APPENDIX D

ON THE APPLICATION OF THE NUMBER CIPHER TO THE DOTTED PRINTING

The problem which I now put before myself was to make dots in a printed book in which I could repeat accurately and simply the setting forth of the biliteral cipher. I had, of course, a clue or guiding principle in the combinations of numbers with the symbols of “a” and “b” as representing the Alphabetical symbols. Thus it was easy to arrange that “a” should be represented by a letter untouched and “b” by one with a mark. This mark might be made at any point of the letter. Here I referred to the cipher itself and found that though some letters were marked with a dot in the centre or body of the letter, those both above and below wherever they occurred showed some kind of organised use. “Why not,” said I to myself, “use the body for the difference between “a” and “b;” and the top and bottom for numbers?”

No sooner said than done. I began at once to devise various ways of representing numbers by marks or dots at top and bottom. Finally I fixed, as being the most simple, on the following:

Only four numbers—2, 3, 4, 5—are required to make the number of times each letter of the symbol is repeated, there being in the original Baconian cipher, after the elimination of the ten variations already made, only three changes of symbol to represent any letter. Marks at the top might therefore represent the even numbers “2” and “4”—one mark standing for “two” and two marks for “four”; marks at the bottom would represent the odd numbers “3” and “5”—one mark standing for “three” and two marks for “five.”

Thus “a a a a a” would be represented by “̤a” or any other letter with two dots below: “a a a a b” by ä b, or any other letters similarly treated. As any letter left plain would represent “a” and any letter dotted in the body would represent “b” the cipher is complete for application to any printed or written matter. As in the number cipher, the repetition of a letter could be represented by a symbol which in this variant would be the same as the symbol for ten or “0.” It would be any letter with one dot in the body and two under it, thus—̤t.

For the purpose of adding to the difficulty of discovery, where two marks were given either above or below the letter, the body mark (representing the letter as “b” in the Biliteral) might be placed at the opposite end. This would create no confusion in the mind of an advised decipherer, but would puzzle the curious.

On the above basis I completed my key and set to my work of deciphering with a jubilant heart; for I felt that so soon as I should have adjusted any variations between the systems of the old writer and my own, work only was required to ultimately master the secret.

The following tables will illustrate the making and working—both in ciphering and de-ciphering—of the amended Biliteral Cipher of Francis Bacon: