A. E. Verrill—The Bermuda Islands; Geology. 113 
This goes on till a large unsupported mass of the cliff falls away 
by its own weight. The fall is often hastened by reason of vertical 
fissures or weak places in the cliffs. Great angular blocks of stone, 
thus fallen off, lie in front of the cliffs at the eastern end of the 
sound, and especially at the base of Abbot’s Head (fig. 21). The 
latter are said to have fallen off only a few years ago, but I did not 
learn the date. They show, as yet, scarcely any wear, but those 
that are submerged are partly covered with corals, etc. As there 
are no violent waves in the sound, such masses are not so soon 
destroyed as on the exposed shores. 
Figure 21.—Abbot’s Head, on Harrington Sound, showing the recently fallen 
masses of rock at base. 
In most photographs these narrow deep undercuttings show only 
as a dark line, looking like a dark shadow, at the foot of the cliff, as 
in fig. 20.* 
Sharks Hole, at the southeastern end of the sound, is a large 
arch-way or tunnel, penetrating deeply into the cliff, and about half 
* See also pl. Ixxi, these Trans., vol. xi, and ‘‘The Bermuda Islands,” same 
plate, in which the long cliff, west of Sharks Hole, is shown to be thus under- 
eut. Also pl. lxxiii, showing Sharks Hole. 
