236 PORTILLO PASS. [CHAP. xv. 



Papin's digester. Hence the potatoes, after remaining for some hours 

 in the boiling water, were nearly as hard as ever. The pot was left on 

 the fire all night, and next morning it was boiled again, but yet the 

 potatoes were not cooked. I found out this, by overhearing my two 

 companions discussing the cause ; they had come to the simple con- 

 clusion, "that the cursed pot (which was a new one) did not choose to 

 boil potatoes. 



March zind. After eating our potato-less breakfast, we travelled 

 across the intermediate tract to the foot of the Portillo range. In the 

 middle of summer cattle are brought up here to graze ; but they had 

 now all been removed : even the greater number of the guanacos had 

 decamped, knowing well that if overtaken here by a snow-stonn, they 

 would be caught in a trap. We had a fine view of a mass of mountains 

 called Tupungato, the whole clothed with unbroken snow, in the midst 

 of which there was a blue patch, no doubt a glacier ; a circumstance of 

 rare occurrence in these mountains. Now commenced a heavy and long 

 climb, similar to that up the Peuquenes. Bold conical hills of red 

 granite rose on each hand ; in the valleys there were several broad 

 fields of perpetual snow. These frozen masses, during the process of 

 thawing, had in some parts been converted into pinnacles or columns,* 

 which, as they 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, when the snow was continuous, and afterwards the sur- 

 rounding 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 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 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 



* This structure in frozen snow was long since observed by Scoresby in 

 the icebergs near Spitzbergen, and lately, with more care, by Colonel 

 Jackson (Journal of Geographical Society, vol. v., p. 12) on the Neva. Mr. 

 Lyell (" Principles," vol. iv., p. 360) has compared the fissures, by which the 

 columnar structure seems to be determined, to the joints that traverse nearly 

 all rocks, but which are best seen in the non-stratified masses. I may 

 observe, that in the case of the frozen snow, the columnar structure must be 

 owing to a " metamorphic " action, and not to a process during deposition. 



