116 G. G. Hubbard — Air and Water, Temj^erature and Life. 



deflected by Japan, and flows northward as the Kuroshiwo 

 current, recrossing the Pacific in a northeasterly direction. 



The Pacific ocean is so wide that it is doubtful if this current 

 would reach the American coast were it not for the drift caused 

 by the wind which blows across the Pacific with strong and 

 steady force. When it strikes the shores of North America it is 

 feebler and has a lower temperature than the Gulf stream of 

 the Atlantic ocean on reaching the coast of Europe. 



The currents of wind strike the coast between the fiftieth and 

 fifty-fifth degrees of north latitude, the region of greatest rain- 

 fall, and are in part deflected northward and southward by the 

 Coast range of mountains ; the remaining portion blows over 

 the mountains and up the valley of the Columbia. Continual 

 fogs and rains abound on these shores, and the coasts of southern 

 Alaska, British Columbia, Washington and Oregon are covered 

 with the densest and largest growth of evergreen forest in the 

 world. These winds prevail as far southward as the latitude of 

 San Francisco, where the southeasterly trade Avinds commence 

 and blow off-shore, leaving southern California and the western 

 coast of Central America a zone of calms, dry and barren. 



While the western coast of the continent is bathed by the 

 waters of the Pacific, its eastern shores are washed by the equa- 

 torial current of the northern Atlantic, which flows around the 

 West India islands, through Caribbean sea and the Gulf of 

 Mexico. The trade winds from the Gulf of Mexico water the 

 eastern coasts of Central America and Mexico, and impinging on 

 the mountains of the interior are deflected toward the north 

 and east over the southeastern states and up the Mississippi 

 valley, where they unite with the warm winds which blow 

 directly up the valley from the Gulf of Mexico, and water the 

 valley of the Mississippi. The rainfall in the upper part of the 

 valley is derived largely from the Rocky mountains, the waters 

 of the Pacific carried b}^ the winds and deposited on the Rocky 

 mountains as rain and snow being again evaporated and carried 

 eastward to fall as rain. 



This great valley extends from Canada southward to the Gulf 

 of Mexico, and from the Rocky mountains eastward to the Alle- 

 ghanies; it is 1,500 miles long and about 2,000 miles wide, the 

 largest and richest valley of the temperate zone. 



A very low and narrow divide separates the Mississippi valley 

 from another great valley extending from the Rocky mountains 



