17G THE OCEAy. 



earth, were doubtless so many bays along the base of the hills of 

 Languedoc. Even since the historical epoch, these inland waters 

 have notably diminished in extent, and vast gulfs, changed into 

 marshes, to the great detriment of the public health, have poisoned 

 the atmosphere with their miasma. That which contributed most 

 actively to the diminution of the surface of the pools were the grans, or 

 passages by which the water of the sea brought in heaps of sand 

 during tempests. These openings, some temporary, and others per- 

 manent, but enlarging and diminishing by turns, and changing place, 

 now in one direction and now in another, do not cease to modify the 

 condition of the etangs and countries on the coast. Here they allow 

 masses of water to break through, which submerge the shores and ex- 

 cavate the soil, and elsewhere they are obstructed, and spread banks 

 of fetid mud as far as the eye can see before the villages of the coast. 

 In order to prevent for the future the transformation of the eiangs 

 into mud and marshes, M. Regy has proposed to replace the old tor- 

 tuous graxs by channels for drainage, which, during the fine weather, 

 allow the lacustrine waters and those of the sea to communicate 

 freely, but the sluices of which would be closed during storms. 



The lidi of Comacchio, as well as those of Venice, and of the ancient 

 city of Aquileia, restrict the basin of the Adriatic, which formerly 

 penetrated much further into the lands to the west and north-east. On 

 the southern coasts of Brazil and the Guinea coast, the littoral ridges 

 thus cut off considerable tracts from the ocean; but nowhere are 

 these levees of sand seen more numerously and batter developed than 

 around the Gulf of Mexico, and on the eastern coasts of the United 

 States. We may say that over a length of about 2500 miles the 

 outline of the American continent is formed of a double coast, the 

 one bathed by the sea and the other by the interior lagunes. In 

 front of the ancient coast, with its irregular indentations, the new 

 shore describes its graceful curves from promontory to promontory, 

 and not even allowing itself to be arrested by the mouths of the 

 rivers, stretches across the outlets in dangerous bars. 



Thus the indented coasts of North Carolina, and the ramified gulfs 

 which cut into these peninsulas, and are prolonged even into the in- 

 terior of the land, in the form of marshes, are masked on the 

 side next the sea by a natural bank nearly 220 miles long, against 

 which the most fearful waves of the northern Atlantic break. 

 These banks so gracefully curved are not constructed by the sea 

 alone. Thej^ are due also to the pressure of the fresh waters brought 

 from the Alleghanys by the iS'euse, the Tar, the Roanoke, and other 



