And what is that black above it?

That is the coal, a few miles off, marked C.

And what is this D, which comes next?

That is what we are on now.  New red sandstone, lying unconformably on the coal.  I showed it you in the bed of the river, as we came along in the cab.  We are here in a sort of amphitheatre, or half a one, with the limestone hills around us, and the new red sandstone plastered on, as it were, round the bottom of it inside.

But what is this high bit with E against it?

Those are the high hills round Bath, which we shall run through soon.  They are newer than the soil here; and they are (for an exception) higher too; for they are so much harder than the soil here, that the sea has not eaten them away, as it has all the lowlands from Bristol right into the Somersetshire flats.

* * * * *

There.  We are off at last, and going to run home to Reading, through one of the loveliest lines (as I think) of old England.  And between the intervals of eating fruit, we will geologize on the way home, with this little bit of paper to show us where we are.

What pretty rocks!

Yes.  They are a boss of the coal measures, I believe, shoved up with the lias, the lias lying round them.  But I warn you I may not be quite right:  because I never looked at a geological map of this part of the line, and have learnt what I know, just as I want you to learn simply by looking out of the carriage window.

Look.  Here is lias rock in the side of the cutting; layers of hard blue limestone, and then layers of blue mud between them, in which, if you could stop to look, you would find fossils in plenty; and along that lias we shall run to Bath, and then all the rocks will change.

* * * * *

Now, here we are at Bath; and here are the handsome fruit-women, waiting for you to buy.

And oh, what strawberries and cherries!

Yes.  All this valley is very rich, and very sheltered too, and very warm; for the soft south-western air sweeps up it from the Bristol Channel; so the slopes are covered with fruit-orchards, as you will see as you get out of the station.

Why, we are above the tops of the houses.

Yes.  We have been rising ever since we left Bristol; and you will soon see why.  Now we have laid in as much fruit as is safe for you, and away we go.

Oh, what high hills over the town!  And what beautiful stone houses!  Even the cottages are built of stone.

All that stone comes out of those high hills, into which we are going now.  It is called Bath-stone freestone, or oolite; and it lies on the top of the lias, which we have just left.  Here it is marked F.

What steep hills, and cliffs too, and with quarries in them!  What can have made them so steep?  And what can have made this little narrow valley?

Madam How’s rain-spade from above, I suppose, and perhaps the sea gnawing at their feet below.  Those freestone hills once stretched high over our heads, and far away, I suppose, to the westward.  Now they are all gnawed out into cliffs,—­indeed gnawed clean through in the bottom of the valley, where the famous hot springs break out in which people bathe.