Page:Isaiah Bowman - Desert Trails of Atacama (1924).pdf/25

 by a cinder cone or local lava flow. The broad plain of the nitrate desert is known as the pamtpa and is set between two mountain systems. On the eastern horizon the western range of the Andes (in the Iquique region) rises by a broad and rather regular slope to an even crest visible from the passes near the coast; on the west is the Coast Range.

On my first pack-train journey into northern Chile where the nitrate desert begins I was delighted to find all my ex- pectations of desert scenery realized. lor the first fifty miles there was but a single spot where a natural growth of green could be seen from the trail and but one other where there was any green growth at all, and that beside a desert well about which were clustered a few low huts. All the rest was naked rock and sand, brown and yellow in color yet appearing stark and colorless in tone in the midday sun when the whole land- scape is overlighted; glowing with color as the sun declines and the shadows of the ravines come out. [t is the end of the day that brings out the colorful mood of the desert. The afternoon winds raise huge clouds of dust, and, as the sun's rays filter through the murky atmosphere at sunset, they range from lively yellow at the beginning to violet, which in turn deepens gradually to a series of purples that glorify the sky for a short half hour until displaced by the grays that deepen into night.

At the eastern edge of the desert there are in places moun- tains of great topographic simplicity, as east of [quique; while in other places they show great complexity, as where deep canyons bordered by variegated rocks nick the high mountain wall with its crown of volcanoes and wide bordering volcanic flows. The snows of the higher cordillera give the summit peaks a clearer outline against the dark blue and purple back- ground of the sunset sky in the east. From the mountains the desert plain appears to extend indefinitely westward and to have a much wider range of color and form. Distant and lonely a village stands on a narrow terrace at the canyon border, its green barley and alfalfa fields ending at the edge of an abrupt scarp where the floods of the rainy season and those from the melting snows tear holes in the defensive ram-