He was almost in utter darkness, and was surprised that the way proved so easy.

By leaning forward and peering into the gloom he could generally distinguish the most shadowy outlines of the nearest part of the support, which, had it been slightly further removed, would have been altogether beyond his reach.
It was unreasonable to expect the favorable conditions to continue, and they did not.

The time came very soon when, after one of his leaps, the youth paused to collect himself, and was unable to distinguish the next rock projecting above the roaring current.

The canyon just there was wider than usual, and he stooped over and gazed to the right and left in turn, hoping to discover the indispensable support.
"It must be somewhere near," he reflected, "else Hank and the rest of them could have ascended no further; perhaps they did not do so." He gazed up the walls of darkness, but saw nothing that could help solve the question.

If there was a cave near at hand its presence was betrayed by no friendly light.