had told him something of the kind. A subterraneous chamber in the rock actually exists under the great pyramid, as was discovered by Caviglia, and there are pyramids into whose lower chambers the Nile has long since infiltrated. Professor Maspero found his exploration of the pyramids of Lisht, south of Dahshûr, stopped by the water which had filled them, and Professor Petrie had the same experience in the brick pyramid of Howâra, though here the infiltration of the water seems to have been caused by a canal dug in Arab times. But the pyramids of Gizeh stand on a plateau of limestone rock secure against the approach of water, and the story reported by Herodotos is more probably the result of misapprehension on his own part than of intentional falsehood on the part of his guides. His ready credence of it, however, can be explained only by the condition of the country at the time of his visit. The whole land was covered with water, and in going to Memphis he had to sail by the pyramids themselves. It was in a boat that his visit to them must have been made; and it was easy, therefore, to believe that a canal ran from the water on which he sailed through the tunnelled rock whereon they stood. He did not know that the lowest chamber of the pyramid was high above the utmost level of the flood.