was in even better shape, he was not exactly sorry for the
absence of his friends.

"Contact!" called the young inventor, when Jackson had stepped
back, indicating it was time to throw over the switch.

"Let her go!" cried Tom, and the next moment the motor was in
operation, but so silently that his voice and that of Mr. Damon's
could easily be heard above the machinery.

"Good, Tom! That's good!" cried Mr. Swift, and Tom easily heard
his father's voice, though under other, and ordinary,
circumstances this would have been impossible.

True, the hearing of Tom and Mr. Damon was muffled to a certain
extent by the heavy leather and fur-lined caps they wore. But Tom
had several small eyelet holes set into the flaps just over the
opening of the ears, and these holes were sufficient to admit
sounds, while keeping out most of the cold that obtains in the
upper regions.

The aeroplane moved swiftly along the level starting ground,
and away from the lighted hangars. Faster and faster it swung
along as Tom headed it into the wind, and then, as the speed of
the motor increased, the Air Scout suddenly left the earth and
went soaring aloft as she had done before.

But there was this difference. She moved almost as silently as
a great owl which swoops down out of the darkness--a bit of the
velvety blackness itself. Up and up, and onward and onward, went