112 PHYSICAL GEOGRAPHY OF THE SEA, AND ITS METEOEOLOGY. 



as to its hypsometry. It is traversed by large icebergs, which 

 are more favourable to the recondensation of its vapours than so 

 many islets would be. Warm waters are in the middle of it, and 

 both the east and the west winds, which waft its vapours to the 

 land, have, before reaching the shores, to cross currents of cool 

 water, as the in-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 onlj^ necessary to refer to the North Pacific, where 

 there are no icebergs nor marked contrasts between the tem^Dera- 

 ture 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 sailors describe the weather, in their 

 loo--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 vapours by the cool temperatures of the ice- 

 bergs 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. Oregon in America, and 

 Prance 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, 30. None of the 

 islands which curtain the shores of Europe are visited as abun- 

 dantly by rains as are those in the same latitudes which curtain 

 our north-west 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 (§ 171) 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. Limited capacity of winds to take up and transport, for the 

 rivers of Europe and America, vapour from the North Atlantic. — It 

 may well be doubted whether the south-westerly winds — which 



* Keith Johnston. t Army Meteorological Eegister, 1855. 



% Keith Jolmston, " Physical Atlas." 



