Observations in the North Atlantic. 351 



The trade-wind disappeared on the 26th, in lat. 26°. By 

 the following morning, the wind had drawn round to SE. by E., 

 and was attended by a considerable rise of the dew-point, as 

 was observed outside the trade in the eastern part of the At- 

 lantic. In higher latitudes, northerly winds caused a rapid 

 fall of the temperature and dew-point, while a change to the 

 southward was generally followed by the elevation of both. 



The observations on the sea water, and drift of the currents, 

 possess considerable interest. In examining these it is neces- 

 sary to observe, that, while the temperature and specific gra- 

 vity of the water refer to a given point only, the drift of the 

 current is that observed during the previous twenty-four hours ; 

 so that were a ship to run from still water into a current a 

 little before noon, the temperature and specific gi-avity of the 

 water of the current would be obtained, though the drift would 

 not become obvious until the following noon. Also, were a 

 ship, at noon, near the edge of a current, sailing out of it into 

 still water, the disappearance of the current, which would be- 

 come obvious from next day's reckoning, should be associated 

 with the temperature and specific gravity obtained that day, 

 and vice versa. 



The great equatorial current, directed to the NW. by the 

 coast of South America, sets past Barbadoes and the islands to 

 leeward, into the Caribbean Sea, with considerable velocity. 

 To the northward of Barbadoes, however, for some distance, 

 whether from the islands being more thickly grouped, or from 

 the diminished depth of the sea, the current seems altered in 

 direction. From Barbadoes to 15° 17' N., for instance, the 

 general drift was, on the 10th and 11th February, N. 82° E., 

 seven miles ; from that latitude, however, to 17° 41' N, the 

 drift in the following twenty-four hours was, N. 50° W., eight 

 miles ; and, up to next noon, when completely clear of the 

 leeward islands, it was, N. 68° W., twenty-nine miles. The 

 vessel seems to have left this current just before noon on the 

 ] 3th ; for, although the temperature of the water Avas then the 

 same as on the preceding day, its specific gravity on the 12th 

 was 1-02801, and on the 13th 1-02774 only ; the drift, too, up 

 to noon on the 14th, was, N. 34° E., seven miles, and to the 

 same time on the 15th, N. 14° E., four miles, the same in 



