20 
GEOLOGY OF THE FIRST DISTRICT. 
some distance from the shore, has disappeared in several places by the falling of the cliffs. 
There are no data by which to estimate the inroads of the sea on this coast. 
From Nepeague beach to two miles west of Southampton, the south coast of Long Island 
is protected by a broad and slightly inclined sand beach, which breaks the force of the surf 
as it rolls in from the ocean. From Southampton, westward, the coast of the island is pro¬ 
tected by long narrow alluvial islands, from one mile to five or six distant from the main island. 
Some parts of the north shore of the south branch of the island, from Montauk point 
towards Sag harbor, are washing away, but not so rapidly as on the south side of this branch 
of the island. 
The eastern parts of Gardiner’s and Plum islands, which are composed of loose materials, 
are washing away in consequence of the very strong tidal currents and the heavy sea rolling 
in upon their shores from the open ocean. The action upon these coasts is so rapid as to 
attract the attention of the inhabitants ; and calculations even have been made, as to the time 
that will probably elapse before they will have disappeared. Rocks (boulders) that have 
formed a part of Plum island, may now be observed at low water, a mile or more from the 
present shore. Little Gull island, on which a light-house is located, was disappearing so 
rapidly a few years ago, that it became necessary to protect it from the farther inroads of the 
ocean by encircling it with a strong sea wall. Oyster-pond point is wearing away rapidly by 
the combined action of the waves during the heavy northeast storms, and the strong tidal cur¬ 
rent that flows with great velocity through Plum gut. A small redoubt about a quarter of a 
mile west of the point, is nearly washed away; and Mr. Latham, the owner of the farm, says, 
that several rods in width have disappeared since his remembrance. During the heavy storm 
of October 12, 1836, the sea made a clear breach over about a quarter of a mile of the eastern 
part of the point, washed away all the light and fine materials, and cut a shallow channel 
through which the tide has since flowed. The effects of this storm were very marked on the 
shores of Long Island, and particularly on the north coast. The cliffs were undermined, and 
crumbled or slid dowu, exposing the geological structure, and presenting beautiful coast sec¬ 
tions of the strata. 
The importance of a thorough understanding of the causes now in action that serve to shoal 
water, and wash away the land or shift the position of the deposits, by the engineer engaged 
in the construction of public works, such as breakwaters, piers, fortifications, etc., and even 
the location of towns and cities, is obvious to all, and yet they are but little studied. 
Coney island, which is mostly alluvial, is rapidly washing away on its south side, where 
it is exposed to the full force of the ocean swell. A new direction given to the tidal currents 
by some recently formed bar, is probably the cause. Mr. John Wyckoff, who lives near the 
Ocean House, remarked that the sandy part of the island was a mile broad, not many years 
ago, though now it is not more than half that breadth. He informed me that every storm 
made a sensible difference, and that some years ago the sand-hills south of the Ocean House 
were covered with small pines and bushes ; and that in a single night, during a violent storm, 
the trees and bushes, and much of the earth, were washed away. 
