Tom's heart gave a bound of hope.

Chapter Twenty

Just in Time

While Dr. Hendrix was in his office, getting ready to make the thrilling trip through the air with Tom, the young inventor spent a few minutes going over his monoplane. The wonderful little craft had made her first big flight in excellent time, though Tom knew she could do better the farther she was flown. Not a stay had started, not a guy wire was loose. The motor had not overheated, and every bearing was as cool as though it had not taken part in thousands of revolutions.

"Oh, I can depend on you!" murmured Tom, as he looked to see that the propeller was tight on the shaft. He gave the bearing a slight adjustment to make sure of it.

He was at this when the specialist reappeared. Dr. Hendrix, after his first show of excitement, when he had made his decision to accompany Tom, had resumed his usual calm demeanor. Once again he was the grave surgeon, with his mind on the case before him.

"Well, is my auto ready?" he asked absentmindedly. Then, as he saw the little aeroplane, and Tom standing waiting beside it, he added: "Oh, I forgot for the moment that I was to make a trip through the air, instead of in my car. Well, Mr. Swift, are we all ready?"

"All ready," replied the young inventor. "We're going to make fast time, Dr. Hendrix. You'd better put this on," and Tom extended a face protector.

"What's it for?" The physician looked curiously at it.