us; for this underground country which we are going to explore is very
extensive, very dark, and, in some places, very dangerous.

Here is a black man who will go with us. He has a lantern, and he says
he knows every nook and corner of the place. So we engage him, get
some lanterns for ourselves, and in we go. We commence to go downwards
very soon after we have passed from the outer air and sunshine, but it
is not long before we stand upon a level surface, where we can see
nothing of the outside world. If our lanterns went out, we should be
in pitchy darkness.

Now we are in the Mammoth Cave of Kentucky!

This vast cavern, which stretches so many miles beneath the surface of
the earth, has never been fully explored; but we are going over as
much of it as our guide is accustomed to show to visitors, and if our
legs are not tired before we get back I shall be very much surprised,
for the trip will take us all day. The floor on which we are now
standing is smooth and level, and runs back into the interior of the
cave fully a thousand yards. This place they call the "Audubon
Gallery"--after our famous naturalist who made birds the study of his
life. His works are published in enormous volumes, costing about one
hundred and fifty dollars apiece. Perhaps your father will get you
one.

We pass quickly through this gallery, where there is not much to see,
although, to be sure, they used to manufacture saltpetre here. Think
of that! A manufactory in the bowels of the earth! Then we enter a
large, roundish room called the "Rotunda," and from this there are a
great many passages, leading off in various directions. One of these,