"You take my advice," insisted Mr. Sharp. "Airships are going to be
used more in the future than you have any idea of. You get that device
patented."

Tom did so, and, not many years afterward he was glad that he had, as
it brought him quite an income.

It required several days' work on the Red Cloud before it was in shape
for another trial. During the hours when he was engaged in the big
shed, helping Mr. Sharp, the young inventor spent many minutes calling
to mind the memory of a certain fair face, and I think I need not
mention any names to indicate whose face it was.

"She promised to go for a ride with me," mused the lad. "I hope she
doesn't back out. But I'll want to learn more about managing the ship
before I venture with her in it. It won't do to have any accidents
then. There's Ned Newton, too. I must take him for a skim in the
clouds. Guess I'll invite him over some afternoon, and give him a
private view of the machine, when we get it in shape again."

About a week after the accident at the school Mr. Sharp remarked to
Tom one afternoon

"If the weather is good to-morrow, we'll try another flight. Do you
suppose your father will come along?"

"I don't know," answered the lad. "He seems much engrossed in
something. It's unusual, too, for he most generally tells me what he
is engaged upon. However, I guess he will say something about it when
he gets ready."