IMPROVEMENTS IN APPARATUS TO FACILITATE THE COM- MUNICATION BY CYPHER
Year: 1854

page_text: LETTERS PATENT to John Hall Brock Thwaites, of Bristol, Dentist, for
the Invention of "IMPROVEMENTS IN APPARATUS TO FACILITATE THE COM-
MUNICATION BY CYPHER."
Sealed the 10th October 1854, and dated the 7th August 1854.
PROVISIONAL SPECIFICATION left by the said John Hall Brock Thwaites
at the Office of the Commissioners of Patents, with his Petition, on the
7th August 1854.
I, JOHN HALL BROCK THWAITES, of Bristol, Dentist, hereby declare tho
nature of the Invention for "IMPROVEMENTS IN APPARATUS TO FACILITATE THE
COMMUNICATION BY CYPHER" to be as follows:-
The object of this Invention is to construct and combine apparatus for the
purpose of facilitating the employment of a system of cypher, invented by me,
and which, I believe, will offer greater difficulty to decipher than any other
known system. The principle of the communication of cypher invented by
me consists of employing a series of alphabets which can be arranged from
time to time in any order; and when an arrangement or combination has
been agreed on by two correspondents at a distance, any communication may
be made between them so long as the key to the combination of the alphabets
is not divulged; and as the setting or combining of the alphabets may be said

page_text: to be almost infinite, the discovery of the key may be treated as impossible,
the key consisting of some word or set of letters on the moveable alphabets,
arranged opposite a letter of a fixed alphabet.
My apparatus consists of a series of narrow scales in a suitable frame,
every alternate scale being fixed, and the others moveable, and capable of
being slided, so as to bring any letter on the sliding scales opposite any letter
in its neighbouring fixed scale. The scales are all similarly divided by trans-
verse lines, and in each space is a letter; the letters, by preference, being
arranged alphabetically, commencing-with-A at the top space of each scale,
and ending with Z at the bottom space of each scale; and the sliding scales
are twice the length of the others, and have each two alphabets thereon.
Supposing a suitable frame to have been arranged with a series of scales,
such as above described, the corresponding letters of the fixed alphabets
ranging in the same line across the frame, it will be evident that any word
or any succession of letters may be arranged opposite any letter of the first or
outer fixed alphabet to the left hand of the apparatus; thus, supposing the
word good be selected as the key between two correspondents, that word
might be spelled opposite any.letter of the first or other fixed alphabet, in any
way the correspondents may agree on, by moving the moveable scales, to
bring the proper letters of the moveable scales opposite and in a line with the
agreed on letter in the agreed on scale. And to facilitate these arrange-
ments and combinations it is desirable to have the letters on the fixed scales
different in color from those in the moveable scales; say, black for the fixed
scales, and red for the moveable scales. Under this supposition, and supposing,
further, that the letter B of the first fixed scale be agreed on, the scales would
for the time being stand thus:-
.

page_text: And in this state the apparatus will be retained so long as the word "good" op-
posite B in the first fixed alphabet be retained as the key. And the use of the
apparatus to transmit a communication is as follows:-The person sending the
intended communication, having written it down, will then have reference to
the apparatus, in order to write the same in cypher; thus, supposing the com-
munication to commence with "You must come, you must," the corresponding
party would look opposite the letter Y in the first fixed alphabet to see what
letter was there, and he would find the letter D; them on the second move-
able alphabet he would find opposite the letter O the letter B, and opposite
the letter U on the third fixed alphabet he would find on the third moveable
alphabet the letter H, and he would write D, B, H, which would be the
cypher for the word "You;" and as the first word had employed the three first
scales, the first letter of the second word would commence on the fourth fixed
scale, and the corresponding party would look to the letter M on the fourth
fixed scale and he would find the letter O; he would then look on the fifth
fixed scale for the letter U, and he would find the letter Z, and so on, till he
had written down in cypher the whole communication; and the supposed com-
mencement of the message "You must come, you must," would run thus:-
D, B,.H; 0, Z, F, G; E, T, Z, R; A, T, H; Z, W, X, G; so that it will be
seen, that although the same letters may come over and over again, they will
in the cypher scarcely ever appeared twice represented by the same letter.
The apparatus may be conveniently made with ten fixed and ten moveable
scales, but other number of scales may be combined into an apparatus, and the
reading may be from left to right or right to left, and the cypher may be taken
from the moveable scales or from the fixed ones. The scales I make of metal,
ivory, bone, papier mâché, gutta percha, porcelain, glass, leather, textile fabrics,
cardboard, marble, stone, slate, whalebone, felt, horn, wood protected by glass,
plastic materials, paper, wood stamped, embossed, or engraved with letters, and
they may be combined or mounted in any suitable frame or case, and the fixed
as well as the moveable scales may have on them more than one alphabet..