10 BERTHA'S VISIT TO HER 



times find my head too unsteady to be able to 

 write. 



16th. We have seen a great deal of sea-weed 

 for some days*; they suppose it to be drifted 

 here by the Gulf-stream. I asked the captain 

 to explain to me what the Gulf-stream is ; and 

 he told me that the trade-wind, which constantly 

 blows across the Atlantic ocean from the east- 

 ward, forces the sea into the Gulf of Mexico, 

 and makes it rise there above its natural level. 

 From the Gulf it escapes by the narrow channel 

 between the West India islands and Florida, and 

 takes a north-easterly direction along the coast 

 of North America, as far as the island of New- 

 foundland. It is there turned off to the south- 

 east, and runs to the Azores, or perhaps to the 

 coasts of Europe and Africa, before it spreads 

 out and entirely loses itself in the surrounding 

 ocean. The first accurate account of this great 

 current was published by Dr. Franklin, who had 

 discovered that, after being heated in the torrid 

 zone, it cools so gradually that its temperature 

 continues always higher than that of the ocean 

 through which it flows so much so, that ships 

 can tell when they enter it or leave it, by dipping 

 a thermometer into the sea, Its velocity is very 

 great, as it is said to run at the rate of four 

 or five miles an hour, when it first leaves the 

 Gulf. 



