"Rad, just exactly what sort of a man was this one you speak of?" asked Tom.

"Why, he were a gen'man--"

"Yes, I know that much. You've said it before. But was he an Englishman, an American--or--"

Tom paused and waited for an answer.

"I think he were a Frenchman," spoke Eradicate. "I done didn't see him eat no frogs' laigs, but he smoked a cigarette dat had a funny smell, and he suah was monstrous polite. He suah was a Frenchman. I think."

Tom and Ned laughed at Eradicate's description of the man, but Tom's face was soon grave again.

"Tell us more about him, Rad," he suggested. "Did he seem especially interested in the fire?"

"No, sah, Ma.s.sa Tom, he seemed laik he was more special interested in mah mule, Boomerang. He done asted how long I had him, an' how much I wanted fo' him, an' how old he was."

"But every once in a while he put in some question about the fire, or about our shops, didn't he, Rad?" Tom wanted to know.

The colored man scratched his kinky head, and glanced with a queer look at Tom.

"How yo' all done guess dat?" he asked.

"Answer my question," insisted Tom.

"Yes, sah, he done did ask about yo', and de wuks, ebery now and den,"

Rad confessed. "But how yo' all knowed dat, Ma.s.sa Tom, when I were a-tellin' yo' all about him astin' fo' mah mule, done gets me--dat's what it suah does."

"Never mind, Rad. He asked questions about the plant, that's all I want to know. But you didn't tell him much, did you?"

Eradicate looked reproachfully at his master.

"Yo' all done knows me bettah dan dat, Ma.s.sa Tom," the old colored man said. "Yo' all know yo' done gib orders fo' n.o.body t' talk about yo'

projections."

"Yes, I know I gave those orders," Tom said, with a smile, "but I want to make sure that they have been followed."

"Well, I done follered 'em, Ma.s.sa Tom."

"Then you didn't tell this queer stranger, Frenchman, or whatever he is, much about my place?"

"I didn't tell him nuffin', sah. I done frowed dust in his eyes."

Ned uttered an exclamation of surprise.

"Eradicate is speaking figuratively," Tom said, with a laugh.

"Dat's what I means," the colored man went on. "I done fooled him. When he asted me about de fire I said it didn't do no damage at all--in fack dat we'd rather hab de fire dan not hab it, 'case it done gib us a chance t' practice our hose drill."

"That's good," laughed Tom. "What else?"

"Well, he done sort ob hinted t' me ef we all knowed how de fire done start. I says as how we did, dat we done start it ourse'ves fo'

practice, an dat we done expected it all along, an' were ready fo' it.

Course I knows dat were a sort of fairy story, Ma.s.sa Tom, but den dat cigarette-smokin' Frenchman didn't hab no right t' asted me so many questions, did he?"

"No, indeed, Rad. And I'm glad you didn't give him straight answers. So he's coming here later on, is he?"

"T' see ef I wants t' sell mah mule, Boomerang, yais, sah. I sort ob thought maybe you'd want t' hab a look at dat man, so I tole him t'

come on. Course I doan't want t' sell Boomerang, but ef he was t' offer me a big lot ob money fo' him I'd take it."

"Of course," Tom answered. "Very well, Rad. You may go on now, and don't say anything to anyone about what you have told me."

"I won't, Ma.s.sa Tom," promised the colored man, as he went off muttering to himself.

"Well, what do you make of it, Tom?" asked Ned of his chum, as they walked on toward the shed of the new, big aerial warship.

"I don't know just what to think, Ned. Of course things like this have happened before--persons trying to worm secrets out of Eradicate, or some of the other men."

"They never succeeded in getting much, I'm glad to say, but it always keeps me worried for fear something will happen," Tom concluded.

"But about this Frenchman?"

"Well, he must be a new one. And, now I come to think of it, I did hear some of the men speaking about a foreigner--a stranger--being around town last week. It was just a casual reference, and I paid little attention to it. Now it looks as though there might be something in it."

"Do you think he'll come to bargain with Eradicate about the mule?" Ned asked.

"Hardly. That was only talk to make Eradicate unsuspicious. The stranger, whoever he was, sized Rad up partly right. I surmised, when Rad said he asked a lot of questions about the mule, that was only to divert suspicion, and that he'd come back to the subject of the fire every chance he got."

"And you were right."

"Yes, so it seems. But I don't believe the fellow will come around here. It would be too risky. All the same, we'll be prepared for him.

I'll just rig up one of my photo-telephone machines, so that, if he does come to have a talk with Rad, we can both see and hear him."

"That's great, Tom! But do you think this fellow had anything to do with the fire?"

"I don't know. He knew about it, of course. This isn't the first fire we've had in the works, and, though we always fight them ourselves, still news of it will leak out to the town. So he could easily have known about it. And he might be in with those who set it, for I firmly believe the fire was set by someone who has an object in injuring me."

"It's too bad!" declared Ned. "Seems as though they might let you alone, if they haven't gumption enough to invent things for themselves."

"Well, don't worry. Maybe it will come out all right," returned Tom.

"Now, let's go and have a look at my aerial warship. I haven't shown it to you yet. Then we'll get ready for that mysterious Frenchman, if he comes--but I don't believe he will."

The young inventor unlocked the door of the shed where he kept his latest "pet," and at the sight which met his eyes Ned Newton uttered an exclamation of surprise.

"Tom, what is it?" he cried in an awed voice.

"My aerial warship!" was the quiet answer.

Ned Newton gave vent to a long whistle, and then began a detailed examination of the wonderful craft he saw before him. That is, he made as detailed an examination as was possible under the circ.u.mstances, for it was a long time before the young bank clerk fully appreciated all Tom Swift had accomplished in building the Mars, which was the warlike name painted in red letters on the big gas container that tugged and swayed overhead.