AGASSIZ: BERMUDAS. 211 



bounded on the north by a chain of islands of which St. David is the 

 most prominent, and on the east by a chain of smaller islands, the con- 

 tinuation of the spit east of Tuckerstown, which is the easternmost point 

 of the main island. Outside of Castle Harbor on the north extends 

 a chain of islands which bound St. George Harbor, the largest of 

 which is St. George Island. Endless islets and rocks flank the south 

 shore from Tuckerstown to Church Bay, where tlie main island makes 

 a sweep to the southwest as far as Wreck Hill. It is separated by a 

 narrow chamiel from Somerset Island, to the northward. 



From Somerset Xarrows a chain of small islands extends to the north- 

 east, on the last of which is built the dockyard. The north shore of the 

 main island is flanked by numerous islands, which form Hamilton 

 Harbor, Port Royal Bay, Great Sound, and the connecting waters to 

 the westward of Spanish Point (Plate III.). At tlie eastern end of tlie 

 main island a narrow channel opens into Little or Harrington Sound, 

 which covers the greater part of that end of the island. The position 

 of the former Bermudian land is indicated by isolated rocks, like North 

 Rock (Plate VIII.), the Pilchard Dicks, the Southwest Breaker, the 

 South Reef, the Mills and Northeast Breakers, and others rising above 

 the general level 6i the broad belt of ledge flats which completely sur- 

 round the summit of the Bermuda mountain. These flats leave only 

 here and there a narrow passage into the interior sounds, bounded by 

 the many belts of flats crossing the inner waters. The principal passages 

 are the Narrows, or Ship Channel, Hog Fish Cut, Chub Cut, North 

 Rock, and Mills Breaker channels, in addition to a few insignificant boat 

 passages. The Narrows is really the only channel navigable for heavy 

 draught vessels. 



The Lagoon, lying to the northward and northwestward of the 

 islands, is bounded by the curve of the outer ledge flats. They are sub- 

 merged at low water, except at a few points such as the North Rock, 

 Mills Breaker, Southwest Breaker, and others marked on the , chart 

 (Plate I.). The depth of the Lagoon is in general from seven to nine 

 fatlioms, though a few of the deeper points are twelve or thirteen 

 fathoms. Between the outer ledge flats and the islands are found the 

 many secondary flats, called Elies Flat, Cowground Flat, Brackish Pond 

 Flats, Green Flats, Bailey Bay Flats, Three Hill Shoals, and the like, 

 which consist of endless patches of ]\Iillepores and Gorgonians, reaching 

 many of them to within a few inches of the surface. The Gorgonians 

 and Algae which cover the patches have grown upon the remnants of 

 ledges of the proto-Bermudian land that attest to its former existence 



