d 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 mile