front of his father, and began to explain them in detail.

"I really think you have something great there, Tom!" exclaimed Mr.
Swift, at length. "It is a very small monoplane, to be sure, but I think
with the new principle you have introduced it will work; but, if I were
you, I'd shape those wing tips a little differently."

"No, they're better that way," said Tom pleasantly, for he did not often
disagree with his father. "I'll show you from a little model I have
made. I'll get it right away."

Anxious to demonstrate that he was right in his theory, Tom hurried from
the library to get the model of which he had spoken. He left the roll of
plans lying on a small table near where his father was seated.

"There, you see, dad," said the young inventor as he re-entered the
library a few minutes later, "when you warp the wing tips in making a
spiral ascent it throws your tail wings out of plumb, and so--"

Tom paused in some amazement, for Mr. Swift was lying back in his chair,
with his eyes closed. The lad started in alarm, laid aside his model,
and sprang to his father's side.

"He's had another of those heart attacks!" gasped Tom. He was just going
to call Mrs. Baggert, when Mr. Swift opened his eyes. He looked at Tom,
and the lad could see that they were bright, and did not show any signs
of illness.

"Well, I declare!" exclaimed the inventor. "I must have dozed off, Tom,
while you were gone. That's what I did. I fell asleep!"