THE INSULATION OF ST. MICHAEL'S MOUNT. 3 
recent time the Mount was permanently a peninsula ; or fail to see 
that its present insulation must be ascribed either to the mere 
wasting of the coast of the mainland by the action of the waves, or 
to a more or less general subsidence of the district, attended, per- 
haps, by such wasting. There is no other alternative. As it was 
the object of my paper to prove that the latter was the true cause, 
I proceeded first to show that the rival hypothesis—insulation by 
encroachment without subsidence—could not be entertained ; having 
been led to this conclusion by a personal visit to the spot and a 
careful study of its physical geography and geology. It was obvious 
that though the cliff at Marazion—the nearest point of the main- 
land—was but little calculated to resist the unbroken action of the 
waves, it was so effectually protected by the Mount from the only 
quarter whence very destructive seas could be sent—from S.W. to 
S.E.—that its recession would in all probability be so slow as to 
be scarcely appreciable. This conclusion was fully confirmed by 
the evidence of all the inhabitants with whom I conversed, as 
they assured me that in their time there had been no wasting of 
the cliff. It cannot be doubted, however, that the Marazion plain 
did formerly extend further towards the Mount, and it may 
possibly have reached it in some very remote antiquity. The 
_ former was evident from the fact that the plain terminated, not in 
a slope, but in a low vertical cliff, consisting of a sub-aerial accumu- 
lation of clay and angular stones. The cliff, moreover, was partially 
protected by a wall: but, on the other hand, though the space 
between it and the houses was very narrow, the wall itself was 
so slender as to show that it was neither intended, nor expected 
to be called on, to resist powerful attempts at encroachment. In 
fact, it seemed to be a protection against sub-aerial agencies rather 
than against violent waves. Moreover, several parts of the cliff 
were entirely undefended, and these had by no means retreated, 
even to the extent of a single inch, more than those protected by 
the wall.* 
* During a visit to Marazion since this paper was written, I observed 
the following fact, strongly confirmatory of the belief of the natives that if 
the cliffs recede at all they do so at a very slow rate. A house standing, 
it was said, on 60 feet by 60 feet, was in course of erection, on a narrow 
tongue of the sub-aerial material, having the sea-clifi no more than 12 feet 
from it on the west, and from 30 to 40 feet on the east. On my remarking 
that the site seemed a very precarious one, especially for so large and valu- 
able a house, the workmen assured me that there was no risk whatever. 
