He found Ned waiting for him when he came downstairs.

"How is he?" asked the young business manager.

"In rather a bad way--mentally, at least," and Tom told of the lost formulae. "Do you know, Ned," he went on, "I have an idea!"

"You generally do have--lots of 'em!" Ned rejoined.

"But this is a new one," went on Tom. "You saw what trouble they had this evening to get a stream of water to the top stories of that factory, didn't you?"

"Yes, the pressure here isn't what it ought to be," Ned agreed. "And some of our engines are old-timers."

"Why is it necessary always to fight a fire with water?" Tom continued.

"There are plenty of chemicals that will put out a fire much quicker than water."

"Of course," Ned answered. "There are plenty of chemical fire extinguishers on the market, too, Tom. If your idea is to invent a new hand grenade, stay off it! A lot of money has been lost that way."

"I wasn't thinking of a hand grenade," said Tom, as he drew some sheets of paper across the table to him. "My idea is on a bigger scale.

There's no reason, Ned, why a big fire in a tall building, like a sky-sc.r.a.per, shouldn't be fought from above, as well as from below. Now if I had the right sort of chemicals I could--"

Tom paused in a listening att.i.tude. There was the rush of feet and a voice cried:

"I'll get them! I'll get the scoundrels!"

CHAPTER IV

AN EXPERIMENT

"That can't be Koku and Rad in one of their periodic squabbles, can it?" asked Ned.

"No. It's probably Mr. Baxter," Tom answered. "The doctor said he might get violent once or twice, until the effects of his shock wore off.

There is some quieting medicine I can give him. I'll run up."

"Guess I'd better go along," remarked Ned. "Sounds as if you'd need help."

And it did appear so, for again the frenzied shouts sounded:

"I'll get 'em! I'll get the scoundrels who stole my secret formulae that I worked over so many years! Come back now! Don't put the match near the powder!"

Tom and Ned hurried to the room where the unfortunate chemist had been put to bed, to find him out in the hall, wrapped in a bedquilt, and with Mrs. Baggert vainly trying to quiet him. Mr. Baxter stared at Tom and Ned without seeing them, for he was in a delirium of fever.

"Have you my formulae?" he asked. "I want them back!"

"You shall have them in the morning," replied Tom soothingly. "Lie down, and I'll bring them to you in the morning. And drink this," he added, holding out a gla.s.s of soothing mixture which the doctor had ordered in case the patient should become violent.

Josephus Baxter glared about with wild eyes, but between them Tom and Mrs. Baggert managed to get him to drink the mixture.

"Bah! It's as bad as some of my chemicals!" spluttered the chemist, as he handed back the gla.s.s. "You are sure you'll have my formulae in the morning?" he asked, as he turned to go back to his room.

"I'll do my best," declared Tom cheerfully. "Now please lie down."

Which, after some urging, Mr. Baxter consented to do. Eradicate wanted to lie down in the hall outside the excited chemist's door to guard against his emerging again, but Tom decided on Koku. The giant, though not as intelligent as the colored man, was more efficient in an emergency because of his great strength. Eradicate was getting old, and there was a pathetic droop to his figure as he shuffled off when Koku superseded him.

"Ah done guess Ah ain't wanted much mo'," muttered Rad sadly.

"Oh, yes, you are!" cried Tom, as, the excitement over, he walked downstairs with Ned. "I'm going to start something new, Rad, and I'll need your help."

"Will yo', really, Ma.s.sa Tom?" exclaimed faithful Rad, his face lighting up. "Dat's good! Is yo' goin' off after mo' diamonds, or up to de caves of ice?"

"Not quite that," answered the young inventor, recalling the stirring experiences that had fallen to him when on those voyages. "I'm going to work around home, Rad, and I'll need your help."

"Anyt'ing yo' wants, Ma.s.sa Tom! Anyt'ing yo' wants!" offered the now delighted Rad, and he went to bed much happier.

"Well, to resume where we left off," began Ned, when he and Tom were once more by themselves, "what's the game?"

"Oh, I don't know that it's much of a game," was the answer. "But I just have an idea that a big fire in a towering building can be fought from above with chemicals, as well as from the ground with streams of water.

"Well, I guess it could be," Ned agreed. "But how are you going to get your chemicals in at the top? Shoot 'em up through a hose? If you do that you'll need a special kind of hose, for the chemicals will rot anything like rubber or canvas."

"I wasn't thinking of a hose," returned Tom. "What then?" asked the young financial manager.

"An airship!" Tom exclaimed with such sudden energy that Ned started.

"It just came to me!" explained the youthful inventor. "I was wondering how we could get the chemicals in from the top, and an airship is the solution. I can sail over the burning building and drop the chemicals down. That will douse the blaze if my plans go right."

Ned was silent a moment, considering Tom's daring plan and project.

Then, as it became clearer, the young banker cried:

"Blamed if I don't think that's just the thing, Tom! It ought to work, and, if it does, it will save a lot of lives, to say nothing of property! A fire in a sky-sc.r.a.per ought to be fought from above. Then the extinguisher element, whether chemicals or water, could be dropped where they'd do the most good. As it is now, with water, a lot of it is wasted. Some of it never reaches the heart of the fire, being splashed on the outside of the building. A lot more turns to steam before it hits the flames, and only a small percentage is really effective."

"That's my notion," Tom said.

"Then go ahead and do it!" urged his friend. "You have my permission!"

"Thanks," commented Tom dryly. "But there are several things to be worked out before we can start. I've got to devise some scheme for carrying a sufficient quant.i.ty of chemicals, and invent some way of releasing them from an airship over the blaze. But that last part ought to be easy, for I think I can alter my warfare bomb-dropping attachment to serve the purpose.

"What I really need, however, is some new chemical combination that will quickly put a really big blaze out of business. There are any number of these chemicals, but most of them depend on the production of carbon dioxide. This is the product of some solution of a carbonate and sulphuric acid, and I suppose, eventually, I'll work out something on that order. But I hope I may get something better."

"You haven't delved much into chemistry, have you?"

"No. And I wish now that I had. I see my limitations and realize my weakness. But I can brush up a little on my chemistry. As for the mechanical part, that of dropping the extinguisher on the blaze, I'm not worrying over that end."

"No," agreed Ned. "You have enough types of airships to be able to select just the best one for the purpose. But, say, Tom!" he suddenly cried, "why not ask him to help you?"

"Who?"

"Mr. Baxter. He's a chemist. And though he says his formulae are about dyes and fireworks, maybe he can put you in the way of inventing a chemical solution that will be death to fires."