No. 161.] 
83 
by successive slides along the line of one of these springs, and in 
some instances, these valleys form the only places for roads to the 
beach. A great number of examples of these slides may be seen 
a little west of Petty's Bight, between Hudson's and Roanoke 
Points, and between Eastbrook and Swesey's landing. One of the 
most remarkable slides is at Fresh Pond creek. The land having 
thus slidden down within the reach of the surf, is carried away at 
high tides, and during storms, thus allowing new slides to take 
place in succession. The degradation of the land on this part of 
coast, on individual farms, is comparatively trifling, but in the ag- 
gregate, during a series of years, it is a matter of some moment. 
It is a loss that cannot be remedied, except at too great an ex- 
pense; but the loss is local, not general; for the materials washed 
away from one place are deposited in another, and as much land 
is probably recovered from the sea as is destroyed by it, 
Sand-Dunes. 
Sand-dunes are low hills of loose sand, which have been piled 
up by the wind like drifting snow heaps, and like them, are fre- 
quently changing their magnitude and position, so that, in some pla- 
ces, productive lands are buried by the moving materials, while in 
others they are uncovered by their removal. An instance was 
mentioned to me of land in Southampton having been inundated by 
sand, and after a lapse of about fifty years, it was uncovered by its 
drifting off. On sea-coasts and in some places in the interior of a 
country, the atmosphere is often clouded during high winds, with 
the lighter particles of drifting sand, while the heavier are rolled 
along on the surface. Every obstacle which creates an eddy cur- 
rent in the wind, as a rock, fence, bush or tree, causes a deposite of 
sand, which often serves as a nucleus of a hillock. The sand-banks, 
when first formed, present almost as much variety of outline and 
form as snow-drifts after a snow-storm. Examples were observed 
on the north shore of Long Island during the heavy winds of October, 
where heaps of drift sand, two or three feet deep, were formed in 
a few hours behind boulders and blocks of rock, which created eddy 
currents in the wind. Sand-banks several feet deep were observed 
in some of the ravines next the beach, that had been formed be- 
tween the time of the storm of the 12th, and the time observed on 
the 17 th October. A small pond near Horton's point, has been 
converted into a meadow by the drifting sand filling it up, within 
the remembrance of Mr. Horton, of Southold. 
