ination, the boys quickly found their two-seater
aircraft awaiting their coming. Quite a crowd stood around, and made
guesses concerning the possible reason for the captain's order that this
plane should be made ready for a journey, with enough supplies of
gasolene and oil aboard to cover any ordinary emergency.

Tom took no chances. He believed the attendants had faithfully carried
out all directions, but to make doubly sure he looked over things
himself. It was his life and Jack's that were at stake, and not those of
the attendants; so he persisted in testing this and that thing until he
felt certain everything was as it should be.

"Is it time we started, Tom?" asked his companion, when this procedure
had resulted satisfactorily.

"We'll wait just ten minutes more," he was told. "I've figured
everything down to a fraction, and expect to proceed by clock-work. We
want to be well over the line before the moon peeps up. After that we
can loaf a bit, and let the old lady get a little way above the horizon.
That's so we may have the benefit of her light when we want to land."

The minutes passed slowly. Meanwhile the crowd increased, every man who
chanced to be abroad at that hour of the night gathering to see the two
Americans start on their mysterious errand. All sorts of guesses were
indulged in, many of them of the wildest character. Jack hearing some of
this talk, which he half understood, was convulsed in silent laughter
over the remarkable ideas that seemed to possess the minds of those
French mechanicians and hostlers.

Finally Tom stood up.

"It's time!" he said simply, and Jack understood without any further
explanation. He at once proceeded to climb into his seat and complete
his simple preparations for the work in hand, being already fully
dressed in his fur-lined garments, and with his warm hood and goggles in
place.

A minute afterwards Tom called out the word that started the propellers
whirling. The motor took up the refrain, and hummed merrily, as though
glad to be busy again. Then they were pushed along for a start,
gathering momentum so quickly that the mechanicians dropped back to
watch the dark object vanish almost wholly from their sight along the
level field.

Both boys noticed the great difference between this two-seater and their
own active little Nieuports. How clumsy this machine was, and how slow
to answer to the call of the pilot! Yet it would be far better for their
purpose than two