Valparaiso -- Portillo Pass -- Sagacity of Mules -- Mountain- torrents -- Mines, how discovered -- Proofs of the gradual Elevation of the Cordillera -- Effect of Snow on Rocks -- Geological Structure of the two main Ranges, their distinct Origin and Upheaval -- Great Subsidence -- Red Snow -- Winds -- Pinnacles of Snow -- Dry and clear Atmosphere -- Electricity -- Pampas -- Zoology of the opposite Side of the Andes -- Locusts -- Great Bugs -- Mendoza -- Uspallata Pass -- Silicified Trees buried as they grew -- Incas Bridge -- Badness of the Passes exaggerated -- Cumbre -- Casuchas -- Valparaiso.
There are very few valleys which lead to the central ranges, and the mountains are quite impassable in other parts by beasts of burden.
Hence we must conclude, that both the Peuquenes and Portillo ranges were partially upheaved and exposed to wear and tear, when the conglomerate was forming; but as the beds of the conglomerate have been thrown off at an angle of 45 degs.
Our first step now was to move our camp upward to the very edge of the perpetual snows which cap this lofty range.
With our hut as a base we sallied forth in search of a pass across the range.
When we were abroad pushing our trail farther and farther toward the distant break which, we assumed, marked a feasible way across the range, we never knew at what second some great engine of clawed and fanged destruction might rush upon us from behind, or lie in wait for us beyond an ice-hummock or a jutting shoulder of the craggy steeps.
The captain was convinced, however, that the stream was too insignificant to drain so wide a valley and the adjacent mountains: he encamped, therefore, at an early hour, on its borders, that he might take the whole of the next day to reach the main river; which he presumed to flow between him and the distant
range of western hills.
It was eight o'clock when the train passed through the defiles of the Humboldt
Range, and half-past nine when it penetrated Utah, the region of the Great Salt Lake, the singular colony of the Mormons.
The mountain on which they stood, elevated perhaps a thousand feet in the air, was a high cone that rose a little in advance of that range which stretches for miles along the western shores of the lake, until meeting its sisters miles beyond the water, it ran off toward the Canadas, in confused and broken masses of rock, thinly sprinkled with evergreens.
The land had been cleared of wood for a reasonable distance around the work, but every other part of the scene lay in the green livery of nature, except where the limpid water mellowed the view, or the bold rocks thrust their black and naked heads above the undulating outline of the mountain ranges.
This view of the necessity of a large stock of the same species for its preservation, explains, I believe, some singular facts in nature, such as that of very rare plants being sometimes extremely abundant in the few spots where they do occur; and that of some social plants being social, that is, abounding in individuals, even on the extreme confines of their range.
On the confines of its geographical range, a change of constitution with respect to climate would clearly be an advantage to our plant; but we have reason to believe that only a few plants or animals range so far, that they are destroyed by the rigour of the climate alone.
