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Page:Popular Science Monthly Volume 26.djvu/100

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90
THE POPULAR SCIENCE MONTHLY.

heard and window-sashes were shaken at Concepcion. After a short period of rest, in January, 1865, its activity was again resumed. Antuco is only a few miles south of Chilian. It was visited by Pöppig in 1827, and by Domeyko in 1845, while it was in full activity, and it still sends up faint columns of smoke. The Imperial, or Yaima, in Araucania, was in action in 1852 and 1864, but has since not given any sign of an eruption. An eruption was observed in Yillarica about 1860, but nothing since; and the fact that the snow on the top of the mountain does not exhibit any marks of change indicates that its forces are weak. Next to this volcanic center comes Osorno, to which may be added others farther south that have not yet been accurately observed. Among these is one at the southern end of Middle Island, in the Strait of Magellan, which the men of the English ship-of-war Penguin saw at the end of 1877 in full activity. Heavy subterranean rumblings are no rarity in any part of Chili.

In all only ten known Chilian craters can be pronounced with certainty to be now active volcanoes. Obviously the neighborhood of these subterranean furnaces can not be regarded as belonging to the quiet regions of the earth. No part of the earth's surface is so prolific of earthquakes as the western half of South America; and here they are more frequent and severe on the Pacific coast than on the eastern side of the Andes. On this coast they are often accompanied with scenes of horror and woe that surpass description. To the direct consequences in the loss of life and the destruction of buildings are frequently added the ravages of fire breaking out in the ruins and consuming all that has not been already crushed. The seaport towns are exposed to a still further danger of destruction by the rushing tidal-wave which follows the extraordinary retreat of the waters with which the earthquake phenomena are usually accompanied. These evils and more were suffered in their worst form during and after the earthquakes of March, 1881, with which Mendoza was visited, and August, 1868, which laid waste a considerable stretch of the coast, with many towns.

With these volcanic and seismic phenomena is associated a steady elevation of the Chilian coast, which has amounted, according to the indications of the shore-terraces, to from six metres at Cape Three Mountains, to three hundred and ninety-seven metres at Concepcion, within the present geological period. Darwin has averaged the rate at about seventeen centimetres a year. The Island of Santa Maria, in the northwest of the Bay of Arauco, rose three metres during the earthquake of 1835, but afterward sank to its old level. Depressions also seem to have taken place in former periods. The elevating force is more intensive in the Chilian Andes than in the neighboring countries, and, as it is still in operation, it is destined probably to carry the loftiest peaks of the Cordilleras to a still greater height. The frequent occurrence of the ending huapi—Indian for island—in the names of