"Stand by, everybody," sharply ordered Ned. And then, as Bob's shoulders appeared through the hatchway, the commander of the air ship gave a final look about.
"Let go all," he cried sharply. "Everybody!"
For a moment only one clinging workman careened the buoyant craft and then, straight up, the Cibola bounded like a rubber ball.
"Good-bye, all," came from Ned, cap in hand, as he leaned from the bridge.
There were cheers from below and the Cibola was at last free and afloat.
"Sit down here and keep quiet," sharply ordered Ned as Bob crawled out on deck. Then the commander of the balloon disappeared below.
There were almost immediately several sharp, muffled explosions, and then the white propeller began to turn. The balloon was drifting quickly toward the northwest and rising—Bob could see its shadow following on the sandy plain. Then the arms of the propeller turned faster and faster and a velvet whirr in the cabin showed that the engine was falling to work. As the propeller blades settled into a steady hum the vibration of the car indicated increased speed. This Bob could also detect from the more swiftly flying shadow.
The shadow was also growing smaller, and this meant that the Cibola was still ascending. Now the shadow paused and turned. Alan had thrown the rudder over and the balloon had responded instantly. The aeroplane arms stretched out horizontally on each side of the car. Ned, reappearing, took a quick look at the altitude gauge and again disappeared. The aeroplane arms dipped in front almost forty-five degrees and the current, blown back by the propeller, struck them with a jar. The craft again responded and slowly took a downward slant.
Propeller, rudder and aeroplane being at work, Ned again appeared.
"Go below," he ordered sharply, "and bear a hand when needed."