70 THE OCEAN 



winds carry to high latitudes the warm surface 

 waters from the south, whereas in the western 

 part near Nova Scotia the prevailing north- 

 westerly winds in the cold months of the year 

 carry the cold Arctic waters southward. The 

 lowering of the surface temperature off the 

 north-west coast of Africa is the direct result 

 of the curving round of the prevailing winds 

 in this part of the North Atlantic to north- 

 west and north, thus transferring the surface 

 waters from higher to lower latitudes. A 

 lowering of the temperature from similar 

 causes is seen off the west coasts of all the 

 continents in trade wind latitudes, where the 

 prevailing winds blow out from deserts, and 

 from higher to lower latitudes (therefore from 

 colder to warmer regions), and are conse- 

 quently dry evaporating winds. On the 

 other hand, a raising of the temperature is seen 

 in these latitudes off the east coasts of the 

 continents, where the prevailing winds pass 

 from lower to higher latitudes (therefore from 

 warmer to colder regions), and thus tend to 

 precipitate their moisture in the form of 

 warm rains. 



Variation of Temperature. — The temperature 

 of the surface waters of the ocean varies from 

 day to day and from year to year at any one 

 place, but to a much less extent than on land. 

 The sun's heat is readily absorbed at the sur- 



