re.

But how do you know that they lie on the limestone?

Look into that corner of the river, as we turn round, and you will see
with your own eyes. There are the sandstones, lying flat on the turned-
up edges of another rock.

Yes; I see. The layers of it are almost upright.

Then that upright rock underneath is part of the great limestone hill
above. So the hill must have been raised out of the sea, ages ago, and
eaten back by the waves; and then the sand and pebbles made a beach at
its foot, and hardened into stone; and there it is. And when you get
through the limestone hills to Bristol, you will see more of these same
red sandstone rocks, spread about at the foot of the limestone-hills, on
the other side.

But why is the sandstone two worlds newer than the limestone?

Because between that sandstone and that limestone come hundreds of feet
of rock, which carry in them all the coal in England. Don't you remember
that I told you that once before?

Oh yes. But I see no coal between them there.

No. But there is plenty of coal between them over in Wales; and plenty
too between them on the other side of Bristol. What you are looking at
there is just the lip of a great coal-box, where the bottom and the lid
join. The bottom is the mountain limestone; and the lid is the new red
sandstone, or Trias, as they call it now: but the coal you cannot see. It
is stowed inside the box, miles away from here. But now, look at the
cliffs and the downs, which (they tell me) are just like the downs in the
Holy Land; and the woods and villas, high over your head.

And what is that in the air? A bridge?

Yes--that is the famous Suspension Bridge--and a beautiful work of art it
is. Ay, stare at it, and wonder at it, little man, of course.

But is it not wonderful?

Yes: it was a clever trick to get those chains across the gulf, high up
in the air: but not so clever a trick as to make a single stone of which
those piers are built, or a single flower or leaf in those woods. The
more you see of Madam How's masonry and carpentry, the clumsier man's
work will look to you. But now we must get ready to give up our tickets,
and go ashore, and settle ourselves in the train; and then we shall have
plenty to see as we run home; more curious, to my mind, than any
suspension bridge.

And you promised to show me all the different rocks and soils as we went
home, because it was so dark when we came from Reading.

Very good.