386 THE DEPTHS OF THE SEA. [CHAP. vin. 



23'3 C. at the beginning of December, while the 

 sea-water beyond the stream showed only 16*9 C. 

 Under north latitude 40 41 the water is, accord 

 ing to Humboldt, at 22'5 C. within, and 17'5 C. 

 without the stream." 1 



The Gulf-stream off the coast of North America 

 has been most carefully examined by the officers of 

 the United States Coast Survey, at first under the 

 superintendence of Professor Bache, and latterly 

 under the direction of the present able head of the 

 bureau, Professor Pierce. In 1860 Professor Bache 

 published an account of the general result. 2 Pour- 

 teen sections through the Gulf-stream had been care 

 fully surveyed at intervals of about 100 miles along 

 the coast the first almost within the Gulf of Mexico, 

 from Portingas to Havana, and the last off Cape 

 Cod, lat. 41 N., where the stream loses all parallel 

 ism with the American coast and trends to the east 

 ward. These sections fully illustrate the leading 

 phenomena during this earlier part of its course 

 of this wonderful current, which Professor Bache 

 well characterizes as " the great hydrographic feature 

 of the United States." 



Opposite Portingas, passing along the Cuban coast, 

 the stream is unbroken and the current feeble ; the 

 temperature at the surface is about 26'7 C. Issuing 

 from the Strait of Bernini the current is turned 

 nearly directly northwards by the form of the land ; 



1 Professor Buff, op. cit. p. 199. 



2 Lecture on the Gulf-stream, prepared at the request of the 

 American Association for the Advancement of Science, by A. D. Bache, 

 Superintendent U.S. Coast Survey. From the American Journal of 

 Science and Arts, vol. xxx. November 1860. 



