sion. "But, Jack, do you know I shouldn't be
surprised to learn that the shell was not from an airship at all."

"Where would it be from then?"

"The Germans may have massed such a lot of troops at some point opposite
the French lines, that they have broken through and have brought up
some of their heavy guns."

Jack shook his head.

"I don't believe they could do it," he said. "You know the nearest
German line is about seventy miles from Paris. If they had started to
break through, and had any success at all, the news would have reached
here before this. And reinforcements would be on the way. No, it can't
be. There must be some other explanation."

"But what is it?" asked Tom. "They've got to get nearer than seventy
miles to bombard Paris. You know that."

"I don't think I really _know_ anything about this war," said Jack
simply. "So many strange, things have happened, so many old theories
have been discarded, and so many new things have been done that we don't
know where we are."

"Well that's true. And yet how could the Germans get near enough to
bombard Paris without some word of it coming in?"

"I don't know. But the fact remains. Now let's get to where the second
shell fell. Maybe we can see a fragment of it and--"

Once again the words were interrupted by an explosion. This time it was
closer and the shock was greater.

"That's the third!" cried Jack.

"Yes," added Tom, looking at his watch, "and it's just half an hour
since the first one fell. That indicates they're firing every fifteen
minutes. Jack, there's something weird about this."

"You're right. That last one came rather close, too. I wonder where it
fell?"

A man, passing them, running in a direction away from the sound of the
last explosion, heard Jack's question. He paused long enough to say;
"That shell fell in Rue Lafayette. Several buildings are in ruins. Many
have been killed! It is terrible!"

"Rue Lafayette!" gasped Jack. "That--"

"That's where my father is supposed to be staying!" exclaimed Tom.
"Come! We must see what happened!"

CHAPTER VII

TOM'S FATHER

With anxious hearts the Air Service boys ran on. There was no need to
ask their way, for they had but to follow the throng toward the scene of
the most recent exhibition of the Hun's frightfulness and horror.

As they drew near the Rue Lafayette, where Mr. Raymond had said he
intended to stay while in Paris, the boys were halted by an officer on
the outski