Again he advanced the spark and gasolene levers, and the comparatively
frail craft vibrated so that it seemed as if she would fly apart.

"Now?" yelled Tom.

"Eleven hundred and fifty!" cried Ned.

"Good! That'll do it. She'll give more after she's been running a while.
We'll go up."

Ned scrambled to his seat, and Tom followed. He had an arrangement so
that he could slip loose the retaining rope from his perch whenever he
was ready.

Waiting until the motor had run another minute, the young inventor
pulled the rope that released them. Over the smooth starting ground that
formed a part of the Swift homestead darted the aeroplane. Faster and
faster she moved, Ned gripping the sides of his seat.

"Here we go!" cried Tom, and the next instant they shot up into the air.

Ned Newton had ridden many times with his chum Tom, and the sensation of
gliding through the upper regions was not new to him. But this time
there was something different. The propellers seemed to take hold of the
air with a firmer grip. There was more power, and certainly the speed
was terrific.

"We're going fast!" yelled Ned into Tom's ear.