45 



[see Geogr. Mittheilungen, Heft VI. and VII., 1870, and 

 maps] brings forward strong evidence to prove the extension 

 of this current to the western shores of Europe, and into the 

 Arctic Ocean. His curves of temperature embody the results 

 of more than 100,000 observations on the temperature of the 

 North Atlantic at all seasons of the year, and point out the 

 Gulf-stream-current as the principal, if not the only, channel 

 by which the warm waters of the Equatorial region are trans- 

 ferred into the North Atlantic and Arctic Oceans. 



The Deep Sea Explorations carried on on board H.M.S. 

 Lightning and Porcupine from 1868 to 1870 by Dr. Carpenter, 

 Professor Wyville Thomson, and Mr. J. Gwynn Jeffreys have 

 revealed the existence of a deep stratum of warm water reach- 

 ing down to a depth of 800 fathoms, and extending along the 

 west coast of Ireland, Scotland, and the Shetland Isles. Other 

 temperature observations of even more recent date [see Peter- 

 mann's Geogr. Mitthiel, Heft XII., 1870, and Heft I., 187 1] 

 show that the stratum of water of Equatorial origin continues 

 along the west coast of Norway, passes round the North 

 Cape, where it sends off one branch towards the western coast 

 of Spitzbergen, another branch towards the west coast of 

 Nowaja Zembla, and a third along the shores of Lapland and 

 the White Sea. 



The principal permanent cause of the Gulf-stream-current 

 as Sir John Herschel lays it down in his Physical Geography, 

 must be looked for in the action of the Trade-winds. Owing 

 to the combined influence of the S.E. and N.E. Trades a large 

 mass of water is carried from the northern and southern 

 hemispheres towards the Equatorial regions, from whence, 

 after its temperature has been raised to about 8o° F., it is 

 driven into the Carribean Sea and the Gulf of Mexico, 

 where it undergoes a further heating process. At last, 

 flowing out of the Straits of Florida, under the name 

 of the Gulf-stream, it spreads itself over the North At- 



