Chapter VII WarningsFor a moment or two Tom Swift did not seem to comprehend what Ned had said. He remained staring, first at his chum, who stood pointing, and from him Tom's gaze wandered to the top of the door. It may have been, and probably was, that Tom was thinking of other matters at that instant. But Ned said again:
"Wouldn't that do, Tom? Check the recoil of the gun with whatever stuff is in that arrangement!"
A sudden change came over Tom's face. It was lighted up with a gleam of understanding.
"By Jove, Ned, old man!" he cried. "I believe you've struck it! And to think that has been under my nose, or, rather, over my head, all this while, and I never thought of it. Hurray! That will solve the problem!"
"Do you think it will?" asked Ned, glad that he had contributed something,
