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 Bathstone freestone, or oolite; and it lies on the top of the lias, which we have just left. Here it is marked

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.

Is that why the place is called Bath?

Of course. But the Old Romans called the place Aquæ Solis—the waters of the sun; and curious old Roman remains are found here, which we have not time to stop and see.

Now look out at the pretty clear limestone stream running to meet us below, and the great limestone hills closing over us above. How do you think we shall get out from among them?

Shall we go over their tops?

No. That would be too steep a climb, for even such a great engine as this.

Then there is a crack which we can get through?

Look and see.

Why, we are coming to a regular wall of hill, and—

And going right through it in the dark. We are in the Box Tunnel.

There is the light again: and now I suppose you will find your tongue.

How long it seemed before we came out!

Yes, because you were waiting and watching, with nothing to look at: but the tunnel is only a mile and a quarter long, after all, I believe. If you had been looking at fields and hedgerows all the while, you would have thought no time at all had passed.

What curious sandy rocks on each side of the cutting, in lines and layers!

Those are the freestone still: and full of fossils they are. But do you see that they dip away from us? Remember that. All the rocks are sloping eastward, the way we are going; and each new rock or soil we come to lies on the top of the one before it. Now we shall run down hill for many a mile, down the back of the oolites, past pretty Chippenham, and Wootton Bassett, towards Swindon spire. Look at the country, child; and thank God for this fair English land, in which your lot is cast.

What beautiful green fields; and such huge elm-trees; and orchards; and flowers in the cottage gardens!

Ay, and what crops, too: what wheat and beans, turnips and mangold! All this land is very rich and easily worked; and hereabouts is some of the best farming in England. The Agricultural College at Cirencester, of which you have so often heard, lies thereaway, a few miles to our left; and there lads go to learn to farm, as no men in the world, save English and Scotch, know how to farm.

But what rock are we on now?

On rock that is much softer than that on the other 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?

Yes.

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 green sand, 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 they were mostly soft clays, she cut them out very easily, till she came down, or nearly down, to the harder freestone rocks which run along on our left hand, miles away; and so she scooped out this great vale, which we call here the Vale of White Horse; and further on, the Vale of Aylesbury; and then the Bedford Level; and then the dear ugly old Fens.

Is this the Vale of White Horse? Oh, I know about it; I have read "The Scouring of the White Horse."

Of course you have; and when you are older you will read a jollier book still,—"Tom Brown's School Days"—and when we have passed Swindon, we shall see some of the very places described in it, close on our right.