114 G. G. Hubbard — Air and Water, Temperature and Life. 



globe on its axis, and the direction and velocity of the wind 

 modify its movement. 



South America. 



By this circulation the equatorial waters of the Atlantic blow 

 across that ocean, impinge against the coast of South America, 

 and are deflected northward and southward. The southeasterly 

 trade winds blowing over it become surcharged with moisture 

 and pass directly up the valley of the Amazon, watering the 

 earth with frequent rains for 2,000 miles to the foot-hills of the 

 Andes, where some of this moisture is deflected by the moun- 

 tains southeastward to water southern Brazil; the remainder 

 ascends the slopes of the Andes until it is condensed and falls 

 as rain and snow, and only dry winds blow across the compara- 

 tively narrow plains between the Andes and the Pacific. The 

 vapor from the Atlantic falling in rain over the valley of the 

 Amazon and along the eastern slope of the Andes and the Cor- 

 dilleras flows back to the ocean through the Orinoco, the Amazon 

 and la Plata, and makes the interior of South America one of 

 the richest countries of the world. 



The Amazon, a great mediterranean sea as it is often rightly 

 called, is projected into the heart of the continent. Its total fall 

 from the foot-hills of the Cordilleras to the ocean is not over 300 

 or 400 feet, affording for the largest vessels uninterrupted navi- 

 gation and innumerable harbors for 1,500 miles into the interior, 

 and 1,000 miles further for smaller vessels. The aggregate navi- 

 gable waters of the main stream and its tributaries are estimated 

 at 50,000 miles. The moist winds abundantly water the valley 

 and modify its climate. Their influence in tempering the climate 

 is felt directly more than 1,000 miles up the valley, and indi- 

 rectly still further, through the shadows thrown by the clouds 

 and through the rainfall and the cooling effect of the drops of 

 rain falling from a high altitude. It is from 8° to 10° cooler 

 than on either side of this rain belt, and it is more healthful 

 than other equatorial regions. The tropical woods are so thick 

 and the creepers and undergrowth so luxuriant that animal life 

 is almost entirely confined to the trees above and the waters 

 below. Nature has thus far been more powerful than man, who 

 has struggled in vain to subdue this fertile valley to his use. 



The winds that pass up the valley of Rio de la Plata to the 

 mountains of Peru, Bolivia and Argentina are not so heavily 



