204 CURRENTS OF THE SEA; 



Gulf of Mexico, into the "North Atlantic, there 

 can be no doubt that the temperature of the coasts 

 of France and Germany, of Great Britain and 

 Scandinavia, would fall several degrees. 



In the great inland seas of Europe there are 

 likewise regular well-marked currents. Thus 

 there is a regular and strong current from the 

 Baltic, through the Sound, into the North Sea. 

 From this we must conclude, that its surface does 

 not lose by evaporation so much as it gains by the 

 plentiful supplies which it receives from rivers. 

 In the Mediterranean, on the other hand, to whose 

 surface the prevailing south wind yields up a part 

 of the heat which it has taken up from the scorch- 

 ing sands of the African Desert, the evaporation is 

 so strong that the water poured in by the rivers 

 and from the Black Sea through the Straits of 

 Constantinople and the Dardanelles, is not 

 enough to replace it. We find therefore a con- 

 tinual current setting into it all the year round 

 from the Atlantic. It was formerly believed that 

 there was an out-flow underneath answering to this 

 in-flow at the surface ; but later researches have 

 shown that the two coasts forming the Straits of 

 Gibraltar are connected by a reef of rocks reach- 

 ing in many places nearly up to the surface, while 

 the sea on both sides of the narrow channel has a 

 very great depth. Besides, this notion is dis- 

 proved by the fact that the Mediterranean has a 



