100 THREE CRUISES OF THE " BLAKE." 



basin, in the north-eastern parts of which a depth of over 2,500 

 fathoms has been obtained. The only line yet run directly 

 across the main basin of the Eastern Caribbean has been 

 sounded by the " Albatross " from Curagoa to Alta Vela, a 

 small island on the south coast of San Domingo. The deepest 

 water found was 2,694 fathoms, — the average depth nearer 

 the South American side of the basin being about 2,300 fathoms 

 until within a short distance of the land. 



The topography of the Western Caribbean is strikingly dif- 

 ferent from that of the eastern basin. The soundino-s of Com- 

 mander Bartlett have developed an immense submarine valley, 

 extending nearly due east for about seven hundred miles, from 

 the southern extremity of Cuba towards the Chinchorro Bank, 

 off the coast of Honduras. This valley has an average breadth 

 of about eighty miles, and an average depth of over two thou- 

 sand fathoms. Towards its eastern extremity it attains the 

 depth of nearly 3,200 fathoms, and its greatest depth is 3,428 

 fathoms twenty miles south of Grand Cayman. So that the 

 highest peaks of the chain of mountains skirting the southern 

 shore of Cuba, which rise to 8,400 feet, are really 28,000 feet 

 above the bottom of this great submarine valley, distant only 

 fifty miles in a straight line. As Commander Bartlett has said, 

 the little Cayman, Grand Cayman, and Misteriosa banks are 

 the summits, just appearing above tide-mark, of a submarine 

 range of an average height of nearly twenty thousand feet. 

 This deep valley, which has most appropriately been called 

 "Bartlett Deep," forms a loop to the eastward of Cozumel 

 Island, south of Pine Island towards the Pickle Bank. To- 

 wards the Yucatan Channel, which connects the Western Carib- 

 bean with the Gulf of Mexico, the bottom shelves gradually, 

 rising to a height of 1,164 fathoms, — the deepest part of the 

 channel between Yucatan and Cape San Antonio. The West- 

 ern Caribbean connects with the deep tongue of the Atlantic, 

 reaching north of San Domingo through the Windward Passage, 

 the deepest part of which is 873 fathoms. 



We could have no better example than the Gulf of Mexico 

 affords of the deceptive character of the shore-line for obtain- 

 ing a correct idea of a hydrographic basin. (Fig. 59.) This is 



