source of Bahia Creek which is followed to the Acré or Aquiry river, thence up the latter to its source, whence if east of the 69th meridian it runs direct to the 11th parallel which will form the boundary line to the Peruvian frontier. This frontier gave about 60,000 sq. m. of territory to Brazil, for which the latter gave an indemnity of £2,000,000 and about 1158 sq. m. of territory on the Matto Grosso frontier. The boundary with Paraguay is unsettled, but an unratified treaty of the 23rd of November 1894 provides that the line shall start from a point on the Paraguay river 3 m. north of Fort Olimpo and run south-west in a straight line to an intersection with the Pilcomayo in long. 61° 28′ W., where it unites with the Argentine boundary. The boundary with Chile was greatly modified by the results of the war of 1879–83, as determined by the treaties of 1884, 1886 and 1895, Bolivia losing her department of the littoral on the Pacific and all access to the coast except by the grace of the conqueror. Provisions were made in 1895 for the cession of the port of Mejillones del Norte and a right of way across the province of Tarapacá, but Peru protested, and negotiations followed for the cession of Cobija, in the province of Antofagasta. These negotiations proved fruitless, and in 1904 Bolivia accepted a pecuniary indemnity in lieu of territory. The new boundary line starts from the summit of the Sapaleri (or Zapalegui), where the Argentine, Bolivian and Chilean boundaries converge, and runs west to Licancaur, thence north to the most southern source of Lake Ascotán which it follows to and across this lake in the direction of the Oyahua volcano, and thence in a straight line to the Tua volcano, on the frontier of the province of Tarapacá. From this point the line follows the summits of the Cordillera Silillica north to the Cerro Paquiza, on the Tacna frontier, and to the Nevado Pomarape, near the frontier of Peru. Thence it continues north to an intersection with the Desaguadero, in about 16° 45′ S. lat., follows that river to the Winamarca lagoon and Lake Titicaca, and crosses the latter diagonally to Huaicho on the north shore. From this point the line crosses the Cordillera Real through the valley of the San Juan del Oro to Suches Lake, follows the Cololo and Apolobamba ranges to the headwaters of the Sina river, and thence down that stream to the Inambari. Thence the line either follows the latter to its confluence with the Madre de Dios, or the water-parting between that river and the Tambopata or Pando, to the valley of the Madre de Dios, from which point it runs due north to 12° 40′ S. lat., and north-west to the new Brazilian frontier. The N.W. angle on the map represents the Bolivian claim until the settlement of 1909, which gave the territory to Peru.
Physiography.—Roughly calculated, two-fifths of the total area
