Then came two or three easy movements onward, bringing the fugitive abreast of the sink, which was larger than it had appeared from below, and Ralph shuddered as he felt that any one who approached the vortex would for a certainty be dragged down.
For a few moments he clung there, the nervous thoughts of what might be if he slipped and were caught in the whirlpool being sufficient to half paralyse him; then turning angry at his feeling of cowardice, he reached boldly out again, found fresh hand-hold, and did the same again and again, till he was a dozen yards beyond the sink-hole, and had to stop and think.

For the wall was smoother than ever; the stream ran stronger; the distance between the two sides being less, it looked deeper; and the next place where he could find hand-hold was apparently too far to reach.
Still, it was his only chance, and taking fast hold with his right, and somehow thinking the while of Mark's passage along the surface of the High Cliff, he reached out farther and farther, pressing his breast against the rock, edging his feet along, and then stopping at his fullest stretch, to find the little root of ivy he aimed at grasping still six or seven inches away.
The dead silence preserved by the men below was broken by the barking of one of the dogs.

Then all was still again, and Ralph felt that his only chance was to steady himself for a moment with his feet, loosen his hold with his right hand, and let himself glide along the face of the rock forward till his left touched the ivy, and then hold on.
If he missed catching hold--?
"I mustn't think of such a thing," he muttered; and he at once put his plan into action, letting himself glide forward.
As a scholar, fresh from a big school, he ought to have been more mathematically correct, and known that in describing the arc of a circle his left hand would go lower; but he did not stop to think.

The consequence was that as his fingers glided over the rough stone, they passed a few inches beneath the tough stem he sought to grasp, and once in motion, he could not stop himself.

He clutched at the stone with his right hand, and his nails scratched over it, as he vainly strove to find a prominence or crevice to check him; but all in vain; the pressure of the running water on the lower part of his body helped to destroy his balance, and with a faint cry, he went headlong into the gliding stream, the men simultaneously giving vent to a yell, half of horror, half of satisfaction.
"The sink-hole! Shall I be sucked down ?" was the thought that flashed across the lad's brain, like a lurid light, as he went under; then he struck out vigorously for the side, and as he rose to the surface saw that he was being drawn toward the hole where it gaped horribly, and closed, and gaped again, a few yards away.
If any boy who reads this cannot swim, let him feel that he is sinning against himself, and neglecting a great duty, till he can plunge without a trace of nervousness into deep water, and make his way upon the surface easily and well.