"I hope nothing like that happens until we get away," spoke Mr. Damon, fervently.
"What had we better do?" inquired Tom.
"Get away, unless you want to discover some more of their secrets,"
advised Bill. "Those fellows are planning something, but I can"t find out what it is. They are suspicious of me, I think. But they are up to something, and I believe, it would be best for you to leave while you have the chance. It may not be healthy to stay. That"s why I did my best to untie you."
"We appreciate what you have done," declared Mr. Jenks, "but I want my rights. I must learn a few more facts about how to make diamonds from lightning flashes, and then I will have the same secret they cheated me out of. I think if we wait a while we may be able to see the parts of the process that are not quite clear to us. What do you say, Tom Swift?"
"Well, I would like to learn the secret," replied the lad, "and if Bill thinks it"s safe to stay here a while longer--"
"Oh, I guess it will be safe enough," was the reply. "Those fellows won"t bother about you now that they are about to make some more diamonds. Besides, they think you"re all tied up. Yes, you can stay here and watch, I reckon. I"ve got a couple of guns, and--"
"Then we"ll stay," decided Tom. "We can put up a better fight now."
Silently, in their prison, but which they could now leave whenever they pleased, the adventurers watched the diamond makers once more. The same process they had witnessed before was gone through with. The white b.a.l.l.s were put inside the steel box and sealed up. Then they waited for the storm to reach its height.
That this would not be long was evidenced by the mutterings of thunder which every moment grew louder. The outburst of electrical fury was likely to take place momentarily, and that it would be unusually severe was shown by the precautions taken by the diamond makers. They attached a number of extra wires, and brought out some insulated, hard rubber platforms, on which they themselves stood. Tom and Mr. Jenks were much interested in watching this detail of the work, and sought to learn how each part of the process was done.
"I almost think we can make diamonds, Tom, when we get back to civilization," whispered Mr. Jenks.
"I hope we can," answered Tom, "and we can"t get back any too soon to suit me. I want to be in my airship again."
"I don"t blame you. But look, they are getting ready to adjust the switch."
The adventurers ceased their whispered talk, and eagerly watched the diamond makers. Folwell and Munson were hurrying to and fro in the big cave, attending to the adjustments of the machinery.
"On your insulated plates--all of you," Folwell gave the order. "This is going to be a terrific storm. The gage shows twice the power we have ever used, and it"s creeping up every minute! We"ll have more diamonds than ever had before!"
"Yes, if the mountain isn"t destroyed," added Mr. Parker, in a low voice. "I predict that it will be split from top to bottom!"
"Comforting," thought Tom, grimly.
"I guess we"re all ready," said Folwell, in a low tone to Munson. "We"d better get insulated ourselves. I"m going to throw the switch."
He did so. A moment later the man who had before given warning of the storm came dashing in. He was very much excited.
"It"s awful!" he cried. "The lightning is striking all over! Big rocks are being split like logs of wood!"
"Well, it can"t do any damage in here," said Munson. "We are well protected. Get on one of the plates," and he motioned to one of the hard-rubber platforms that was not occupied. The roar and rumble of the storm outside had given place to short terrific crashes. In their small cave the adventurers could feel the solid ground shake.
A bluish light began dancing about the electrical wires. There was a smell of sulphur in the air. Crash after crash resounded outside. A flash of flame lit up the whole interior of the cave. It came from the copper switch.
"Something"s wrong with the insulation!" cried Munson.
"Don"t go near it!" yelled Folwell. "If you value your life, stand still!"
Hardly had he spoken than inside the cavern there sounded a report like that of a small cannon. A big ball of fire danced about the middle of the cave and then leaped on top of the steel box.
"This is a fearful storm," cried Munson.
The adventurers in the cave did not know what to say or do. They were in deadly peril.
Suddenly there came a crash louder than any that had preceded it. The whole side of the cave where the switches were was a ma.s.s of bluish flame. Then came a ripping, tearing sound, and a tangle of wires and copper connections were thrown to the floor. At the same time the steel box, containing the materials from which diamonds were made, turned blue, and flames shot from it.
"It"s all up with us!" cried Munson. "Run for it, everybody! The wires are down, and this place will be an electric furnace in another minute!"
He leaped toward the exit from the cave.
"What about those fellows?" asked Folwell, indicating the place where Tom and the others had been tied.
"They"ll have to do the best they can! It"s every man for himself, now!"
yelled Munson. There was a wild scramble from the cavern.
"Come on!" cried Tom. "We must escape! It"s our only chance!"
He leaped into the big cave, followed by the others. Already long tongues of electrical fire were shooting out from the walls and roof as Tom Swift and his companions, evading them as best they could, sought safety in flight.
CHAPTER XXV--THE MOUNTAIN SHATTERED--CONCLUSION
"Can"t we get some of the diamonds?" cried Mr. Damon, as he raced along behind Tom. "Now"s our chance. Those fellows have all gone!" The odd man made a grab for something as he ran.
"It"s as much as our lives are worth," declared the young inventor. "We dare not stop! Come on!"
"I"d like to investigate some of the machinery," spoke Mr. Jenks, "but I wouldn"t stop, even for that."
"The storm is too dangerous," called Bill Renshaw. "I can show you a shorter way out than the one those fellows have taken. Follow me."
"No way can be too short," said Mr. Parker, solemnly. "This mountain will go to pieces shortly, I think!"
Tom shuddered. He remembered how narrow had been their escape when Earthquake Island sank into the sea. And that some terrific upheaval was now imminent might be judged from the awful reports that sounded more plainly as the adventurers raced toward the opening of the cave. It was like the bombardment of some doomed city.
Mr. Jenks and Tom cast one longing look behind at the complicated and expensive machinery that had been installed in the cave by the diamond makers. They had abandoned it, and in it lay the secret of making precious gems. But there was no time to stop now, and investigate.
"This way," urged Bill Renshaw. "We"ll soon be out."
"But won"t it be dangerous to go outside?" asked Mr. Damon. "Shan"t we be struck by lightning? There is some protection in here."
"None at all," said Mr. Parker, quickly. "This mountain is a natural lightning rod. To stay here in this cave will be sure death when the storm gets directly over it. And that will be very soon. We must get on insulated ground. Is there any part of this mountain that does not contain iron ore?" the scientist asked of the former spirit.
"Yes; the way out by which we are going lands on a dirt hill."
"That"s good; then we may be saved."
On they ran. They had no lanterns, but the blue light of the electricity, as it leaped from point to point inside the cave, where there were outcroppings of iron ore, made the place bright enough to see.