The only thing to do was to drift down the river and trust to luck to find a landing-place. In their extremity they shouted at the top of their voices to let their comrades know of their plight, but their cries were unanswered and they began to wish that they had saved their breath to use in the task of keeping the canoe steady in the current.
While they had been pondering their situation, moreover, they had been swept with almost incredible rapidity down the river. The walls here grew narrower and narrower and the water fairly boiled in its narrow confines. Its dark surface was flecked with white foam, and to make matters worse, as the walls closed in the light became fainter, till the boys were being carried downward through almost subterranean darkness.
In the intense gloom their white strained faces shone out like pallid beacon-lights.
"Hold her steady," said Frank in a tense voice as the canoe wobbled crazily in the swollen current.
"I'm doing the best I can," gasped out poor Harry desperately plying his paddle.
It the canoe was to get broadside onto the current, even for the fraction of a second, Frank well knew that nothing could save them. It was a terrible situation.
Helplessly they were being borne at dizzy speed to what seemed almost certain death—for certain it was that they could not hold out much longer. Already their overstrained muscles were only mechanically doing their duty, but before long Frank realized that even his-well-trained young body must collapse—and then, what?
Suddenly there was borne to their ears a sound that made both boys chill with terror.
It was a mighty roaring like the furious boiling of some giant kettle. A thousand shouting voices seemed blended into one to form the music, of this ominous orchestra. Louder the noise grew and louder, as the pass through which the river now tore like a runaway race-horse grew narrower and blacker.
What could the awful uproar mean?