TEMPERATURES. 



233 



(Figs. 160, 161), and in 1853 off Cape Canaveral (Fig. 162), off 

 St. Simon's Island, Ga. (Fig. 163), and off Charleston, S. C, by 

 Lieutenant - Commanders Craven and Maffitt. These sections 



Fig. 159. 



show that the temperatures of the line across the Gulf Stream 

 from Gun Key are, as a whole, colder than those at the above- 

 named points. 



We seem here to have positive proof that the large body of 



Fig. 160. 



Fig. 161. 



warm water to the north of the straits adjoining the colder 

 water of the Gulf Stream must mainly derive its heat from the 

 equatorial current itself, and that it does not come wholly from 

 the superheated water of the Gulf of Mexico. Some of the 



