Atacama. I. A S. W. department of Bolivia, bounded by Peru, the Bolivian department of Potosi, the Argentine Confederation, Chili, and the Pacific ocean; area, about 70,000 sq. m.; pop. about 8,000. The greater portion of the department is a dry sandy desert entirely uninhabited, which is supposed to have been for ages the burial place of the aboriginal Peruvians. There are a few fertile valleys in the north. Anhydrous sulphate of soda is abundant in almost every part of the department, and large masses of solid iron have also been found in different localities. Gold, silver, copper, salt, and alum are also among the mineral productions. The capital is Cobija, or Puerto de la Mar, the only seaport which Bolivia possesses. II. The most northern province of Chili, including the portion of the desert of Atacama lying S. of the preceding department, the separating line being the parallel of lat. 24° S., according to the treaty of 1866, and bounded E. by the Argentine Confederation, S. by the province of Coquimbo, and W. by the Pacific; area, about 38,000 sq. m.; pop. in 1868, 81,615. The province is divided into the departments of Caldera, Co-piapo, Freirina, and Vallemar. It abounds in mineral wealth, including perhaps the richest silver and copper mines in the world.

Of the former it has 247 and of the latter 994 which are now worked. The silver mines were discovered as lately as 1832, by a shepherd, Juan Godoy, and they have yielded since then ores to the value of over $100,000,000, fully one third of which amount has been derived from the mines of Chanarcillo. A village of over 1,500 inhabitants, which contains a free school, a church, a hospital, and a post office, now marks the spot of the discovery, and is named Juan Godoy. It is situated on the Chafiarcillo hills, 51 m. S. E. of Copiapo, the capital of the department, with which city it is connected by railroad. Within a circuit of 25 leagues from Copiapo are 19 silver-mining districts, of which those of Chanarcillo, Tres Puntas, and Agua Amarga are the most important. The metal is found in a variety of combinations, of which sulphurets, chlorides, and chloro-bromides are the most important. A railway 101 m. long, the first ever built in South America (1850), connects the port of Caldera, one of the best on the whole coast of Chili, with Copiapo and with the mining districts further east.