in diameter, and drops down like a grey beard, we have named it Noah's
Beard.

"In the eighth tier we find very beautiful formations of carbonate of
lime, and the box work is decidedly blue, the boxes larger, and their
partitions one half inch thick.

"We have been deeper than the eighth tier but in narrow crevices barely
admitting a man of average stature. In these the calcareous coating is
much thicker than in any higher portions of the cave, but very little
sign of box work is seen.

"Sometimes we make a comparison between the cave and a sponge. Take for
instance a sponge as large as an apple barrel and there would be holes
in it as big as a man's thumb and closed hand. Now take a sponge, four
miles square and five hundred feet deep with holes in proportion to the
little sponge, and you have an illustration of The Wonderful Wind Cave,
of Custer County, South Dakota."




CHAPTER XI.

WIND CAVE CONTINUED.


PEARLY GATES AND BLUE GROTTO ROUTE.

A very much longer, more beautiful, and also more difficult journey than