Tom owned several planes, but of the two-winged variety the one he best liked was the Hummer, a small but speedy craft. This machine was kept in a hanger near the flying field, and it did not take the young inventor long to have her run out that he might test the engine.

“She sure sounds sweet, Mr. Swift,” remarked the mechanician who assisted him.

“Yes, Dirk, she’s throbbing like a wild duck. I guess I’ll take her up for a time.”

Going back to the office Tom reported to Ned that everything about the Hummer was in good shape and that he would probably be gone for the remainder of the day. As there was no good landing place near the home of Mary Nestor it was necessary for her to come to Tom’s flying field, and while he was getting ready he sent one of his men for the young lady in an automobile. But first Tom called her on the telephone.

“Oh, Tom!” exclaimed Mary, as soon as she found who was on the wire, “I was just going to call you up!”

“You were?”

“Yes, it’s awfully important! I want to see you very much!”

“Well, you’ll have that pleasure directly.”

“Oh, Tom, don’t joke about it! It is important.”

“What’s the trouble, Mary,” the young inventor asked, seriously enough now.