"Yes, I heard you yell," Tom said. "But what I wanted to know is, did you see anyone near the red shed at the time?"

"No, Ma.s.sa Tom, I done didn't."

"I wonder if Mr. Damon did? I must ask him," went on the young inventor. "Come, on, Ned, we'll go up to the house. Everything is all right here, I think. Whew! But that was some excitement. And I didn't show you my aerial warship after all! Nor have you settled that recoil problem for me."

"Time enough, I guess," responded Ned. "You sure did have a lucky escape, Tom."

"That's right. Well, Koku, what is it?" for the giant had approached, holding out something in his hand.

"Koku found this in red shed," went on the giant, holding out a round, blackened object. "Maybe him powder; go bang-bang!"

"Oh, you think it's something explosive, eh?" asked Tom, as he took the object from the giant.

"Koku no think much," was the answer. "Him look funny."

Tom did not speak for a moment. Then he cried:

"Look funny! I should say it did! See here, Ned, if this isn't suspicious I'll eat my hat!" and Tom beckoned excitedly to his chum, who had walked on a little in advance.

CHAPTER V

A QUEER STRANGER

What Tom Swift held in his hand looked like a small cannon ball, but it could not have been solid or the young aviator would not so easily have held it out at arm's length for his friend Ned Newton to look at.

"This puts a different face on it, Ned," Tom went on, as he turned the object over.

"Is that likely to go off?" the bank clerk asked, as he came to a halt a little distance from his friend.

"Go off? No, it's done all the damage it could, I guess."

"Damage? It looks to me as though it had suffered the most damage itself. What is it, one of your models? Looks like a bomb to me."

"And that's what it is, Ned."

"Not one of those you're going to use on your aerial warship, is it, Tom?"

"Not exactly. I never saw this before, but it's what started the fire in the red shed all right; I'm sure of that."

"Do you really mean it?" cried Ned.

"I sure do."

"Well, if that's the case, I wouldn't leave such dangerous things around where there are explosives, Tom."

"I didn't, Ned. I wouldn't have had this within a hundred miles of my shed, if I could have had my way. It's a fire bomb, and it was set to go off at a certain time. Only I think something went wrong, and the bomb started a fire ahead of time.

"If it had worked at night, when we were all asleep, we might not have put the fire out so easily. This sure is suspicious! I'm glad you found this, Koku."

Tom was carefully examining the bomb, as Ned had correctly named it.

The bank clerk, now that he was a.s.sured by his chum that the object had done all the harm it could, approached closer.

What he saw was merely a hollow sh.e.l.l of iron, with a small opening in it, as though intended for a place through which to put a charge of explosives and a fuse.

"But there was no explosion, Tom," explained Ned.

"I know it," said Tom quietly. "It wasn't an explosive bomb. Smell that!"

He held the object under Ned's nose so suddenly that the young bank clerk jumped back.

"Oh, don't get nervous," laughed Tom. "It can't hurt you now. But what does that smell like?"

Ned sniffed, sniffed again, thought for a moment, and then sniffed a third time.

"Why," he said slowly, "I don't just know the name of it, but it's that funny stuff you mix up sometimes to put in the oxygen tanks when we go up in the rarefied atmosphere in the balloon or airship."

"Manganese and potash," spoke Tom. "That and two or three other things that form a chemical combination which goes off by itself of spontaneous combustion after a certain time. Only the person who put this bomb together didn't get the chemical mixture just right, and it went off ahead of time; for which we have to be duly thankful."

"Do you really think that, Tom?" cried Ned.

"I'm positive of it," was the quiet answer.

"Why--why--that would mean some one tried to set fire to the red shed, Tom!"

"They not only tried it, but did it," responded Tom, more coolly than seemed natural under the circ.u.mstances. "Only for the fact that the mixture went off before it was intended to, and found us all alert and ready--well, I don't like to think what might have happened," and Tom cast a look about at his group of buildings with their valuable contents.

"You mean some one purposely put that bomb in the red shed, Tom?"

"That's exactly what I mean. Some enemy, who wanted to do me an injury, planned this thing deliberately. He filled this steel sh.e.l.l with chemicals which, of themselves, after a certain time, would send out a hot tongue of flame through this hole," and Tom pointed to the opening in the round steel sh.e.l.l.

"He knew the fire would be practically unquenchable by ordinary means, and he counted on its soon eating its way into the carbide and other explosives. Only it didn't."

"Why, Tom!" cried Ned. "It was just like one of those alarm-clock dynamite bombs--set to go off at a certain time."

"Exactly," Tom said, "only this was more delicate, and, if it had worked properly, there wouldn't have been a vestige left to give us a clue. But the fire, thanks to the ballast sand in the dirigible, was put out in time. The fuse burned itself out, but I can tell by the smell that chemicals were in it. That's all, Koku," he went on to the giant who had stood waiting, not understanding all the talk between Tom and Ned. "I'll take care of this now."

"Bad man put it there?" asked the giant, who at least comprehended that something was wrong.

"Well, yes, I guess you could say it was a bad man," replied Tom.

"Ha! If Koku find bad man--bad for that man!" muttered the giant, as he clasped his two enormous hands together, as though they were already on the fellow who had tried to do Tom Swift such an injury.

"I wouldn't like to be that man, if Koku catches him," observed Ned.

"Have you any idea who it could be, Tom?"