they saw, was nothing
else than the dry cataract of a river, strewn with boulders, and
then they suddenly turned to each other with an exclamation at the
thought, "What had become of the river?"

"It's queer!" said Venning. "Where is the water?"

On looking around, they beard for the first time a peculiar
subterranean rumbling, and going back a few feet, saw the river
disappear in a smooth, green slide down into a wide fissure. They
stood looking down, fascinated at this mysterious, silent, and
stealthy disappearance of the waters that come with such a sparkle
out of the bright valley; then dropped stones down, and stooped
their heads in vain to catch even the slightest sound out of the
depths. The fissure was about twenty feet wide, with a sloping lip
on the near side, and a straight wall on the far or forest side. The
slope seemed to carry the water to the left, and with a desire to
discover its course, they tugged at a large post which stood against
the wall of the gorge and rolled it into the fissure. It whizzed
away down into the dark, and nearly dragged Compton after it, for
the sleeve of his coat caught on a projecting point, and he was
jerked on to his knees, being saved from further danger by the coat
tearing.

"Thanks," he said, looking a little white; "I am quite satisfied
that the water disappears."

"I rather think," said Venning, "that we have pulled up a gate-post.
See, there is one on the other side. A few tree-trunks thrown across
would make a fine barricade. Come on back into the valley."

They went back slowly, looking up at the dark walls of the rocky
gorge, and Venning stopped.

"See that rock up there?"

"Looks as if it would drop at any moment."

"Remember what Muata said about Hassan drowning out the valley."

"One of his figures of speech."

"S'pose that rock fell; it would just about fill up this passage,
river and all. And if it did not quite, a few men working from the
ledge, which you see would be behind the dam, could easily fill up
the cracks. Then the river could be dammed and the valley flooded."

"They'd have to blast the rock, and the task would be too
troublesome."

They returned slowly through the defile, stopping at the place where
the warrior had sprung out on Compton, and on reaching the valley,
went down among the rustling bananas and among the gardens, where
the women stopped their work to shout out merry greetings, and to
offer them earth-nuts, wild cherries, s