"It beat your calculations by one minute, Lieutenant Laigney."
"Ah! Then this means—" and the younger officer seemed as excited as the major had been when Tom and Jack told him what they had seen.
"It means," finished the commanding officer, "that, in all likelihood, these young men have discovered the location of the big German cannon."
"Discovered it!" cried Jack. "Why we didn't see anything!"
"Nothing but those queer lights," added Tom.
Major de Trouville smiled at them, and Lieutenant Laigney nodded his head in assent.
"Those queer lights, as you call them," said the ordnance expert, "were the flashes of a new explosive. What the Germans call it I do not know. For want of a better name we call it Barlite, from the name of Professor Barcello, one of our experimenters, who discovered it. But a spy stole the secret and gave it to Germany. They must have managed to perfect it, though we have not used it as yet, owing to the difficulty in constructing a gun strong enough to withstand its terrific power."
"And do you mean they're using this explosive in the big German gun?" asked Jack.
