Major Palmer mentions the presence of marine shells in the Bitter Lake as showing that it was formerly filled with salt water from the Gulf of Suez. He says further:--“This communication subsequently became broken by the gradual elevation of the neck of land eleven miles long which now separates the lakes from the head of the gulf--an interesting fulfilment of the prophecy in Isaiah xi. 15--‘and the Lord shall utterly destroy the tongue of the Egyptian sea.’ Darius, about B.C. 500, restored the connection by cutting a canal through the isthmus, which after a period of disuse was reopened by Ptolemy Philadelphus, about B.C. 250. Traces of Darius’s canal are still seen, in a very perfect state, though its bed has since risen above the level of high water in the gulf. If, as can hardly be doubted, there was a connection, at least tidal, between the lakes and the gulf at the time of the Exodus, the only course eastward from Egypt which would have been ordinarily practicable for the march of hosts, must have passed to the north of the Great Bitter Lake, crossing the belt of dry ground which, interrupted only by the Timsah and Ballah Lakes, extends between it and the Menzaleh Lake, and the Children of Israel must have been following one such route when, at Etham, they were directed to turn and encamp before Pi-ha-horoth.”
These views of Major Palmer’s are shared by M. Naville, by Sir Wm. Dawson, and others, and have been decisively confirmed by the geological survey of the region. In 1883 the Committee of the Palestine Exploration Fund sent out Professor Hull, the eminent geologist, accompanied by Major Kitchener, R.E., and other competent men, and this party investigated the geology of Lower Egypt, of the Desert of Sinai, the Valley of the Arabah, and the southern portion of Palestine. The results were very remarkable. It appears, for instance, that at a distant period of the past the waters of the seas, lakes, and gulfs of all this region stood some two hundred feet higher than they do now--the proof being found in the fact that at the height of two hundred feet the limestone rocks have been bored into by the well-known “shell-fish,” the pholas, while the sands and gravels at that height contain shells and corals and crinoids, of the same species as those which still inhabit the waters of the Gulf of Suez. With the waters at that height the whole of Lower Egypt would be submerged, together with extensive tracts on either side of the Gulf of Suez. But this occurred in the distant past, probably many ages before mankind dwelt in these regions at all. There was, however, a more recent period, as the land slowly rose out of the waters--and Professor Hull thinks it may have coincided with the time of the Exodus--when the waters were just 26 feet higher than they are at present, and then, although Lower Egypt would not be submerged, the Gulf of Suez must have extended northward as far as the Bitter Lakes, making an arm of the sea about a mile wide and 20 or 30 feet deep.