•28 THE BOTTOM OF THE SEA. 



and fourth from 3000 to 4000 fathoms. Any greater 

 depth is indicated by the blanks. On referring iu 

 the chart (fig. 8j, it will be seen that a depth ex- 

 ceeding 4000 fathoms is thus marked between New- 

 foundland and the Bermuda Islands, in the track of 

 the Gulf Stream. The plummet there descends to 

 a depth of about 5000 fathoms, or nearly 30,000 feet. 

 Westward of the Canary Islands is another deep point, 

 the indication of the plummet being about 24,300 feet. 



A marked region of this ocean-bed, having a depth 

 which varies from about 3000 to 4000 fathoms, ex- 

 tenfls from the south of Newfoundland, rounds the 

 Bermudas, and follows very nearly the direction of 

 the American coast to the extreme latitude of Florida. 

 It then winds south-east, keeping a certain distance 

 from the Antilles, and terminating near the north- 

 eastern extremity of that archipelago. 



A second remarkable trough, separated from the 

 last-mentioned by a submarine chain of mountains, 

 extends like a long gutter from the north-west to the 

 south-east, even beyond the equator. It is nearer to 

 the Brazilian than to the African coast. 



Throughout these regions, which are the deepest in 

 the Atlantic Ocean, the bottom exhibits great irregu- 

 larity. The gulf deepens rapidly from the coast of 

 America and the Antilles, but slopes gently from 

 Europe and Africa. We observe, in fact, that the 



