In Strabo, book i. pages 38 and 50, it appears that Eratosthenes was acquainted with the existence of the strait, of which the later geographers make no mention. It existed still in the time of Moses (Exodus xiv. 2), for he encamped at Pi-ha-chiroht, the "mouth of the strait." Moreover, Strabo mentions that Sesostris made an attempt to cut through the isthmus, but that he was not able to accomplish it. That in very remote times the sea really did flow through is proved by the result of the geological investigations on the isthmus made by the Suez Canal Commission, of which M. Renaud presented a report to the Academy of Sciences on the 19th June 1856. In that report, among other things, appears the following: "Une question fort controversée est celle de savoir, si à l'époque où les Hebreux fuyaient de l'Egypte sous la conduite de Moïse, les lacs amers faisaient encore partie de la mer rouge. Cette dernière hypothèse s'accorderait mieux que l'hypothèse contraire avec le texte des livres sacrés, mais alors il faudrait admettre que depuis l'époque de Moïse le seuil de Suez serait sorti des eaux." With regard to this question, it is certainly of importance to fall in with an account in this Frisian manuscript, from which it seems that in the sixteenth century before Christ the connection between the Bitter Lakes and the Red Sea still existed, and that the strait was still navigable. The manuscript further states that soon after the passage of the Geertmen there was an earthquake; that the land rose so high that all the water ran out, and all the shallows and alluvial lands rose up like a wall. This must have happened after the time of Moses, so that at the date of the Exodus (1564 B.C.) the track between Suez and the Bitter Lakes was still navigable, but could be forded dry-foot at low water. This point, then, is the commencement of the isthmus, after the forming of which, the northern inlet was certainly soon filled up as far as the Gulf of Pelusium. The map by Louis Figuier, in the "Année scientifique et industrielle" (première année), Paris, Hachette, 1857, gives a distinct illustration of the formation of this land. Another statement, which occurs only in Strabo, finds also here a confirmation. Strabo alone of all the Greek writers relates that Nearchus, after he had landed his troops in the Persian Gulf, at the mouth of the Pasitigris, sailed out of the Persian Gulf by Alexander's command, and steered round Arabia through the Arabian Gulf. As the account stands, it is not clear what Nearchus had to do there, and what the object of the further voyage was. If, as Strabo seems to think, it was only for geographical discovery, he need not have taken the whole fleet. One or two ships would have sufficed. We do not read that he returned. Where, then, did he remain with that fleet?