Tom and Jack had. That was part of their training, to keep a note of extraordinary happenings and the time. Often seemingly slight matters have an important bearing on the future.
They found Lieutenant Laigney in his quarters, making what seemed to be some intricate calculations. He saluted the major and nodded to the boys, whom he had met before.
"Lieutenant," began Major de Trouville, "these young gentlemen have something to tell you. I want you to think it over in the light of what you told me about the action of that new explosive you said the Germans might possibly be using."
"Very good, Major. I shall be delighted to be of any service in my power," was the answer.
Then Tom and Jack described what they had seen, giving the location of the colored lights as nearly as they could, and the exact time they had noted them.
"How long would it take a shell to reach Paris, fired at a distance of eighty miles from the city?" asked the major.
The lieutenant made some calculations, and announced the result of his findings.
"Then," went on the commanding officer, "if a shell was fired from the big gun, say at the moment when these two scouts observed the tri-colored fire, it should have reached Paris at seven-fifty-three o'clock."
"As nearly as can be calculated, not knowing the exact speed of the projectile, yes," answered the lieutenant.
Major de Trouville picked up the telephone and asked to be connected with the wireless station.