The lad was of an inventive mind, as was his father, and in the succeeding books of the series, which you will find named in detail elsewhere, I related how Tom got a motorboat, made an airship, and later a submarine, in all of which craft he had strenuous times and adventures.

His electric runabout was quite the fastest car on the road, and when he sent his wonderful wireless message he saved himself and others from Earthquake Island. He solved the secret of the diamond makers, and, though he lost a fine balloon in the caves of ice, he soon had another air craft--a regular sky-racer. His electric rifle saved a party from the red pygmies in Elephant Land, and in his air glider he found the platinum treasure. With his wizard camera, Tom took wonderful moving pictures, and in the volume immediately preceding this present one, called "Tom Swift and His Great Searchlight," I had the pleasure of telling you how the lad captured the smugglers who were working against Uncle Sam over the border.

Tom, as you will see, had, with the help of his father, perfected many wonderful inventions. The lad lived with his aged parent, his mother being dead, in the village of Shopton, in New York State.

While the house, which was presided over by the motherly Mrs. Baggert, was large, it was almost lost now amid the many buildings surrounding it, from balloon and airship hangars, to shops where varied work was carried on. For Tom did most of his labor himself, of course with men to help him at the heavier tasks. Occasionally he had to call on outside shops.

In the household, beside his father, himself and Mrs. Baggert, was Eradicate Sampson, an aged colored man-of-all-work, who said he was called "Eradicate" because he eradicated dirt. There was also Koku, a veritable giant, one of two brothers whom Tom had brought with him from Giant Land, when he escaped from captivity there, as related in the book of that name.

Mr. Damon was, with Ned Newton, Tom's chum, the warmest friend of the family, and was often at Tom's home, coming from the neighboring town of Waterford, where he lived.

Tom had been back some time now from working for the government in detecting the smugglers, but, as you may well suppose, he had not been idle. Inventing a number of small things, including useful articles for the house, was a sort of recreation for him, but his mind was busy on one great scheme, which I will tell you about in due time.

Among other things he had just perfected a new style of magneto for one of his airships. The magneto, as you know, is a sort of small dynamo, that supplies the necessary spark to the cylinder, to explode the mixture of air and gasoline vapor. He was trying out this magneto in the Humming Bird when the accident I have related in the first chapter occurred.

"There! He's coming to!" exclaimed Mrs. Baggert, as she leaned over Tom, who was stretched out on the sofa in the library. "Give him another smell of this ammonia," she went on, handing the bottle to Mr.

Swift.

"No--no," faintly murmured Tom, opening his eyes. "I--I've had enough of that, if you please! I'm all right."

"Are you sure, Tom?" asked his father. "Aren't you hurt anywhere?"

"Not a bit, Dad! It was foolish of me to go off that way; but I couldn't seem to help it. It all got black in front of me, and--well, I just keeled over."

"I should say you did," spoke Mr. Peterson.

"An' ef he hadn't a-been there to cotch yo' all," put in Eradicate, "yo' all suah would hab hit de ground mighty hard."

"That's two services he did for me today," said Tom, as he managed to sit up. "Cutting that wire--well, it saved my life, that's certain."

"I believe you, Tom," said Mr. Swift, solemnly, and he held out his hand to his old mining partner.

"Do you need the doctor?" asked Mr. Damon, who was at the telephone.

"He says he'll come right over--I can get him in Tom's electric runabout, if you say so. He's on the wire now."

"No, I don't need him," replied the young inventor. "Thank him just the same. It was only an ordinary faint, caused by the slight electrical shocks, and by getting a bit nervous, I guess. I'm all right--see,"

and he proved it by standing up.

"He's aLl right--don't come, doctor," said Mr. Damon into the telephone. "Bless my keyring!" he exclaimed, "but that was a strenuous time!"

"I've been in some tight places before," went on Tom, as he sat down in an easy chair, "and I've had any number of shocks when I've been experimenting, but this was a sort of double combination, and it sure had me guessing. But I'm feeling better every minute."

"A cup of hot tea will do you good," said motherly Mrs. Baggert, as she bustled out of the room. "I'll make it for you."

