plashing as the strong manati made its attempt to escape; but the head
of the harpoon was deeply buried in its flesh, and, with the attached
cord, Guapo soon hauled the animal ashore. It was as much as he and Don
Pablo could do to drag it on dry land; but the knife soon took it to
pieces; and then several hours were spent in making it fit for
preservation. Its fat and flesh yielded enough to fill every spare
vessel our travellers had got; and, when all were filled, the balza was
pushed off, and they continued their voyage without any fear of short
rations for some time to come.

CHAPTER FIFTY.

THE CLOSING CHAPTER.

After many days of difficult navigation the balza floated upon the broad
and mighty Amazon, whose yellowish-olive flood flowed yet fifteen
hundred miles farther to the Atlantic Ocean.

The current was in most places over four miles an hour, and the
navigation smooth and easy--so that our travellers rarely made less than
fifty miles a-day. There was considerable monotony in the landscape, on
account of the absence of mountains, as the Amazon, through most of its
course, runs through a level plain. The numerous bends and sudden
windings of the stream, however, continually opening out into new and
charming vistas, and the ever-changing variety of vegetation, formed
sources of delight to the travellers.

Almost every day they passed the mouth of some tributary river--many of
these appearing as large as the Amazon itself. Our travellers were
struck with a peculiarity in relation to these rivers--that is, their
variety of colour. Some were whitish, with a tinge of olive, like the
Amazon itself; others were blue and transparent; while a third kind had
waters as black as ink. Of the latter class is the great river of the
Rio Negro--which by means of a tributary (the Cassiquiare) joins the
Amazon with the Orinoco.

Indeed, the rivers of the Amazon valley have been classed into _white,
blue_, and _black_. Red rivers, such as are common in the northern
division of the American continent, do not exist in the valley of the
Amazon.

There appears to be no other explanation for this difference in the
colour of rivers, except by supposing that they take their hue from the
nature of the soil through which these channels run.

But the _white_ rivers, as the Amazon itself, do not appear to be of
this hue merely because they are "muddy." On the contrary, they derive
their colour, or most of it, from some