"Well?" said Jack.
"Well, I heard a soft footstep and the crackling of some twigs. I looked round and my bag of specimens had gone. Now which of you boys played that foolish joke on me?"
"I"ll give you my word we know nothing about it, professor," declared Tom. "d.i.c.k and I have been working all the morning unpacking stuff from the Wondership."
The professor looked at them incredulously.
"That"s right," struck in Zeb, "they haven"t been out of my sight."
"But--but," stammered the professor, "my dear sir, that bag of specimens didn"t walk off, you know. Besides," he added, "I heard a human footfall distinctly."
"It may not have been the boys, though," spoke up Jack seriously.
"Indeed, who else then?" inquired the professor stiffly.
"An unwelcome neighbor," replied Jack. "We are not alone on this island."
"Not alone? What do you mean?" demanded the professor in thunderstruck tones.
"Just this, that there is someone else on it. Who or what it is I don"t know."
And Jack went on to explain all that he had seen.
CHAPTER x.x.xIII.
THE SECRET AT LAST.
Mysteries are always uncomfortable. As Jack proceeded with his narrative, d.i.c.k and Tom looked nervously about them. Even the boys" two elders looked grave. The presence of a man on the island was almost inexplicable. But Jack"s story was so circ.u.mstantial that there was no room to suppose that he might be mistaken. Besides, he had the bit of canvas to show, the sc.r.a.p that he had taken from the thornbush.
After dinner Tom and d.i.c.k resumed their work of unloading necessaries from the Wondership. Jack and the two elder members of the party discussed plans.
"You haven"t found any trace of mineral-bearing rock yet, have you, professor?" asked Jack.
The professor shook his head.
"Not a speck of anything that even remotely corresponds with the black sand that Zeb brought East with him," said the man of science, dejectedly.
"It isn"t possible that we have been fooled," said Zeb.
"Or landed on the wrong island," struck in Jack.
"It must be the right island," declared Zeb.
"How do you make that out?" asked Jack.
"Well, it"s got every mark on it that the map gives, for one thing," said Zeb.
"That"s so," agreed the professor, and then he added hopefully: "However, I haven"t covered half the ground yet."
Tom and d.i.c.k came tramping back at that juncture. They carried some canned goods and d.i.c.k bore the rusty shovel that they had seen the day before sticking up in the black barren.
"It was sticky and moist out there," he said, "but I figured we could always use this shovel, so I went out and brought it along."
He flung himself down full length in the shade for it was hot and there was not a breath of wind to fan the canyon. The professor, who sat facing d.i.c.k, concentrated his attention for an instant on the soles of the youngster"s boots. Then he leaped up with a yell that startled them.
"What is it? The wild man?" gasped d.i.c.k, looking round him in alarm.
"No, your boots, your boots; look at them!" cried the professor.
"Is there a snake on them?" cried d.i.c.k, preparing to jump up.
"Don"t move! Don"t move for your life!" fairly screamed the dumpy little geologist, springing forward. He fell on his knees at d.i.c.k"s boots as if they had been sacred, and with trembling fingers flaked off, into his left palm, some black mud which stuck to them.
Then he stood erect, his face aglow with triumph and enthusiasm such as the man of science rarely permitted himself.
"Gentlemen," he said, with a flourish, "there is no reason to look further for the mineral-bearing ground."
"You have found it?" choked out Jack.
"Yes."
"Where?"
"On d.i.c.k Donovan"s boots."
They looked at him as if they thought he had suddenly gone demented. d.i.c.k examined his boots carefully as if he expected to see money plastered all over them.
The professor extended his palm. In it lay the black earth he had sc.r.a.ped from d.i.c.k"s boots. In it tiny particles glittered and gleamed like myriads of infinitesimal eyes.
"Z. 2. X.," said the professor in solemn tones, and he waved his hand down toward the black barren where the moist, unhealthy-looking bare patch lay quivering and sweltering in the sun. A kind of haze hung above it, like a very thin fog.
"There it is," he went on, "down there. Waiting to be extracted from that black earth. Look."
He shook the black earth from his palm. Where it had lain there was a red, irritated-looking patch. The professor showed it. It looked like a slight burn.
"Did that stuff do it?" asked Jack.
"Yes; and that"s almost as definite a proof as an a.n.a.lysis, of its intense radio activity. You noticed that the sample that Zeb had was enclosed in a leaden tube. That was the reason. Such powerful stuff would inflict bad burns if not handled properly."
"So that was why you made us include asbestos gloves and foot coverings and black goggles in the outfit?" cried Tom, who had been much puzzled over the reason for that part of the equipment.
"That was why," said the professor, "and that also is the reason we brought along those lead containers. Z. 2. X. or its ally, radium, or in fact vanadium or any of the allied radio-active metals, would destroy any other sort of container."
"Let"s go down now and start digging," suggested impulsive d.i.c.k.
"Don"t venture out there till you are fully equipped for the job," said the professor. "Serious results might ensue. In the meantime, I am going to a.n.a.lyze this sample in order to be doubly sure."
