"Yah-h-h hum." Stacy Brown yawned loudly. "Yah-hum," breathed Walter Perkins, half rousing himself from his nap.
"Ho-ho-hum," added the deep bass voice of Professor Zepplin.
"Yah--see here, stop that!" commanded Ned Rector, suddenly raising himself to a sitting posture. "You've done nothing but stretch your mouth in yawns ever since we reached Montana. See, you've waked up the whole camp."
"Ho-hum," said Chunky.
"Say, what ails you?" demanded Tad, putting down by supreme force of will, his own inclination to yawn.
"I--I guess--yah--it must be the--the mountain air. Yah-hum," yawned the fat boy.
Pink-eye coughed off among the cedars.
"What means all this disturbance, young gentlemen?" demanded the Professor.
"It's Chunky and the bronchos yawning," Ned Rector informed him.
"So did you," observed Stacy Brown.
"Did what?"
"Yawned. See, see! Your mouth's open now. You're going to yawn this very second You----"
His taunts were lost in the shouts of the Pony Riders. Ned Rector's face was set determinedly, a vacant expression having taken full possession of his eyes.
"He is going to yawn," announced Walter solemnly. "Stake down the camp."
In spite of his determination not to yield to the impulse of the moment, Ned's mouth slowly opened to its extreme capacity, accompanied by a deep intake of breath.
"Y-a-h-h-h-hum!" he exploded.
"Got you that time. He--he----" Walter's words died away in a long-drawn, gaping yawn.
Ned waited to hear no more. With a yell he projected himself at the fat boy. Stacy, however, observing the move, had quickly rolled to one side. Ned struck the ground heavily.
Stacy was rolling over and over now as if his very life depended upon getting away. He could not spare the time to get up and run, so he continued to roll over and over, making no mean progress at that.
"Go it, Chunky!" shouted Walter in high glee.
The scene, dimly lighted by the smouldering camp-fire, was so ludicrous as to send the boys into shouts of laughter. All were thoroughly awake now. They had made camp at sunset on the banks of the East Fork, of what was known as Fennell's Creek, a broad, deep stream which, joining its companion fork some ten miles further down, flowed into the clear waters of the Yellowstone. Here they had cooked their supper after many attempts, made with varying degrees of success and much laughter. Later they had rolled themselves into their blankets and gone to sleep.
They had been awakened by Stacy Brown's yawns. In a moment each had taken his turn at yawning, but all took the interruption good-naturedly, save Ned Rector. By this time he had grown very much excited. No sooner would he pounce upon the spot where Stacy appeared to be, than the fat boy by a few swift rolls would propel himself well beyond the reach of his irate companion.
"It'll be the worse for you when I do get you," cried Ned.
At that moment Ned tripped over a limb, and, plunging headlong, measured his length on the ground.
The sympathy of the camp was with the rolling Chunky.
"Get a net," shouted Walter.
"No, rope him, Ned. That's the only way you ever will catch him," jeered Tad.
Both boys were dancing about their companions, shivering in their pajamas and uttering shouts of glee.
"He's a regular high roller," said Tad.
"No, not a high roller," answered Walter.
"Here, here!" admonished the Professor. "Stop this nonsense. I want to go to sleep. I don't mind you young gentlemen enjoying yourselves, but midnight is rather late for such pranks, it strikes me. Into your blankets, every one of you."
It was doubtful that the boys even heard his voice. If they did, they failed entirely to catch the meaning of his words, so absorbed were they in the mad scramble of Ned Rector and Stacy Brown.
"Roll, Chunky, roll!" urged Walter, jumping up and down in his bare feet.
"Good thing he's fat. If he weren't so round he could never do it," mocked Tad. "I'll bet he was a fast creeper when be was a baby."
The ponies, disturbed by the noise and excitement, had scrambled to their feet and were moving about restlessly in the bushes where they were tethered.
"Master Stacy, you will get up at once!" commanded the Professor sternly.
"I can't," wailed the fat boy.
"Then I'll help you," decided the Professor firmly, striding toward the spot where he had last heard the lad's voice.
"Look out for the river!" warned Tad, as the thought of what was below the boy suddenly occurred to him.
"Help, help! I'm rolling in," cried Stacy.
"There he goes, down the bank! Grab him!" shouted Walter.
