CHAPTER XX
THE BIG GUN
For a moment Tom and Jack did not quite know what to make of theexcitement of Major de Trouville. And excited he certainly was beyond adoubt.
"You must come and tell this to Lieutenant Laigney at once," he said."It may mean something important. Are you sure of the sequence of thecolors?" he asked. "That makes all the difference."
"There was first an orange tint," said Tom, "which was followed by greenand purple, the last gradually dying out."
"Orange, green and purple," murmured the major. "Can it be that forwhich we are seeking?"
He hurried along with the boys, seemingly forgetting, in his haste andexcitement, that he was their ranking officer. But, as has been noted,the aviators are more like friends and equals than officers and men.There is discipline, of course, but there is none of the rigidity seenin other branches of the army. In fact the very nature of the workmakes for comradeship.
Tom and Jack knew, slightly, the officer to whom Major de Trouvillereferred. Lieutenant Laigney was an ordnance expert, and the inventor ofa certain explosive just beginning to be used in the French shells. Itwas simple, but very powerful.
"You must tell him what you observed--the strange colored lights, myboys," said the major. "By the way, I hope you carefully noted the timeof the colored flares."
Tom and Jack had. That was part of their training, to keep a note ofextraordinary happenings and the time. Often seemingly slight mattershave an important bearing on the future.
They found Lieutenant Laigney in his quarters, making what seemed to besome intricate calculations. He saluted the major and nodded to theboys, whom he had met before.
"Lieutenant," began Major de Trouville, "these young gentlemen havesomething to tell you. I want you to think it over in the light of whatyou told me about the action of that new explosive you said the Germansmight possibly be using."
"Very good, Major. I shall be delighted to be of any service in mypower," was the answer.
Then Tom and Jack described what they had seen, giving the location ofthe colored lights as nearly as they could, and the exact time they hadnoted them.
"How long would it take a shell to reach Paris, fired at a distance ofeighty miles from the city?" asked the major.
The lieutenant made some calculations, and announced the result of hisfindings.
"Then," went on the commanding officer, "if a shell was fired from thebig gun, say at the moment when these two scouts observed thetri-colored fire, it should have reached Paris at seven-fifty-threeo'clock."
"As nearly as can be calculated, not knowing the exact speed of theprojectile, yes," answered the lieutenant.
Major de Trouville picked up the telephone and asked to be connectedwith the wireless station.
"Have you had any reports of the bombarding of Paris this evening?" heasked. "Yes? What time did the first, or any particular shell, arrive?Ah, yes, thank you. That is all at present."
He turned to the others, after having listened to the reply and put theinstrument away.
"One of the shells exploded in a Paris street at seven-fifty-two o'clockthis evening," he said.
"It beat your calculations by one minute, Lieutenant Laigney."
"Ah! Then this means--" and the younger officer seemed as excited as themajor 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 hishead in assent.
"Those queer lights, as you call them," said the ordnance expert, "werethe 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 ProfessorBarcello, one of our experimenters, who discovered it. But a spy stolethe 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 inconstructing 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, "And that we really saw it being fired?" cried Tom.
"That is my belief," said the lieutenant. "This explosive burns, whenfired from a gun, first with an orange flame, changing to green and thento purple, as the various gases are given off."
"Those are the very colors we saw!" exclaimed Jack.
"Yes," went on Major de Trouville. "And when I heard you mention them,and when I recalled that Lieutenant Laigney had spoken of a certainexplosive that gave off a tri-colored light, I suspected you had hit onthe German secret."
"And do you believe we actually saw the giant cannon being fired atParis?" asked Tom.
"Without a doubt. The time of the arrival of one of the shells coincidesalmost to the minute with the time that would elapse after the missilewas sent on its way, and this was when you saw the queer flashes. Youhave discovered the area where the big gun is placed. All that is needednow are some exact observations to give us the exact spot."
"And then we can destroy it!" cried the lieutenant. "Then the menace tobeloved Paris will have passed!"
"And thanks to our brave American friends!" cried the major, shakinghands with Tom and Jack. "You will win promotion for this!" he murmured.
"But the big gun isn't found yet," said Jack.
"Why, if you are right, sir," Tom said to the major, "the shells mustpass right over our camp."
"They probably do. But at so far above--several miles up so as to reachthe height of thirty-five--that we never know it. We neither see themnor hear them. Boys, I believe you have located the big gun! All thatnow remains is to destroy it!"