Part 3—Chapter III.
Valley of the Amazon.
Standing on the eastern spur of the Andes, between 3 degrees and 4 degrees south of the equator, the eye of the traveller may see in imagination a vast valley, clothed with a dense forest, stretching towards the far-distant Atlantic. Behind him, on the west, tower the lofty peaks of the Cordilleras; on his left, in a northerly direction, appear the mountains and highlands of Venezuela and Guiana; while to the south rise the serras and table-lands of the Brazils. It is the Valley of the Amazon, in which more than half of Europe might be contained. Down the centre flows a mighty stream, the tributaries of which alone contain a bulk of water greater than all the European rivers put together.
Upwards of five hundred miles away to the south of the spot where the traveller stands, is the little lake of Lauricocha, near the silver-mines of Cerro de Pasco in Peru, just below the limit of perpetual snow—14,000 feet above the level of the sea. This lake has the honour of giving birth to the mighty stream: its waters forming the River Tunguragua, which, roaring and foaming in a series of cataracts and rapids through rocky valleys, flows northerly till it reaches the frontier of Ecuador. It then turns suddenly to the east, which direction it maintains, with a slightly northerly inclination, for two thousand miles—its volume greatly increased by numerous large streams, each of which is by itself a mighty river—till, attaining a width which may vie with that of the Baltic, it rushes with such fierce force into the Atlantic as to turn aside on either hand the salt-waters of the ocean. Thus the seaman approaching the shore of South America, when still out of sight of land, may lower his bucket and draw up the fresh-water which, it may be, has issued forth weeks before from the sides of the Andes. The whole length of the river, following its main curves, is but little under three thousand miles, while the tributaries from north to south stretch over seventeen hundred miles.
The basin of the Amazon may be considered like a shallow trough lying parallel to the equator, the southern sides having double the inclination of the northern, the whole gently sloping eastward. The channel of the river lies rather to the north of the basin, some hills rising directly above its waters; while the falls of several rivers to the south are two hundred miles above their mouths. Two thousand miles from its mouth the depth of the river is never less than eighteen feet, while many of its tributaries at their embouchures are of equal depth; and at the junction of the great rivers the hollows of its bed attain a depth of twenty-four fathoms. At Tabalingua, two thousand miles from its mouth, it is a mile and a half broad; and lower down, at the entrance of one of its tributaries—the Madeira—it measures three miles across. Still further to the east its sea-like reaches extend to the north for ten miles, with still wider lake-like expanses, so that the eye of the voyager can scarcely reach the forest-covered banks on the opposite side; while if the River Para is properly considered one of its branches, its measurement from shore to shore, across a countless number of islands, is one hundred and eighty miles—equal to the breadth of the widest part of the Baltic.
After receiving the waters of numerous streams, many of which flow for considerable distances parallel with its shores, and are united by a network of channels, it is joined by its most considerable northern tributary—the Rio Negro. This stream, rising in the mountains of Venezuela, and passing amidst the Llanos, robbing the Orinoco of part of its waters, has already, before it reaches the Amazon, flowed for a course of one thousand five hundred miles. It is called the Negro from its black colour. It is here not less than nineteen fathoms deep, and three thousand six hundred paces broad. The next great affluent is the Yapura, which, rising in the mountains of New Granada, takes a south-easterly course for one thousand miles, its principal mouth entering the Amazon opposite the town of Ega; but it has numberless small channels, the streams of which, two hundred miles apart, flow into the great river. The upper part of the Amazon is frequently called the Solimoens, which name it retains as far south as the mouth of the River Negro.
About sixty miles further east, its largest southern affluent—the gigantic Madeira—unites its milky waters with the turbid stream of the main river. One branch, the Beni, rises in the neighbourhood of the ancient Cuzco in Peru, near Lake Titicaca, its whole extent from the centre of the province of Bolivia being nearly the length of the Amazon itself. At its mouth it is two miles wide and sixty-six feet deep; and five hundred miles up it is a mile wide. Numerous islands are found in its course: for nearly five hundred miles it is navigable for large vessels, when a cataract intervenes. Were it not for this, there would be a free navigation from the centre of the province of Bolivia to the ocean, embracing islands the size of many of the Old World provinces, and widening into broad lakes. The monarch of waters flows on between its low forest-clothed banks till, four hundred miles from its mouth, it reaches the Strait of Obydos, where it is narrowed to two thousand paces. Through this channel its waters rush with immense force, calculated at five hundred thousand cubic feet in one second—sufficient to fill all the streams in Europe, and swell them to overflowing. No plummet has hitherto sounded the depth of its bed at this point, the force of the stream probably rendering the operation almost impracticable.
Its last two great tributaries are the Tapajos, six times the length of the Thames, and the Xingu, twice that of the Rhine; while further east a narrow channel unites it with the River Para, into which flows the broad stream of the Tocantins. This river, rising in the Minas-Geraes, six hundred miles from Rio Janeiro, is one thousand six hundred miles long, and ten miles wide at its mouth. Opposite to Para is the large island of Marajo; and if Professor Agassiz is right in supposing that the continent once extended much further to the east than it now does, this island may properly be considered in the centre of the mouth of the river, and the River Para might then properly be called one of its true embouchures. But only a few of the streams which feed the Amazon have been named. Numberless other rivers swell its waters, united to it by countless channels which form a wonderful network throughout the whole region, joining also many of the main rivers