“He’s having a fearful battle!” gasped Walter, whose face had gone deathly pale.

Professor Zepplin nodded, unable to speak.  By a triumph of strength, backed by his cool head and keen judgment, Tad brought himself out of this dangerous pocket of water, only to meet others.  His strength seemed to be failing now.

“Haul him back!” ordered the Professor hoarsely.  “Haul him back!”

They tried, but at that moment the rope parted—–­sawed in two over a sharp edge of rock!

CHAPTER XIII

A BATTLE MIGHTILY WAGED

The land end of the rope fell limp in the hands of Jim Nance and Ned Rector.

“It’s gone—–­gone!” wailed Ned.

“That settles him,” answered the guide in a hopeless tone.

“Oh, he’s lost, he’s lost!” cried Walter.  “Can no one do anything?”

Chunky, with sudden determination, threw off his coat, and started on a run for the river.  Dodging the Professor’s outstretched hands, Chunky sprang into the water.

With a roar Dad hurled the rope toward the fat boy.  The guide had no time in which to fashion a loop, but he had thrown the rope doubled.  Fortunately the coil caught Chunky’s right foot and the lad was hauled back feet first, choking, half drowned, his head being dragged under water despite his struggles to get free.

The instant they hauled him to the bank the Professor seized the lad and began shaking him.

“Leggo!  Lemme go, I tell you.  I’m going after Tad!”

Stacy Brown was terribly in earnest this time.  He was fighting mad because they had pulled him back from what would have been sure death to him.  They had never given Stacy credit for such pluck, and Ned and Walter gazed at him with new interest in their eyes.  It was necessary to hold the fat boy.  He was still struggling, determined to go to Tad’s rescue.

In the meantime their attention had been drawn from Tad for the moment.  When they looked again they failed to find him.

“There he is,” shouted Ned, as the boy was seen to rise from the water and plunge head foremost into it again.  Tad did not appear to be fighting now.

“He’s helpless!  He’s hurt!” cried the Professor.

“I reckon that’s about the end of the lad,” answered Nance in a low tone.  “There’s nothing we can do but to wait.”

“I see him again!” shouted Walter.

They could see the lad being tumbled this way and that, hurled first away from the shore, then on toward it.  Nance was regarding the buffeted Pony Rider keenly.  He saw that Tad was really nearing the shore, but that he was helpless.

“What has happened to him?” demanded the Professor hoarsely.  “Is he drowned?”

“It’s my opinion that he has been banged against a rock and knocked out.  I can’t tell what’ll be the end of it, but it looks mighty bad.  There he goes, high and dry!” fairly screamed Dad, while his whiskers tilted upwards at a sharp angle.