112 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



THE OCEAN.* 



DEPTH. 



Under the direction of Dr. Patterson, Superintendent of the 

 U. S. Coast Survey, the work of deep-sea soundings, the ob- 

 servations for serial temperatures from surface to bottom, 

 current observations, and deep-sea dredgings in the Gulf of 

 Mexico and the Yucatan and Florida channels have been 

 continued this year by the steamer Blake, Lieutenant-Com- 

 mander C. D. Sigsbee, U.S.N., Assistant Coast Survey, com- 

 manding, associated with Professor Alexander Agassiz, who 

 directed the dredgings. The apparatus for deep-sea sound- 

 ings with wire, and for securing bottom and water specimens, 

 have been brought to a high state of perfection by Com- 

 mander Sigsbee ; and such improvements have been made in 

 the dredges and trawls as to insure success, where all previ- 

 ous efforts have failed, notably when dredging in soft muddy 

 bottoms. The formation of the bottom of the Gulf of Mexico 

 has been completely mapped out. Serial temperatures, with 

 specimens of the bottom, and of water from various depths 

 from surface to bottom, have been obtained in all parts of 

 the Gulf and of its immediate approaches, thus adding enor- 

 mously to the data for solving the problem of its circulation, 

 with those of the entrance and exit of the Gulf Stream. The 

 greatest depth found was 2080 fathoms. The name of Sigs- 

 bee Deep lias been given to a large basin to the northward 

 and westward of the Yucatan Bank, lying within the 2000- 

 fathom curve, and extending from lat. 22 30' to lat. 25 N., 

 and from long. 90 to long. 95 W. The increase of depth 

 is very abrupt on the slope of the Yucatan Bank, but much 

 more gradual towards the coasts of the United States and 

 of Mexico. 



During the months of December, 1811, and January and 

 February, 1878, a line of deep-sea soundings was run by the 

 U. S. steamer ^se, Commander W.Scott Schley commanding, 

 between St. Paul de Loando, Africa, and Cape Frio, Brazil, 

 via St. Helena, and passing just to the southward of Trinidad 

 Island. The soundings were made with wire, using Captain 



Prepared with the assistance of Commander E. P. Lull, U.S.N. 



