The Pepiri-guazú was one of the limits between the possessions
of Portugal and Spain. Its lower course is about 250 ft. wide,
but higher up it narrows to about 30 ft., and runs with great violence
between high wooded banks. It is navigable for canoes for about
70 m. above its mouth, as far as its first fall. The Rio Negro has a
delta of several large islands at its confluence with the Uruguay.
Its head-waters are in the southern part of Rio Grande do Sul,
but the main river belongs entirely to the state of Uruguay, which
it cuts midway in its course from north-east to south-west. Its
lower reaches are navigable for craft of moderate draught.
From the time the Uruguay leaves the coast range of Brazil it runs for a long distance through a beautiful, open, hilly country,Course of the Uruguay. but afterwards enters a forest belt of high lands. At the river Pepiri-guazú it turns suddenly to the south-west, and continues this course to its junction with the Paraná and Plata. Near Fray Bentos, 61 m. before reaching the Plata, it forms a great lake, about 56 m. long and from 4 to 6 m. wide. At Punta Gorda, where it debouches into the Plata, it is only 1 m. to 1½ m wide but is 90 ft. deep. From the Pepiri-guazú junction its banks are high and covered with forest as far down as 27° 30′ S., where the river is 2300 ft. wide and from 10 to 40 ft. deep. The Uruguay is much obstructed by rocky barriers. Four miles below its confluence with the Pepiri-guazú it has a cataract, about 8 m. long, with a total fall of 26 ft. at low water. The river near the Pepiri-guazú is 1550 ft. wide, but about 1½ m. before reaching the cataract its width is reduced to 600 ft. Along the cataract it is closed in between high precipitous walls of black rock only 70 ft. apart. Above Punta Gorda, 212 m., is the Salto Grande, which has a length of 15 m. of rapids, the greatest single fall being 12 ft., and the difference of level for the entire length of the reefs 25 ft. These cross the river diagonally, and during floods all, excepting a length of 1½ m. of them, are submerged. Nine miles below the Salto Grande is the Salto Chico, which bars navigation during six months of the year, but in flood-time may be passed in craft drawing 5 ft. of water. The Uruguay can be navigated at all seasons by vessels of 4½ ft. draught as far up as the Salto Chico, and of 14 ft. up to Paysandú for a greater part of the year. Fray Bentos may be reached all the year round by any vessel that can ascend the Paraná. Above the navigable lower river there is launch and canoe navigation for many hundreds of miles upon the main artery and its branches, between the rapids which are met with from time to time. The Uruguay has its annual floods, due to the rains in its upper basin. They begin at the end of July and continue to November, attaining their maximum during September and October. At the narrow places the river rises as high as 30 ft., but its average rise is 16 ft. It flows almost for its entire course over a rocky bed, generally of red sandstone, at times very coarse and then again of extremely fine composition. Except in floods, it is a clear-water stream, and even at its highest level carries comparatively little silt.
The Paraná (the “Mother of the Sea” in Guarani) drains a vast area of southern Brazil. It is formed by the union of the Rio The Paraná and its Affluents. Grande and Paranáhyba, and is about 1600 m. long from its extreme source in Goyaz to its junction with the Paraguay, and thence 600 more to the Plata estuary. Its average width for the latter length is from 1 to 3 m. Its Rio Grande branch descends from the slope of the Serra di Mantiqueira, in the region where the orographic system of Brazil culminates near the peak of Itatiaia-assú, almost in sight of Rio de Janeiro. It is about 680 m. long, but only navigable in the stretches between the many reefs, falls and rapids which interrupt its regular flow. Among its numerous affluents the principal one is the Rio das Mortes, rising in the Serra Mantiqueira. It is 180 m. long, with two sections, of a total of 120 m., which are navigable for launches. The main branch of the Paraná, the Paranáhyba, rises in about 15° 30′ S., on the southern slopes of the Pyreneos Mountains. It drains a little-known region of Goyaz and western Minas Geraes, lying upon the immediate southern watershed of Brazil.
Besides these rivers, the Paraná has many long and powerful affluents from the Brazilian states of São Paulo and Paraná. Most of them, although obstructed by rapids, are navigable for launches and canoes. Among the eastern tributaries are the Tiété, the Paraná-panema, formerly known as the Anemby, and the Iguazú.
The Tiété, over 700 m. long, rises in the Serra Paranápicaba and flows in a north-west direction. Its course is broken by fifty four raipids, and the lower river by two falls, the Avanhandava, 44 ft. drop, and the Itapurá, 65 ft.
The Paraná-panema is about 600 m. long, and rises in a ramification of the Serra Paranápicaba which overbooks the Atlantic Ocean. Its general course is north-west. It is navigable for a distance of only about 30 m. above its mouth, and for its whole course it has so many obstructions that it is useless for commercial purposes.
The Iguazú, also called the Rio Grande de Curutiba, has its sources on the slopes of the Serra do Mar of Brazil, and flows nearly west, through thick forests, along the line of 26° S. Its navigation is difficult even for small craft, as it is full of reefs, rapids and cataracts. Sixteen miles above its mouth is the magnificent Salto del Iguazú, sometimes called the Victoria Fall, round which canoes have to be transported 37 m. before quiet water is reached again. The width of the falls, measured along their crest or edge, is 2½ m.; part of the river takes two leaps of about 100 ft each, but a portion of it plunges down the whole depth in unbroken mass. Its mouth is about 800 ft. wide, and the depth in mid-river 40 ft.
