He turned tail and ran, disappearing almost instantly into the thicker woods. And his mates, after a moment of wavering, sped after him. Lewis was left alone, quite helpless because of the ammonia fumes.

As a matter of fact not all of O'Malley's predicament was due to Koku. The rascal, exhausted by his run and half blind through fright and rage, had stumbled, fallen, and struck his head on a root, which rendered him unconscious.

This, of course, Lewis and his ruffians did not know. All the men of the railroad president's gang saw was the gigantic Koku coming along in great strides, bearing the unconscious O'Malley, who was a burly fellow, as though he were a featherweight. No wonder they fled from such a monster.

Tom had reached the switch, and he was several seconds ahead of the freight locomotive. The engineer saw the open switch then; but he was too late to stop his train.

Going into reverse, however, helped some. Tom seized the switch lever and threw it over, locking it in place, just as the forward trucks thundered upon the joint. The train swept by in safety, and the engineer leaned from his cab window to wave a grateful hand at the young inventor.

Neither the engineer nor the crew of the freight understood the meaning of the scene at the timber siding. All they learned was that Tom Swift had saved the freight from a possible wreck.

The young inventor turned sharply from the switch and motioned with his hand to Koku.

"Throw that fellow into the cab, Koku," he commanded.

The giant did as he was told, just as Ned Newton came panting to the spot.

"Did they do any harm, Tom?" he cried. Then he saw Montagne Lewis standing by, and he seized his chum's arm. "Do you see what I see, Tom?" he demanded, earnestly.