"You cut that wire as neatly as any lineman could," went on Tom, glancing from Mr. Peterson out of the window to where one of his workmen was repairing the break. "When I flew over it in my airship I never gave a thought to the trailer from my wireless outfit. The first I knew I was caught back, and then pulled down to the balloon shed roof, for I tilted the deflecting rudder by mistake.

"But, Mr. Peterson," Tom went on, "I haven't seen you in some time.

Anything new on, that brings you here?" for the fortune-hunter had called at the Swift house after Tom had gone out to the shop to get his airship ready for the flight to try the magneto.

"Well, Tom, I have something rather new on," replied Mr. Peterson. "I hoped to interest your father in it, but he doesn't seem to care to take a chance. It's a lost opal mine on a little-known island in the Caribbean Sea not far from the city of Colon. I say not far--by that I mean about twenty miles. But your father doesn't want to invest, say, ten thousand dollars in it, though I can almost guarantee that he'll get five times that sum back. So, as long as he doesn't feel that he can help me out, I guess I'd better be traveling on."

"Hold on! Wait a minute. Don't be in a hurry," said Mr. Swift.

Mr. Peterson was an old friend, and when he and Mr. Swift were young men they had prospected and grub-staked together. But Mr. Swift soon gave that up to devote his time to his inventions, while Mr. Peterson became a sort of rolling stone.

He was a good man, but somewhat visionary, and a bit inclined to "take chances"--such as looking for lost treasure--rather than to devote himself to some steady employment. The result was that he led rather a precarious life, though never being actually in want.

"No, pardner," he said to Mr. Swift. "It's kind of you to ask me to stay; but this mine business has got a grip on me. I want to try it out. If you won't finance the project someone else may. I'll say good-bye, and--"

"Now just a minute," said Mr. Swift. "It's true, Alec, I had about made up my mind not to go into this thing, when this accident happened to Tom. Now you practically saved his life. You--"

"Oh, pshaw! I only acted on the spur of the moment. Anyone could have done what I did," protested the fortune-hunter.

"Oh, but you did it!" insisted Mr. Swift, "and you did it in the nick of time. Now I wouldn't for a moment think of offering you a reward for saving my son's life. But I do feel mighty friendly toward you--not that I didn't before--but I do want to help you. Alec, I will go into this business with you. We'll take a chance! I'll invest ten thousand dollars, and I'm not so awful worried about getting it back, either--though I don't believe in throwing money away."

"You won't throw it away in this case!" declared Mr. Peterson, eagerly.

"I'm sure to find that mine; but it will take a little capital to work it. That's what I need--capital!"

"Well, I'll supply it to the extent of ten thousand dollars," said Mr.

Swift. "Tom, what do you think of it? Am I foolish or not?"

"Not a bit of it, Dad!" cried the young man, who was now himself again.

"I'm glad you took that chance, for, if you hadn't--well, I would have supplied the money myself--that's all," and he smiled at the fortune-hunter.

CHAPTER III

PLANNING A BIG GUN

"BUT, Tom, I don't see how in the world you can ever hope to make a bigger gun than that."

"I think it can be done, Ned," was the quiet answer of the young inventor. He looked up from some drawings on the table in the office of one of his shops. "Now I'll just show you--"

"Hold on, Tom. You know I have a very poor head for figures, even if I do help you out once in a while on some of your work. Skip the technical details, and give me the main facts."

The two young men--Ned Newton being Tom's special chum--were talking together over Tom's latest scheme.

It was several days after Tom's accident in the airship, when he had been saved by the prompt action of Mr. Peterson. That fortune-hunter, once he had the promise of Mr. Swift to invest in his somewhat visionary plan of locating a lost opal mine near the Panama Ca.n.a.l, had left the Swift homestead to arrange for fitting out the expedition of discovery. He had tried to prevail on Tom to accompany him, and, failing in that, tried to work on Mr. Damon.

"Bless my watch chain!" exclaimed that odd gentleman. "I would like to go with you first rate. But I'm so busy--so very busy--that I can't think of it. I have simply neglected all my affairs, chasing around the country with Tom Swift. But if Tom goes I--ahem! I think perhaps I could manage it--ahem!"

"I thought you were busy," laughed Tom.

"Oh, well, perhaps I could get a few weeks off. But I'm not going--no, bless my check book, I must get back to business!"