54 : The Atlantic 



west Greenland shore determined the locations sought out by at least 

 four successive groups of voyagers: Eskimos, Norse, Danes, Yankee 

 and other whalers. 



The Portuguese mariners under Henry the Navigator were encour- 

 aged and able to undertake their explorations of the west coast of 

 Africa with crude vessels because their outward passages were always 

 aided by favorable currents and the Portuguese and northeast trades; 

 the Benguela Current almost blocked them farther south until Diaz 

 dared to take his ship offshore. 



Cabral made an independent discovery of South America while on 

 the way to India because the southeast trades and the South Equato- 

 rial Current carried him off course. 



So it goes right down to our days: the Savannah, the first powered 

 vessel to cross the Atlantic, was more assisted in her crossing by a 

 judicious use of the Gulf Stream than by her steam power plant. 



During World War II submarines came into the Mediterranean 

 without using motors or propellers, and thus without being detected 

 by sound, by submerging a little but letting the everpresent surface 

 current carry them in. They left the Mediterranean by submerging to 

 somewhat lower depth and letting the flood of everpresent heavier, 

 saltier water carry them out over the sill into the broad Atlantic. . . . 



These are scattered and not always important examples of the 

 way in which the ocean has influenced human undertakings and also 

 of the way in which men with knowledge of the ocean have used it 

 to their advantage. The remainder of this book shows in a more lei- 

 surely and systematic fashion the part the Atlantic has played in 

 human history. 



