No. 2. — Reports on the Bcaults of Dredging, under the Supervision 

 of Alexander Agassiz, along the Atlantic Coast of the United 

 States, during the Summer of 1880, bi/ the U. S. Coast Survey 

 Steamer ''Blake" COMMANDER J. E. Bartlett, U. S. K, Com- 

 manding. 



(Published by permission of Carlile P. Patterson and J. E. Hilgakd, Super- 

 intendents of the U. S. Coast and Geodetic Survey.) 



XXII. 



A Chapter in the History of the Gulf Stream. By Alexander 



Agassiz. 



The soundings of the "Blake" during the dredging season of 1880 

 developed some striking features in the profile of the slope extending 

 eastward from the shore along the Atlantic coast, south of Cape Hat- 

 teras to the northern extremity of Florida. The soundings previously 

 taken in deep water between the northern extremity of the Bahair^as 

 and Cape Hatteras varied greatly, and but little reliance could be placed, 

 upon them. The few lines run in 1880 normal to the coast, and the 

 line run pai-allel to the so-called axis of the Gulf Stream, showed the 

 probable existence of an immense submarine plateau extending eastward, 

 from the Atlantic shores. Either the eastern edge of this plateau was 

 not reached in 1880, or else the soundings indicated a very gradual 

 slope from the shore to deep water along the whole coast line south of 

 Cape Hatteras as far as the northern part of Florida. 



Everywhere else along the Atlantic coast of the United States, north 

 of Cape Hatteras and in the Gulf of Mexico, the continental line of one 

 hundred fathoms is most plainly marked, forming the upper edge of 

 the more or less abrupt descent leading into deep water with a regular 

 hiclination. Owing to the absence of this hundred-fathom line south 

 of Cape Hatteras, it became an interesting problem to trace the exact 

 profile of that part of the coast, and to extend it into deep water. The 

 season of 1881 was spent by Commander Bartlett in the "Blake," 

 under the direction of the Hon. Carlile P. Patterson, the late Superin- 



VOL. XI. — NO. 2. 



