18 PHYSIOGRAPHY AND GEOLOGY 



turn are being planed down to submarine banks. (Plate II, Pig. 1, and Plate 

 III.) In fact, the entire archipelago as it exists to-day is only a fraction of 

 what it must have been in times gone by. 



It must be remembered that the Bahama Islands are honey-combed with 

 caverns and that these cavities give the waves an excellent chance to attack and 

 tear the rock asunder. Evidences of this are seen on every hand. From the 

 shore where precipitous bluffs come down to meet the waves, the former 

 frequently contain huge caverns which have been carved out by the waves as 

 they have enlarged smaller openings which originally occurred in the rocks. 

 These are of very common occurrence along the sea-shore but " The Caves " 

 (Plate IX, Fig. 3), seven miles west of Nassau, furnishes as good an example 

 as any and at the same time is within easy reach. This cavern has been 

 excavated in the face of an ancient sea-cliff which now stands two hundred 

 feet or more back from the shore and iive or ten feet above sea level. It is 

 about 35 feet deep by 30 high, and leads into the heart of a hill in the rear. 

 This cave probably existed first as a subterranean cavern, which was broken 

 into and enlarged by the waves when the island stood somewhat lower than 

 to-day. The cutting of the sea^cliff and the enlarging of the cavern was carried 

 on at one and the same time. Glass Window, Eleuthera and Hole-in-the-Wall 

 near Elbow Cay, Abaco, are other instances of wave work in original sub- 

 terranean caverns. In these latter cases, however, the caverns have been 

 eroded at both ends, leaving only a thin section in the middle. These elevated 

 sea-cliffs, j cut by an ancient erosion, are not uncommon in the Bahamas. 

 Another good example of them beside one already mentioned, occurs on the 

 east side of Andros just south of Morgans Bluffs. The topography indicates 

 that they were cut by the waves and their position shows that the surface of 

 the Islands stood 5 or 10 feet lower than now. 



In the introduction of this chapter it was stated that the Bahama Islands 

 were located in the midst of the hurricane area of the West Indies. This fact 

 will be more fully appreciated by an examination of Plates XVIII-XXIV, 

 which show the tracks of hurricanes in the Bahamas since 1878. During 

 ordinary storms the waves from the. Atlantic roll in unchecked to break on the 

 unprotected shores of the Bahamas, but these breakers are as nothing com- 

 pared to the tremendous seas which are hurled against the Islands during 

 hurricanes. In many places, particularly along exposed shores, immense 

 blocks of limestone have been heaped into huge piles well up on the shore 

 beyond the reach of the ordinary storm breakers. A typical example of this 



