“Yes. Mr. Damon is game and Father insists on accompanying us. I think I’ll take Koku along—he might come in handy in case anything should happen.”

It was decided to make the start from the big field outside of the Swift plant, and one morning one of the planes and its accompanying passenger car was rolled out on the level stretch. To make the test under the same conditions that would prevail when the airline express was in service, Tom and his friends entered the passenger car at one end of the field.

“We will imagine,” explained Tom, “that we have just landed here from the plane that brought us from Long Island to Chicago on the first lap of the transcontinental flight. Now we will run over and attach ourselves to the other plane.”

As has been said, the passenger car could move under its own power, as can an automobile. Tom started the motor and skillfully guided the car under the waiting aeroplane. In a moment workmen had fastened the clamps.

“Let her go!” Tom called to the pilot in the aeroplane, and the big propellers began to revolve with a thundering sound. The engine seemed working perfectly and a moment later the whole machine—the airline express—began to roll forward across the field. There was a moment of doubt as to whether or not the aeroplane would raise itself and the heavy weight it had to carry, but Tom had made his calculations well, and, to his delight and that of his friends, the machine began to soar upward.

“Hurray!” cried Ned. “She’s doing it!”

“Yes, we’re off on the first real flight, anyhow,” agreed Tom.

“It works better than I expected,” Mr. Swift said. All along he had been a bit skeptical about this new scheme.

A little later they were sailing over Lake Carlopa and Mr. Damon, looking down from one of the observations of the car, said:

“Aren’t we flying a bit low, Tom?”