rests, fields, villages, and the silver ribbon
of a river. But all were racing by, and that, even more than the wind
rushing past, gave him an idea of the speed at which they were going. He
took a long, long look and then returned the glasses.

"It's tremendous," he said. "I confess that at first I felt both fear
and physical ill. But I am getting over it, and I feel instead the
thrill of swift motion."

"It's because we have a perfect piece of track."

"There's no track in the air!"

"Oh, yes, there is. If you'd thought a moment you'd have known it,
though I'll admit it's a shifting one. When you stand on the ground and
turn your eyes upward all the sky looks alike. But it's far from it.
It's full of all kinds of winds, currents and strata, pockets, of which
all aviators stand in deadly fear, mists, vapors, clouds of every degree
of thickness and complexion, and then you have thunder and lightning,
just as you do on land and sea. It's these shifting elements that make
the navigation of the air so dangerous, John. The whole question would
be solved, if there was nothing but stationary air, growing thinner in
exact proportion as we rise. But such a condition of aerial peace could
not be reached unless we could go up fifty miles, where there is no air,
and that we'll never be able to do."

"How high are we now?"

"About three thousand feet. Draw that collar more closely about your
neck. You may not feel cold, because of the new fire in your blood, but
you are cold, nevertheless. Now, see those whitish streams below us.
They're little clouds, vapor mostly, they don't contain rain. You've
read the 'Arabian Nights,' haven't you, John?"

"Yes, and I know just the comparison you're thinking of."

"What is it, then? See if you're right."

"The roc, great, fabled bird, flying through the air with those old
Arabs perched on its back."

"Right! He guessed right the very first time. That's one of your
Americanisms, isn't it? Oh, I know a lot of your choicest expressions.
Hit it up lively! That's what we're doing. He's full of pep! That's what
we are; aren't we, John? Come across with a double play! And we're doing
that, too."

"I don't know that your baseball metaphor is exactly right, Philip, but
your heart is certainly in the proper place. When do we get to France?"

"Don't talk about that yet, because it's impossible to approximate. This
smooth track will not go on forever. It's lasted longer than usual
already. T