At the same instant there appeared the leaders of the onrush.

Great, half-famished looking brutes, whose red mouths gaped open ferociously and whose eyes burned wickedly.

But Roy had hardly had time to shout his warning before an accident, entirely unexpected, occurred. His foot caught on a stone and he came down with a crash. The next moment the pack would have been upon him, but Peggy jerked the rifle she had selected to her shoulder and fired into the midst of the savage horde. With a howl of anguish one of the creatures leaped high in a death agony and came toppling down among his mates, a limp, inanimate ma.s.s. This checked the surging onrush for an instant, and in that instant Roy was on his feet and sprinting briskly toward the girls.

Straight for the aeroplanes they headed. Reaching them they entrenched themselves in what they could not but feel was an immensely insecure position.

"Thank you, sis," was all that Roy, with a bit of a choke in his voice, was able to gasp out before the leaders of the pack were on them.

More by instinct than with any definite idea, the young people began desperately pumping lead into the seething confusion of gray backs and red gaping mouths.

All at once poor Jess, half beside herself with terror, gave a throaty little gasp.

"I think I'm going to faint," she exclaimed feebly.

Peggy gave her a sharp glance.

"You'll do no such thing, Jess Bancroft," she said sharply, although the pity in her eyes belied the harshness of the words, "if you do I'll--I'll never speak to you again!"

The words had their calculated effect, and Jess made a brave rally.

At almost the same instant a shot from Roy's rifle brought down the largest of the creatures of the desert, a big hungry looking brute with tawny, scraggy hair and bristling hackles. As he rolled over with a howl of anguish and rage a sudden wavering pa.s.sed through the pack. It was like a wind-shadow sweeping over a field of summer wheat.

"Hooray, we've got them beaten!" shouted Roy, enthusiastically.

The lad was right. Their leader fallen, the remainder of the pack had seemingly no liking for keeping up the attack. Still snarling they began to retreat slowly--a backward movement, which presently changed into a mad, helter skelter rush. Panic seized on them, and down the dry arroyo they fled, a dense cloud of yellow, pungent dust rising behind them. In a few seconds all that remained to tell of the battle in the gulch were the still bodies of the brutes that had fallen before the boy and girl aviators' rifles.

They were contemplating the scene when, from further up the gully, there came a sound that set all their pulses beating.

It was the shout of a human voice.

"Thank heaven you were not too late!"

While they were still standing stock still in startled immobility at the recognition of Mr. Bell's voice, there came another hail.

"h.e.l.lo, Jess! h.e.l.lo, Peggy and Roy!"

Emerging from the cloud of dust which was still thick, there staggered toward them two uncanny looking figures in which they had at first some difficulty in recognizing Mr. Bell and Jimsy Bancroft.

But when they did what a shout went up!

It echoed about the dead hills and rang hollowly in the silent gully. An instant later the reunited adventurers were busily engaged in exchanging greetings of which my readers can guess the tenor. Then came explanations.

"On arriving in the arroyo," said Mr. Bell, "Jimsy and I decided to set out at once to examine the mine site, and lay if off for purposes of proper location with the United States government. I must tell you that the mine--or rather the site of it--is located in that cavern yonder further up the arroyo."

"Why it was round the entrance to that that the coyotes were gathered when we first dropped!" cried Peggy.

"Exactly. And very much to our discomfort, too, I can tell you,"

rejoined Mr. Bell dryly.

"They had you besieged!" exclaimed Roy.

"That's just it, my boy. They must have been famished, or they never would have gathered up the courage to do it, for, as a rule, one man can put a whole pack of the brutes to flight. I suppose, however, they realized that they had us cornered, for, with a sort of deadly deliberation, they seated themselves round the mouth of the cavern, seemingly awaiting the proper time for us to be starved out or driven forth by thirst. Luckily, however, we had canteens with us and a scanty supply of food, otherwise it might have been the last of us."

Jess shuddered and drew very close to Jimsy.

"And you had no weapons," volunteered Roy.

"Ah, I see you encountered our guns in the cha.s.sis of the aeroplane.

No, foolishly, I'll admit, we omitted to arm ourselves for such a short excursion. Of course we never dreamed of any danger of that sort in this lonely place, and least of all from the source from which it came. But I can, tell you, it was an ugly feeling when, on preparing to emerge with some specimens of the ore-bearing rocks, we found ourselves facing a grim semi-circle, banked dozens deep, of those famished coyotes. They greeted our appearance with a howl, and when we tried to scare them off they just settled down on their haunches to wait."

"Their silence was worse than their yapping and barking, I think,"

struck in Jimsy.

"It certainly was," agreed Mr. Bell; "both of us tried to keep up good hearts, but when the night pa.s.sed and morning still found the brutes there, things began to look bad. Of course we knew that you would set out to look for us when we did not return, but we did not know if you would reach here in time."

"But you did," cried Jimsy, regarding the dead bodies of coyotes the vanquished pack had left behind.

"And excellent work your rifles did, too," declared Mr. Bell warmly.

"Our rifles and--the Girl Aviators," said Roy, and proceeded to tell the interested listeners from the cavern some incidents which caused them to open their eyes and regard our girls with unconcealed admiration.

CHAPTER X

RESCUED BY AEROPLANE

"What's that down there?"

Roy pointed downward from the aeroplane to a small black object crawling painfully over the glistening white billows of alkali far below them.

The lad, his sister and Jess were on their way back from the arroyo in which the battle with the coyotes had occurred. Mr. Bell and Jimsy had been left behind, for the former was anxious to "prospect"

his mine as thoroughly as possible in order to ascertain if it gave indications of living up to its first rich promise. A brief inspection of the cave had thoroughly disgusted Peggy and Jess.

"Is this a rich gold mine!" Jess had cried, indignantly regarding the dull walls on which the torches had glowed unflatteringly; "it looks more like the interior of the cellar at home."

"All is not gold that glitters," Mr. Bell had responded with a smile. At the same moment he had flaked off a chunk of dark colored metal with his knife.

"There, Miss Jess," he exclaimed, handing it to the girl, "that is almost pure gold, and I am in hopes that there is lots more where that came from."

And they had been kind enough not to laugh too immoderately at Jess's discomfiture.

A short time later, having located a water hole and partaken of a good lunch, Roy and his companions had re-embarked and started back to camp with the joyful tidings that the missing adventurers had been found. They had been under way but a short time when Roy's attention had been attracted by the moving dot which had caused him to utter the exclamation recorded at the beginning of this chapter.

Against the flat, baking, quivering expanse of alkali the crawling splotch of black showed up as plainly as a blot of ink on a sheet of clean white blotting paper. Peering over the edge of the cha.s.sis they all scrutinized it closely.

"It's--it's a man!" cried Jess at length.