Only his head showed over the water, but the ears were pricking straight and high, and it never once swerved back toward the nearer shore.
Their progress at first was good, but as they neared the central portion of the water they were swept many yards downstream for one that they made in a transverse direction.

Twice they missed projecting rocks by the narrowest margin, and then something like an exceedingly thin and exceedingly strong arm caught Anthony around the shoulders.

It tugged back, stopped all their forward progress, and let them sweep rapidly down the stream and back toward the shore.
Turning his head he caught a glimpse of Nash sitting calmly in his saddle, holding the rope in both hands--and laughing.

The next instant he saw no more, for the current placed a taller rock between him and the bank.

On that rock the line of the lariat caught, hooking the swimmers sharply in toward the bank.