out of the scourings of that vast mass of chalk was our gravel-pit
made.

Of that, and also of the Hind Head sands below it.

For you will find a great deal of sharp sand in our gravel-pits,
which has not, I believe, come from the grinding of chalk flints;
for if it had been ground, it would not be the sharp sand it is; the
particles would be rounded off at the edges. This is probably sand
from the Hind Head; from what geologists term the greensands, below
the chalk.

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