s basin is constantly
swept by westerly winds. It is not a narrow valley surrounded by high
mountains which border its banks, but a huge plain, measuring three
hundred and fifty leagues from north to south, scarcely varied with a
few knolls, whose whole extent the atmospheric currents can traverse
unchecked.

Professor Agassiz very properly protested against the pretended
unhealthiness o the climate of a country which is destined to become one
of the most active of the world's producers. According to him, "a soft
and gentle breeze is constantly observable, and produces an evaporation,
thanks to which the temperature is kept down, and the sun does not give
out heat unchecked. The constancy of this refreshing breeze renders the
climate of the river Amazon agreeable, and even delightful."

The Abbe Durand has likewise testified that if the temperature does not
drop below 25 degrees Centigrade, it never rises above 33 degrees, and
this gives for the year a mean temperature of from 28 degrees to 29
degrees, with a range of only 8 degrees.

After such statements we are safe in affirming that the basin of the
Amazon has none of the burning heats of countries like Asia and Africa,
which are crossed by the same parallels.

The vast plain which serves for its valley is accessible over its whole
extent to the generous breezes which come from off the Atlantic.

And the provinces to which the river has given its name have
acknowledged right to call themselves the healthiest of a country which
is one of the finest on the earth.

And how can we say that the hydrographical system of the Amazon is not
known?

In the sixteenth century Orellana, the lieutenant of one of the brothers
Pizarro, descended the Rio Negro, arrived on the main river in 1540,
ventured without a guide across the unknown district, and, after
eighteen months of a navigation of which is record is most marvelous,
reached the mouth.

In 1636 and 1637 the Portuguese Pedro Texeira ascended the Amazon to
Napo, with a fleet of forty-seven pirogues.

In 1743 La Condamine, after having measured an arc of the meridian at
the equator, left his companions Bouguer and Godin des Odonais, embarked
on the Chinchipe, descended it to its junction with the Maranon, reached
the mouth at Napo on the 31st of July, just in time to observe an
emersion of the first satellite of Jupiter--which allowed this "Humboldt
of the eighteenth century" to accurately determine the latitude an