“You think so, now,” said the boy with a smile. “But I reckon what’s here is as much yours as it was his—or more. Much obliged for the offer, but I think my mother would make a fuss if I took anything.”

The captain only shrugged his broad shoulders. In an instant the boy had replaced the propeller and was at his new friend’s side.

“Captain,” he said in almost a whisper, “don’t you say a thing to her. But I have an idea—and it’s a dandy. It’s a big idea, and it’s goin’ to take both you and me to work it out—”

“Bully for you!” exclaimed the captain. “But it ain’t another motor boat, is it?”

For answer, Andy hurried to the captain’s desk and picked up an illustrated paper he had seen there. As he held it before the boat builder, he placed his finger on one of the pictures and glanced at his companion with snapping eyes.

“A flyin’ machine? An aeroplane?” the captain almost shouted.

For answer, Andy’s hand shot up as if warning silence. With the other he pointed toward the bungalow.

“My mother,” he whispered significantly. “See that?” he continued, pointing to the pictured propeller. “And see that?” he added, indicating the motor. “They are the only hard things about an aeroplane. And we’ve got ’em both!”

The captain’s mouth was wide open in amazement. He scratched his chin and then suddenly asked: