106 A. EF. Verrill—The Bermuda Islands; Geology. 
natural bridge across part of it (fig. 14), on Cooper’s Island, was 
probably also an underground passage. Basset’s cave on Somerset 
Island, said to be over a mile long, but without stalactites, appears to 
have been another large passage-way for a stream, and there are 
many others. 
Figure 14.—Chasm and natural bridge on Cooper’s Island. This appears to 
have been an ancient underground water-way, now partly submerged, from 
which the roof has mostly fallen. 
- The small size of the present islands and the porous and cavernous 
nature of the rocks preclude the formation of streams with the 
existing amount of rainfall. 
A certain amount of solvent action on the shore limestones and 
exposed reefs is also effected by the salt spray that dashes over them. 
This action extends considerably above high-water mark in exposed 
places. It results in eroding the limestone into a very rough, pitted, 
or honeycombed surface, coarse or fine. The intervening spaces run 
up into sharp edges and jagged points, and the whole surface 
becomes hard from secondary infiltration with calcium carbonate.* 
D. Erosion by the waves. 
This subject has been repeatedly referred to in the previous pages. 
A brief description will be given, in this place, of the various phases, 
or at least some of the more important ones, of the subject. 
* See figures 8, 9, 10, 15, 18, and pl. xxii, figs. 1, 2; also pp. 66, 67. 
