But he must allow that the friability of
the land must have been originally much greater than now, for
hundreds of years.
But again, does that fact really cut off any great space of time
from his hundreds of thousands of years? For when the land first
rose from the sea, that glen was not there. Some slight bay or bend
in the shore determined its site. That stream was not there. It
was split up into a million little springs, oozing side by side from
the shore, and having each a very minute denuding power, which kept
continually increasing by combination as the glen ate its way
inwards, and the rainfall drained by all these little springs was
collected into the one central stream. So that when the ground
being bare was most liable to be denuded, the water was least able
to do it; and as the denuding power of the water increased, the
land, being covered with vegetation, became more and more able to
resist it. All this he has seen, going on at the present day in the
similar gullies worn in the soft strata of the South Hampshire
coast; especially round Bournemouth.
So the two disturbing elements in the calculation may be fairly set
off against each other, as making a difference of only a few
thousands or tens of thousands of years either way; and the age of
the glen may fairly be, if not a million years, yet such a length of
years as mankind still speak of with bated breath, as if forsooth it
would do them some harm.
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