And I have a better proof of this—­at least I should have in every gravel-pit at Eversley—­in a few pieces of a stone which is not chalk-flint at all; flattish and oblong, not more than two or three inches in diameter; of a grayish colour, and a porous worm-eaten surface, which no chalk-flint ever has.  They are chert, which abound in the greensand formation; and insignificant as they look, are a great token of a most important fact; that the currents which formed our sands and gravels set from the south during a long series of ages, first till they had washed away all the chalk off the Weald, and next till they had washed away a great part of the sands, which then became exposed, the remains whereof form great commons over a wide tract of Surrey.

Now let me pause, and ask you to observe one thing.  How, in inductive science, we arrive, by patient and simple observation of the things around us, at the most grand and surprising results.  Of course I am not giving you the whole of the facts which have made this argument certain.  I am only giving you enough to make it probable to you.  Its certainty has been proved by many different men, labouring in many different parts of England, and of the Continent also, and then comparing their discoveries together; often, of course, making mistakes; but each working on patiently, and correcting their early mistakes by fresh facts, till they have at last got hold of the true key to the mystery, and are as certain of the existence of the great island of the Weald, and its gradual destruction by the waves and currents of an ancient sea, as if they had seen it with their bodily eyes.  You must take all this, of course, as truth from me to-night; but you may go and examine for yourselves; and see how far your own common sense and observations agree with those of learned geologists.

The history of this great Wealden island to the south-east of us is obscure enough; but a few general facts, which bear upon our gravel-pit, I can give you.

I must begin, however, ages before the Wealden island existed; when the chalk of which its mass was composed was at the bottom of a deep ocean.

We know now what chalk is, and how it was made.  We know that it was deposited as white lime mud, at a vast sea-depth, seemingly undisturbed by winds or currents.  We know that not only the flint, but the chalk itself, is made up of shells; the shell of little microscopic animalcules smaller than a needle’s point, in millions of millions, some whole, some broken, some in powder, which lived, and died, and decayed for ages in the great chalk sea.

We know this, I say.  We had suspected it long ago, and become more and more certain of it as the years went on.  But now we seem to have a proof of it which is past gainsaying.