He felt up the rock, and found that, at about the height of his head, the water came over an obtuse angle.

Climbing a foot or two, he discovered that the opening whence it issued was large enough for him to enter.
Only one who has at some time passed where lengthened creeping was necessary, will know how Richard felt, with water under him, pitch-darkness about him, and the rock within an inch or two of his body all round.

By and by the slope became steeper and the ascent more difficult.

The air grew very close, and he began to fear he should be stifled.

Then came a hot breath, and a pair of eyes gleamed a foot or two from his face.