270 TEMPERATURE OF THE PAMPAS. 



one period of his expedition over the Pampas, at 

 the rate of more than a hundred and forty miles 

 daily, and that for weeks together, and he pro- 

 nounced this mode of life to be pleasant and 

 exhilarating. 



The temperature of the Pampas, like that of every 

 other portion of the globe lying under the same 

 parallel of latitude, is extremely hot during the 

 summer months, but in winter the degree of cold is 

 not much less than that which prevails with us. 

 Those who traverse the woody region, or the vast 

 unvaried surface of the prairie, frequently observe 

 the remains of animals which have perished from 

 fatigue or sickness, and which have dried up without 

 undergoing the process of decomposition, in a man- 

 ner like that which occurs in the deserts of Africa. 

 This curious fact is owing to the level nature of the 

 country, to its distance from the sea, and the dry- 

 ness of the atmosphere ; and hence we have reason to 

 believe that if the Pampas had consisted of rock and 

 sand, the difficulty of crossing it, from extreme heat, 

 would have been nearly equal to that of the African 

 desert of Sahara. For the sun-beams, acting both 

 on air and land, communicate to the latter a more 

 rapid and permanent degree of heat ; consequently, 

 the lower portion of air derives from the earth, if 

 unclothed with verdure, a higher temperature than 

 belongs to it, and when it rises into the upper region 

 of the atmosphere, its place is immediately supplied 

 by another stream of air. This stream is heated in 

 its turn, and then rapidly ascends ; and thus a con- 

 stant current of hot air arises from off the surface, 

 and necessarily prevents those water-urns of the 



