The physical features of the country naturally depend upon its geological formation. The ranges of hills, east and west of Jordan, are formed almost entirely of beds of cretaceous limestone, which were once continuous. The Jordan Valley coincides with a line of fault; that is to say, the rocky strata cracked in an irregular line from north to south, and the country west of this fault sank down bodily, so that the higher strata of rocks on that side abut now against the lower strata on the eastern side. With this depression to begin with, the rains and torrents have gradually sculptured the valley into its present form. The maritime district of Palestine, stretching from the base of Carmel southwards by Joppa and Gaza to the Desert of Beersheba, consists of a series of low hills from 300 feet to 400 feet high, separated by valleys and alluvial plains extending inland to a varying distance. The coast line is bordered by a line of sand-hills, which, when unrestrained by some physical barrier, are ever moving inland with disastrous effect. The district is largely composed of beds of sand and gravel, which have once been the bed of the outer sea; while along the line of many of the rivers and streams a deposit of rich loam of a deep brown colour covers considerable areas, and yields abundant crops of wheat and maize to the cultivators. Professor Edward Hull, the eminent geologist, who was commissioned by the Palestine Exploration Society to investigate the geology of the Desert and the Holy Land, reported the results to the Committee, in an elaborate Memoir, in which he treats of the maritime district, the table-land of Western Palestine and the Tih Desert, the depression of the Jordan Valley and its continuation southward to the Gulf of Akabah, the elevated plateau east of Jordan, and the mountainous tract of the peninsula of Sinai. Utilising the labours of his predecessors, Russeger, Fraas, Lartet, Vignes, &c., he sometimes confirms their results, and sometimes adds to our knowledge. [Illustration: GEOLOGICAL SKETCH MAP of SINAI & PALESTINE (_based chiefly upon the Maps of M.M. Lartet, Hull & Zittel_.) _The figures represent deviations above the sea level in English feet; those with a minus mark represent depressions below sea level._]