MAEINE GEOTTOES. 151 



may specially cite those of Finland, near Wasa, tliose in the en- 

 virons of Royan, on the right bank of the Gironde, and, above aU, 

 those of the Bahama Islands. In many of these islands, all the 

 wells, without exception, are regulated by the flow of the sea * 



There are even certain coasts opening so deeply into large hollows, 

 on the side towards the sea, that the waves penetrate to a great dis- 

 tance into the interior of the continent. A curious example of this 

 is seen in that part of Louisiana known under the name of the 

 Attakapas. There, the prairies of the coast, protected against the 

 tempests of the Gulf of Mexico by chains of sand-banks and long 

 islands parallel to the shore, incessantly gain upon the ocean. But 

 they are only solid on the surface, for their roots are bathed by the sea- 

 water, which advances far into a bay with invisible outlines. The 

 fishermen do not fear to venture on these floating meadows, resem- 

 bling fens in every respect, and it is by piercing the ground under- 

 neath their feet that they procure the fish hidden in these retreats. 



Nevertheless, such floating shores can only exist on a small num- 

 ber of coasts, where the physical circumstances are quite excep- 

 tional ; usually it is by grottoes and caverns hollowed out of the 

 solid rock that the waters of the ocean penetrate far into the land. 

 It is not to be doubted that there are below the level of the sea mul- 

 titudes of those rocky galleries, but only those are known that are 

 open to the strike of the waves, like the azure grotto of Capri. 

 Lower down, the water closes the entrance to the lateral caverns, 

 which will doubtless long remain unknown to us. But if we can- 

 not explore grottoes still filled by the sea, we can at least see on 

 elevated coasts like those of Scandinavia, immense caverns which the 

 waves once freely traversed. One of the most imposing grottoes in 

 the whole world is that which penetrates the splendid rock ot 

 Torghatten, rising like an enormous pyramid to more than 900 

 feet, on an island of northern Norway. This gallery, through 

 which seamen see the light glimmering, is of an astonishmg regu- 

 larity The thresholds of the immense portals, one of which has an 

 arch of nearly 234 feet and the other of nearly 144 feet span, are 

 found on each side to have the same elevation of 375 feet above the 

 level of the sea. The ground, covered with fine sand, is almost 

 level, and formed like the floor of a tunnel, where carriages might 

 roll The lateral walls present almost throughout a pohshed surlace, 

 as if they had been cut by the hand of man, and rise vertically to 

 the spring of the arch; only towards the centre of the grotto the 

 * R. Thomassy, Bulletin de la Societe de Geogra^lne, 1864. 



