A. E. Verrili— The Bermuda Islands; Geology. 99 
It seemed to me that there were some indications of such a terrace 
formation, in some places along the west side of Castle Harbor ; 
around Mullet Bay and Hungry Bay ; and in various other places. 
But I did not have sufficient time to make a careful study of this 
question. It would, perhaps, require many careful excavations in 
undisturbed localities, if such could be found. But as the soil has 
been constantly cultivated there for nearly 300 years, it probably 
would be hard to find localities with the soil in its original state. 
At any rate, Ido not know that any careful studies of this kind 
have ever been made there. 
As the question now stands, the elevated beach formations, which 
occur at numerous places, are the most important evidence, and they 
lead us to believe that a reélevation has actually occurred, as claimed 
in a former chapter (pp. 76-78). If this be true, it is most probable 
that it was contemporaneous with the post-Champlain elevation of 
Nova Scotia and New England. 
20. Changes due to Erosion. 
The erosion of the Bermuda limestones has taken place chiefly in 
five ways: A, by the solvent action of the carbonic acid in rain 
water and salt spray ; B, by the direct mechanical effects of rain ; 
C, by the mechanical action of streams, either above ground or sub- 
terranean; D, by the mechanical action of the waves, both above 
and below sea-level ; E, by the action of tidal currents and currents 
caused by the winds. The last is probably the least important. 
A. Subaerial erosion due to carbonic acid in the rain-water. 
In the Bermudas, owing to the equable climate and absence of frost, 
the phenomena of erosion and subaerial disintegration of the rocks 
are very much simplified, as compared with Europe and the greater 
part of North America. There is every reason for believing that 
the present conditions have continued for an immense period of time, 
without much change in this respect, though great changes in the 
amount of rainfall are probable. Therefore, observations that would 
give a fairly accurate measure of the present average rate of disin- 
tegration of the limestone would be of great value in determining 
the time required for the great changes that have taken place in past 
ages. We might, by a careful study of the formation of the “red 
soil,” as a decomposition product, or insoluble residue left after the 
solution of the limestone, be able to estimate approximately the total 
