or BATABAICO. 187 



of the water is composed of broken pieces, cemented by 

 carbonate of lime, in which grains of quartzose sand are 

 set. Whether rocks formed by polypi still living are found 

 at great depth below this fragmentary rock of coral ; or 

 whether these polypi are raised on the Jura formation, are 

 questions which I am unable to answer. Pilots believe that 

 the sea diminishes in these latitudes, because they see the 

 chain of rocks augment and rise, either by the earth which 

 the waves heave up, or by successive agglutinations. It is 

 not impossible that the enlarging of the channel of Bahama, 

 by which the waters of the Gulf-stream issue, may cause, 

 in the lapse of ages, a slight lowering of the waters south 

 of Cuba, and especially in the gulf of Mexico, the centre of 

 the great current which runs along the shores of the United 

 States, and casts the fruits of tropical plants on the coast of 

 Norway.* The configuration of the coast, the direction, 

 the force, and the duration of certain winds and currents, 

 the changes which the barometric heights undergo through 

 the variable predominance of those winds, are causes, the 

 concurrence of which may alter, in a long space of time, 

 and in circumscribed limits of extent and height, the equi- 

 librium of the seas.f When the coast is so low, that the level 

 ot the soil, at a league within the island, does not change to 

 extent of a few inches, these swellings and diminution of 

 the waters strike the imagination of the inhabitants. 



The Cayo bonito (Pretty Rock), which we first visited, fully 

 merits its name from the richness of its vegetation. Every- 

 thing denotes that it has been long above the surface of the 

 ocean; and the central part of the Cayo is not more depressed 



* " The Gwlf-stream, between the Bahamas and Florida, is very little 

 wider than Beh ring's Strait ; and yet the water rushing through this 

 passage is of sufficient force and quantity to put the whole Northern 

 Atlantic in motion, and to make its influence be felt in the distant strait 

 of Gibraltar and on the more distant coast of Africa." (Quarterly Rev. 

 February, 1818.) 



f I do not pretend to explain, by the same causes, the great pheno. 

 mena of the coast of Sweden, where the sea has, on some points, the 

 appearance of a very unequal lowering of from three to five feet in one 

 hundred years. The great geologist, Leopold yon Buch, has imparted 

 new interest to these observations, by examining whether it be not rather 

 some parts of the continent of Scandinavia which insensibly heaves up. An 

 analogous supposition was entertained by the inhabitants of Dutch Guiana. 



