Suddenly Chester sat bolt upright
"By George!" he exclaimed.
"What's the matter now?" asked Hal in surprise.
"I've an idea."
"Strange," replied Hal, with a smile; "but let's hear it."
"Well, in the first place, you took an airship ride to-day. How did you like it?"
"Like it? Oh, I liked it all right. Why?"
"You saw Fritz work the thing. Did you get the hang of it?"
Hal jumped to his feet with a subdued exclamation.
"I see what you are getting at!" he declared. "An airship! Why didn't I think of it myself?"