270 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



tween the Leeward Islands and the main, and diagonal lines on and oif 

 the coast of the United States of Colombia. The eastern part of the 

 Caribbean Sea is the deepest ; the greatest depth was 2,844 fathoms, in 

 latitude 13° 25', longitude 66° 25'. Still deeper water, however, was 

 found off the Honduras coast, there being 3,169 fathoms GO miles SW. 

 of the Grand Cayman. 



One interesting discovery was that of a submarine ridge connecting 

 the islands of Santa Cruz and Porto Rico, the least depth on which was 

 578 fathoms and the greatest 900, while on either side was found over 

 2,000 fathoms. 



Aves Islet, 100 miles westward of Guadaloupe, 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 1.000 fathom curve. 



All these features are shown in a plaster cast of the West Indies and 

 Caribbean Sea, made at the Hydrographie Office, Navy Department. 



The longitude of Cape San Antonio lighthouse, west end of Cuba, 

 Mas determined by sextant observations, the longitude being carried 

 by five chronometers from Key West, Fla., and depending on that of 

 the Soldiers' Monument, being 81° 48' 25" W. 



The general results of the study of the currents are as follows : 



The general surface drift in the Caribbean Sea is to the westward, 

 being much the stronger in the eastern part, where as much as 3 knots 

 was found off (northward of) the Leeward Isles. The tidal influences 

 at Grenada Island unquestionably extend GO miles to the westward, 

 and near the shores of Santo Domingo and Jamaica there are many 

 eddies, &c, that may be somewhat tidal. The direction and strength 

 of the wind have an influence upon the exact set of the stream : but it is 

 noticeable that iu the eastern portion of the Caribbean Sea the set is 

 generally to the southward of west iu the northern part, and to the 

 northward of west in the southern part. For 200 or 300 miles west- 

 ward of the Gulf of Paria the current ran 2 to 3 knots to about NW. by 

 \V\, in spite of a NE. breeze. 



In the broad channel between Yucatan and Honduras in the west and 

 Cuba and Jamaica iu the east the currents are extremely erratic. The 

 amount of northwesterly drift in twenty-four hours was found generally 

 to tally with what vessels have usually experienced there; but during 

 individual hours or portions cf a day there were remarkable fluctuations 

 noted. In one'instance the current was to WNW. 2i knots at one time; 

 in less than two hours it was setting feebly eastward, and again in two 

 hours more to SW., and so on. This may be caused by the extraordinary 

 variations in the depth, nearly 3,200 fathoms being found 75 miles east- 

 ward of Swan Islet (GO feet high), 3,000 fathoms at 40 miles southeast- 

 ward of Misteriosa Bank (10 fathoms), and so on. 



During the summer and autumn of 1884 the soundings taken by the 

 Albatross were off the coast between Hatteras and Nantucket, in vari- 

 ous depths up to 2,700 fathoms. Nothing was found of special hydro- 

 graphic value. 



