“Some sort of eagle, larger than any ever seen in these parts,” ventured Sam.

“No, that’s as far off as Nat was.”

“A kite, carrying an engine, working a camera, for taking moving pictures at night,” was Bony’s guess.

“No,” said Will. “It’s your turn, Jack.”

Jack thought for a minute. He glanced at the big shed, and then started, as a sudden idea came to him.

“A balloon?” he asked.

“No, but you’re nearest to it. Shall I tell them, Uncle Andy?”

Mr. Swaim nodded.

“It’s a great aeroplane!” exclaimed Will.