"Why, the dear old thing!" cried Grace. "To think of him leaving his
uncivilized state to do anything so utterly civilized and modern as to
help with a flying machine."

"And he does it well, too," went on David. "He is not only thoroughly
interested but he keeps guard out here in case any one should try to break
in. There are his cot and things in the corner. He sleeps in the open
unless it rains. Then he sleeps inside."

As the old hunter did not put in an appearance David decided to wait no
longer.

"Why can't we all help?" asked Grace. "What must we do? Please tell us."

"All right," answered David, "just give it a shove into the open space,
and you'll see how she gradually rises for a flight."

After making a careful examination of all the parts of the aëroplane, and
starting the engine, David took his seat in the machine.

Then the two boys, assisted by Grace and Nora, pushed it swiftly out into
the broad open space back of the ruin.

Suddenly the machine began to rise. Slowly, at first, then seeming to
gather strength and confidence like a young bird that has learned to fly
at last, it soared over the apple trees. David, white, but very calm,
quietly worked the levers that operated the little engine. When he had
risen about a hundred feet, he began to dip and soar around the orchard in
circles. He appeared to have forgotten his friends, watching anxiously
below. He did not notice that little Mrs. Gray's knees had suddenly