DRY AND CLEAR ATMOSPHERE. 77 



of the atmosphere, was very remarkable. Trav- 

 ellers havhig observed the difficulty of judging 

 heights and distances amidst lofty mountains, have 

 generally attributed it to the absence of objects of 

 comparison. It appears to me that it is fully as 

 much owing to the transparency of the air con- 

 founding objects at different distances, and like- 

 wise partly to the novelty of an unusual degree of 

 fatigue arising from a little exertion, habit being 

 thus opposed to the evidence of the senses. I am 

 sure that this extreme clearness of the air gives a 

 peculiar character to the landscape, all objects ap- 

 pearing to be brought nearly into one plane, as in 

 a drawing or panorama. The transparency is, I 

 presume, owing to the equable and high state of 

 atmospheric drj-ness. This dryness was shown by 

 the manner in which woodwork shrank (as I soon 

 found by the trouble my geological hammer gave 

 me) ; by articles of food, such as bread and sugar, 

 becoming extremely hard ; and by the preservation 

 of the skin and parts of the flesh of the beasts 

 which had perished on the road. To the same 

 cause we must attribute the singular facility with 

 which electricity is excited. INIy flannel waistcoat, 

 when rubbed in the dark, appeared as if it had 

 been washed with phosphorus ; every hair on a 

 dog's back crackled ; even the linen sheets, and 

 leathern straps of the saddle, when handled, emit- 

 ted sparks. 



March 23(7,— The descent on the eastern side 

 of the Cordillera is much shorter or steeper than 

 on the Pacific side ; in other words, the mountains 

 rise more abruptly from the plains than from the 

 alpine country of Chile. A level and brilliantly 

 white sea of clouds was stretched out beneath our 

 feet, shutting out the view of the equally level Pam- 

 pas. We soon entered the band of clouds, and did 

 G2 



