106 THE PHYSICAL GEOGRAPHY OF THE SEA. 



shore current counter to the Gulf Stream on the western side, and 

 the cool drift from the north on the east side. In illustration of 

 this view, and of the influence of the icebergs and cold currents 

 of the Atlantic upon the hypsometry of that ocean, it is only nec- 

 essary to refer to the North Pacific, where there are no icebergs 

 nor marked contrasts between the temperature of its currents. 

 Ireland and the Aleutian Islands are situated between the same 

 parallels. On the Pacific islands there is an uninterrupted rain- 

 fall during the entire winter. At other seasons of the year sail- 

 ors describe the weather, in their log-books, there as " raining 

 pretty much all the time." This is far from being the case even 

 on the western coasts of Ireland, where there is a rain-fall of only 

 47"^ inches — probably not more than a third of what Oonalaska 

 receives. And simply for this reason : the winds reach Ireland 

 after they have been robbed (partially) of the vapors by the cool 

 temperatures of the icebergs and cold currents which lie in their 

 way ; whereas, such being absent from the North Pacific, they 

 arrive at the islands there literally reeking with moisture. Ore- 

 gon in America, and France on the Bay of Biscay, are between the 

 same parallels of latitude ; their situation with regard both to 

 wind and sea is the same, for each has an ocean to windward. 

 Yet their annual rain-fall is, for Oregon, f 65 inches, for France, 

 80. None of the islands which curtain the shores of Europe are 

 visited as abundantly by rains as are those in the same latitudes 

 which curtain bur northwest coast. The American water-shed 

 receives about twice as much rain as the European. How shall 

 we account for this difference except upon the supposition that 

 the winds from the Pacific carry more rain than the winds from 

 the Atlantic ? Why should they do this, except for the icebergs 

 and cool streaks already alluded to ?:j: 



284. It may well be doubted whether the southwesterly winds 

 Limited capacity of — which arc the prevailing winds in this part of 



winds to take op ^ . ^ . ^ , . o t^ 



and transport,, for the . Atlantic — carrv into the interior oi Europe 



the rivers of Europe , . ^ ^ . . • i i 



and America, vapor much morc moisturc than they bring with tnem 



from the North At- . tat- mi • • i 



lantic. into the Atlantic. They enter it with a mean an- 



nual temperature of 60°, with an average dew point of about 55°. 

 They leave it at a mean temperature varying from 60° to 40°, ac- 



* Keith Johhston. f Army Meteorological Register, 1855. 



X Keith Johnston, "Physical Atlas." 



