466 
COAST DUNES. 
waslied coasts of seas with sandy bottoms, there exist several 
conditions favorable to the formation of sand deposits along 
high-water mark.* If the land winds are of greater fre- 
* There are various reasons why the formation of dunes is confined to 
low shores, and this law is so universal, that when bluffs are surmounted 
by them, there is always cause to suspect upheaval, or the removal of a 
sloping beach in front of the bluff, after the dunes were formed. Bold 
shores are usually without a sufficient beach for the accumulation of large 
deposits; they are commonly washed by a sea too deep to bring u'p sand 
from its bottom; their abrupt elevation, even if moderate in amount, 
would still be too great to allow ordinary winds to lift the sand above 
them; and their influence in deadening the wind which blows toward 
them would even more effectually prevent the raising of sand from the 
beach at their foot. 
Forchhammer, describing the coast of Jutland, says that, in high winds, 
“ one can hardly stand upon the dunes, except when they are near the 
water line and have been cut down perpendicularly by the waves. Then 
the wind is little or not at all felt—a fact of experience very common on 
our coasts, observed on all the steep shore bluffs of two hundred feet in 
height, and, in the Faroe Islands, on precipices two thousand feet high. In 
heavy gales in those islands, the cattle fly to the very edge of the cliffs for 
shelter, and frequently fall over. The wind, impinging against the vertical 
wall, creates an ascending current which shoots somewhat past the crest 
of the rock, and thus the observer or the animal is protected against the 
tempest by a barrier of air.”— Leonhard und Bronx, Jahrbuch , 1841, p. 8. 
The calming, or rather diversion, of the wind by cliffs extends to a con¬ 
siderable distance in front of them, and no wind would have sufficient 
force to raise the sand vertically, parallel to the face of a bluff, even to the 
height of twenty feet. 
It is very commonly believed that it is impossible to grow forest trees 
. on sea-shore bluffs, or points much exposed to strong winds. The obser¬ 
vations just cited tend to show that it would not be difficult to protect trees 
from the mechanical effect of the wind, by screens much lower than the 
height to which they are expected to grow. Recent experiments confirm 
this, and it is found that, though the outer row or rows may suffer from 
the wind, every tree shelters a taller one behind it. Extensive groves have 
thus been formed in situations where an isolated tree would not grow at all. 
Piper, in his Trees of America, p. 19, gives an interesting account of Mr. 
Tudor’s success in planting trees on the bleak and barren shore of Nahant. 
“Mr. Tudor,” observes he, “has planted more than ten thousand trees at 
Nahant, and, by the results of his experiments, has fully demonstrated that 
trees, properly cared for in the beginning, may be made to grow up to the 
