There was nothing to be done.

In the sheer exhaustion of his resources, in his numb despondency, he neglected even to drive the horse out of the water.

How long he sat there it would be hard to say.

Several times he roused himself to utter a "Halloo!" But the roar of the rain swallowed up his voice, which was husky with emotion.
After a while he heard a plashing in the water, which was not that of the rain.

He thought it must be the sound of a canoe-paddle.