ures and faults of the
existing strata, have been altogether removed, and the surface left
plain? In South Wales there are localities where 11,000 feet in
thickness have been bodily carried away. Whether, therefore, the strata
that have been formed, and which remain to strike us with astonishment
at their prodigious mass, were considered; or those that have been
destroyed, not, however, without leaving unmistakable traces of
themselves; the processes of wearing away to furnish material as well as
the accumulation, of necessity required the lapse of long periods of
time. The undermining of cliffs by the beating of the sea, the
redistribution of sands and mud at the bottom of the ocean, the washing
of material from hills into the lowlands by showers of rain, its
transport by river courses, the disintegration of soils by the influence
of frost, the weathering of rocks by carbonic acid, and the solution of
limestone by its aid in water--these are effects which, even at the
quickest, seem not to amount to much in the course of the life of a man.
A thousand years could yield but a trifling result.

We have already alluded to another point of view from which these
mechanical effects were considered. The level of the land and sea has
unmistakably changed. There are mountain eminences ten or fifteen
thousand feet in altitude in the interior of continents over which, or
through which shells and other products of the sea are profusely
scattered. And though, considering the proverbial immobility of the
solid land and the proverbial instability of the water, it might at
first be supposed much more likely that the sea had subsided than that
the land had risen, a more critical examination soon led to a change of
opinion. Before our eyes, in some countries, elevations and depressions
are taking place, sometimes in a slow secular manner, as in Norway and
Sweden, that peninsula on the north rising, and on the south sinking, at
such a rate that, to accomplish the whole seven hundred feet of
movement, more than twenty-seven thousand years would be required if it
had always been uniform as now. Elsewhere, as on the south-western coast
of South America, the movement is paroxysmal, the shore line lifting for
hundreds of miles instantaneously, and then pausing for many years. In
the Morea also, range after range of old sea cliffs exist, some of them
more than a thousand feet high, with terraces at the base of each; but
the Morea has been well