ut 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 shell 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 shell.

"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?"

"Not the least. Of course I know I have enemies, Ned. Every successful
inventor has persons who imagine he has stolen their ideas, whether he
has ever seen them or not. It may have been one of those persons, or
some half-mad crank, who was jealous. It would be impossible to say,
Ned."

"It wouldn't be Andy Foger, would it?"

"No; I don't believe Andy has been in this neighborhood for some time.
The last lesson we gave him sickened him, I guess."

"How about those diamond-makers, whose secret you discovered? They
wouldn't be trying to get back at you, would they?"

"Well, it's possible, Ned. But I don't imagine so. They seem to have
been pretty well broken up. No, I don't believe it was the
diamond-makers who put this fire bomb in the red shed. Their line of
activities didn't include this branch. It takes a chemist to know just
how to blend the things contained in the bomb, a