122 PRESENT MARINE ENCROACHMENTS. 
land more northwardly or in the South Hams,—in 
short, that theland was formerly continued outwards 
to the sea in the manner of a gradual descent, 
(considered in the mass)—we see at once, how 
great an usurpation has been effected. In surveying 
the coast, it seems often as if as much as half of a 
hill had thus been gradually sacrificed to the do¬ 
mains of the ocean. The whole coast presents a 
continued series of small coves, and isolated, irre¬ 
gular rocks, produced by the constant ferment of 
the sea. We see also, instances of points of land 
being severed and becoming insulated masses, the 
structure of these being denser and more resisting 
than the removed material, such is the Shag Rock 
in Plymouth Sound. In another spot, the yielding 
of the rock has left a more considerable islet called 
the Mewstone, between which and the land adja¬ 
cent, a very trifling depth of water remains at low 
tides, and perhaps not 100 years since, it might 
have been accessible on the retreat of the sea. A 
similar remark applies to St. Michael’s Mount in 
Cornwall, though here, the marine action has occa¬ 
sioned but a narrow intervening strait.* Burrow 
Island seems to come but partially under the same 
rule with the two last cases, it appears originally to 
have been a hill belonging to the adjacent series, 
and slopes immediately to the land side, the wear 
therefore occasioned by the sea must have been 
but little in the intermediate space. The invasions 
of the sea are evinced differently on the northern 
coast of Cornwall, where, on some of the low 
grounds between the hills, vast hillocks of sand 
have been deposited, and are gradually being aug¬ 
mented, whereby, considerable tracts of pasturage 
have been lost to the agriculturist. 
♦Homan Coins have been found at the base of St. Michael’s Mount. 
