Chapter XX. The Wireless Plant
 

The castaways had been on Earthquake Island a week now, and in that time had suffered many shocks. Some were mere tremors, and some were so severe as to throw whole portions of the isle into the sea. They never could tell when a shock was coming, and often one awakened them in the night.

But, in spite of this, the refugees were as cheerful as it was possible to be under the circumstances. Only Mr. Jenks seemed nervous and ill at ease, and he kept much by himself.

As for Tom, Mr. Damon and Mr. Fenwick, the three were busy in their shack. The others had ceased to ask questions about what they were doing, and Mr. Nestor and his wife took it for granted that Tom was building a boat.

Captain Mentor and the mate spent much time gazing off to sea, hoping for a sight of the sail of some vessel, or the haze that would indicate the smoke of a steamer. But they saw nothing.

"I haven't much hope of sighting anything," the captain said. "I know we are off the track of the regular liners, and our only chance would be that some tramp steamer, or some ship blown off her course, would see our signal. I tell you, friends, we're in a bad way."

"If money was any object--," began Mr. Jenks.

"What good would money be?" demanded Mr. Hosbrook. "What we need to do is to get a message to some one--some of my friends--to send out a party to rescue us."

"That's right," chimed in Mr. Parker, the scientist. "And the message needs to go off soon, if we are to be saved."

"Why so?" asked Mr. Anderson.

"Because I think this island will sink inside of a week!"

A scream came from the two ladies.

"Why don't you keep such thoughts to yourself?" demanded the millionaire yacht owner, indignantly.

"Well, it's true," stubbornly insisted the scientist.

"What if it is? It doesn't do any good to remind us of it."

"Bless my gizzard, no!" exclaimed Mr. Damon. "Suppose we have dinner. I'm hungry."

That seemed to be his remedy for a number of ills.

"If we only could get a message off, summoning help, it would be the very thing," sighed Mrs. Nestor. "Oh, how I wish I could send my daughter, Mary, word of where we are. She may hear of the wreck of the Resolute, and worry herself to death."

"But it is out of the question to send a message for help from Earthquake Island," added Mrs. Anderson. "We are totally cut off from the rest of the world here."

"Perhaps not," spoke Tom Swift, quietly. He had come up silently, and had heard the conversation.

"What's that you said?" cried Mr. Nestor, springing to his feet, and crossing the sandy beach toward the lad.

"I said perhaps we weren't altogether cut off from the rest of the world," repeated Tom.

"Why not," demanded Captain Mentor. "You don't mean to say that you have been building a boat up there in your little shack, do you?"

"Not a boat," replied Tom, "but I think I have a means of sending out a call for help!"

"Oh, Tom--Mr. Swift--how?" exclaimed Mrs. Nestor. "Do you mean we can send a message to my Mary?"

"Well, not exactly to her," answered the young inventor, though he wished that such a thing were possible. "But I think I can summon help."

"How?" demanded Mr. Hosbrook. "Have you managed to discover some cable line running past the island, and have you tapped it?"

"Not exactly." was Tom's calm answer, "but I have succeeded, with the help of Mr. Damon and Mr. Fenwick, in building an apparatus that will send out wireless messages!"

"Wireless messages!" gasped the millionaire. "Are you sure?"

"Wireless messages!" exclaimed Mr. Jenks. "I'll give--" He paused, clasped his hands on his belt, and turned away.

"Oh, Tom!" cried Mrs. Nestor, and she went up to the lad, threw her arms about his neck, and kissed him; whereat Tom blushed.

"Perhaps you'd better explain," suggested Mr. Anderson.

"I will," said the lad. "That is the secret we have been engaged upon--Mr. Damon, Mr. Fenwick and myself. We did not want to say anything about it until we were sure we could succeed."

"And are you sure now?" asked Captain Mentor.

"Fairly so."

"How could you build a wireless station?" inquired Mr. Hosbrook.

"From the electrical machinery that was in the wrecked Whizzer," spoke Tom. "Fortunately, that was not damaged by the shock of the fall, and I have managed to set up the gasolene engine, and attach the dynamo to it so that we can generate a powerful current. We also have a fairly good storage battery, though that was slightly damaged by the fall."

"I have just tested the machinery, and I think we can send out a strong enough message to carry at least a thousand miles."

"Then that will reach some station, or some passing ship," murmured Captain Mentor. "There is a chance that we may be saved."

"If it isn't too late," gloomily murmured the scientist. "There is no telling when the island will disappear beneath the sea."

But they were all so interested in Tom's announcement that they paid little attention to this dire foreboding.

"Tell us about it," suggested Mr. Nestor. And Tom did.

He related how he had set up the dynamo and gasolene engine, and how, by means of the proper coils and other electrical apparatus, all of which, fortunately, was aboard the Whizzer, he could produce a powerful spark.

"I had to make a key out of strips of brass, to produce the Morse characters," the lad said. "This took considerable time, but it works, though it is rather crude. I can click out a message with it."

"That may be," said Mr. Hosbrook, who had been considering installing a wireless plant on his yacht, and who, therefore, knew something about it, "you may send a message, but can you receive an answer?"

"I have also provided for that," replied Tom. "I have made a receiving instrument, though that is even more crude than the sending plant, for it had to be delicately adjusted, and I did not have just the magnets, carbons, coherers and needles that I needed. But I think it will work."

"Did you have a telephone receiver to use?"

"Yes. There was a small interior telephone arrangement on Mr. Fenwick's airship, and part of that came in handy. Oh, I think I can hear any messages that may come in answer to ours."

"But what about the aerial wires for sending and receiving messages?" asked Mr. Nestor.

"Don't you have to have several wires on a tall mast?"

"Yes, and that is the last thing to do," declared Tom. "I need all your help in putting up those wires. That tall tree on the crest of the island will do," and he pointed to a dead palm that towered gaunt and bare like a ship's mast, on a pile of rocks in the centre of Earthquake Island.