extraordinary
fact has been discovered:

That over a great part of the Pacific Ocean sinking is going on, and
has been going on for ages; and that the greater number of the
beautiful and precious South Sea Islands are only the remnants of a
vast continent or archipelago, which once stretched for thousands of
miles between Australia and South America.

Now, applying the same theory to limestone beds, which are, as you
know, only fossil coral reefs, we have a right to say, when we see in
England, Scotland, Ireland, limestones several thousand feet thick,
that while they were being laid down as coral reef, the sea-bottom,
and probably the neighbouring land, must have been sinking to the
amount of their thickness--to several thousand feet--before that
later sinking which enabled several hundred feet of millstone grit to
be laid down on the top of the limestone.

This millstone grit is a new and a very remarkable element in our
strange story. From Derby to Northumberland it forms vast and lofty
moors, capping, as at Whernside and Penygent, the highest limestone
hills with its hard, rough, barren, and unfossiliferous strata.
Wherever it is found, it lies on the top of the "mountain," or
carboniferous limestone. Almost everywhere, where coal is found in
England, it lies on the millstone grit. I speak roughly, for fear of
confusing my readers with details. The three deposits pass more or
less, in many places, into each other: but always in the order of
mountain limestone below, millstone grit on it, and coal on that
again.

Now what does its presence prove? What but this? That after the
great coral reefs which spread over Somersetshire and South Wales,
around the present estuary of the Severn,--and those, once perhaps
joined to them, which spread from Derby to Berwick, with a western
branch through North-east Wales,--were laid down--after all this, I
say, some change took place in the sea-bottom, and brought down on
the reefs of coral sheets of sand, which killed the corals and buried
them in grit. Does any reader wish for proof of this? Let him
examine the "cherty," or flinty, beds which so often appear where the
bottom of the millstone grit is passing into the top of the mountain
limestone--the beds, to give an instance, which are now quarried on
the top of the Halkin Mountain in Flintshire, for chert, which is
sent to Staffordshire to be ground down for the manufacture of chi