And you come here to educate yourselves; to educe and bring out your own powers of perceiving, judging, reasoning; to improve yourselves in the art of all arts, which is, the art of learning.  That is mental education.

Now if a gravel-pit will teach you a little about these things, you will surely call it a rich gravel-pit.  If it helps you to wisdom, which is worth more than gold; which is the only way to get gold wisely, and spend it wisely; then we will call our pit no more a gravel-pit, but a wisdom-pit, a mine of wisdom.

Let us go out, then, in fancy (for it is too cold to go out in person) to Hook Common, scramble down into the first gravel-pit we come to, and see what we can see.

The first thing we see is a quantity of stones, more or less rounded, lying in gravel and poor clay.

Well—­what do those stones tell us?

These stones, as I told you when I addressed you last, are ancient and venerable worthies.  They have seen a great deal in their time.  They have had a great deal of knocking about, and have stood it manfully.  They have stood the knocking about of three worlds already; and have done their duty therein; and they are ready (if you choose to mend the road with them) to stand the knocking about of this fourth world, and being most excellent gravel, to do their duty in this world likewise; which is more, I fear, than either you or I can say for ourselves.

Three worlds?

Yes.  Standing there in the gravel-pit, I see three old worlds, in each of which these stones played their part; and this world of man for the fourth, and the best of all—­for man if not for the stones.  I speak sober truth.  Let me explain it step by step.

You know the chalk-hills to the south; and the sands of Crooksbury and the Hind Head beyond them.  There is one world.

You know the clays and sands of Hook and Newnham, Dogmersfield and Shapley Heath, and all the country to the north as far as Reading.  There is a second world.

You know the gravel-pit itself; and all the upper soils and gravels, which are spread over the length and breadth of the country to the north.  There is a third world.

Let us take them one by one.

First, the chalk.

The chalk-hills rise much higher than the surrounding country; but you must not therefore suppose that they were made after it, and laid on the top of it.  That guess would be true, if you went south-east from here toward the Hind Head.  The chalk lies on the top of the sands of Crooksbury Hill, and the clays of Holt Forest; but it dips underneath the sands of Shapley Heath, and the clays of Dogmersfield, and reappears from underneath them again at Reading.

Thus you at Odiham stand on the edge of a chalk basin; of what was once a sea, or estuary, with shores of chalk, which begins at the foot of the High Clere Hills, and runs eastward, widening as it goes, past London, into the Eastern Sea.  Everywhere under this great basin is the floor of chalk, covered with clays and sands, which, for certain reasons, are called by geologists Tertiary strata.