DESCRIPTION OF ARABIA. 39 



keeping always in advance ; while the intermediate 

 space glows like a furnace, occasioned by the quiv- 

 ering undulating motion of that quick succession 

 of vapours and exhalations which are extracted 

 by the solar rays. Every object is magnified to the 

 eye, insomuch that a shrub has the appearance of a 

 tree, and a flock of birds might be mistaken for a 

 caravan of camels. The most singular quality of 

 this vapour (Sirab), or mirage as it is termed, is its 

 power of reflection, — objects are seen as from the 

 surface of a lake, and their figure is sometimes 

 changed into the most fantastic shapes. 



These naked deserts are encircled, or sometimes 

 intersected, by barren mountains, which run in almost 

 continuous ridges, and in diflferent directions, from 

 the borders of Palestine to the shores of the Indian 

 Ocean. Their summits tower up into rugged and 

 insulated peaks, but their flinty bosoms supply no 

 humidity to nourish the soil ; they concentrate no 

 clouds to screen the parched earth from the wither- 

 ing influence of a tropical sky. The refreshment 

 of cooling breezes, periodically enjoyed in other 

 sultry climates, is here unknown. The air is dry 

 and suflfocating. Hot and pestilential winds fre- 

 quently diflfuse their noxious breath, alike fatal to 

 animal and vegetable life. The steppes of Russia 

 and the wilds of Tartary are decked by the hand of 

 nature with lofty trees and luxuriant herbage ; but 

 in the Arabian deserts vegetation is nearly extinct. 

 The sandy plains give birth to a straggling and 

 hardy brushwood ; while the tamarisk and the aca- 

 cia strike their roots into the clefts of the rocks, 

 and draw a precarious nourishment from the nightly 

 dews. An inspired pen has truly described this 

 steril country as " a land of deserts, and of pits ; 

 a land of drought, and of the shadow of death ; a 

 land that no man passed through." — (Jer. ii. 6.) 



This general aspect of desolation is occasionally 

 relieved by verdant spots, or valleys with little 



