The hydroplanes which were on toggle-joint arms had been lifted up off the ground, and could be let down when it was desired to float on water.
“I think we’ll go up by means of the gas bag, and not use the aeroplane wings now,” decided Jerry. “We haven’t room enough to get a good start, now that the Comet is larger than she was formerly.”
Accordingly the vapor machine was set in operation, and soon a hissing announced that the gas was entering the big bag that formed the superstructure of the Comet. Some of the boys’ friends had gathered to see them off, and Mr. Slade was present, for he was vitally interested in the success of the remodelled motor-ship.
“How’s the pressure?” called Jerry to Ned, who was in the engine room, while the tall lad took his place in the steering house.
“About five hundred pounds,” was the reply.
“That’s enough. We’re ready to go up. Andy, you help Bob cast off the anchor ropes. Professor——”
“Oh, there’s no use asking him to do anything,” spoke Bob in a low voice to his chum. “He’s just seen a new kind of a bug crawling around on deck, and he’s after it on his hands and knees.”
“All right, I guess we won’t disturb him then,” decided the tall lad. “We can manage. Get ready to cast off, Chunky.”
A little more gas was allowed to go into the bag. The motor-ship was pulling and tugging at the anchor ropes, as if eager to be free to rise in the air.
“Let her go!” suddenly called Jerry.