t about it in that way. Now
think, Harry, what letter occurs most frequently in the English tongue."

"Well," replied his friend, "I have never given any thought to the
matter, so I couldn't say immediately; but I should say that the letter
A occurs as often as any."

"It certainly does often occur, as you say," agreed Roger; "but the
letter E occurs more often than any other letter, and, knowing that, I
am going to look for the number that occurs most often in the cipher,
and I feel sure that that number will be found to correspond to the
letter E, provided always, of course, that this cryptogram is written in
English."

"Bravo, Roger," shouted Harry; "well thought of! Now, I should never
have hit upon that method if I had been worrying at this thing for
ever."

"S-s-sh--!" Roger whispered. "Be quiet, man; do you want to bring
those spies and jailers upon us? For you assuredly will, if you make
much of that row."

"I am sorry," said Harry. "For the moment I had forgotten where we
were, and I felt so sure that you had hit upon the right method of
translating the cipher that I shouted without thinking."

Roger interrupted his friend: "Do not speak for a few moments. Even
then I thought I caught the sound of some person outside the door; I
pray Heaven that they may not come into the cell!"

The two listened most intently for some minutes, with their ears pressed
up against the wall and door, but caught no sound from outside. So,
after waiting a little time longer, to make perfectly certain, they both
returned to the task in hand.

"Now let us go on where we left off just now," Harry suggested. "You
say that we want to find out the number that occurs most often in the
cryptogram, and allow that to represent E."

"That is so," replied Roger. "Now, let us have a look through it
again."

They both counted up, and presently Harry, who had finished first,
exclaimed--this time in a carefully lowered voice:

"Well, the number 34 occurs oftener than any other; that is, if you are
adding the first two and last two figures of each group together."

"Wait a moment," said Roger, still busily counting. Then, after a
pause, he added:

"Yes, you are right, Harry; the number 34 does occur most frequently;
and we can, I am sure, take it as representing the letter E. Now, going
upon that assumption, A will be represented by 30, B by 31, C by 32, D
by 33, and so on. Now I believe that we have the translation in