that?"

From a far point in the west came a low sound which swelled gradually
into a crash like thunder. In a few moments came another, and then
another and then many. They could see no smoke, no fire, and the very
distance lent majesty to the sound.

John knew well what it was, the thudding of great guns, greater than any
that had been fired before by man on land. Lannes turned ashy-pale.

"It's the cannon, the German cannon!" he said, "and that sound comes
from France. The Kaiser's armies are already over the border, marching
on Paris. Oh, John! John! all the time that I was predicting it I was
hoping that it wouldn't come true, couldn't come true! You Americans
can't understand! In your new country you don't have age-old passions
and hates and wrongs and revenges burning you up!"

"I do understand. It must be a serious battle though. All the planes are
now flying westward, and there goes the Zeppelin too."

"Which leaves us safe for the present. Besides, the twilight is coming."

CHAPTER VII

THE ZEPPELIN

The brilliant sunlight faded into gray, but the European twilight
lingers, and it was long before night came. John and Lannes stood beside
the Arrow, and for a while neither spoke. They were listening to the
thunder of the great guns and they were trying to imagine how the battle
was swaying over the distant and darkening fields. The last of the air
scouts had disappeared in the dusk.

"The sound doesn't seem to move," said Lannes, "and our men must be
holding their own for the present. Still, it's hard to tell about the
location of sound."

"How far away do you think it is?"

"Many miles. We only hear the giant cannon. Beneath it there must be a
terrible crash of guns and rifles. I've heard, John, that the Germans
have seventeen-inch howitzers, firing shells weighing more than two
thousand pounds, and France furnishes the finest roads in the world for
them to move on."

He spoke with bitterness, but in an instant or two he changed his tone
and said:

"At any rate we haven't made a god out of war, and that's why we haven't
seventeen-inch cannon. Perhaps by not setting up such a god we've gained
something else--republican fire and spirit that nothing can overcome."

The twilight now deepened and the darkness increased fast in the wood,
but the deep thunder on the western horizon did not cease. John thought
he saw flashes of fire from the giant cannon, but he was not sure. It
might be sheave