XI. 



THE GULF STREAM. 



The Gulf Stream is the best known and at the same time the 

 most remarkable example of the effect of oceanic circulation 

 upon the distribution of temperature in connection with the 

 currents of the North Atlantic. It has long been known to 

 geographers that a cold current coming from Greenland joins 

 the Labrador current, and extends in a southerly direction along 

 the eastern coast of the United States, while a warm current 

 pouring through the Straits of Florida flows in the opposite di- 

 rection -^ along the coast of the southern Atlantic States, and is 

 deflected from the Banks of Newfoundland, crossing the Atlan- 

 tic diagonally. This body of warm water makes itself felt along 

 the west coast of the British Islands, penetrating even as far as 

 the coast of Spitzbergen, and perhaps beyond, to Nova Zembla. 

 It is impossible to discuss the results of the more recent inves- 

 tigations of the Gulf Stream carried on by the " Blake," with- 

 out including the general questions of oceanic circulation, and 

 of the thermal conditions of the Atlantic in particular. I shall 

 therefore briefly state such points, derived from the explorations 

 of the " Challenger " and other expeditions, as will assist us in 

 understanding the history and physics of this great oceanic 

 current. 



Sir Charles Lyell has called attention to the fact that in the 



^ Along the American coast the sudden cold green water, which has such a chill- 

 transition from the green, cold, and more ing influence on the climate of the New 

 or less turbid water found along the coast England States, follows the line of the 

 and continental shelf, into the deep blue Atlantic coast of the United States far 

 waters of the warm Gulf Stream, is one towards the base of the peninsula of Flo- 

 which has been noticed by all who have rida. 

 passed from the shore seaward. This 



