26 Natural History Hlt.leiix. 



rent from the tropics, acting ay an effectual barrier for the 

 protection of the sensitive coral polyps. Doctor J. Walter 

 Fewkes speaks of a Phvsalia which he found carried as far 

 north as the Ba\' of Fund}', where it was doubtless surprised 

 bv the cold reception given it by the icy arctic current. 



Numerous attempts at an explanation of the Gu^f Stream 

 ha\e been made. " Some have sought to explain it by the 

 different densitv of the water in polar and tropical regions; 

 others find its cause in the convexity of the earth's surface, 

 and still others regard the trade winds as the prime agent in 

 causing the flow of the stream. However that may be, it is 

 evident that the great equatorial current splits itself on Cape 

 St. Roque. on the South American coast, one portion going 

 south along the Brazilian shores, and another flowing north- 

 ward to the Carribean Sea. Here it again breaks, part going 

 to the east of the Windward Islands, and the remainder, which 

 is ordinarilv regarded as the source of the Gulf Stream proper, 

 banking up in the Gulf of Mexico by way of the Yucatan 

 Channel, the old Bahama Channel, and the Bemini Channel. 

 x\fter swirlino- uround in the Gulf of Mexico and becoming 

 greath' heated in the process, this great volume of warm water 

 finds an outlet, and scours along between Cuba and the 

 Florida Reefs, and then betw^een the Bahamas and the penin- 

 sula of Florida, where it is concentrated into a stream about 

 fort\"-flve miles wide, with a current of at least four knots per 

 hour. Pouring out of this channel it widens as it proceeds 

 northward and eastward, linalh' reaching the shores of Great 

 Britain and Northern Europe, rendering habitable vast areas 

 of land which would otherwise be as bleak as Labrador. Sir 

 Wyville Thomson sa3-s. •• I have seen no reason to modif}' 

 the opinion .... that the remarkable conditions of cli- 

 mate on the coasts of Northern Europe are due in a broad 

 sense solely to the (julf Stream.'"^ 



The beneflcent work of this great hydrographic feature is 

 not conflned to warming the northern shores of Europe. At 

 the ver}- beginning of its course as the Gulf Stream, it has pre- 



1 •■ Depths of tlic Sim," p:m-|-' I:)!!. 



