1888.] 521 [Fewkes. 



shapes showing everywhere the inroads which the sea is making on 

 the soft aeolian limestones of the islands. 



It seems to me not a great mistake to compare the large lagoons 

 or sounds with similar, though small productions of this erosive 

 power of the water everywhere visible throughout these islands. 

 There is no reason known to me why we should limit the power of 

 erosion to caverns of a few hundred feet in size, and not accept the 

 undoubted truth that these smaller basins are due to this force 

 while the larger sounds arose by subsidence. There is nothing but 

 size which distinguishes Castle Harbor from a cavern, the roof of 

 which has fallen and been washed away ; both are thought to belong 

 in the same category and were probably formed in the same way. 



The lofty cliffs bordering a part of Harrington's Sound show that 

 its wall has suffered great erosion. If the cliff is extended to its 

 original size before this erosion, it would very much reduce the 

 size of the sound itself. The presence of islands in Harrington's 

 Sound with cliffs of some altitude also indicates extensive erosion. 

 If these were restored to their original extent, the size of the sound 

 would be very greatly limited. 



One great objection which might be urged against regarding the 

 sounds of the Bermudas as due to the falling in of caves, due to 

 erosion of the sea, is the fact that there are so few islands in them, 

 or such small remnants of their former supports. When we re- 

 flect, however, that the erosion of the water possibly went deep into 

 the submarine rocks, the depth of the eroded portion might be great 

 enough to submerge a large part of the roof after it had fallen. 



Why, it may be asked, are some of these sounds, as for instance, 

 Castle Harbor and Harrington's Sound, separated by a narrow 

 stretch of land, and why is Hamilton's Sound shut off from the sea 

 b} 7, such a narrow strip of soft limestone? It would seem as if both 

 these barriers would have long ago disappeared under the same 

 forces which formed the sounds, and as if instead of a basin, par- 

 tially enclosed, we ought to find a simple wearing away of the coast 

 lines into deep bays and gulfs. While the contiguity of two sounds 

 as Harrington's Sound and Castle Harbor, and the separation of 

 either from the ocean by the narrow strips of land, would seem 

 effectually to discredit a belief that they were formed by erosion, 

 it is possible to ascribe the arrangement to a secondaiy condition. 



While many might accept the theory that the sounds of Bermuda 

 are due in part to erosion rather than to submergence, others would 

 find difficulty in the acceptation of the theory as far as the whole 



