744 THE POPULAR SCIENCE MONTHLY. 



sand — the wear of the shore would be arrested and the yearly en- 

 croachments of the ocean would cease. 



With regard to the inundation of Atlantic City by the sea in 

 the great September storm of 1889 it should be said that this 

 catastrophe ought not to be considered very wonderful, since the 

 greater portion of the city is less than ten feet above mean tide, 

 and the highest point recorded by the New Jersey State Survey 

 is only thirteen feet above that level. As ordinary tides rise a 

 foot above this plane, and spring tides nearly two feet, it is evi- 

 dent that a prolonged easterly storm would soon cause a consider- 

 able area to be overflowed. Since the bays and channels which 

 lie between the beach and the mainland are almost completely 

 landlocked and the inlets are relatively narrow, the water-level is 

 soon raised to a height of two or three feet above the meadows, 

 and this is sufficient to cover most of the railroad tracks. To be 

 sure, no such inundation as the recent one has occurred since At- 

 lantic City became a place of importance, nor do the old residents 

 on the coast remember such a storm in former years ; but it is 

 evident that, while the beaches were uninhabited, such a storm as 

 the one in question would attract less attention, since it would 

 cause little if any loss of property. 



The genesis of the beaches is still a matter for speculation, but 

 it may be safely affirmed that they originated as sand-bars, formed 

 under water by wave and current action. How these bars were 

 brought above water, so that the wind could exert its constructive 

 power, is uncertain. A plausible hypothesis is, that while the 

 ocean was breaking on the mainland shore and forming the 

 Quaternary terraces, which may be seen there, sand-bars were 

 made under water, and that the continental elevation which raised 

 these terraces to their present position from twenty-five to eighty 

 feet above tide, brought these sand-bars above water into a hori- 

 zon of ^Eolian action. Once above the sea, the beaches would 

 maintain their existence. A continued elevation of the coast 

 would add to their seaward extent and a depression would cause 

 a westward recession until they were brought to rest by contact 

 with the mainland shore. In New Jersey the latter condition 

 may be observed between Long Branch and Point Pleasant and 

 also at Cape May. 



So far as it is known to the writer, the only way in which a 

 beach can be entirely destroyed is by an inlet shifting its position. 

 In this case the beach obliterated is replaced by the extension of 

 an adjacent beach. 



Of the beaches south of New Jersey not enough is known to the 

 writer to permit of a detailed biographical sketch. Their form and 

 structure show that they have been subject to the same formative 

 agencies and vicissitudes as those already described. In addition 