"Where?" demanded Ned, not fully grasping the import of the warning.
"There, there! Don't you see him? Right in front of you. He's going to fall into the river!"
Stacy had forgotten that they were encamped on the east shore of the fork and that the broad stream was flowing rapidly along just below him. The banks at that point were high and precipitous, the water almost icy cold, being fresh from the clear mountain streams a few miles above. In spots it was deep and treacherous.
Frantically grasping at weeds and slender sprouts, as he rolled down the almost perpendicular bluff, Stacy yelled lustily for help. From the soft, sandy soil the weeds came away in his hands, without in the slightest degree checking his progress.
Tad realized the danger perhaps more fully than did the others. In the darkness the lad might slip into one of the treacherous river pockets and drown before they could reach him.
Grasping his rope which lay beside his cot. Tad sprang to the top of the bluff, swinging the loop of his lariat above his head as he ran.
He could faintly make out the figure of his companion rolling down the steep bank.
"Hold up your hand so I can drop the rope over you," shouted Tad, at the same time making a skillful cast.
His aim was true. The rawhide reached the mark. Chunky, however, feeling it slap him smartly on the cheek, brushed the rope aside in his excitement, not realizing what it was that had struck him.
"Grab it!" roared Tad, observing that he had failed to rope the lad.
With a mighty splash, Stacy Brown plunged into the stream broadside on.
"He's in! I heard him strike!" cried Walter.
With a warning cry to the others to bring lights, Tad, without an instant's hesitation, leaped over the bluff and went shooting down it in a sitting posture.
"Tad's gone in, too," shouted Walter excitedly, as their ears caught a second splash. It was more clean cut than had been Stacy's dive, and might have passed unnoticed had they not known the meaning of the sound.
Ned Rector stood as if dazed. He knew that somehow he had thoughtlessly plunged his companions into dire peril.
"Wha--what is it?" he stammered.
"They're in the river! Don't you understand?" answered Walter sharply, moving forward as if to follow over the bank in an effort to rescue his companion.
"Keep back!" commanded the Professor. "You'll all drown if you go over that bank."
The Professor, with more presence of mind than the others, had sprung up and rushed for the camp-fire, from which he snatched a burning ember.
At any other time the sight of his long, gaunt figure, clad in a full suit of pink pajamas, dashing madly about the camp, would have excited the lads to uproarious merriment. But laughter was far from their thoughts at that moment.
"Use your eyes! Do you see him?" demanded Professor Zepplin, peering down anxiously into the shadows.
"No. Oh, Tad!" shouted Ned. There was no reply to the boy's hail. "Thaddeus!" roared the Professor. Still no answer.
Down the stream a short distance they could hear the water roaring over the rocks, from where it dropped some twenty feet and continued on its course. The falls there were known as Buttermilk Falls, because of the churning the water received in its lively drop, and more than one mountaineer had been swept over them to his death in times of high water. Between the camp and these falls there was a sharp bend in the river, and ere the boys had recovered from their surprise, their companions undoubtedly had been swept around the bend and on beyond their sight.
"Do--do you--do you think----" stammered Walter.
"They have gone down stream," answered the Professor shortly. "Run for it, boys! Run as you never ran before!"
Ned dived for the thicket where the ponies were tethered. It was the work of a moment only to release Bad-eye. Without waiting to saddle him, Ned threw himself upon the surprised animal's back, and with a wild yell sent the broncho plunging through the camp.
He was nearly unseated when Bad-eye suddenly veered to avoid stepping into the camp-fire, which Ned Rector in his haste had forgotten.
The lad gripped the pony's mane and hung on desperately until he finally succeeded in righting himself, all the while kicking the pony's sides with his bare feet to urge him on faster.
They were out of the camp, tearing through the thicket before the Professor and Walter had even gotten beyond the glow of the fire. Ned was obliged to make a wide detour instead of taking a short cut across the bend made by the river. There were rocks in his way, so that a few moments of valuable time were lost before he reached the stream on the other side of the obstruction.
"Come, we must run," urged the Professor. "I'm afraid both of them may have gone over the falls."
"Oh, I hope he is not too late!" answered Walter, with a half sob, as they ran regardless of the fact that sharp sticks and jagged stones were cruelly cutting into their feet.