Mayutata. All of the upper branches of the river Madeira find their way to the falls across the open, almost level Mojos and Beni plains, 35,000 sq. m. of which are yearly flooded to an average depth of about 3 ft. for a period of from three to four months. They rival if they do not exceed in fertility the valley of the Nile, and are the healthiest and most inviting agricultural and grazing region of the basin of the Amazon.
The Purús, a very sluggish river, enters the Amazon west of the Madeira, which it parallels as far south as the falls of the latter stream. It runs through a continuous forest at the bottom of the great depression lying between the Madeira river, which skirts the edge of the Brazilian sandstone plateau, and the Ucayali which hugs the base of the Andes. One of its marked features is the five parallel furos[1] which from the north-west at almost regular intervals the Amazon sends to the Purús; the most south-westerly one being about 150 m. above the mouth of the latter river. They cut a great area of very low-lying country into five islands. Farther down the Purús to the right three smaller furos also connect it with the Amazon. Chandless found its elevation above sea-level to be only 107 ft. 590 m. from its mouth. It is one of the most crooked streams in the world, and its length in a straight line is less than half that by its curves. It is practically only a drainage ditch for the half-submerged, lake-flooded district it traverses. Its width is very uniform for 1000 m. up, and for 800 m. its depth is never less than 45 ft. It is navigable by steamers for 1648 m. as far as the little stream, the Curumahá, but only by light-draft craft. Chandless ascended it 1866 m. At 1792 m. it forks into two small streams. Occasionally a cliff touches the river, but in general the lands are subject to yearly inundations throughout its course, the river rising at times above 50 ft., the numerous lakes to the right and left serving as reservoirs. Its main tributary, the Aquiry or Acre, enters from the right about 1104 m. from the Amazon. Its sources are near those of the Mayutata. It is navigable for a period of about five months of the year, when the Purús valley is inundated; and, for the remaining seven months, only canoes can ascend it sufficiently high to communicate overland with the settlements in the great india-rubber districts of the Mayutata and lower Beni; thus these regions are forced to seek a canoe outlet for their rich products by the very dangerous, costly and laborious route of the falls of the Madeira.
The Juruá is the next great southern affluent of the Amazon west of the Purús, sharing with this the bottom of the immense inland Amazon depression, and having all the characteristics of the Purús as regards curvature, sluggishness and general features of the low, half-flooded forest country it traverses. It rises among the Ucayali highlands, and is navigable and unobstructed for a distance of 1133 m. above its junction with the Amazon.
The Javary, the boundary line between Brazil and Peru, is another Amazon tributary of importance. It is supposed to be navigable by canoe for 900 m. above its mouth to its sources among the Ucayali highlands, but only 260 have been found suitable for steam navigation. The Brazilian Boundary Commission ascended it in 1866 to the junction of the Shino with its Jaquirana branch. The country it traverses in its extremely sinuous course is very level, similar in character to that of the Juruá, and is a fostered wilderness occupied by a few savage hordes.
The Ucayali, which rises only about 70 m. north of Lake Titicaca, is the most interesting branch of the Amazon next to the Madeira. The Ucayali was first called the San Miguel, then the Ucayali, Ucayare, Poro, Apu-Poro, Cocama and Rio de Cuzco. Peru has fitted out many costly and ably-conducted expeditions to explore it. One of them (1867) claimed to have reached within 240 m. of Lima, and the little steamer “Napo” forced its way up the violent currents for 77 m. above the junction with the Pachitea river as far as the river Tambo, 770 m. from the confluence of the Ucayali with the Amazon. The “Napo” then succeeded in ascending the Urubamba branch of the Ucayali 35 m. above its union with the Tambo, to a point 200 m. north of Cuzco. The remainder of the Urubamba, as shown by Bosquet in 1806 and Castelnau in 1846, is interrupted by cascades, reefs and numberless other obstacles to navigation. Señor Torres, who explored the Alto Ucayali for the Peruvian government, gives it a length of 186 m., counting from the mouth of the Pachitea to the junction of the Tambo and Urubamba. Its width varies from 1300 to 4000 ft., due to the great number of islands. The current runs from 3 to 4 m. an hour, and a channel from 60 to 150 ft. wide can always be found with a minimum depth of 5 ft. There are five bad passes, due to the accumulation of trees and rafts of timber. Sometimes enormous rocks have fallen from the mountains and spread over the river-bed causing huge whirlpools. “No greater difficulties present themselves to navigation by 10-knot steamers drawing 4 ft. of water.”
The Tambo, which rises in the Vilcanota knot of mountains south of Cuzco, is a torrential stream valueless for commercial purposes. The banks of the Ucayali for 500 m. up are low, and in the rainy season extensively inundated.
The Huallaga (also known as the Guallaga and Rio de los Motilones), which joins the Amazon to the west of the Ucayali, rises high among the mountains, in about 10° 40′ S. lat., on the northern slopes of the celebrated Cerro de Pasco. For nearly its entire length it is an impetuous torrent running through a succession of gorges. It has forty-two rapids, its last obstruction being the Pongo de Aguirre, so called from the traitor Aguirre who passed there. To this point, 140 m. from the Amazon, the Huallaga can be ascended by large river steamers. Between the Huallaga and the Ucayali lies the famous “Pampa del Sacramento,” a level region of stoneless alluvial lands covered with thick, dark forests, first entered by the missionaries in 1726. It is about 300 m. long, from north to south, and varies in width from 40 to 100 m. Many streams, navigable for canoes, penetrate this region from the Ucayali and the Huallaga. It is still occupied by savage tribes.
The river Marañon rises about 100 m. to the north-east of Lima. It flows through a deeply-eroded Andean valley in a north-west direction, along the eastern base of the Cordillera of the Andes, as far as 5° 36′ S. lat.; then it makes a great bend to the north-east, and with irresistible power cuts through the inland Andes, until at the Pongo de Manseriche[2] it victoriously breaks away from the mountains to flow onwards through the plains under the name of the Amazon. Barred by reefs, and full of rapids and impetuous currents, it cannot become a commercial avenue. At the point where it makes its great bend the river Chinchipe pours into it from southern Ecuador. Just below this the mountains close in on either side of the Marañon, forming narrows or pongos for a length of 35 m., where, besides numerous whirlpools, there are no less than thirty-five formidable rapids, the series concluding with three cataracts just before reaching the river Imasa or Chunchunga, near the mouth of which La Condamine embarked in the 18th century to descend the Amazon. Here the general level of the country begins to decrease in elevation, with only a few mountain spurs, which from time to time push as far as the river and form pongos of minor importance and less dangerous to descend. Finally, after passing the narrows of Guaracayo, the cerros gradually disappear, and for a distance of about 20 m. the river is full of islands, and there is nothing visible from its low banks but an immense forest-covered plain. But the last barrier has yet to be passed, the Pongo de Manseriche, 3 m. long, just below the mouth of the Rio Santiago, and between it and the old abandoned missionary station of Borja, in 38° 30′ S. lat. and 77° 30′ 40″ W. long. According to Captain Carbajal, who descended it in the little
- ↑ A furo is a natural canal—sometimes merely a deviation from the main channel, which it ultimately rejoins, sometimes a connexion across low flat country between two entirely separate streams.
- ↑ Pongo is a corruption of the Quichua puncu and the Aymará ponco, meaning a door. The Pongo de Manseriche was first named Marañon, then Santiago, and later Manseric, afterwards Mansariche and Manseriche, owing to the great numbers of parrakeets found on the rocks there.
