or more they traveled on in almost unbroken silence. On
either side the shore was invisible, and overhead the glare of the torch
revealed only black, empty space. The same intense silence prevailed,
not even the faintest murmur of the river being audible.

This peaceful monotony, however, was rudely shattered. A low humming
sound was heard in the distance, which rapidly increased in volume, and
left no room to doubt that a course of rapids was below. At Guy's
suggestion Forbes relieved Sir Arthur of the torch, and scarcely had
this change been effected when the current carried them into a swirling
mass of spray.

Both canoes grated and bumped against rocks, and then, before the
frightened occupants could realize that it was over, the sullen roar was
fading away in the distance, and the smooth current was bearing them
rapidly ahead.

This little episode considerably relieved their minds. If no more
dangerous water than that lay before them, there was little cause for
apprehension. A skilled eye and a strong hand would overcome the
difficulty.

Presently, for the first time, rocky walls appeared, now on one side,
now on the other, but they fell sheer to the water, and gave no
opportunity for landing. The atmosphere of the cavern was pure and
fresh, a fact not readily accounted for, since no glimmer of daylight
was anywhere visible.

Guy began to grow sleepy, a sensation which was shared by his
companions, for it was many hours since they had had any rest. It was
impossible to tell how long or how far they had traveled. All passage of
time was lost, and the periods for eating and sleeping must be regulated
by their own feelings. Instinct goes wrong in such cases; yet there was
little doubt that the night had come.

A sharp lookout was kept on the shores, but, as the current swept them
past the same monotonous ledges without a break, it began to look as
though they would be compelled to take turns at sleeping in the bottom
of the canoes.

They were paddling close along the right shore when a sudden cry from
Canaris, who was almost abreast of the other boat, and farther out in
the current, attracted general attention, and peering out on the river
they saw a dim object some yards away.

The current bore them past it, but by dint of hard paddling the canoes
were headed diagonally up stream, and a few moments later a landing was
made on the lower end of a small spit of white sand, ten or fifteen
yards in diameter.