272 OASES. 



Elim, three score and ten of these beacon trees, seen 

 from a distance, invited the Israelites to refresh 

 themselves heside twelve wells of water. 



But oases are unnecessary in the Pampas, for 

 there, far as the eye can reach, the earth is screened 

 from the effect of heat by a rich growth of grass and 

 clover. Little or no upward current consequently 

 arises to prevent the clouds from pouring forth their 

 rain, and hence those plains are crossed without 

 difficulty, while towards the vast Cordilleras, noble 

 trees and shrubs, refreshed by frequent showers, 

 present a striking contrast to the unvaried surface of 

 the prairie. 



Widely different from the Pampas, with its lux- 

 uriant herbage and wooded region, is that mighty 

 plain which stretches beyond the fertile and undu- 

 lating valleys of the Caraccas, and the shores of the 

 lake of Jacaraqua, dotted over with islands. The 

 traveller who passes from those fertile and peopled 

 regions, covered with beautiful trees, and producing 

 fruits and flowers in abundance, seems to have 

 crossed the very boundary of civilized life. Behind 

 him are thriving towns and pleasant villages, arts, 

 and intellectual improvements; before him a gloomy 

 wilderness, where, for a long distance, no hill, nor 

 even undulation, varies the surface of the desert, 

 excepting here and there a few isolated banks, which, 

 though apparently of small extent when compared 

 with the measureless sweep of the barren plain on 

 which they rest, often comprise a space of more 

 than one hundred miles, and appear like sand-banks 

 in the midst of a waveless sea. Further on, in the 

 lone wilderness, rise impenetrable thickets, or vast 



