7G PORTILLO PASS. 



made it difficult for the cargo mules to pass. On 

 one of these columns of ice a frozen horse was 

 sticking as on a pedestal, but ^'v^th its hind legs 

 straight up in the air. The animal, I suppose, must 

 have fallen with its head downward into a hole 

 when the snow was continuous, and afterwards the 

 surrounding parts must have been removed by the 

 thaw. 



When nearly on the crest of the Portillo, we 

 were enveloped in a falling cloud of minute frozen 

 spicula. This was very unfortunate, as it contin- 

 ued the whole day, and quite intercepted our view. 

 The pass takes its name of Portillo from a narrow 

 cleft or doorway on the highest ridge, through 

 which the road passes. From this point, on a clear 

 day, those vast plains, which uninterruptedly ex- 

 tend to the Atlantic Ocean, can be seen. We 

 descended to the upper limit of vegetation, and 

 found good quarters for the night under the shelter 

 of some large fragments of rock. We met here 

 some passengers, who made anxious inquiries about 

 the state of the road. Shortly after it was dark 

 the clouds suddenly cleared away, and the effect 

 was quite magical. The great mountains, bright 

 with the full moon, seemed impending over us on 

 all sides, as over a deep crevice : one morning, 

 very early, I witnessed the same striking effect. 

 As soon as the clouds were dispersed it froze se- 

 verely ; but as there was no wind, we slept veiy 

 comfortably. 



The increased brilliancy of the moon and stars 

 at this elevation, owing to the perfect transparency 



pared the fissures, by which the columnar structures seems to be 

 determined, to the joints that traverse nearly all rocks, but which 

 are best seen in the non-stralilied masses. I may observe, that 

 in the case of the frozen snow the columnar structure must be 

 owing to a " metamoryihic" action, and not to a process during 

 deposition. 



