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Show 396 PASSAGE OF CORDILLERA. March, 1835. though false appearances of gathering rain -storms : we may imagine that the wind, which coming from the eastward is thus banked up by the line of mountains, would become staO'nant and irregular in its movements. Having crossed the Peuquenes, we descended into the mountainous country, intermediate between the two ranges, and then took up our quarters for the night. The elevation was probably not much under 11,000 feet, and the vegetation in consequence exceedingly scanty. The root of a small scrubby plant served as fuel, but it made a miserable fire, and the wind was piercingly cold. Being quite tired with my day's work, I made up my bed as quickly as I could, and went to sleep. About midnight I observed the sky became suddenly clouded: I awakened the arriero to know if there was any danger of bad weather ; but he said that without thunder and lightning there was no risk of a heavy snowstorm. The peril is imminent, and the difficulty of subsequent escape great, to any one overtaken by bad weather between the two Cordillera. A certain cave offers the only place of refuge: Mr. Caldcleugh, who crossed on this same day of the month, was detained there for some time by a heavy fall of snow, as is related in his travels. Casuchas, or houses of refuge, have not been built in this pass as in that of U spallata, and therefore, during the autumn, the Portillo is little frequented. I may here remark, that within the main Cordillera rain never falls, for during the summer, the sky is cloudless, and in winter snow-storms alone occur. At the place where we slept, water necessarily boiled, from the diminished pressure of the atmosphere, at a much lower temperature than it does in a less elevated country ; the case being the converse of that of a Papin's digester. In consequence of this, 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 conclusion, " that the March, 1835. PASSAGE OF CORDILLERA. 397 cursed pot (which was a new one) did not choose to boil potatoes." MARCH 22n.-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 aU been removed ; even the greater number of the guanacoes had decamped, knowing well, that, if overtaken by a snow-storm, 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. From one peak my arriero said he had once seen smoke proceeding; and I thought I could distinguish the form of a large crater. In the maps Tupungato figures as a single mountain; this Chileno method of giving one name to a tract of mountains is a fruitful source of error. In the region of snow there was a blue patch, which no doubt was a glacier ;-a phenomenon that has been said not to occur in these mountains. Now commenced a heavy and long climb, similar t~ that up the Peuquenes. Bold conical hills of red granite rose on each hand ; and in the valley there were several broad fields of perpetual snow. These frozen masses, during the process of thawing, had in some parts assumed the form of pinnacles or columns, which, as they were high and close together, caused some difficulty on account of the cargo mules. This structure in frozen snow was long since observed by Scoresby in the icebergs near Spitzbergen, and lately, with more care, by Colonel Jackson* on the Neva. 0~ ~ne of these columns of ice a frozen horse was exposed, stiCking as on a pedestal, but with its hind legs straight up in the air. To account for its strange position, we must • Journal of Geograph. Soc., vol. v., p. 12. Mr. Lyell (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 in the case of the frozen snow, the columnar structure must be owing to ~ " metamorphic" action' and not to a process during deposition. |
