20 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [DcC. 9, 



longer dependent upon the salt and bitter waters of Ain Mousa and 

 a groLip of similar springs in the valley of the isthmus, which for- 

 merly supplied it, but receives good fresh water from the Mle by 

 means of the so-called siveet-v^ater canal — a work probably of greater 

 importance and significance to the wellbeing of the conntry and of 

 the transit-trade than the more pretentious, but still unfinished, ma- 

 ritime canal, from which such great results are expected by its 

 spirited promoters. 



Moses's Wells to WadyAmara. — From Ain Mousa to the southward 

 for about 25 or 30 miles the desert presents the same general features 

 as those last described, a gently swelHng or terraced plain of sands and 

 gravel, several miles broad, occupying the whole of the tract between 

 the sea and the rise of the hills. The ground is covered with stunted 

 bushy plants, affording a tolerable amount of feed for the camels du- 

 ring the spring time, and as long as any water from the winter rains 

 remains in the pools formed on the damp retentive ground, where the 

 gypseous shales and clays are close to the surface ; but later, or 

 during the summer and autumn months, the whole becomes parched 

 up and horribly barren and desolate. Sand-scored stones are abun- 

 dant everywhere. Their prevalence is to be accounted for by the 

 ceaseless activity of the sand-drift, as, even when the air is 

 apparently calm and still, there will generally be enough wind 

 moving to set the sand .in motion on the ground and a few inches 

 above it. As a rule, the hardest rocks are the best polished, — this 

 being more especially the case with quartz, jasper, carnelian, and 

 similar siliceous substances ; while the limestones, in addition to being 

 polished, are furrowed and scored in every direction, and their sur- 

 faces studded with numberless small reticulating grooves, resembling 

 the hill-shading on a topographical map. Occasionally masses or 

 portions of crystals of calcite arc found, which, under the same in- 

 fluence, have been etched in a manner in many respects similar to 

 that produced by the action of a liquid solvent ; and the crystals show 

 a tendency to decrement along the principal directions of cleavage. 

 Many of the limestone-pebbles are also blackened in a peculiar 

 manner, probably }ij some cryptogamic or other low form of vege- 

 table life. 



The plain of the desert is broken through by the numerous chan- 

 nels which convey the water of the main valleys to the sea ; but these 

 are so small and slightly marked that they might easily be overlooked 

 by travellers passing through the country in the summer time, when 

 the u]oper watercourses are . quite dry, only the recently dried and 

 partially cracked muddy, surf aces in places showing signs of where 

 the last water had been licked up by the fiery atmosphere of the 

 desert. In the winter time, however, a sudden heavy rainfall in 

 the hills occasionally sends such a flood of water rolling down that 

 the whole plain in; the neighbourhood of the Wady is turned for the 

 time into a lake ; and, according to the statements of the Arabs, 

 camel-trains have occasionally been delayed for many days, until the 

 flood has subsided ; and men have actually been drowned when sud- 

 denly overtaken by the waters in the low ground. The wormwood- 



