Sir Arthur Conan Doyle: The Return of Sherlock Holmes

3. The Adventure of the Dancing Men. (continued)

"Having once recognised, however, that the symbols stood for letters, and having applied the rules which guide us in all forms of secret writings, the solution was easy enough. The first message submitted to me was so short that it was impossible for me to do more than to say with some confidence that the symbol XXX stood for E. As you are aware, E is the most common letter in the English alphabet, and it predominates to so marked an extent that even in a short sentence one would expect to find it most often. Out of fifteen symbols in the first message four were the same, so it was reasonable to set this down as E. It is true that in some cases the figure was bearing a flag and in some cases not, but it was probable from the way in which the flags were distributed that they were used to break the sentence up into words. I accepted this as a hypothesis, and noted that E was represented by XXX.

"But now came the real difficulty of the inquiry. The order of the English letters after E is by no means well marked, and any preponderance which may be shown in an average of a printed sheet may be reversed in a single short sentence. Speaking roughly, T, A, O, I, N, S, H, R, D, and L are the numerical order in which letters occur; but T, A, O, and I are very nearly abreast of each other, and it would be an endless task to try each combination until a meaning was arrived at. I, therefore, waited for fresh material. In my second interview with Mr. Hilton Cubitt he was able to give me two other short sentences and one message, which appeared -- since there was no flag -- to be a single word. Here are the symbols. Now, in the single word I have already got the two E's coming second and fourth in a word of five letters. It might be `sever,' or `lever,' or `never.' There can be no question that the latter as a reply to an appeal is far the most probable, and the circumstances pointed to its being a reply written by the lady. Accepting it as correct, we are now able to say that the symbols XXX stand respectively for N, V, and R.