THE region which is drained by rivers flowing from the maritime cordillera and the eastern range of the Andes into lake Titicaca consists of elevated plateaux, seldom less than 13,000 feet above the sea, which were originally inhabited by the Aymara race of Indians, a people differing in some respects from the Indians of Cuzco and further north, and whose civilization dates from a period far anterior to that of the Incas. Their language is different from the Quichua of the Incas, though evidently a sister tongue, and it is still spoken by the Aymara Indians from Puno to the central parts of Bolivia, including all the shores of lake Titicaca. I did not, however, observe much difference between the Indians of Puno, who speak Aymara, and the Quichua Indians of Cuzco. The men are, perhaps, somewhat stouter; but they are the same race in all essential points. The lake of Titicaca, the great feature in the region inhabited by the Aymara Indians, is about eighty miles long by forty broad; being by far the largest lake in South America. It is divided into two parts by the peninsula of Copacabana; the southern division, called the lake of Huaqui, being eight leagues long by seven, and united to the greater lake by the strait of Tiquina. A number of rivers, which are swollen and of considerable volume during the rainy season, flow into the lake. The largest of these is the Ramiz, which is formed by the junction of the two rivers of Pucara and Azangaro, and enters the lake at its north-west corner. The Suchiz, formed by the rivers of Cavanilla and Lampa, also flows into the lake on its north side, as well as the Yllpa and Ylave; while on the eastern side are the rivers Huarina, Escoma, and Achacache, all flowing from a low lateral chain, parallel with the great eastern Andes, whose gigantic peaks of Illimani and Sorata form the principal feature of the views from all parts of the lake. Much of the water thus flowing in is drained off by the great river Desaguadero, which flows out of the south-west corner, and disappears in the swampy lake of Aullagas, in the south of Bolivia; and perhaps a greater quantity is taken up by evaporation; for the volume of water which flows in during the rainy season, when the sun travels north, is drunk up again when the tutelar deity of the lake returns, between April and September.[147] Indeed it is evident that the waters are steadily receding, under the combined influence of evaporation and of the sediment brought down by the rivers. Lake Titicaca is very deep in some places, the deepest part being on the Bolivian side; but in others it is so shoal that there is only just room to force the balsas through the rushes. The winds blow from the eastward all the year round, sometimes in strong gales, so as to raise a very heavy sea, during the day-time; but at night they are occasionally westerly. Along the western shore there are acres of tall rushes, and the east winds blow