The hopes that Mr. Baxter would be greatly improved in the morning were doomed to disappointment. He was in no actual danger, the doctor said, but his recovery from the effects of the smoke he had breathed was not as rapid as desired or hoped for.

"He's suffering from some shock," said the physician, "and his mental condition is against him. He ought to be kept quiet, and if you can't have him here, Mr. Swift, I can arrange to have him sent to a hospital."

"I wouldn't dream of it!" Tom exclaimed. "Let him stay here by all means. We have plenty of room, and Mrs. Baggert has been wishing for some one to nurse. Now she has him."

So it was arranged that the chemist should remain at the Swift home, and he gave a languid assent when they spoke to him of the matter. He really was much more ill than seemed at first.

But as everything possible had been done, Tom decided to go ahead with the new idea that had come to him—that of inventing an aerial chemical fire-fighting machine.

"And if we get a chance, Ned, we'll try to get back those secret formulae Mr. Baxter claims to have lost," Tom declared. "I have heard some stories about that fireworks firm, which make me believe there may be something in Baxter's story."

"All right, Tom, I'm with you any time you need me," Ned promised.

The young inventor lost little time in beginning his operations. As he had said, the chief need was a fire extinguishing chemical solution or powder. Tom resolved to try the solution first, as it was easier to make. With this end in view he proceeded to delve into old and new chemistry books. He also sought the advice of his father.

And one day, when Ned called, Tom electrified his chum with the exclamation:

"Well, I'm going to give it a try!"