CHAPTER XII
FOR PERILOUS SERVICE
Tom and Jack spent some little time looking at the strange German shell. It was of peculiar construction, arranged so that the two explosive charges would detonate together or separately, according as the mechanism was set.
But in this case it had failed to work, and the shell, falling in a bed of soft sand, near some new buildings which were going up, had not been fired by concussion, as might have happened.
"And it was just French luck that it didn't go off," observed Jack.
"That's right," agreed Tom. "If they hadn't had this whole shell to examine they wouldn't know about the big gun."
So all the theories, fantastic enough some of them, about great airships hovering over the beautiful city, and dropping bombs from a great height, were practically disproved.
"Well, now that you have decided it is a big German gun, the next question is, where is it and what are you going to do about it?" ob-
