76 



THE OCEAN. 



principal markets of the Antilles and Mississippi States, are, so to 

 say, at the source of the Gulf-stream. New York is situated facing 

 the principal bend of this current, at the spot where the vast river 

 flowing from the Antilles bends towards Europe. Finally, Liverpool, 

 among so many other considerable ports washed by the Gulf-stream 

 on its arri\al at the coasts of the Old AYorld, is the one which is 

 most directly in the path of its waters. 



"VYhen Franklin discovered, in 1775, that the mariner has only to 

 plunge a thermometer in the water of the Atlantic to discover if he 

 is sailing over the Gulf-stream or outside its course, the illustrious 

 savant immediately perceived the importance of this fact for navi- 

 gation, lie even thought for a long time he must conceal it, from a 

 fear that the English government, then at war with the American 

 Colonics, would profit by this discovery to send ships and men more 

 rapidly against the revolted provinces. After the definite establish- 

 ment of American Inde])endcnco, no peril of this kind being any 

 longer to be feared, all navigators were enabled for the future to 

 know precisely the high road which they had to follow in the open 

 sea to reach Eiiroj^e most expeditiously from America, and what 

 particular line to avoid in order to effect the journey in an op- 

 posite direction. Towards the middle of the last century, the whalers 



10" CO" 60° W" 



Fig. 23.— Route of Steam-packets, after Maury. 



of Nantucket and the skippers of Rhode Island had already from ex- 

 perience come to choose two different routes for going and returning. 



