1835.] ON THE CREST OF THE PORTILLO. 323 



were high and close together, 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 with its hind legs 

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

 fallen with its head downward into a hole, wdien 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 continued the whole day, and^ 

 quite intercepted our vieu^ 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 extend 

 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 severely ; 

 but as there was no wind, we slept very comfortably. 



The increased brilliancy of the moon and stars at this 

 elevation, owing to the perfect transparency of the atmo- 

 sphere, was very remarkable. Travellers having 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 confounding 

 objects at different distances, and likewise 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 

 r^Mves a peculiar character to the landscape, all objects 

 appearing 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 dryness, 



structure secrna to be determined, to th« joint* that traverse nearly all rocks, 

 iat wliich arc bcKt aeen in the non-stratified niasNCH. I may ul>8crve, that in the 

 ise of the frozen Bnow, the columnar striKture must be owing to a "meta- 

 inorphic" action, ond nut to a proccM during deposition. 



