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!"
"Oh!" said Tom, much relieved. "I was afraid you were ill again. Now, in this model, as you will see by the plans, it is necessary———"
He paused, and looked over at the table where he had left the drawings. They were not there!
