Encroachnttnts of the Sea. 127 



lowing sketch, hastily taken, will give some idea of the aspect of the 

 northwestern part of this cliff, as seen by a person standing on the 

 beach below, close to the water — To exhibit it in perfection, the vari- 

 ous lively colors of the different kinds of clay should be put upon it. 



Oblique View of the Clay Cliffs at Gay Head. 



A similar bank of clay occurs at the Light House in Truro, near 

 the extremity of Cape Cod. It lies exposed to the unbroken fury of the 

 wide Atlantic, and the marks of slow encroachment upon the land 

 are quite manifest. Indeed, it is the prevailing opinion in that region, 

 that this Cape is wearing away along the whole extent of its eastern 

 extremity, and extending farther into Massachusetts Bay on the op- 

 posite side. I have no doubt that this is the case. For the general 

 current on that coast is towards the south. 



The same I presume is true of a considerable portion of the eastern 

 shore of Nantucket. From data, on which Lt. Prescott places con- 

 siderable confidence, he infers, that in one place, the loss of land with- 

 in half a century, has amounted to 3 or 4 rods in width. 



This advance of the ocean, however, must not all be imputed to the 

 action of currents. For when once a sand bank of considerable 

 height has been raised on the coast, the sea breezes will drive it 

 inwards farther than the land breezes will bring it back. This 

 inland march is quite obvious on Chatham Beach, in the situation 

 of a swamp, which, 50 years ago, was in the center of the beach ; 

 but now lies near the eastern shore ; the body of the sands having 

 moved farther west. A salt meadow formerly situated on the wes- 

 tern side of the beach, adjoining the old north passage into Chatham 