Jack gave a deep sigh of relief. After all, it was not a dream. They had found the valuable earth. It was now only a question of transportation. His father"s fortunes were saved. The radio-"phone would be rushed to perfection and placed on the market within a short time of their return home.
While Jack lay back and indulged in daydreams, the others watched the professor as he tested the black sand over a portable a.s.saying furnace and made all sorts of experiments to determine its value and the proportion of the different precious metals contained in it.
There was a slight rustling in the bushes behind him. Jack, whose nerves had been rather on edge since the occurrences of the preceding night and that morning, faced round quickly.
The next instant he uttered a loud shout.
Peering out of the bushes was a hideous, hairy face, more like an ape"s than a human being"s. From it glowed two wild, piercing eyes, like those of a beast of prey.
As Jack shouted and the others started toward him, the face vanished like a flash.
CHAPTER x.x.xIV.
THE INTERLOPERS.
"Well, we"ll git ter ther bottom uv this afore we leave ther island," declared Zeb vehemently, "but right now, pussonally, I"m more interested in gitting those lead carboys filled up with Z. 2. X. and gitting away from here."
"So are we," said Jack, thinking of his father.
They all donned their asbestos gloves and foot coverings under the professor"s directions and put on the huge black goggles that had been brought along at the scientist"s directions.
"I guess we"d scare that wild man into conniption fits if he could see us now," chuckled Tom, surveying his mates as they started out for the black barren.
"Yes, we look like a lot of men from Mars," agreed d.i.c.k.
Armed with shovels they attacked the dark, soft earth at a place the professor indicated. For an hour or more they worked and filled three of the lead carboys. Then Jack spoke.
"It"s queer," he said, "but I begin to feel terribly tired, and I haven"t worked long, either."
"So do I," said Tom. "I don"t feel as if I could lift another shovelful."
"I"m all in," added d.i.c.k, throwing down his spade.
"Same here. Jes" "bout tuckered out," chimed in Zeb.
"It"s the effect of the stuff we are working in," said the professor. "Anyhow, we"ve done enough for to-day. We"ll load the lead carboys on the Wondership and then knock off. I don"t want you boys to get sick."
They took the loaded carboys to the grounded craft and the professor sealed and soldered a cover on each of them. Then they went back to the camp. Curiously, as soon as they reached it, the la.s.situde they had felt while working on the black barren left them. Jack proposed a hunting trip to Tom. d.i.c.k said he wanted to write up his notes from which, on their return, he was going to construct a big "story" for his paper.
The two chums struck out across the island. They met with fairly good luck. Jack brought down some rabbits and a partridge. Tom got three partridges and some squirrels. Game appeared to be plentiful on the island and Jack had a theory that at one time it must have been connected with the mainland.
At last their walking brought them out on the upper end of the island facing the smaller spot of land above. As they emerged from the trees, both boys got a big surprise.
Two boats had just been beached there!
"What in the world!" stammered out Jack.
"Who can----" began Tom, when the question was answered. The boys saw three figures coming down to the beach. They, seemingly, had been looking for a camp site.
"It"s that fellow, Bill Masterson," explained Jack.
"So it is, and those other two are his cronies. The sneaks, they"ve followed us here!" cried Tom indignantly.
"Let"s watch from behind these bushes and see what they do," said Jack.
They watched from a place of concealment while the three youths on the island above unloaded the second boat which they had towed down the river, carrying their camping equipment and provisions in it. They set up their tents quite boldly in full view of the other island and then proceeded to build a fire.
"How on earth did they get down the river without having a spill?" cried Jack.
"How did they know where Rattlesnake Island was?" wondered Tom, neither of the boys, of course, knowing of the opened letters.
"They seem prepared to make a long stay," commented Tom, after a minute, "but it"s a wonder they weren"t wrecked."
"I don"t know," said Jack. "Zeb says the river is much higher now than he has ever seen it. That means that the rapids are not so dangerous as at low water. But they were taking quite a chance, at that."
The boys watched for a while longer and then returned to camp with their game and their news.
"If they try to land on this island, we"ll soon chase "em off," declared d.i.c.k vehemently.
"Then they"d have a case at law agin us," said Zeb.
"How do you mean?" asked Jack.
"Wa"al, we ain"t filed no claim yet and in the eyes of the law them deposits down there in the black barren is as much theirs as ours."
That evening Zeb occupied himself with making several signs of intention to file claim which he intended to post all round the black barren, thus marking it off as if it had been a mine. Before they went to bed, Jack and Tom made another excursion to the upper end of the island where they watched the campfires of the interlopers for some time.
Suddenly, while they watched, they saw one of the boats with three figures in it shoved off. The craft began to drop down the river. Masterson, who was at the oars, steered straight for Rattlesnake Island.
"They"re going to land here," declared Jack.
"What do you think of that for nerve," gasped Tom.
"The worst of it is, we can"t stop them."