"It must be perfectly wonderful to fly through the air," said Miss
Nestor one day, when Tom and Mr. Damon had the Humming-Bird out on the
testing ground, trying the engine, which had been keyed up to a higher
pitch of speed. "I consider it perfectly marvelous, and I can't imagine
how it must seem to skim along that way."

"Come and try it," urged Tom suddenly. "There's not a bit of danger.
Really there isn't."

"Oh! I'd never dare do it!" replied the girl, with a gasp. "That machine
is too swift by name and swift by nature for me."

"Why don't you take Miss Nestor on a grass-cutting flight, Tom?"
suggested Mr. Damon. "Bless my lawn mower! but she wouldn't be
frightened at that."

"Grass cutting?" repeated the girl. "What in the world does that mean?"

"It means skimming along a few feet up in the air," answered the young
inventor, who had now fully recovered from the effects of the blow given
him by the midnight intruder. In spite of many inquiries, no clues to
his identity had been obtained.

"How high do you go when you 'cut grass,' as you call it?" asked Miss
Nestor, and Tom thought he detected a note of eager curiosity in her
voice.

"Not high at all," he said. "In fact, sometimes I do cut off the tops of
tall daisies. Come, Mary! Won't you try that? I know you'll like it, and
when you've been over the lawn a few times you'll be ready for a high