the forest stands up to its middle in the water, and
shady dells are transformed into navigable creeks.[157] Swarms of
turtles leave the river for the inland lakes; flocks of wading birds
migrate to the banks of the Negro and Orinoco to enjoy the cloudless sky
of the dry season; alligators swim where a short time before the jaguar
lay in wait for the tapir; and the natives, unable to fish, huddle in
their villages to spend the "winter of their discontent." The Lower
Amazon is at its minimum in September or October. The rise above this
lowest level is between seven and eight fathoms. If we consider the
average width of the Amazon two miles, we shall have a surface of at
least five thousand square miles raised fifty feet by the inundation. An
extraordinary freshet is expected every sixth year.

[Footnote 157: The flooded lands are called _gapos_.]

The Atlantic tide is perceptible at Obidos, four hundred and fifty miles
above Para, and Bates observed it up the Tapajos, five hundred and
thirty miles distant. The tide, however, does not flow up; there is only
a rising and falling of the waters--the momentary check of the great
river in its conflict with the ocean. The "bore," or _piroroco_, is a
colossal wave at spring tide, rising suddenly along the whole width of
the Amazon to a height of twelve or fifteen feet, and then collapsing
with a frightful roar.

The Amazon presents an unparalleled extent of water communication. So
many and far reaching are its tributaries, it touches every country on
the continent except Chile and Patagonia. South America is well nigh
quartered by its river system: the Amazon starts within sixty miles of
the Pacific; the Tapajos and Madeira reach down to the La Plata; while
the Negro mingles its waters with those of the Orinoco. The tributaries
also communicate with each other by intersecting canals, so numerous
that central Amazonia is truly a cluster of islands. Wagons and
railroads will be out of the question for ages hence in this aquatic
basin. No other river runs in so deep a channel to so great a distance.
For two thousand miles from its month there are not less than seven
fathoms of water. Not a fall interrupts navigation on the main stream
for two thousand five hundred miles; and it so happens that while the
current is ever east (for even the ocean can not send up its tide
against it), there is a constant trade-wind westward, so that navigation
up or down has always something in its