CHAPTER XII
THE FALSE BOTTOM
For a moment the queer box itself was forgotten in the wonderment overthe cipher. That it would prove a solution to the mystery, if such therewas, and that it was not a joke, was believed by all. Even Allen, calmas he usually was, displayed some excitement. The girls themselves couldnot conceal their eagerness.
"How are you going to make sense out of that?" asked Roy, who did notlike to spend much time over anything. "It's worse than Greek."
"Most ciphers are," agreed Allen. "The only way to translate it is to goat it with some sort of system. I'll need plenty of paper, and somepencils."
"I'll tell you what to do," said Mr. Nelson. "Make several copies of thecipher, and we can all work on it at once. It will be a sort of game."
And a fascinating game it proved. The possibility that the queer paperin the iron box might contain directions for finding some hiddentreasure made it all the more alluring.
"There are any number of ciphers," Allen explained, when several copieshad been made of the original. "The simplest is to change the letters ofthe alphabet about, using Z for A, and so on. Another simple one is tomake figures stand for letters, as No. 1 is A, and so on. But those areso simple that only a schoolboy would use them."
"What are same of the more difficult ciphers?" asked Betty.
"Well, there are so many I don't know that I could explain them all. Butthe most simple of the difficult ones is the taking of a number ofarbitrary signs or symbols to represent the letters of the alphabet.That is what was done in Poe's 'Gold Bug,' you remember. Unless theperson has a copy of the list of signs and symbols it is very difficultto decipher that cipher, or decode it, as they say in governmentcircles."
"Ahem!" exclaimed Will, with an important air, as all eyes were turnedon him. "I ought to know something about that, but you see they haven'ttrusted me with the code book yet. Now then, Allen, how are we to goabout this Chinese puzzle?"
"If I had that story of Poe's here, it would be rather easier," Allensaid. "As it is, we shall have to do a little preliminary work. To startoff with we will take the letter E."
"Why E?" asked Roy.
"Because of all the letters in the ordinary use of English, that lettermost frequently occurs," Allen answered. "In other words, if you take awritten, or printed, page, and count up the letters, you will find thatE is used most frequently."
"What is the next one?" asked Mollie. "Oh, isn't this fascinating,girls!"
"It will be more fascinating to discover the secret," Betty said.
"I don't know what letter is next in importance, or, rather frequency,"Allen answered. "But we will each take a book and by counting theletters on a page we can find out."
"Some work!" groaned Roy. But they began it. Even Mr. and Mrs. Nelsonwere interested enough in the novel game to attempt it.
It took some little time, but at last Betty and Allen, who were workingtogether, announced that they found A to be the next most predominatingletter after E. And the others' search agreed with this. Then in ordercame o, i, d, h, n, and so on.
But they did not do that in one day, or even two, for they found itrather tiring to the eyes. So that it was not until three days afterthe finding of the box that Allen was ready with the ground-work of hiscipher translation.
In the meanwhile the motor boat had been repaired and was ready forservice. The weather had cleared, and in the intervals of working overthe mysterious paper in the box the boys, escorted by the girls, went tothe place where it had been found. The hole in the sand was just as theyhad left it.
"The men haven't come back to discover their loss," said Betty.
"Or, if they have, they are leaving the ground undisturbed with a viewto getting a clue to the one who took the box," Allen said, with a lookat Betty.
The next day a real attempt was made to decipher the code. As Allen hadsaid, it was made up of several letters, numbers and arbitrary signs,some of them resembling Chinese characters in form.
"The thing to do," said Allen, "is to pick out the letter, number orsign that occurs most frequently. In other words, the predominating one.And that will be E, for E is the predominating letter in anycommunication. Now we'll begin."
They all had great hopes, but, alas! they were doomed to disappointment.For either Allen's system was wrong, or else the cipher did not followthe plan of any of the well known ones. They succeeded in decipheringit, after a fashion, but the result was a meaningless jumble of wordsthat told them nothing. The word "treasure" did not even occur; that is,according to the translation made by Allen.
"Well, I give up," he said, with a sigh of disappointment. "I surethought I could make something of it, but I can't."
"Maybe Will could send it to some of his Secret Service friends,"suggested Grace.
"Yes, I could do that," her brother assented. "Let's let the governmentexperts take a crack at it, Allen."
"I'm willing," assented the young lawyer.
Betty was in a corner of the big sitting room, the bay window of whichgave a beautiful view of the ocean. She had the queer box in her lap,and was turning it from side to side, now and then holding it to her earand shaking it.
"What are you doing, Betty Nelson?" asked Grace, coming in from a walkto town.
"I was just listening to see if there was any hidden mechanism in thisbox," answered the Little Captain. "I wonder if there's a ruler anywhereabout?" she went on.
She found a foot ruler, and with that began measuring inside andoutside the box, jotting down some figures on a piece of paper.
"What's this--a new way to work out the cipher I couldn't solve?" askedAllen, coming in.
"Don't talk to me for a minute, please," said Betty, puckering up herforehead.
She seemed to be adding and subtracting, and then she suddenly cried:
"I thought so! I thought so! It is the only way to account for thethickness of it."
"The thickness of what?" asked Allen.
"The bottom of that box!" went on Betty. "It has a false bottom. I'msure of it. Look here! It is seven inches deep on the outside, and onlyfive inches deep inside. Where are those two missing inches except in afalse bottom?"
In her excitement Betty tapped on the inside of the bottom of the boxwith the ruler, and then a strange thing happened.
There was a clicking, springing sound, and the bottom of the iron boxseemed to rise up in two parts, like the twin doors of a sidewalkelevator hatchway. The false bottom had been found, and as it swung upout of the way there was disclosed an opening in which lay a packagewrapped in white tissue paper.
"Oh! Oh!" cried Betty, staring at the box "I--I've found it--thetreasure!"