74 2 THE POPULAR SCIENCE MONTHLY. 



a stone sea-wall, the rate of encroachment varying from ten to 

 thirty feet a year. 



Besides these alterations produced in the beaches by their 

 westward progress, the variations in the positions of the inlets 

 and the subsidence of the coast have caused many important 

 changes. The history of the Shrewsbury Inlets has already been 

 given ; it remains to mention a few of those south of Point 

 Pleasant. 



Squan and Island Beaches, which now form a peninsula about 

 twenty miles long, terminating at Barnegat Inlet, were separated 

 from 1750 to 1812 by Cranberry Inlet, which was nearly opposite 

 the mouth of Tom's River. Since 1812 near the site of this old 

 inlet there have been others of brief duration, and one is said 

 to have existed before 1755 opposite the mouth of the Metede- 

 conk River, which separated Squan Beach from the mainland. 



The old Barnegat Lighthouse is said to have stood nearly six 

 hundred yards north of the present south shore of the inlet, at a 

 point now occupied by the center of the channel. In 1855 the 

 old tower was at the water's edge, so that the inlet has moved 

 southward approximately twenty yards per year. 



Absecon Inlet, which separates Brigantine Beach from Abse- 

 con Beach, has encroached upon the latter about four hundred 

 yards in twenty years ; and the ocean front of that portion of Ab- 

 secon Beach which is occupied by Atlantic City extended in 1855 

 nearly half a mile farther east than it did in 1885. About 1875 

 jetties were built which arrested the action of the tidal currents, 

 and, the wear of the shore being thus prevented, a considerable 

 area was restored. 



Submerged tree-stumps and other evidences of a subsidence of 

 the coast may be found on the beaches and the salt meadows, but 

 a detailed enumeration of them would be beyond the scope of the 

 present article. 



In Cape May County the depression has not been less than 

 twenty feet, and has possibly been much greater. The evidence 

 of some old buildings on the shore of Delaware Bay suggests a 

 subsidence of about four feet during the last two centuries. 



It is doubtful whether depression alone has caused the wear of 

 the coast. A comparison of the present outline of Holly Beach 

 with that determined by a survey in 1772 shows an accretion on 

 the south and east, since the latter date, more than three and a 

 half miles long and averaging three eighths of a mile in width, 

 and on many other beaches a similar growth has taken place. 

 During the past five years the ocean has rapidly encroached upon 

 these beaches, while the subsidence of the coast, so far as we 

 know, has been uniform throughout the past two centuries. It 

 would appear, therefore, that the growth and decay of the beaches 



