"You have to vol-plane back to earth."

"Vol-plane?" and there was a questioning note in Mr. Damon's voice.

"Yes, glide down from whatever height you are at when the engine
stalls. Come down in a series of dips from the upper currents.
Vol-planing, the French call it, and I guess it's as good a word as
any."

"Have you ever done it?" asked the odd character.

"Oh, yes, several times."

"Then, bless my fur overcoat! I can do it, too, Tom. When will you
be ready to start?"

"To-morrow morning. Now you are sure you won't get nervous and want
to jump, if the engine happens to break down?"

"Not a bit of it. I'll vol-plane whenever you are ready," and Mr.
Damon laughed.

"Well, we'll hope we won't have to," went on Tom. "And I'll be very
glad of your company. Mr. Fenwick will, no doubt, be pleased to see
you. I've never met him, and it will be nice to have some one to
introduce me. Suppose you come out and see what sort of a craft you
are doomed to travel in to-morrow, Mr. Damon. I believe you never
saw my new monoplane."

"That's right, I haven't, but I'd be glad to. I declare, I'm getting
to be quite an aviator," and Mr. Damon chuckled. A little later,
Tom, having informed his father of the sending of the message, took
his eccentric friend out to the shop, and exhibited the BUTTERFLY.

As many of you have seen the ordinary monoplane, either on
exhibition or in flight, I will not take much space to describe
Tom's. Sufficient to say it was modeled after the one in which
Bleriot made his first flight across the English channel.

The body was not unlike that of a butterfly or dragon fly, long and
slender, consisting of a rectangular frame with canvas stretched
over it, and a seat for two just aft of the engine and controlling
levers. Back of the seat stretched out a long framework, and at the
end was a curved plane, set at right angles to it. The ends of the
plane terminated in flexible wings, to permit of their being bent up
or down, so as to preserve the horizontal equilibrium of the craft.

At the extreme end was the vertical rudder, which sent the monoplane
to left or right.

Forward, almost exactly like the front set of wings of the dragon
fly, was the large, main plane, with the concave turn toward the
ground. There was the usual propeller in front, operated by a four
cylinder motor, the cylinders being air cooled, and set like the
spokes of a wheel around the motor box. The big gasolene tank, and
ot