LETTER III. 



Voyage to Teneriffe Continued. 



During the week past we have been sailing under the 

 most propitious circumstances. We have made 20° of 

 longitude, and are now in the Gulf Stream, receiving its 

 utmost benefits. We entered it on the 11th instant, at 

 four o'clock in the afternoon, which was obvious from an 

 increase of temperature of the water. A thermometer 

 being immersed, indicated 72° F.,* two degrees higher 

 than at noon of the same day. Yesterday the temperature 

 of the atmosphere at noon, in latitude 40° 4' N., and 

 longitude 57° 41' W. was 82°, and that of the ocean at 

 the surface 80°, which is 15° higher than it was near 

 Sandy Hook, at noon on the day of our departure. 



This great current may be explained as follows : — 

 '' Between the tropics, especially from the coast of Senegal 

 to the Caribbean Sea, there is a stream that always flows 

 from east to west, and which is named the Equinoctial Cur- 

 rent. Its mean rapidhy may be estimated at ten or eleven 

 miles in twenty-four hours. This movement of the waters, 

 which is also observed in the Pacific Ocean, having a 

 direction contrary to that of the earth's rotation, is supposed 

 to be connected with the latter only in so far as it changes 

 into trade-winds those aerial currents from the poles, which, 

 in the lower regions of the atmosphere, carry the cold air 

 of the high latitudes towards the equator ; and it is to the 

 general impulse which these winds give to the surface of 



*It will be unrlcrstood that the variations of temperature expressed in this work, 

 are noted after Fahrenheit's scale, except otherwise specified. 



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