chap, viii.] THE GULF-STREAM. 379 



" So, after all, there is an under-current setting outwards in 

 the Straits of Gibraltar. 



" Repeating my thanks for this interesting memoir, believe 

 me, dear Sir, 



" Yours very truly, 



"J. F. \V. Hreschel. 



"Dr. W. B. Carpenter •." l 



The second view, supported by Dr. Petermann of 

 Gotlia, and by most of the leading authorities in 

 physical geography in Germany and Northern 

 Europe, and strongly urged by the late Sir John 

 Herschel in his 'Outlines of Physical Geography' 

 published in the year 1846, attributes nearly the 

 whole of the sensible phenomena of heat-distribution 

 in the North Atlantic to the Gulf-stream, and to the 

 arctic return-currents which are induced by the 

 removal of tropical water towards the polar regions 

 by the Gulf-stream. If we for a moment admit that 

 to the Gulf-stream is due almost exclusively the 

 singular advantage in climate which the eastern 

 borders of the North Atlantic possess over the 

 western, the origin of this great current, its extent 

 and direction, and the nature and amount of its 

 influence, become questions of surpassing interest. 

 Before considering these, however, it will be well 

 to define what is here meant by the term ' Gulf- 

 stream,' for even on this point there has been a good 

 deal of misconception. 



I mean by the Gulf-stream that mass of heated 

 water which pours from the Strait of Florida across 

 the North Atlantic, and likewise a wider but less 

 definite warm current, evidently forming part of the 

 same great movement of water, which curves north- 

 1 Nature, vol. iv. p. 7L 



