“Look out!” yelled the tall lad. “We’re falling! You’ll have to volplane down!”
“I know,” replied Ned, coolly. He and his chums had done this before, both in emergencies and when they had purposely shut off the engine.
Volplaning down in an airship is like coasting down hill on a sled, only in the former case the hill is nothing more substantial than a bank of air. But by letting the airship slide down on slanted wings, and then by sending it sharply upward, by means of the vertical rudder, its speed can be nicely controlled, so that a landing can be made.
This was what the boys aimed to do. Ned was now at the wheel and controls in place of Jerry, who, seeing that his chum had matters well in hand, turned to look downward through the binoculars.
“Can you see the puffs of smoke?” asked Bob.
“No, I can’t,” murmured Jerry, not taking his eyes from the instruments.
“I wonder what made the engine stop?” asked Ned. “Did you have plenty of gas, Jerry?”
“Sure! Both tanks filled before we left. Wait, I’ll try the self starter.”
He set this in motion but it did not operate the engine. There seemed to be something broken, and as the motor was not readily accessible from the cabin the boys would have to wait until a landing was made.
This was in a fair way to be accomplished, and near the spot of their former camp. Ned was scanning the ground, which seemed coming up to meet them, for a smooth place on which to let the airship run along on its wheels.