at the bottom of the sea, or in the upper air,
we cannot tell. But the fact is certain, that off the surface of
Wales, south of Ffestiniog a mass of solid rock as high as the Andes
has been worn down and carried bodily away; and that a few miles
south again, the peak of Arran Mowddy, which is now not two thousand
feet high, was once--either under the sea or above it--nearer ten
thousand feet.

If I am asked whither is all that enormous mass of rock--millions of
tons--gone? Where is it now? I know not. But if I dared to hazard
a guess, I should say it went to make the New Red sandstones of
England.

The New Red sandstones must have come from somewhere. The most
likely region for them to have come from is from North Wales, where,
as we know, vast masses of gritty rock have been ground off, such as
would make fine sandstones if they had the chance. So that many a
grain of sand in Chester walls was probably once blasted out of the
bowels of the earth into the old Silurian sea, and after a few
hundreds of thousands of years' repose in a Snowdonian ash-bed, was
sent eastward to build the good old city and many a good town more.

And the red marl--the great deposit of red marl which covers a wide
region of England--why should not it have come from the same quarter?
Why should it not be simply the remains of the Snowdon Slate? Mud
the slate was, and into mud it has returned. Why not? Some of the
richest red marl land I know, is, as I have said, actually being made
now, out of the black slates of Ilfracombe, wherever they are
weathered by rain and air. The chemical composition is the same.
The difference in colour between black slate and red marl is caused
simply by the oxidation of the iron in the slate.

And if my readers want a probable cause why the sandstones lie
undermost, and the red marl uppermost--can they not find one for
themselves? I do not say that it is the cause, but it is at least a
causa vera, one which would fully explain the fact, though it may be
explicable in other ways. Think, then, or shall I think for my
readers?

Then do they not see that when the Welsh mountains were ground down,
the Silurian strata, being uppermost, would be ground down first, and
would go to make the lower strata of the great New Red Sandstone
Lowland; and that being sandy, they would make the sandstones? But
wherever they were ground through, the Lower Cambrian slates would be