AND TEMPERATURE OF THE SEA. 35? 



scried it 2; the thermometer at 8f; h being raised by sea-water fresh 

 drawn only to 76; by 9 the heat was reduced to 73, and in of 

 an hour more, to 71 nearly: all this time the wind blew fresh, 

 and they were going ^ knots an hour on a north-western course. 

 The water now began to lose the fine transparent blue colour of the 

 ocean, and to assume something of a greenish olive tinge, a well- 

 known indication of soundings. Accordingly, between 4 and 5 in 

 the afternoon ground was struck with the lead at the depth of 80 

 fathoms, the heat of the sea being then reduced to 69. In the 

 course of the following night and next day, as they came into shal- 

 lower water and nearer the land, the temperature of the sea 

 gradually sunk to 65 9 , which was nearly that of the air at the 

 time. 



Bad weather on the 26th prevented them from taking an obser. 

 vation of the sun ; but on the 27th, though it was then cloudy at 

 noon, they calculated the latitude from 2 altitudes, and found it 

 to be 33 26' N. The difference of [this latitude from that which 

 was observed on the 25th, being 2 23', was so much greater than 

 could be deduced from the ship's run marked in the log-book, as to 

 convince the seamen that they had been set many miles to the north* 

 ward by the current. 



From these observations, the writer thinks it may be concluded, 

 that the gulf-stream, about the 33d degree of north latitude, and 

 the /6th degree of longitude west of Greenwich, is, in the month 

 of April, at least 6 degrees hotter than the water of the sea through 

 which it runs. As the heat of the sea-water evidently began to in- 

 crease in the evening of the 25th, and as the observations show that 

 they were getting out of the current when he first tried the heat it] 

 the morning of the 26th, it is most probable that the ship's run 

 during the night is nearly the breadth of the stream measured ob- 

 liquely across ; that , as it blew a fresh breeze, could not be much 

 Jess than 25 leagues in 15 hours, the distance of time between the 

 two observations of the heat, and hence the breadth of the stream 

 may be estimated at 2O leagues. The breadth of the Gulf of Flo- 

 rida, which evidently bounds the stream at its origin, appears by 

 the charts to be 2 or 3 miles less than this, excluding the rocks and 

 sand-banks which surround the Bahama Islands, and the shallow 

 water that extends to a considerable distance from the coast of 

 Florida ; and the correspondence of these measures is very remark* 



2 A 3 



