The Old Red Sandstone; or, New Walks in an Old Field
John Stuart Mill · en
multitudinous fragments of gneiss, torn from its sides by the sea,
or loosened by the action of frosts and storms, and rolled down its
precipices, is only a few hundred yards away;--its base, where these
lie thickest, has been swept by tempests, chiefly from the east, for
thousands and thousands of years; and the direct effect of these
tempests, regarded as transporting agents, would have been to strew
this stony tract with those detached fragments. The same billow that
sends its long roll from the German Ocean to sweep the base of the
Sutor, and to leap up against its precipices to the height of eighty
and a hundred feet, breaks in foam, only a minute after, over this
stony tract; which has, in consequence, its sprinkling of fragments
of gneiss, transported by an agency so obvious. But for every one
such fragment which it bears, we find at least ten boulders that have
been borne for forty and fifty miles in the opposite direction from
the interior of the country--a direction in which no transporting
agency now exists. The tempests of thousands of years have conveyed
for but a few hundred yards not more than a tithe of the materials
of this tract; nine tenths of the whole have been conveyed by an
older agency over spaces of forty and fifty miles. How immensely more
powerful, then, or how immensely protracted in its operation, must
that older agency have been!
[Footnote AH: A concretionary limestone of the Old Red system in
England, variegated with purple and green, was at one time wrought as
a marble.--_Silurian System_, Part i. p. 176.]