Chapter XXI
A New Explosive
The young inventor was idly handling some pieces of the very hard rockthat had cropped out in the tunnel cut. Tom had tested it, he hadpulverized it (as well as he was able), he had examined it under themicroscope, and he had taken great slabs of it and set off under it, oron top of it, charges of explosive of various power to note the effect.But the results had not been at all what he had hoped for.
"What's to be done, Tom?" repeated the contractor.
"Well, Mr. Titus," was the answer, "the only thing I see to do is tomake a new explosive."
"Can you do it, Tom?"
The reply was characteristic.
"I can try."
And in the days that followed, Tom began work on a new line. He hadbrought from Shopton with him much of the needful apparatus, and hefound he could obtain in Lima what he lacked.
A message to his father brought the reply that the new ingredients Tomneeded would be shipped.
"The kind of explosive we need to rend that very hard rock," the younginventor explained to the Titus brothers, "is one that works slowly."
"I thought all explosions had to be as quick as a flash," said Walter.
"Well, in a sense, they do. Yet we have quick burning and slow-burningpowders, the same as we have fuses. A quick-burning explosive is allright in soft rock, or in soil with rock and earth mingled. But in rockthat is harder than flint if you use a quick explosive, only the outersurface of the rock will be scaled off.
"If you take a hammer and bring it down with all your force on a hardrock you may chip off a lot of little pieces, or you may crack therock, but you won't, under ordinary circumstances, pulverize it as wewant to do in the tunnel.
"On the other hand, if you take a smaller hammer, and keep tapping therock with comparatively gentle blows, you will set up a series ofvibrations, that, in time, will cause the hard rock to break up intoany number of small pieces.
"Now that is the kind of explosive I want--one that will deal asuccession of constant blows at the hard rock instead of one great bigblast."
"Can you make it, Tom?"
"Well, I don't know. I'll do the best I can."
From then on Tom was busy with his experiments.
Work on the tunnel did not cease while he was searching for a newexplosive. There was plenty of the old explosive left and charges ofthis were set off as fast as holes could be drilled to receive it. Butcomparatively little was accomplished. Sometimes more rock would beloosed than at others, and the native laborers, now seemingly perfectlycontented, would be kept busy. Again, when a heavy blast would be setoff hardly a dozen dump cars could be filled.
But the work must go on. Already the time limit was getting perilouslyclose, and the contractors did not doubt that their rivals were onlywaiting for a chance to step in and take their places.
Nothing more had been seen or heard of the bearded man, Waddington, orBlakeson & Grinder. But that the rival firm had not given up wasevidenced by the efforts made in New York to cripple, financially, thefirm in which Tom was interested. In fact, at one time the Titusbrothers were so tied up that they could not get money enough to paytheir men. But Tom cabled his father, who was quite wealthy, and Mr.Swift loaned the contractors enough to proceed with until they coulddispose of some securities.
It might be mentioned that Tom was to get a large sum if the tunnelwere completed on time, so it was to his interest and his father's, tobring this about if he could.
Tom kept on with his powder experiments. Mr. Damon helped him, for thatgentleman had succeeded in putting the affairs of the wholesale drugbusiness on a firm foundation, and there was no more trouble aboutgetting the supplies of cinchona bark to market. The natives seemed tohave taken kindly to the eccentric man, or perhaps it was thereputation of Tom Swift and his electric rifle that induced them towork hard.
It must not be supposed that Professor Bumper was idle all this while.
He came and went at odd times, accompanied by his little retinue ofIndians, a guide and a native cook. He would come back to the tunnelcamp, where he made his headquarters, travel stained, worn and weary,with disappointment showing on his face.
"No luck," he would report. "The hidden city of Pelone is still lost."
Then he would retire to his tent, to pour over his note-books, and makea new translation of the inscription on the golden plates. In a day orso, refreshed and rested, he would prepare for another start.
"I'll find it this time, surely!" he would exclaim, as he marched offup the mountain trail. "I have heard of a new valley, never beforevisited by a white man, in which there are some old ruins. I'm surethey must be those of Pelone."
But in a week or so he would come back, worn out and discouraged again.
"The ruins were only those of a native village," he would say. "Notrace of an ancient civilization there."
The professor took little or no interest in the tunnel, though heexpressed the hope that Tom and his friends would be successful. Butindustrial pursuits had no charm for the scientist. He only lived tofind the hidden city which was to make him famous.
He heard the story of the queer shaft leading down into the bore underthe mountain, and, for a time, hoped that might be some clue to thelost Pelone. But, after an examination, he decided it was but the shaftto some ancient mine which had not panned out, and so had beenabandoned after having been fitted with a balanced rocky door, perhapsfor some heathen religious rite.
There seemed to be no further trouble among the Indian tunnel workers.Those who had disappeared--who had, seemingly, gone willingly up theknotted rope to hide themselves in the valley--kept on with their work.If they told their fellows why and where they had gone, the others gaveno sign. The evil spirits of the tunnel had been exorcised, and therewas now peace, save for the blasts that were set off every so often.
Tom tried combination after combination, testing them inside andoutside the tunnel, always seeking for an explosive that would give aslow, rending effect instead of a quick blow, the power of which wassoon lost. And at last he announced:
"I think I have it!"
"Have you? Good!" cried Job Titus.
"Yes," Tom went on, "I've got a mixture here that seems to give justthe effect I want. I tried it on some small pieces of rock, and now Iwant to test it on some large chunks. Have you brought any downlately?"
"Yes, we have some big slabs in there."
Some large pieces of the hard rock, which had been brought down in arecent blast, were taken outside the tunnel, and in them one afternoonTom placed, in holes drilled to receive it, some of his new explosive.The rocks were set some distance away from the tunnel camp, and Tomattached the electric wires that were to detonate the charge.
"Well, I guess we're ready," announced the young inventor, as he lookedabout him.
The tunnel workers had been allowed to go for the day, and in a logshack, where they would be safe from flying pieces of rock, were Tom,Mr. Damon and the two Titus brothers.
Tom held the electric switch in his hand, and was about to press it.
"This explosive works differently from any other," he explained. "Whenthe charge is fired there is not instantly a detonation and a bursting.The powder burns slowly and generates an immense amount of gas. It isthis gas, accumulating in the cracks and crevices of the rock, that Ihope will burst and disintegrate it. Of course, an explosion eventuallyfollows, as you will see. Here she goes!"
Tom pressed the switch and, as he did so, there was a cry of alarm fromMr. Damon.
"Bless my safety match, Tom!" cried the old man. "Look! Koku!"
For, as the charge was fired, the giant emerged from the woods andcalmly took a seat on the rock that was about to be broken up intofragments by Tom's new explosive.