1890.] NEW YORK ACADEMY OF SCIENCES. 119 



low ranges of limestone and sandstone hills, and an irregular 

 group of bold granitic mountains whose peaks rise to the height 

 of 8,000 feet. Each of these regions is furrowed by wadis, or dry 

 water-courses, which present very different aspects in the three 

 divisions named. In passing from Suez to Sinai, by the usual 

 route, one meets these features in the order named. 



Plains. — The first 53 miles of the journey, occupying about 

 two days and a half, as camels travel, passes over an arid, sterile 

 plain about ten miles wide from the low range of limestone hills 

 on the east, Et Tih, to the Gulf on the west. This plain, like 

 that of El Gaa, to the south, rises gradually from the sea to the 

 foothills, and is undulating towards its southern end. It is 

 crossed by broad, shallow wadis, running east and west, which 

 were perfectly dry at the time of my visit ; Wadi Vferdan, the 

 largest, is depressed but a foot or two below the level of the 

 plain and is approximately three miles in width at about six miles 

 from the point where it enters the sea. 



The most extensive plain on the western side of the Peninsula 

 is that of EI Gaa, which is about 80 miles long and 15 wide at its 

 widest point. From the sea-coast to the mountains bordering it 

 on the east, it rises nearly 1,000 feet, but so gradually as to de- 

 ceive the eye and appear level. It is crossed by many shallow wa- 

 dis, and its northern half is separated from the sea by a range of 

 limestone hills (Jebel-el-Araba) reaching a height of 1,600 feet. 

 When the plain was covered by the sea, this range was probably 

 an island, or series of islands. The plain is rarely broken by 

 hills, the sharp-pointed Kren Utud, conspicuous from a distance, 

 being an exception. I crossed the monotonous desolate waste, 

 from the mouth of the beautiful Wadi Es-Sleh to Tor (or Tur), 

 on the Gulf, a distance of about 15 miles, and noted scarcely 

 a dozen tufts of plants; water is absolutely wanting. North 

 of Tor, however, and east of Jebel-el-Araba, are palm-gardens 

 that extend for several miles in a narrow belt; and these date- 

 bearing trees owe their existence to several saline springs occur- 

 ring at intervals, some of which are quite warm. On this sterile 

 plain, the characteristics of a desert are seen in perfection ; the 

 level expanse is not too broad to conceal the lofty mountains on 

 the east, nor to prevent glimpses of the blue sea on the western 

 horizon ; the floor is a firm hard surface, made up of a compact 

 mixture of gravel and coarse sand, so hard indeed that camels 

 make no impress on it with their broad feet. At some places 

 the surface pebbles are of many shades of brown, intermingled 

 with black and wliite, and these are so closely laid and regularly 

 distributed as to resemble a mosaic pavement, but of course a 

 patternless one. Tlie surface particles are generally coarser 

 than those immediately beneath ; they are chiefly limestone, 



