of the log Andy Foger placed across the road, and now you have saved me from Morse."

"Oh, dat's nuffin, Mistah Swift. Yo' has suah done lots fo' me. 'Sides, mah mule, Boomerang, am entitled t' de most credit dish yeah time. I were comin' down de street, on mah way t' a whitewashin' job, when I seen yo', an yo' lickitysplit machine," for so Eradicate designated a motorcycle. "I knowed it were yo', an' I didn't laik de looks ob dat man. Den I see he had hold ob you, an' I t'ought he were a burglar. So I yelled t' Boomerang t' hurry up. Now, mostly, when I wants Boomerang t' hurry, he goes slow, an' when I wants him t' go slow, he runs away. But dish yeah time he knowed he were comin' t' help yo', an' he certainly did leg it, dat's what he done! He run laik he were goin' home t' a stable full ob oats, an' dat's how I got heah so quick. Den I t'ought ob de whitewash, an' I jest used it."

"It was the most effective weapon you could have used," said Tom, gratefully.

"Deed no, Mistah Swift, I didn't hab no weapon," spoke Eradicate earnestly. "I ain't eben got mah razor, 'case I left it home. I didn't hab no weapon at all. I jest used de whitewash, laik yo' seen me."

"That's what I meant," answered Tom, trying not to laugh at the simple negro's misunderstanding. "I'm ever so much obliged to you, just the same, and here's a half dollar to pay for the whitewash."

"Oh, no, Mistah Swift, I doan't want t' take it. I kin make mo' whitewash."

But Tom insisted, and picked up his machine to sprint for home. Eradicate started to tell over again, how he urged Boomerang on, but the lad had no time to listen.

"But I didn't hab no weapon, Mistah Swift, no indeedy, none at all, not even mah razor," repeated Eradicate. "Only de pail ob whitewash. That is, lessen yo' calls mah bresh a weapon."

"Well, it's a sort of one," admitted Tom, with a laugh as he started his machine. "Come around next week, Rad. We have some dirt eradicating for you to attend to."

"Deed an' I will, Mistah Swift. Eradicate is mah name, an' I eradicates de dirt. But dat man such did look odd, wif dat pail ob whitewash all ober him. He suah did look most extraordinarily. Gidap, Boomerang. See if yo' can break some mo' speed records now."

But the mule appeared to be satisfied with what he had done, and, as he rode off, Tom looked back to see the colored man laboring to get the sleepy, animal started.

The lad did not tell his father of the adventure with Morse, but he related the occurrence to Mr. Sharp.

"I'd like to get hold of that scoundrel, and the others in the gang!" exclaimed the balloonist. "I'd take him up in the airship, and drop him down into the lake. He's a bad man. So are the others. Wonder what they want around here?"

"That's what's puzzling me," admitted Tom. "I hope dad doesn't hear about them or he will be sure to worry; and maybe it will interfere with his new ideas."

"He hasn't told you yet what he's engaged in inventing; has he?"

"No, and I don't like to ask him. He said the other day, though, that it would rival our airship, but in a different way."

"I wonder what he meant?"

"It's hard to say. But I don't believe he can invent anything that will go ahead of our craft, even if he is my own father, and the best one in the world," said Tom, half jokingly. "Well, I got the bolts, now let's get to work. I'm anxious for a trial trip."

"No more than I am. I want to see if my ideas will work out in practice as well as they do in theory."

For a week or more Tom and Mr. Sharp labored on the airship, with Mr. Jackson to help them. The motor, with its twenty cylinders, was installed, and the big aluminum holder fastened to the frame of the planes. The rudders, one to control the elevation and depression of the craft, and the other to direct its flight to the right or left, were attached, and the steering wheel, as well as the levers regulating the motor were put in place.

"About all that remains to be done now," said the aeronaut one night, as he and Tom stood in the big shed, looking at their creation, "is to fit up the car, and paint the machine."

"Can't we make a trial trip before we fit up the car ready for a long flight?" asked the young inventor.

"Yes, but I wouldn't like to go out without painting the ship. Some parts of it might rust if we get into the moist, cloudy, upper regions."

"Then let's paint it to-morrow, and, as soon as it's dry we'll have a test."

"All right. I'll mix the paint the first thing in the morning."

It took two days to paint the machine, for much care had to be used, and, when it was finished Tom looked admiringly up at it.

"We ought to name it," suggested Mr. Sharp, as he removed a bit of paint from the end of the nose.

"To be sure," agreed Tom. "And hold on, I have the very name for it—Red Cloud!"

"Red Cloud?" questioned Mr. Sharp.

"Yes!" exclaimed Tom, with enthusiasm. "It's painted red—at least the big, aluminum gas container is—and we hope to go above the clouds in it. Why not Red Cloud?"

"That's what it shall be!" conceded the balloonist. "If I had a bottle of malted milk, or something like that, I'd christen it."

"We ought to have a young lady to do that part," suggested Tom. "They always have young ladies to name ships."

"Were you thinking of any particular young lady?" asked Mr. Sharp softly, and Tom blushed; as he replied:

"Oh no—of course that is—well—Oh, hang it, christen it yourself, and let me alone," he finished.

"Well, in the absence of Miss Mary Nestor, who, I think, would be the best one for the ceremony," said Mr. Sharp, with a twinkle in his eyes, "I christen thee Red Cloud," and with that he sprinkled some water on the pointed nose of the red aluminum gas bag, for the aeronaut and Tom were on a high staging, on a level with the upper part of the airship.

"Red Cloud it is!" cried Tom, enthusiastically. "Now, to-morrow we'll see what it can do."

The day of the test proved all that could be desired in the way of weather. The fact that an airship was being constructed in the Swift shops had been kept as secret as possible, but of course many in Shopton knew of it, for Andy Foger had spread the tidings.

"I hope we won't have a crowd around to see us go up," said Tom, as he and Mr. Sharp went to the shed to get the Red Cloud in readiness for the trial. "I shouldn't want to have them laugh at us, if we fail to rise."

"Don't worry. We'll go up all right," declared Mr. Sharp. "The only thing I'm at all worried about is our speed. I want to go fast, but we may not be able to until our motor gets 'tuned-up'. But we'll rise."

The gas machine had already been started, and the vapor was hissing inside the big aluminum holder. It was decided to try to go up under the lifting power of the gas, and not use the aeroplane feature for sending aloft the ship, as there was hardly room, around the shops, for a good start.

When enough of the vapor had been generated to make the airship buoyant, the big doors of the shed were opened, and Tom and Mr. Sharp, with the aid of Garret and Mr. Swift, shoved it slowly out.

"There it is! There she comes!" cried several voices outside the high fence that surrounded the Swift property. "They're going up!"

"Andy Foger is in that bunch," remarked Tom with a grim smile. "I hope we don't fail."

"We won't. Don't worry," advised Mr. Sharp.

The shouts outside the fence increased. It was evident that quite a crowd of boys, as well as men, had collected, though it was early in the morning. Somehow, news of the test had leaked out.

The ship continued to get lighter and lighter as more gas was generated. It was held down by ropes, fastened to stakes driven in the ground. Mr. Sharp entered the big car that was suspended, below the aeroplanes.

"Come on, Tom," the aeronaut called. "We're almost ready to fly. Will you come too, Mr. Swift, and Garret?"

"Some other time," promised the aged inventor.