THE FALSE BOTTOM
For a moment the queer box itself was forgotten in the wonderment over
the cipher. That it would prove a solution to the mystery, if such there
was, and that it was not a joke, was believed by all. Even Allen, calm
as he usually was, displayed some excitement. The girls themselves could
not conceal their eagerness.
"How are you going to make sense out of that?" asked Roy, who did not
like to spend much time over anything. "It's worse than Greek."
"Most ciphers are," agreed Allen. "The only way to translate it is to go
at it with some sort of system. I'll need plenty of paper, and some
pencils."
"I'll tell you what to do," said Mr. Nelson. "Make several copies of the
cipher, 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 paper
in the iron box might contain directions for finding some hidden
treasure made it all the more alluring.
"There are any number of ciphers," Allen explained, when several copies
had been made of the original. "The simplest is to change the letters of
the alphabet about, using Z for A, and so on. Another simple one is to
make figures stand for letters, as No. 1 is A, and so on. But those are
so 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. But
the most simple of the difficult ones is the taking of a number of
arbitrary signs or symbols to represent the letters of the alphabet.
That is what was done in Poe's 'Gold Bug,' you remember. Unless the
person has a copy of the list of signs and symbols it is very difficult
to decipher that cipher, or decode it, as they say in government
circles."
"Ahem!" exclaimed Will, with an important air, as all eyes were turned
on him. "I ought to know something about that, but you see they haven't
trusted me with the code book yet. Now then, Allen, how are we to go
about this Chinese puzzle?"
"If I had that story of Poe's here, it would be rather easier," Allen
said. "As it is, we shall have to do a little preliminary work. To start
off with we will take the letter E."
"Why E?" asked Roy.
"Because of all the letters in the ordinary use of English, that letter
most frequently occurs," Allen answered. "In other words, if you take a
written, or printed, page, and count up the letters, you will find that
E 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 the
letters on a page we can find out."
"Some work!" groaned Roy. But they began it. Even Mr. and Mrs. Nelson
were interested enough in the novel game to attempt it.
It took some little time, but at last Betty and Allen, who were working
together, announced that they found A to be the next most predominating
letter after E. And the others' search agreed with this. Then in order
came o, i, d, h, n, and so on.
But they did not do that in one day, or even two, for they found it
rather tiring to the eyes. So that it was not until three days after
the finding of the box that Allen was ready with the ground-work of his
cipher translation.
In the meanwhile the motor boat had been repaired and was ready for
service. The weather had cleared, and in the intervals of working over
the mysterious paper in the box the boys, escorted by the girls, went to
the place where it had been found. The hole in the sand was just as they
had 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 view
to getting a clue to the one who took the box," Allen said, with a look
at Betty.
The next day a real attempt was made to decipher the code. As Allen had
said, 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 or
sign that occurs most frequently. In other words, the predominating one.
And that will be E, for E is the predominating letter in any
communication. 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 follow
the plan of any of the well known ones. They succeeded in deciphering
it, after a fashion, but the result was a meaningless jumble of words
that 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 sure
thought 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 government
experts 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 which
gave 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 ear
and shaking it.
"What are you doing, Betty Nelson?" asked Grace, coming in from a walk
to town.
"I was just listening to see if there was any hidden mechanism in this
box," answered the Little Captain. "I wonder if there's a ruler anywhere
about?" she went on.
She found a foot ruler, and with that began measuring inside and
outside 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?" asked
Allen, coming in.
"Don't talk to me for a minute, please," said Betty, puckering up her
forehead.
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 the
thickness of it."
"The thickness of what?" asked Allen.
"The bottom of that box!" went on Betty. "It has a false bottom. I'm
sure of it. Look here! It is seven inches deep on the outside, and only
five inches deep inside. Where are those two missing inches except in a
false bottom?"
In her excitement Betty tapped on the inside of the bottom of the box
with the ruler, and then a strange thing happened.
There was a clicking, springing sound, and the bottom of the iron box
seemed to rise up in two parts, like the twin doors of a sidewalk
elevator hatchway. The false bottom had been found, and as it swung up
out of the way there was disclosed an opening in which lay a package
wrapped in white tissue paper.
"Oh! Oh!" cried Betty, staring at the box "I--I've found it--the
treasure!"