Although the tumult of the current was almost deafening, he shouted the name of Fred and listened for the response which came not.
It was not difficult for Jack Dudley to form the explanation of why he failed to discern the next support.

Hitherto his leaps had been comparatively trifling.

It would have been no trouble to make them several feet longer.

This was a spot where such a jump was necessary, and therefore he could not discern the rock which would have been visible with the help of the sun or moon.
What should he do?
Turn back or keep on?
It was a most serious question, and he debated it a long time before forming a conclusion.
It is remarkable how readily, at times, we can convince ourselves of the truth of that which we wish to believe.

By and by Jack Dudley was sure he made out the dim outlines of the lower point of a huge rock, just where it ought to have been.
"I can't be mistaken, so here goes!" And go he did, with a vengeance.