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Subsidence along the Sea-coast of New Jei^sey. 351 



" The marshes of the Bay of Fundj are known to have ex- 

 isted at or about their present level for 250 years. It is true that 

 an opinion prevails in some of the marsh-districts that the tides 

 now rise higher than formerly, and in jDroof it is alleged that the 

 dykes are now maintained with greater difficulty, and that tracts 

 of marsh once dyked have been abandoned. The settling of the 

 mud and the narrowing of the tidal channels by new embank- 

 ments may however have produced these effects. For the an- 

 tiquity of these submerged forests we must therefore add to the 

 two centuries and a half which have elapsed since the European 

 occupation of the country, a sufficient time for the deposition of 

 the alluvium of the marshes. On the other hand the state of 

 preservation of the wood^ after making every allowance for the 

 preservative effects of the salt mud, shows that its growth and 

 submergence must belong to the later part of the modern 

 period." 



From the pilots who go out of New York harbor I have not 

 been able to learn that they have observed much variation in the 

 depth of water in the channel, but they say that they probably 

 should not notice it. The report of the Harbor Commissioners 

 shows that local causes are in operation which affect the harbor 

 of New York much more than this regular and slow one. Two 

 intelligent pilots who go out of the Raritan Eiver inform me that 

 there is a greater depth of water in that river than there was 

 thirty years ago. 



After examining all I have been able to find written upon the 

 subject, and after studying it in the field, I can think of no other 

 theory which will apply to all the facts except that of a slow and 

 continued subsidence of the land. 



The rapid wear of the shores may fairly be adduced as con- 

 firming my conclusions in regard to subsidence. A few cases of 

 this rapid wear may be given. Egg Island, a point well known 

 to those who are familiar with Delaware Bay, is put down on 

 the first map made by the proprietors of AVest Jersey in 1694 

 as containing three-hundred acres of land. It now contains only 

 about three-fourths of an acre at low water, and high tides cover 

 3t entirely. I am assured by a surveyor* who has long been en- 

 gaged in his business, and has traced out many old lines which 

 formerly terminated on the shore, that the wear of the salt marsh 

 along Maurice Eiver Cove since the fii^t settlement of the conn- 

 ^^y, is not less than three-fourths of a mile. At the mouth of 

 I>ennis Creek the w^ear is very great — forty rods have been worn 

 off in three years, — and boatmen there tell me that the distance 

 from Dennisville to the Bay is less by a mile than it was when 

 they first knew the creek. At Town Bank the upland comes 

 out to the shore in a bold bank from fifteen to twenty feet high. 



* James L. Smith, Esq. 



