I. A central province of Chili; area, about 6,000 sq. m.; pop. in 1868, 130,672. The entire eastern portion is occupied by rugged spurs of the Andes and very fertile valleys, watered by several rivers flowing through the province to the Pacific. This region abounds in copper, silver, and gold mines; the last were at one time very famous.

In 1862 there were in working order 8 gold, 9 silver, and 228 copper mines. The western part is irrigated by innumerable artificial water courses, supplied from the rivers, by means of which large crops are produced of excellent wheat and other cereals, as well as of hemp of a very superior quality. Such irrigation is rendered indispensable by the extraordinary scarcity of rain. The province is divided into the five departments of Andes, Ligua, Petorca, Patacudo, and San Felipe. Capital, San Felipe de Aconcagua, situated at the foot of the Andes, in a fertile valley 2,000 feet above the Pacific, 55 m. X. E. of Valparaiso; pop. about 7,000.

II. A peak of the Andes in the preceding province, X. E. of San Felipe, in lat, 32° 39' S., lon. 70° W., believed to be the highest in this hemisphere. According to the measurement of M. Pissis, to the results of whose labors more credit is given than to those of any other scientific investigator of the Andes, Aconcagua reaches a height of 6,834 metres, or 22,422 feet, above the level of the ocean, being 997 feet higher than Chimborazo and 1,138 feet higher than Sorata, which were formerly considered the most elevated peaks of the Andean chain. Aconcagua has been described as the cone of an extinguished volcano, and the error probably arises from a widely published statement of Darwin, who asserts that when in the Beagle expedition in 1835 it was reported to him that the volcano of Aconcagua was in eruption. Neither its shape nor its external features would indicate an extinguished volcano; it is a colossal, angular, and serrated mass, without any lava or other vestiges of volcanic action, and can only be seen in all its grandeur from the east, because the mountains which surround it on the west impede the view.

From Valparaiso a view of the peak only, rising far above the summits of even that gigantic chain of mountains, is obtained.