254 SCIENTIFIC RECORD FOR 1884. 



HYDROGRAPHY. 



No new or striking developments have been shown by the hydro- 

 graphic work of the different Governments engaged in making and cor- 

 recting ocean and coast charts during 1884. 



The results of the investigations carried on by the United States 

 Coast Survey during past years in the depths of the sea off the North 

 Atlantic coast and in the Gulf of Mexico and its approaches, are re- 

 vealed in a striking manner by a model which shows the structural 

 features of the two great basins of the Gulf of Mexico and the Bay of 

 North America. This model, constructed under the direction of the 

 Superintendent at the Coast Survey office, presents also representations 

 in relief of the Bahamas, the West India islands, and the Bermudas, 

 and of parts of the continent. The name "Bay of North America" 

 was suggested by the Superintendent at the April meeting of the Na- 

 tional Academy of Sciences, 1884, to designate that great embayment of 

 the North Atlantic which lies west of the meridian of 60° longitude 

 west from Greenwich. 



The United States Fish Commission steamer Albatross, under com- 

 mand of Lieut. Commander Z. L. Tanner, U. S. N., has done a large 

 amount of valuable hydrographic work, in addition to her regular work 

 in connection with the fisheries. In January, 1884, while proceeding 

 from Norfolk to St. Thomas, West Indies, many soundings were made, 

 disproving the existence of the dangers to navigation called, respectively, 

 the Ashton, Perseveranza, and Mouraud Shoals. After leaving St. 

 Thomas, numerous lines of soundings were made to define exactly the 

 submariue ridge separating the Caribbean Sea and Atlantic Ocean, and 

 to ascertain the general contour of the bottom, proving at the same time 

 the non-existence of many vigias or shoals, the alleged existence of which 

 has for many years disfigured the charts. This valuable work was 

 continued until May, and data collected for wiping off many alleged 

 shoals from the charts, among others the Loos and Leighton Rocks, 

 off the south side of Santo Domingo ; Sancho Pardo Shoal, off Cape 

 San Antonio; the Ancona Breakers; and the La Vela Shoal. Aves 

 islet, 100 miles west of Guadeloupe, was found to be the summit of a 

 mountain extremely precipitous on its western slope and extending in a 

 SSE. direction over 150 miles to the 1000 fathom line. On many of the 

 alleged positions of shoals depths of over 2,000 fathoms were found, 

 the greatest depth being 3,169 fathoms, about 60 miles southwest of 

 the Grand Cayman Island, between the Misteriosa Bank and Thunder 

 Knoll. During 1884 the Albatross made 701 deep sea soundings, located 

 with such accuracy as to give them a hydrographic value. In January, 

 1885, many additional soundings were made by the Albatross in the 

 Gulf of Mexico. 



In a paper communicated to Science for January 30, 1885, Com- 

 mander Bartlett, U. S. N., gives an account of the various sounding 



