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 tunnel camp, 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 make a new translation of the inscription on the golden plates.In a day or so, refreshed and rested, he would prepare for another start.
"I'll find it this time, surely!" he would exclaim, as he marched off up the mountain trail."I have heard of a new valley, never before visited by a white man, in which there are some old ruins.I'm sure they 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."No trace of an ancient civilization there."The professor took little or no interest in the tunnel, though he expressed the hope that Tom and his friends would be successful.But industrial pursuits had no charm for the scientist.He only lived to find the hidden city which was to make him famous.
He heard the story of the queer shaft leading down into the bore under the mountain, and, for a time, hoped that might be some clue to the lost Pelone.But, after an examination, he decided it was but the shaft to some ancient mine which had not panned out, and so had been abandoned after having been fitted with a balanced rocky door, perhaps for 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 the knotted rope to hide themselves in the valley--kept on with their work.If they told their fellows why and where they had gone, the othersgave no sign.The evil spirits of the tunnel had been exorcised, and there was now peace, save for the blasts that were set off every so often.
Tom tried combination after combination, testing them inside and outside the tunnel, always seeking for an explosive that would give a slow, rending effect instead of a quick blow, the power of which was soon 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 just the effect I want.I tried it on some small pieces of rock, and now I want to test it on some large chunks.Have you brought any down lately?""Yes, we have some big slabs in there."
Some large pieces of the hard rock, which had been brought down in a recent blast, were taken outside the tunnel, and in them one afternoon Tom placed, in holes drilled to receive it, some of his new explosive.The rocks were set some distance away from the tunnel camp, and Tom attached the electric wires that were to detonate the charge"Well, I guess we're ready," announced the young inventor, as he looked about him.
The tunnel workers had been allowed to go for the day, and in a log shack, 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.
"When the charge is fired there is not instantly a detonation and a bursting.The powder burns slowly and generates an immense amount of gas.It is this gas, accumulating in the cracks and crevices of the rock, that I hope will burst and disintegrate it.Of course, an explosion eventually follows, as you will see.Here she goes!"Tom pressed the switch and, as he did so, there was a cry of alarm from Mr.Damon.
"Bless my safety match, Tom!" cried the old man."Look! Koku!"For, as the charge was fired, the giant emerged from the woods and calmly took a seat on the rock that was about to be broken up intofragments by Tom's new explosive.
