INLAND SEA-CLIFFS. 
103 
ests, only visible at low water, having the trunks of the 
trees erect and their roots attached to them and still 
spreading through the ancient soil as when they were liv¬ 
ing. They occur in too many places, and sometimes at too 
great a depth, to be explained by a mere change in the level 
of the tides, although as the coasts waste away and alter in 
shape, the height to which the tides rise and fall is always 
varying, and the level of high tide at any given point may, 
in the course of many ages, differ by several feet or even 
fathoms. It is this fluctuation in the height of the tides, 
and the erosion and destruction of the sea-ccast by the 
waves, yiat makes it exceedingly difficult for us in a few 
centuries, or even perhaps in a few thousand years, to de¬ 
termine whether there is a change by subterranean move¬ 
ment in the relative level of sea and land. 
We often behold, as on the coasts of Devonshire and Pem¬ 
brokeshire, facts which appear to lead to opposite conclu¬ 
sions. In one place a raised beach with marine littoral 
shells, and in another immediately adjoining a submerged 
forest. These phenomena indicate oscillations of level, and 
as the movements are very gradual, they must give repeat¬ 
ed opportunities to the breakers to denude the land which 
is thus again and again exposed to their fury, although it is 
evident that the submergence is sometimes effected in such 
a manner as to allow the trees which border the coast not 
to be carried away. 
Inland Sea-cliffs. —In countries where hard limestone rocks 
abound, inland cliffs have often retained faithfully for ages 
the characters which they acquired when they constituted 
the boundary of land and sea. Thus, in the Morea, no less 
than three or even four ranges of cliffs are well preserved, 
rising one above the other at different distances from the 
actual shore, the summit of the highest and oldest occasion¬ 
ally attaining 1000 feet in elevation. A consolidated beach 
vnth marine shells is usually found at the base of each cliff, 
and a line of littoral caverns. These ranges of cliff probably 
imply pauses in the process of upheaval when the waves and 
currents had time to undermine and clear away considerable 
masses of rock. 
But the beginner should be warned not to expect to find 
evidence of the former sojourn of the sea on all those lands 
which we are nevertheless sure have been submerged at pe¬ 
riods comparatively modern; for notwithstanding the en¬ 
during nature of the marks left by littoral action on some 
rocks, especially limestones, we can by no means detect sea- 
beaches and inland cliffs everywhere. On the contrary, they 
