152 A, FE. Verrill—The Bermuda Islands; Geology. 
then, as at Shelly Bay, skirted the coast. In doing so they cut 
through the natural protections given by the sea-shrubs and creepers 
which usually abound in such places. From that day the sand, 
supported by constant supplies from the sea, has steadily proceeded 
up the hill to the very summit, a height of 180 feet. It is, however, 
surprising to observe the singular state of arrest under which the 
invader stands before the children of the soil. A few straggling 
cedars, widely scattered in advance of the wood which now bounds 
the space, have been passed by this sand flood, yet the dazzling, dry, 
and almost snow-white sand is checked, before the front rank of the 
Figure 44a.—Drifting sand, or advancing ‘‘sand glacier,” at Elbow Bay, about 
1875. After Thomson. 
trees, in a steep bank, varying from ten to twenty five feet in height, 
and so remarkably well defined that scarcely a particle is scattered 
beyond a distance of 20 yards. Although this inroad commenced so 
long ago, yet the principal advance has been since 1807, from which 
date about 200 yards have been gained on the eastern side. Before I 
left the colony in March, 1833, the sand had reached the northern 
corner of a cottage belonging to a man called Ned Keel (on Mr. 
Butterfield’s estate) and the top of the bank, eight feet high, was on 
a level with the eaves of the shed. During the last fourteen years 
it has progressed, at this point, only about forty yards, in a bed 
from four to eight feet deep, in consequence of the repulsive action 
