ength of the platform.

On to this boat the entire party crowded and they were soon well out on
the shallow river, headed for its opposite bank. The Very Young Man,
seated at the front end of the platform with his legs dangling over and
his feet only a few inches above the silver phosphorescence of the
rippling water underneath, sighed luxuriously.

"This beats anything we've done yet," he murmured. "Gee, it's nice
here!"

When they landed on the farther bank another group of natives was
waiting for them. The party, thus strengthened to nearly forty, started
off immediately into the forest, which on this side of the river
appeared equally dense and trackless.

They appeared now to be paralleling the course of the river a few
hundred yards back from its bank. After half an hour of this traveling
they came abruptly to what at first appeared to be the mouth of a large
cave, but which afterwards proved to be a tunnel-like passageway. Into
this opening the party unhesitatingly plunged.

Within this tunnel, which sloped downward at a considerable angle, they
made even more rapid progress than in the forest above. The tunnel walls
here were perhaps twenty feet apart--walls of a glistening, radiant,
crystalline rock. The roof of the passageway was fully twice as high as
its width; its rocky floor was smooth and even.

After a time this tunnel was crossed by another somewhat broader and
higher, but in general of similar aspect. It, too, sloped downward, more
abruptly from the intersection. Into this latter passageway the party
turned, still taking the downward course.

As they progressed, many other passageways were crossed, the
intersections of which were wide at the open spaces. Occasionally the
travelers encountered other natives, all of them men, most of whom
turned and followed them.

The Big Business Man, after over an hour of this rapid walking downward,
was again near the limit of his endurance, when the party, after
crossing a broad, open square, came upon a sort of sleigh, with two
animals harnessed to it. It was standing at the intersection of a still
broader, evidently more traveled passageway, and in it was an attendant,
apparently fast asleep.

Into this sleigh climbed the three travelers with their guide Lao; and,
driven by the attendant, they started down the broader tunnel at a rapid
pace. The sleigh was balanced upon a broad single runner of polished
stone, with a narrow, slightly shorter outrider on