in
floor they could see nothing but a gray vapor below them. It was also
around them.

"We're passing up through a cloud," said Bob to his father, who had
never been in an airplane before. A moment or two later, the boy
added, as the blue sky could once more be seen below, "Now we're above
it, dad."

"It seems to be getting colder," remarked Mr. Giddings.

"It always gets colder the higher one goes," informed Paul.

"I hope you're not getting cold feet, dad?" grinned Bob.

"Oh, I'm comfortable, thank you," laughed his father. "Say, son, isn't
this as good a time as any to try out the merits of that wireless
'phone of yours? Can you work it from this height?"

"I don't know why I can't--and three times higher," Bob said; "we'll
try it right now. When I left home I told Sis to mind the set there in
my room, and watch for my signal. We'll see now if I can get in touch
with her."

So saying, Bob put on the wireless helmet, threw the switch, and kept
repeating, "Hello, Sis! hello, Sis! hello, Sis!" for a few moments in
the transmitter. Then he said, after a brief silence: "I get you,
Betty. Won't answer you now, as I want dad to talk to you."

With that Bob smiled, removed the headpiece, and slipped it over his
father's head, exchanging seats with him.

Mr. Giddings now heard a voice--the voice of his own daughter--asking
quite distinctly:

"Do you hear me, daddie?"

"I certainly do, Betty," said he; "where are you?"

"Here at home--up in Robert's room. I never thought I'd be sometime
talking with you when you were flying through the air. Mother just
called upstairs and says she can't see the Sky-Bird any longer. Where
are you now?"

"Up above the clouds somewhere just north of Yonkers," replied Mr.
Giddings laconically.

"Oh, goodness! I must run right down and tell mother. Please don't go
too high or too far, daddie, will you?" came the clearly agitated tones
of the daughter. "Is Robert all right?"

"Indeed he is. We'll soon be back with you and tell you all about it.
Everything is working perfectly. Good-bye, Betty!"

And Mr. Giddings arose with a pleased laugh, and hung up the helmet.
"I'll take off my hat to you, Robert," he said. "I never thought your
fussing at home all these years with electric batteries, buzzers, and
what not, would amount to anything like this."

The Sky-Bird II was now running straight ahead with the speed of the
wind, John giving the craft more and more gas