842 M. Humboldt on tlte Difference oftlie 



Nootka), western winds carry strata of air, which even in 

 the severest winter have been heated by contact with the vast 

 surface of the ocean. Led by these ideas, I have considered it 

 of importance to obtain a knowledge of the lowest temperature 

 to which the Atlantic sinks, out of the Gulf Stream, between 

 40° and 50° north latitude (consequently in the latitudes 

 of Spain, France and Germany), I have found that, in the 

 month of January, in 40° latitude, the water of the sea does not 

 sink below 56° Fahr. (10<^.7 R.) and in 45° latitude not below 

 54° Fahr. (9°.8 R.) The much esteemed geographer of India, 

 Major Rennel, who for thirty years has been employed in study- 

 ing the direction of the currents of the Atlantic, and who, during 

 my last visit to England, communicated to me a part of his ma- 

 nuscript materials, has, in 50° latitude, consequently in the zone 

 of the north of Germany, observed in winter a temperature of 

 the sea-water, to which the atmosphere does not reach in the 

 month of January, even in the mild climate of Marseilles. If 

 the relative extent of Asia and North America, of the Pacific 

 and the Northern Atlantic, was different from what it is, the 

 whole system of winds in the northern hemisphere, would, by 

 the unequal heating of the solid, as well as of the fluid, parts 

 of the surface of the earth, be changed in their direction as well 

 as in their intensity. 



Europe is indebted for its milder climate to its position on the 

 globe (the position in which it stands in regard to the neighbour- 

 ing seas) and to its peculiar form. Europe is the western part 

 of the old continent ; and consequently the great Atlantic Ocean, 

 which already in itself has the power of diminishing the cold, and 

 which is besides partly warmed by the Gulf Stream, lies to the 

 west of it. That part of the world which of all others enjoys 

 the greatest share of a tropical climate, the sandy Africa, is so 

 situate that Europe is heated by the strata of air, which, as- 

 cending from Africa, move from the Equator towards the North 

 Pole. Had the Mediterranean not existed, the influence of Af- 

 rica on the temperature and the geographical distribution of 

 plants and animals in Europe, would have been still more consi- 

 derable. The third principal cause of the milder climate of Eu- 

 rope is, that this part of the world does not approach the North 



