lly clear, a vault of blue velvet, against
which anything would show. Far away the cannon groaned and thundered,
and the waves of air pulsed heavily, but John noticed neither now. His
whole attention was centered upon the flag, and what it might call from
the air.

"In such a brilliant atmosphere we can certainly see our visitors from
afar," he said.

"So we can," said Weber, "and lo! another appears out of the east!"

The dark speck showed on the horizon and grew fast, coming apparently
straight in their direction. John did not believe it had seen their flag
at first, owing to the great distance, but was either a messenger or a
scout. As it soon began to descend from its great height in the air,
although still preserving a straight course for the tree, he felt sure
that the flag had now come into its view. It grew very fast in size and
was outlined with startling clearness against the burning blue of the
sky.

The approaching machine consisted of two planes alike in shape and size,
superimposed and about six feet apart, the whole with a stabilizing tail
about ten feet long and six feet broad. John saw as it approached that
the aviator sat before the motor and screw, but that the elevating and
steering rudders were placed in front of him. There were three men
besides the aviator in the machine.

"A biplane," said John.

"Yes," said Weber, "I recognize the type of the machine. It's originally
a French model."

"But in this case, undoubtedly a German imitation. They've seen our
flag, because I can make out one of the men with glasses to his eyes.
They hover about as if in uncertainty. No wonder they can't make up
their minds, because there's the tricolor floating from the top of that
tall tree, and not a thing in the world to explain why it's in such a
place. A man with a rifle is about to take a shot at it. Bang! There it
goes! But I can't see that the bullet has damaged our flag. Look, how it
whips about and snaps defiance! Now, all the men except the aviator
himself have out glasses and are studying the phenomenon of our signal.
They come above the tree, and I think they're going to make a swoop
around the grove near the ground. Lie close, Weber! As I found out once
before, a thick forest is the best defense against aeroplanes. They
can't get through the screen of boughs."

They heard a whirring and drumming, and the biplane not more than fifty
feet above the earth made several circles about the little wood.