The Paraná, at a point 28 m. above the mouth of the Tiété, is interrupted by the falls of Urubuponga, but below these it hasCourse of the Paraná. unobstructed navigation for about 400 m., as far down as the falls of Guaira, in 24° 3′ S., where the river forms a lake 4½ m. long and 2½ m. wide, preparatory to breaching the Serra de Mbaracayú, which there disputes its right of way. It has torn a deep gorge through the mountains for a length of about 2 m., where it is divided into several channels, filled with rapids and cataracts. It finally gathers its waters into a single volume, to plunge with frightful velocity through a long cañon only about 200 ft. wide. From these so-called falls of Guaira, or “Sete Quedas,” as far as its confluence with the Paraguay river, the Paraná has carved a narrow bed through an immense cap of red sandstone, along which it sometimes flows with great rapidity, occasionally being interrupted by dangerous narrows and rapids, where the banks in some places close in to a width of 450 to 600 ft., although the average is from 1200 to 1600 ft. At the south-east angle of Paraguay the Paraná is prevented from continuing its natural southern course to the river Uruguay by the highlands which cross the Argentine province of Misiones, and connect those of Rio Grande do Sul with the Caa-guazú range of Paraguay. Here, therefore, it is turned westwards; but before escaping from its great sandstone bed it is obstructed by several reefs, notably at the rapids of Apipé, which are the last before it joins the placid Paraguay, 130 m. farther on. From the Apipé rapids there is a vast triangular space at the south-western corner of Paraguay but little above sea-level, consisting of low, sandy ground and morasses, at times flooded by the Paraguay river. This district, united to the equally enormous area occupied by the Yberá lagoon and its surrounding morasses, in the northern part of the Argentine province of Corrientes, was probably the delta of the Paraná river when it emptied into the ancient Pampean Sea.
The river Paraguay, the main affluent of the Paraná, rises in Matto Grosso, in the vicinity of the town of Diamantino, aboutThe Paraguay. 14° 24′ S. It flows south-westwards, as far as Villa Maria, along the foot of the high plateau which divides it from the Cuyabá River to the east, and then, turning southwards, soon reaches the morass expansion of Xarayes, which it traverses for about 100 m. A few miles below Villa Maria it receives an affluent from the north-west, the Jaurá, which has its source nearly in contact with the head-waters of the Guaporé branch of the river Madeira. The Cuyabá, which is known as the São Lourenço for 90 m. above its confluence with the Paraguay, has its sources in 13° 45′ S., almost in touch with those of the Tapajos branch of the Amazon. Above the town of Cuyabá it is from 150 to 400 ft. wide, and may be navigated up stream by canoes for 150 m.; but there are many rapids. The town may be reached from the Paraguay River, at low water, by craft drawing 18 in. According to the observations of Clauss, Cuyabá is only 660 ft. above sea-level From the junction of the São Lourenço (or Cuyabá) with the river Paraguay, the latter, now a great stream, moves sluggishly southwards, spreading its waters, in the rainy season, for hundreds of miles to the right and left, as far south as 20°, turning vast swamps into great lakes—in fact, temporarily restoring the region, for thousands of square miles, to its ancient lacustrine condition.
On the west side of the upper Paraguay, between about 17° 30′ and 19° S., are several large, shallow lagunas or lakes which receive Lagoons of Upper Paraguay. the drainage of the southern slopes of the Chiquitos sierras, but represent mainly the south-west overflow of the vast morass of Xarayas. The principal of these lakes, naming them from north to south, are the Uberaba, the Gaiba, Mandioré and the “Bahia” de Caceres. The Uberaba is the largest. The northern division of the lake belongs entirely to Brazil, but the southern one, about two-thirds of its area, is bisected from north to south by the boundary line between Brazil and Bolivia, according to the treaty of 1867. It is in great part surrounded by high ground and hills, but its southern coast is swampy and flooded during the rainy season. The west shore is historic. Here, in 1543, the conquistador, Martinez de Irala, founded the “Puerto de los Reyes,” with the idea that it might become the port for Peru; and from Lake Gaiba several expeditions, in Spanish colonial days, penetrated 500 m. across the Chaco to the frontier of the empire of the Incas. At the Puerto de los Reyes Bolivia laid out a town in December 1900, in the forlorn hope that the “Port” may serve as an outlet for that commercially suffocated country, there being no other equally good accessible point for Bolivia on the Paraguay River.
South of the São Lourenço, the first river of importance which enters the Paraguay from the east is the Taquary, about 19° S. Affluents of the Paraguay. It rises in the Serra Cayapó, on the southern extension of the Matto Grosso table-land. South of this stream about 50 m. a considerable river, the Mondego, with many branches, draining a great area of extreme southern Matto Grosso, also flows into the Paraguay; and still farther south, near 21°, is the Apá tributary, which forms the boundary between Paraguay and Brazilian Matto Grosso.
