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?” “Yes, I think we are,” agreed the young inventor. “Put her up a bit!” he signaled to the pilot through the speaking tube. Back came the answer: “I can’t! Something has gone wrong! I’m losing power! I’m afraid we’re in for a fall!” CHAPTER XVI JASON JACKS Just for a moment or two Tom Swift wished he were in the motor cockpit of the plane instead of in the passenger car with his father and his friends. He had an idea he might so manipulate the controls as to cause the falling plane to increase speed and keep on flying until a safe landing could be made. But in an instant this idea passed. Tom had full confidence in his mechanician, and realized if Harry Meldrum could not prevent a fall Tom himself could not, for Meldrum, taught in the Swift school of flying, was a thoroughly competent and resourceful airman. “What’s wrong?” Tom asked his engineer through the tube. “Oil pump has blown out a gasket! The engine is heating. It’s got to stop soon and we’ll have to come down—in the lake, I guess,” was the grim finish of the report. “Well, I’ve landed in worse places,” remarked Tom. “Is anything going to happen?” his father wanted to know. “I’m afraid there is,” the young inventor answered. “We’re being forced down. I thought everything was all right with the machinery, but you never can tell.” “Bless my accident insurance policy! Do you think we’ll go down right in the water, Tom?” gasped Mr. Damon. “It begins to look so,” was the reply. “But perhaps better there than on land—there won’t be such a shock. The plane has floating compartments, and so has this car—I had them built in as a precaution against water landings. I don’t believe there will be any real danger.” There was no doubt about it—the plane was gradually settling lower and lower—ever coming nearer to the surface of Lake Carlopa.