In regard to the engineering difficulties, so far as they are known, the only records of levels which we have of the elevation of the land between the Red Sea and the Dead Sea are those made at different times by three Frenchmen—Mons. Lartet, Mons. Vigne, and Mons. Luynes. These only differ nineteen feet—the lowest being seven hundred and eighty-one feet, the highest eight hundred; but it must be remembered that these are not the result of actual survey, but of rough estimates, and there may be depressions in the dividing ridge which may have escaped these gentlemen's observation.^[2] The dividing ridge is said to be calcareous rock—the summit level distant fifty-two miles from the Red Sea and fifty-eight from the Dead Sea, which is nearly thirteen hundred feet lower than the level of the ocean—and it is assumed that the engineering work would be facilitated by the scour which would be caused by the sea rushing down such a steep incline in a distance of one hundred miles. It is not, however, proposed to let the full force of the ocean in from this end. The operation of flooding the Jordan valley would be commenced at Haifa; from this point to the sea-level in the Ghor is only twenty-five miles. The highest point in the plain of Esdraelon is one hundred and fifty-seven feet above the sea. Through this it is proposed to cut a canal two hundred feet wide and forty feet deep. The volume of water thus let in, it is calculated, would be regulated to an inflow which would equal about twenty Jordans, and, allowing for evaporation, it is estimated that in five years the Dead Sea and the whole valley of the Jordan would be submerged to the sea-level.