Page:The American Cyclopædia (1879) Volume III.djvu/19

 BOLIVIA 13 its length being variously estimated at from 80 to 120 m., and its average breadth being 40 m. Its surface is dotted with small islands, contain- ing curious ruins. It was on one of these islands, also called Titicaca, that according to the legend Manco Capac and his consort, Mama Oello Huaco, the founders of the inca dynasty, descended to spread civilization through the surrounding nations. Into the lake flow a number of rivers, which during the rainy season are of considerable volume ; and much of the water is drained off by the De- saguadero, its only outlet, a navigable river, varying in width from 25 to 60 yards, which, after a southerly course of nearly 200 m., flows into the swampy lake of Aullagas or Paria, whose surface is perhaps 490 ft. lower than that of Titicaca, and which has no visible issue. In Lake Aullagas are two islands, Panza and Filomena, the latter recently discovered. In the department of Beni is Lake Roguaguado, 1,100 It. above the sea, with an area of about 900 sq. m. ; and in a cultivated valley near Potosi is the remarkable Laguna de Tara- paya, situated in a circular basin on a sort of elevated lawn. While the water in the centre is constantly in a state of violent ebullition, the temperature at the brink is only about 93 F. It is said that in 1825, when an inundation rolled over Callao on the Pacific coast, the water disappeared for a tune from this lagoon. There are numerous other lakes and marshes in the south and east, from which latter the Chi- quito Indians extract copious quantities of salt ; but little is yet known of their precise situa- tion and extent. Bolivia is the centre of the watershed between the feeders of the Amazon and the Plata. The river Beni, whose head waters descend from the mountains near Co- chabamba, receives among other tributaries the Mapiri and Ooroico, holds first a N. W. and afterward a N. E. course, and joins the Ma- mor6, which takes its rise in the centre of the country, and flows in a generally N". course to lat. 10 20' S., where with the Beni it forms the Madeira. Among its tributaries are the Rio Grande, which descends from the 8. de- clivity of the lofty mountains near Cocha- bamba, and after an immense semicircular sweep falls into the Mamore near Trinidad; and the Itenez or Guapor6, which, leaving Brazil about lat. 13 20' 8., forms part of the boundary between that empire and the repub- lic until it unites with the Mamor6 about lat. 1 1 50' 8. The Pilcomayo, formed by the united waters of the Cachimayo, Pilaya, and others, flows first E. and then 8. E. to the Paraguay. The Bermejo rises in the province of Tarija, leaves the republic parallel with the Pilcomayo, and also joins the Paraguay. The Paraguay enters at the 8. E., and, after forming for a distance of about 60 m. the 8. E. boundary, leaves the republic in lat. 20 25' 8. All the large Bolivian rivers send their waters to the Atlantic, while the Pacific receives only the Loa, separating the republic from Peru, and a few mountain streams which force their way through the desert of Atacama. Tra- chytic conglomerates in various stages of de- composition are the dominant element in the formation of the maritime Cordillera, and also in that of the more elevated por- tion of the great plateau of Oruro, as the valley of the Desaguadero is frequently called ; the trachyte of the latter region exhibitin<.'. however, great quantities of quartz crystals and saline efiloresence, and being hence unfavorable 1 to vegetation. Although it has been supposed that some of the conical summits of the Cor- dillera Occidental are extinct volcanoes, no volcanic production is anywhere exhibited in the table land, nor is this region ever visited by earthquakes. In the E. Cordillera granite ap- pears to prevail from the Nevado de Illimani N. W. ; its general direction is N. W. and 8. E., but it is confined to the more elevated peaks. In its vicinity the trachytic formations invaria- bly become micaceous. Overlooking Cobija is a mass of basaltic porphyry ; and E. of the Cordillera Real a few spots of kindred origin mark the eastern limit of plutonic rocks in the lowlands. The Chiquito mountains are formed of gneiss with overlying foliated Silurian strata, the depressions in which formations are filled with sedimentary deposits, containing the fossil remains of colossal mammalia. Overlying this stratum is another of more recent formation, holding shells of existing species. The mineral wealth of Bolivia consists chiefly in its almost inexhaustible silver mines, principal among which are those of the Cerro de Potosi, in whose conical summit there are over 5,000 openings. It is computed that the mines of this mountain yielded from 1545 to 1V8 ( ,I silver amounting in value to $1,000,000,000; or with the government fifths or royal dues, and the amount smuggled, a total of $2,000,- 000,000 in 245 years. This celebrated moun- tain still continues to give an annual yield of $2,250,000. The name Potosi signifies an " eruption of silver." The Indians have at all times been the almost exclusive workers in the mines. Rich silver mines have been dis- covered in the Sierra del Limon Verde near Calamar, which are said to be greater than any hitherto found in Bolivia, and to yield ore equal to that of Potosi. Silver is also found in many other parts of the republic. Gold occurs in numerous parts of the moun- tain system. A huge mass of native gold detached by lightning from the base of Illi- mani was purchased at an enormous price, and sent to the museum of natural history in Ma- drid. In the sands of all the rivers descending from the Cordillera Real to the Beni or its af- fluents gold is found in abundance. The tin mines of Oruro are among the richest in the world; and copper is said to be as abundant in the mountains adjacent to Corocoro as was silver in the Potosi. Lead, salt, sulphur, nitre, and other volcanic products are found in large quantities; but these, in common with the