"No, it wasn't an explosion, properly speaking," said Tom. "You
see, when powder explodes, in a gun, or otherwise, its force is
exerted in all directions, up, down and every way."

"This went mostly backward--in my direction," said Ned ruefully.

"You only thought so," returned Tom. "Most of the power went
out in front, to force out the shot. Part of it, of course, was
exerted on the barrel of the gun--that was sideways--but the
strength of the steel held it in. And part of the force went
backward against your shoulder. That part was the recoil, and it
is the recoil of the guns I figure on putting aboard my aerial
warship that is giving me such trouble."

"Is that what makes you look so blue?" asked Ned.

"That's it. I can't seem to find a way by which to take up the
recoil, and the force of it, from all the guns I want to carry,
will just about tear my ship to pieces, I figure."

"Then you haven't actually tried it out yet?" asked Ned.

"Not the guns, no. I have the warship of the air nearly done,
but I've worked out on paper the problem of the guns far enough
so that I know I'm up against it. It can't be done, and an aerial
warship without guns wouldn't be worth much, I'm afraid."

"I suppose not," agreed Ned. "And is it only the recoil that is
bothering you?"