ld imagine they
would be used only in places of danger."

"Maybe that is the reason."

"Surely there can be no danger for a German airship around here."

"I don't know about that. We have traveled a considerable distance.
Perhaps we are closer to the border than we think."

"Well, we can't get across it any too soon to suit me," declared Chester.

Hal did not reply, and the flight was continued in silence. For more
than an hour the huge machine sailed swiftly through the air. At
length Hal said:

"I guess we had better drop down a bit. Perhaps we may be able to see
something."

Suiting the action to the word, he let the machine glide slowly downward,
until the distant shadow of the earth could once more be seen. Then the
craft sped out on its straightaway course again.

The twinkling of faraway lights drew the boys' attention.

"I wonder what that is?" asked Chester.

"We'll see," was the brief reply.

The machine dropped still lower.

"An army camp!" exclaimed Hal, when he was at last able to make out the
objects below. He shut off his engine, and for a few moments both boys
gave their attention to the awe-inspiring sight.

Dimly they could discern the outlines of the great camp. With its
thousands upon thousands of huts, it spread out like a great fan,
extending almost as far as the eye could see.

"Great Scott!" exclaimed Chester. "There must be a million men
down there!"

"Hardly that many," laughed Hal; "but there are a few. I guess we had
better go a little higher. We might be seen, and a chance bullet might
bring us down in the middle of them."

The machine rose gently again; but, as the airship headed once more upon
its course, there was a muffled explosion, and the machine rocked
dangerously.

"What on earth is the matter now?" demanded Chester.

Hal bent over his engine.

"I don't know what has blown out," he replied. "But the engine has
gone dead."

"Dead!" exclaimed Chester.

"Yes."

"Can you fix it?"

"Not up here. It is impossible. I am not familiar enough with it."

"What shall we do, then?" cried Chester, in alarm.

"We shall have to go down."

"What! And land right in the middle of the German camp?"

"I am afraid so. There is no help for it. However, I shall sail just as
far as possible before we hit the earth."

Slowly the machine dropped, its strong planes still holding it on its
forward course. So gentle was the fall that it was almost
imperceptible; but present