--under the sand hills, perhaps a bed of earth with shells and
bones; under that a bed of peat; under that one of blue silt; under
that a buried forest, with the trees upright and rooted; under that
another layer of blue silt full of roots and vegetable fibre; perhaps
under that again another old land surface with trees again growing in
it; and under all the main bottom clay of the district--what would
common sense tell you? I leave you to discover for yourselves. It
certainly would not tell you that those trees were thrust in there by
a violent convulsion, or that all those layers were deposited there
in a few days, or even a few years; and you might safely indulge in
speculations about the antiquity of the aestuary, and the changes
which it has undergone, with which I will not frighten you at
present.

It will be fair reasoning to argue thus. You may not be always right
in your conclusion, but still you will be trying fairly to explain
the unknown by the known.

But have Rain and Rivers alone made the soil?

How very much they have done toward making it you will be able to
judge for yourselves, if you will read the sixth chapter of Sir
Charles Lyell's new "Elements of Geology," or the first hundred pages
of that admirable book, De la Beche's "Geological Observer;" and
last, but not least, a very clever little book called "Rain and
Rivers," by Colonel George Greenwood.

But though rain, like rivers, is a carrier of soil, it is more. It
is a maker of soil, likewise; and by it mainly the soil of an upland
field is made, whether it be carried down to the sea or not.

If you will look into any quarry you will see that however compact
the rock may be a few feet below the surface, it becomes, in almost
every case, rotten and broken up as it nears the upper soil, till you
often cannot tell where the rock ends and the soil begins.

Now this change has been produced by rain. First, mechanically, by
rain in the shape of ice. The winter rain gets into the ground, and
does by the rock what it has done by the stones of many an old
building. It sinks into the porous stone, freezes there, expands in
freezing, and splits and peels the stone with a force which is slowly
but surely crumbling the whole of Northern Europe and America to
powder.

Do you doubt me? I say nothing but what you can judge of yourselves.
The next time you go up any mountain, look at the loose broken stones
with wh