“Ah, this is something like!” cried Bob. “This is fine! Eh, fellows?”
He had hardly spoken when they were all aware that the Comet, which had been proceeding along on the level, was shooting upward very swiftly. At the same moment Mr. Glassford uttered a cry, and the boys saw him rapidly turning a wheel valve.
“What’s the matter?” asked Jerry.
“The heat of the sun is expanding our gas and causing us to rise,” explained the inventor. “I must let some out, as I don’t want to go any higher.”
But something seemed to be the matter. Mr. Glassford could not open the gas valve, and the motor ship continued to rise.
“I must try the deflecting rudder,” he murmured. “Jerry, come and give me a hand.”
Jerry hurried forward. The pressure on the oblong planes which constituted the deflecting rudder was very great. It required the combined strength of the inventor and Jerry to move the lever a slight distance. And it was only a slight distance that they could move it.
“Something is jammed!” exclaimed Mr. Glassford. “We can’t move the rudder!”
“And we can’t let the gas out,” said Jerry in a low voice. “What’s going to happen?”