side of the oolite
hills: much softer, because it is much newer. We have got off the
oolites on to what is called the Oxford clay; and then, I believe, on to
the Coral rag, and on that again lies what we are coming to now. Do you
see the red sand in that field?

Then that is the lowest layer of a fresh world, so to speak; a world
still younger than the oolites--the chalk world.

But that is not chalk, or anything like it.

No, that is what is called Greensand.

But it is not green, it is red.

I know: but years ago it got the name from one green vein in it, in which
the "Coprolites," as you learnt to call them at Cambridge, are found; and
that, and a little layer of blue clay, called gault, between the upper
Greensand and lower Greensand, runs along everywhere at the foot of the
chalk hills.

I see the hills now. Are they chalk?

Yes, chalk they are: so we may begin to feel near home now. See how they
range away to the south toward Devizes, and Westbury, and Warminster, a
goodly land and large. At their feet, everywhere, run the rich pastures
on which the Wiltshire cheese is made; and here and there, as at
Westbury, there is good iron-ore in the greensand, which is being smelted
now, as it used to be in the Weald of Surrey and Kent ages since. I must
tell you about that some other time.

But are there Coprolites here?

I believe there are: I know there are some at Swindon; and I do not see
why they should not be found, here and there, all the way along the foot
of the downs, from here to Cambridge.

But do these downs go to Cambridge?

Of course they do. We are now in the great valley which runs right
across England from south-west to north-east, from Axminster in
Devonshire to Hunstanton in Norfolk, with the chalk always on your right
hand, and the oolite hills on your left, till it ends by sinking into the
sea, among the fens of Lincolnshire and Norfolk.

But what made that great valley?

I am not learned enough to tell. Only this I think we can say--that once
on a time these chalk downs on our right reached high over our heads
here, and far to the north; and that Madam How pared them away, whether
by icebergs, or by sea-waves, or merely by rain, I cannot tell.

Well, those downs do look very like sea-cliffs.

So they do, very like an old shore-line. Be that as it may, after the
chalk was eaten away, Madam How began digging into the soils below the
chalk, on which we are now; and because t