TOPOGRAPHY OF THE EASTERN COAST. 99 
ing from St. Christopher to Bird Island and about to the lati- 
tude of the Grenadines, showing considerably less than a thou- 
sand fathoms, with fifteen hundred to two thousand fathoms on 
each side. 
The eastern boundary of the Eastern Caribbean is formed by 
the dumb-bell shaped plateau, from which rise the Windward 
Islands. (Fig. 58.) These extend in a gigantic are from Som- 
brero and Santa Cruz to Grenada, Tobago, and Trinidad, leav- 
ing broad, shallow passages between the islands to the north 
of Dominica, with the three comparatively deeper straits sepa- 
rating Dominica, Martinique, St. Lucia, St. Vincent. We next 
come to the still shallower passages over the Grenadines Bank, 
and the deeper passage between that bank and Tobago. This 
island, as well as Trinidad, and all the Leeward Islands to the 
north of Venezuela, lie within the hundred-fathom line.' They 
are all only outposts of the South American continent. From 
the Gulf of Venezuela to. the mouth of the Orinoco the hun- 
dred-fathom line is about ninety to one hundred and twenty 
miles from the South American coast. 
The thousand-fathom line, which extends diagonally across 
the Eastern Caribbean from the south-western extremity of San 
Domingo to a point about one hundred miles north-west of 
Aspinwall, runs towards the Venezuelan coast, and follows the 
line of the hundred-fathom curve, with the exception of an 
indentation from the deep water, extending to the southward 
and eastward, between Curagoa and the mainland. It also 
follows closely the general trend of the south coast of San 
Domingo, Porto Rico, and bears to the west of the Windward 
Islands, being nowhere more than about forty miles from the 
coast-line, and. usually from ten to fifteen miles on the lee side 
of the Windward Islands to the south of Guadeloupe. 
Little is yet known of the depth of the main basin of the 
Eastern Caribbean ; but from the absence of islands and banks, 
it is probable that it is, like the Gulf of Mexico, a huge oval 
The * Albatross," in 1884, ran a line from ten to forty miles. — * Albatross,” 
from Curagoa to the mainland in a south- Hydrographie Report, 1884, J. R. Bart- 
erly direetion, the greatest depth found lett. 
being 738 fathoms at a distance ranging 
