60 DESCRIPTION OF ARABIA. 



the tent, and 156° when exposed to the sun's rays.* 

 The highlands on the coast, and in some parts of the 

 interior, enjoy a more temperate atmosphere. Near 

 Sanaa, about 200 miles inland from Mocha, Nie- 

 buhr was informed that ice had been seen. Storms 

 of hail are not uncommon at Taif ; and snow some- 

 times falls on the hills near Medina. In winter the 

 whole of the Upper Sinai is often covered with 

 snow ; many of the passes are choked up, so that 

 the mountains of Moses and St. Catherine are inac- 

 cessible. Mr. Fazakerley, who ascended them in 

 the month of February, found it very deep ; though 

 he fared better than Pietro delta Valle, who went up 

 in a violent snow-storm, and gives a lamentable ac- 

 count of his adventures on that occasion. For this 

 peculiarity of climate Arabia is partly indebted to its 

 position, hemmed in between the continents of Asia 

 and Africa, and effectually debarred by the latter 

 from the influence of the south-west monsoon, 

 which blows during summer on the coasts of India, 

 and ushers in the periodical rains. 



One great characteristic of this vast continental de- 

 sert is aridity. Whole years occasionally pass away 

 without rain ; the drought is consequently extreme, 

 and destructive of all vegetation. All the highland 

 tracts, and the different ridges which shoot forth 

 into the interior, by attracting clouds and A^apours, 

 enjoy the advantage of frequent and copious showers. 

 Those rains occur at different times of the year, ac- 

 cording to the position of the mountains. On the 

 western declivity of Yemen, and along the shores 

 of the Red Sea, they commence in June and termi- 

 nate in September. This district is also refreshed 

 by a spring rain ; while on the eastern declivity of 

 the same mountains the wet season is between the 

 middle of November and the middle of February, 

 In Hadramaut and Oman, and on the coasts of the 



* Trgrels in Arabia, p. 384. 



