h its bed of under-clay; and
that therefore the land MUST have sunk ere the next bed of soil could
have been deposited, and the next forest have grown on it.

In one of the Rocky Mountain coal-fields there are more than thirty
seams of coal, each with its under-clay below it. What can that mean
but thirty or more subsidences of the land, and the peat of thirty or
more forests or peat-mosses, one above the other? And now if any
reader shall say, Subsidence? What is this quite new element which
you have brought into your argument? You told us that you would
reason from the known to the unknown. What do we know of subsidence?
You offered to explain the thing which had gone on once by that which
is going on now. Where is subsidence going on now upon the surface
of our planet? And where, too, upheaval, such as would bring us
these buried forests up again from under the sea-level, and make
them, like our British coal-field, dry land once more?

The answer is--Subsidence and elevation of the land are common now,
probably just as common as they were in any age of this planet's
history.

To give two instances, made now notorious by the writings of
geologists. As lately as 1819 a single earthquake shock in Cutch, at
the mouth of the Indus, sunk a tract of land larger than the Lake of
Geneva in some places to a depth of eighteen feet, and converted it
into an inland sea. The same shock raised, a few miles off, a
corresponding sheet of land some fifty miles in length, and in some
parts sixteen miles broad, ten feet above the level of the alluvial
plain, and left it to be named by the country-people the "Ullah
Bund," or bank of God, to distinguish it from the artificial banks in
the neighbourhood.

Again: in the valley of the Mississippi--a tract which is now, it
would seem, in much the same state as central England was while our
coal-fields were being laid down--the earthquakes of 1811-12 caused
large lakes to appear suddenly in many parts of the district, amid
the dense forests of cypress. One of these, the "Sunk Country," near
New Madrid, is between seventy and eighty miles in length, and thirty
miles in breadth, and throughout it, as late as 1846, "dead trees
were conspicuous, some erect in the water, others fallen, and strewed
in dense masses over the bottom, in the shallows, and near the
shore." I quote these words from Sir Charles Lyell's "Principles of
Geology" (11th edit.)