SOUTHERN AND WESTERN SHORES OF THE CONTINENT. 343 



their effects as the flames of the prairie. Rising to a hundred 

 feet in height, they are seen approaching, whirling through the 

 air, till the unhappy traveller finds himself surrounded by an 

 overwhelming mass, and, unable to breathe, sinks exhausted 

 on the ground. Flight alone can save him. Many have here 

 perished. On several occasions, troops attempting to cross 

 the desert have been overwhelmed. Others have lost their 

 way when traversing the sandy plains, and have wandered 

 about, in vain seeking for water to quench their burning 

 thirst. On one side is the salt ocean, on the other the rocky 

 precipices of the mountains. Wandering on for hours and 

 hours, at length, exhausted, they have abandoned themselves 

 to despair. These sand-storms occur more especially during the 

 heats of summer, so completely altering the appearance of the 

 country, by covering it with large hillocks, that the most ex- 

 perienced guides find it at times impossible to discover their 

 way; and perhaps, when searching for it, another storm arises, 

 and once more spreads the mounds over the level plain. 



In some places the wdiole soil is covered with a thick 

 crust of salt, white and hard, giving the country the appear- 

 ance of being covered with snow. For months and months 

 together, in many parts not a drop of rain falls. At length 

 a shower descends, and, as if by magic, the grass springs up 

 in spots where not a blade was before visible ; and for a 

 short time the whole country puts on a green mantle, soon, 

 however, to be withered up by the burning heat. 



Northward of this desert region, the land on the shores of 

 the Gulf of Guayaquil and its neighbourhood is covered with 

 the richest vegetation, supported by the numerous streams 

 which descend from the Andes of Quito and Columbia. 



