is explained that he had explored dozens of
caves in his time, including some hundreds of miles of that honeycomb
formation that underlies a portion of Kentucky, to say nothing of the
caverns of the Shenandoah Valley of Virginia, the Black Hills of South
Dakota, and the Ozarks. Of the caves of California, however, he as yet
knew nothing.

Had he not been needed to head the fire crew, he would have loved nothing
better than to have gone with them.

"I knew this was a cave region," he told them as they ate and refreshed
themselves before going back into the black depths--for they had been
gone several hours, it seemed. "Fissured limestone--I noticed it
yesterday when we were down here trying to back-fire. Then what feeds the
Kawa? Not these little flood creeks that dry up almost before the spring
floods are over. Where does all that snow water go to? Some underground
passageway, of course. It seeps through the porous rock to subterranean
channels. By the way, I see there are tracks of muddy feet inside here,
and _your_ feet are dry! The mud must have been left by the Mexicans."

"That's a fact!" exclaimed Radcliffe. "Ace, did you notice any mud along
that passageway? Then we surely took the wrong turn."

"Not necessarily," said Norris. "They might have _come_ from some muddy
cavern, but gone back another way. However, I was going to give you a
little idea of the probable layout of a cave. This one, if--as I
suspect--it feeds the Kawa--likely descends to other levels, till the
lowest one is very nearly on that of the river. Seeping through, here and
there, the rains and melting snows probably collect into a stream."

"Wish you could go with us, old chap," said the Ranger. "But----"

"You'll get along all right, with these things," sighed Norris, "and if
you don't show up again within a few hours, we'll follow your twine," and
he tied one end of the cord ball to a manzanita bush, handing the ball to
Ace. At that moment Ted awoke and insisted that he join them. Norris
reluctantly returned to the fire crew.

CHAPTER VII

THE CAVE

Electing the turn to the left, Radcliffe led the way with his carbide
lamp. Ace and Ted followed with their candles.

This time their choice was quickly verified by the discovery of the
burros, standing patiently with their packs before the pool. (That
accounted for the muddy footprints.) Skirting this on the shelving ledge
as had Pedro and the Mexicans, they traversed the winding