172 



THE OCEAN, 



the opposite way in the direction from north-west to south-east; the 

 two contrary forces have left as witness to their strife this rampart of 

 sand and debris. 



The peninsulas of Cape Sepet, near Toulon, of Quiberon, in Brit- 

 tany, of Monte Argentaro, on the coasts of the Tyrrhenian Sea, and 

 others less known, have been united to the continent by similar con- 

 necting causeways analogous to those of Giens. There, too, the two 

 armies of waves which break in the midst of the strait have gradually 

 erected between them a double wall of separation, consisting of banks 

 of sand and shingle. There, too, the two semicircular jetties have 

 drawn nearer together in their central convexitj'', and the two trian- 

 gular spaces, which separated the respective extremities, have at first 

 been occupied by lagunes. In our days, most of the ponds, gradually 

 filled up by sand, have been transformed into marshes or covered by 

 dunes ; the two littoral ridges have been mingled in a single one. 

 Thus, the narrow isthmus of Chesil-Bank, which extends over a 



Fig. 74.— Peninsula of Cape Sepet. 



length of 16 miles, between the coast of England and the former 

 island of Portland, is composed of a single bank of shingle. In the 

 same manner, the two French islands of Miqueloh, near JSTewfound- 

 land, which were still separate from each other in 1783, have been 

 united since 1829 by a rampart of sand, which the waves of two op- 



