se bundling unnecessary. We fellows will wear our regular working
togs."

Everything being in readiness, the four young men easily pushed the big
airplane out of the building and to a place where it would have a
smooth runway for a hundred yards ahead. The weather was ideal for the
trip. There was little wind, and the few strato-cumulus clouds which
were visible showed great stretches of azure-blue sky between them.

"Everybody climb in," ordered Tom, with a wave of his hand. "I'll
crank her up. You take the joy-stick, John."

All hands complied. Then Tom began to turn the big burnished
propeller, just as John threw a lever from the inside which caused the
auxiliary ground wheel to shoot down and engage the sod. At the same
time the movement of another lever by Paul set the airplane's brakes.

Several times Tom turned the propeller around. Then, with a pop, the
engine cylinders began to fire, Tom jumped swiftly back, and the
propeller whirred like a mad thing. At the same time the Sky-Bird gave
a start, as though to dash forward; but beyond a steady, slight
vibration of her whole body, as Tom slowed down the motor to four
hundred revolutions per minute, there was no indication to her inmates
that she was straining to get away. Tom now quietly mounted the step,
and came into the cabin, pulling the step up after him and closing the
self-locking door.

"That shows you how this third ground wheel acts, dad!" cried Bob
triumphantly to his father, who sat in a chair adjoining. "Now watch
the old girl jump ahead when Paul throws back the brake lever and his
brother lifts the third wheel and gives her more gas!"

The changes were made even as he spoke; the propeller's hum grew into a
mild roar through the cabin walls, and the Sky-Bird leaped away over
the ground, gaining momentum at every yard. To the surprise of even
two such veteran flyers as John Ross and Tom Meeks, the airplane had
gone less than fifty yards when she began to rise as gracefully as a
swallow in response to her up-turned ailerons and elevators. In less
than ten seconds she was well up over the fair-grounds, and the roofs
of all the buildings in the neighborhood were seen below them.

John kept the machine mounting at a good angle until the altimeter
showed them to be up two thousand feet. Then he straightened out the
ailerons and elevators, and began to run on a level keel. The other
inmates of the cabin noticed, by looking through the o