“Now, in English, the letter which most frequently occurs is e. Afterwards, the succession runs thus: a o i d h n r s t u y c f g l m w b k p q x z. E however predominates so remarkably that an individual sentence of any length is rarely seen, in which it is not the prevailing character.
“Here, then, we have, in the very beginning, the groundwork for something more than a mere guess. The general use which may be made of the table is obvious — but, in this particular cipher, we shall only very partially require its aid. As our predominant character is 8, we will commence by assuming it as the e of the natural alphabet. To verify the supposition, let us observe if the 8 be seen often in couples — for e is doubled with great frequency in English — in such words, for example, as ‘meet,’ ‘fleet,’ ‘speed, ‘seen,’ ‘been,’ ‘agree,’ &c. In the present instance we see it doubled less than five times, although the cryptograph is brief.
“Let us assume 8, then, as e. Now, of all words in the language, ‘the’ is the most usual; let us see, therefore, whether they are not repetitions of any three characters in the same order of collocation, the last of them being 8. If we discover repetitions of such letters, so arranged, they will most probably represent the word ‘the.’ On inspection, we find no less than seven such arrangements, the characters being;48. We may, therefore, assume that the semicolon represents t, that 4 represents h, and that 8 represents e — the last being now well confirmed. Thus a great step has been taken.
“But, having established a single word, we are enabled to establish a vastly important point; that is to say, several commencements and terminations of other words. Let us refer, for example, to the last instance but one, in which the combination;48 occurs — not far from the end of the cipher. We know that the semicolon immediately ensuing is the commencement of a word, and, of the six characters succeeding this ‘the,’ we are cognizant of no less than five. Let us set these characters down, thus, by the letters we know them to represent, leaving a space for the unknown —
t eeth.
“Here we are enabled, at once, to discard the ‘th,’ as forming no portion of the word commencing with the first t; since, by experiment of the entire alphabet for a letter adapted to the vacancy we perceive that no word can be formed of which this th can be a part. We are thus narrowed into
t ee,
and, going through the alphabet, if necessary, as before, we arrive at the word ‘tree,’ as the sole possible reading. We thus gain another letter, r, represented by (, with the words ‘the tree’ in juxtaposition.
“Looking beyond these words, for a short distance, we again see the combination;48, and employ it by way of termination to what immediately precedes. We have thus this arrangement:
the tree;4(+?34 the,
or substituting the natural letters, where known, it reads thus:
the tree thr+?3h the.
“Now, if, in place of the unknown characters, we leave blank spaces, or substitute dots, we read thus:
the tree thr . . . h the,
when the word ‘through’ makes itself evident at once. But this discovery gives us three new letters, o, u and g, represented by +? and 3.
“Looking now, narrowly, through the cipher for combinations of known characters, we find, not very far from the beginning, this arrangement,
83(88, or egree,
which, plainly, is the conclusion of the word ‘degree,’ and gives us another letter, d, represented by!.
“Four letters beyond the word ‘degree,’ we perceive the combination
;46(;88*.
“Translating the known characters, and representing the unknown by dots, as before, we read thus:
th.rtee.
an arrangement immediately suggestive of the word ‘thirteen,’ and again furnishing us with two new characters, i and n, represented by 6 and *.
“Referring, now, to the beginning of the cryptograph, we find the combination,
53++!.
“Translating, as before, we obtain
.good,
which assures us that the first letter is A, and that the first two words are ‘A good.’
“To avoid confusion, it is now time that we arrange our key, as far as discovered, in a tabular form. It will stand thus:
| 5 | represents | a |
| ! | “ | d |
| 8 | “ | e |
| 3 | “ | g |
| 4 | “ | h |
| 6 | “ | i |
| * | “ | n |
| + | “ | o |
| ( | “ | r |
| ; | “ | t |
“We have, therefore, no less than ten of the most important letters represented, and it will be unnecessary to proceed with the details of the solution. I have said enough to convince you that ciphers of this nature are readily soluble, and to give you some insight into the rationale of their development. But be assured that the specimen before us appertains to the very simplest species of cryptograph. It now only remains to give you the full translation of the characters upon the parchment, as unriddled. Here it is:
“‘A good glass in the bishop’s hostel in the devil’s seat twenty-one degrees and thirteen minutes northeast and by north main branch seventh limb east side shoot from the left eye of the death’s-head a bee line from the tree through the shot fifty feet out.’”
“But,” said I, “the