"I think the insulation has been burning off some of the wires of the motor," was his answer. "That would make a short circuit and put it out of business. Now if we can only keep afloat long enough to change those wires, we may be able to start the motor again, and keep on our way before we touch ground." "You've struck it!" cried Mr. Vardon. "Dick, you take charge of the wheel--you and any of your friends you want. I'll look over the motor, and make repairs if I can." "And they'll have to be made pretty soon," called out Innis from the pilot-house. "We're falling fast." "Throw her nose up," cried Dick. "That's what we've got to do to save ourselves. We'll volplane down, and maybe we can keep up long enough to have Mr. Vardon put in new wires in place of the burned-out ones. If he can do that, and if we can start the motor--" "It sounds too good to be true," said Innis. "But get in here, Dick, and see what you can do. You've got to volplane as you never did before." "And I'm going to do it!" cried the young millionaire. The motor-room was now free from smoke, and the fire was out. A pile of charred waste in one corner showed where it had started. "That's the trouble--insulation burned off!" cried Mr. Vardon, as he made a quick inspection. "I think I can fix it, Dick, if you can keep her up long enough. Take long glides. We're up a good height, and that will help solve." Then began a curious battle against fate, and, not only a struggle against adverse circumstances, but against gravitation. For, now that there was no forward impulse in the airship, she could not overcome the law that Sir Isaac Newton discovered, which law is as immutable as death. Nothing can remain aloft unless it is either lighter than the air itself, or unless it keeps in motion with enough force to overcome the pull of the magnet earth, which draws all things to itself. I have told you how it is possible for a body heavier than air to remain above the earth, as long as it is in motion. It is this which keeps cannon balls and airships up--motion. Though, of course, airships, with their big spread of surface, need less force to keep them from falling than do projectiles. And when the motor of an airship stops it is only by volplaning down, or descending in a series of slanting shifts, that accidents are avoided. This, then, is what Dick did. He would let the airship shoot downward on a long slant, so as to gain as much as possible. Then, by throwing up the head-rudder, he would cause his craft to take an upward turn, thus delaying the inevitable descent.