AN IMPROVED MODE OF WRITING IN CIPHERS, AND IN APPARATUS THEREFOR.
Year: 1871

page_text: LETTERS PATENT to Ferdinand Silas, of Park Place West, Mornington
Road, in the County of Middlesex, Gentleman, for the Invention
of "AN IMPROVED MODE OF WRITING IN CIPHERS, AND IN APPARATUS
THEREFOR.
"
Scaled the 22nd August 1871, and dated the 25th February 1871.
PROVISIONAL SPECIFICATION left by the said Ferdinand Silas at the
Office of the Commissioners of Patents, with his Petition, on the
25th February 1871.
I, FERDINAND SILAS, of Park Place West, Mornington Road, in the
County of Middlesex, Gentleman, do hereby declare the nature of the
said Invention for "AN IMPROVED MODE OF WRITING; IN CIPHERS, AND IN
APPARATUS THEREfor,” to be as follows (that is to say):-
The cryptograph consists of a table of words and syllables arranged in
columns in alphabetical order. These words and syllables are such as
will form most of the words, simple and compound, which are commonly
used in letters and telegrams. To the left of each column is a slide or

page_text: endless tape, which runs parallel to the column of words. Each tape or
slide bears a double series of numbers printed in two colours, or, as the
case may be, in two different sizes of type. The red numbers are always
to the left, and do not vary on the different slides or tapes, and run from
1 to 100 or less; the black numbers parallel to the red numbers, on the
contrary, run without interruption to any number which may be
considered desirable. The numbers of figures, both red and black, must
be at least double that of the words printed in the column, and may be
any multiple of that number. The black figures must be so arranged
that the first on cach succeeding column shall continue the series from
the last on the proceeding one. To use the table, having fixed upon the
number which is to form the key, which number must always be taken
from the red figures, this red number is drawn or shifted opposite to the
word at the head of each column; but this arrangement may be varied
as the correspondents may agree. The black numbers opposite cach
word will then be used in substitution of that word. The correspondent
in order to decipher the dispatch or letter knowing the number which
forms the key as only to draw that number into the position before
indicated and will find the proper word opposite each black number.
The combinations for fixing the key may be thus infinitely varied at the
pleasure of the correspondent in such a manner as to render the reading
of the cipher impossible for any one ignorant of the key.
The principle above described may be applied to a table of a circular
or cylindrical form with a revolving contro in place of the tape or slides
aforesaid.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Ferdinand Silas in the Great Seal Patent Office
on the 23rd August 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FERDINAND
SILAS, of Park Place West, Mornington Road, in the County of 3
Middlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of February, in tho
year of our Lord One thousand eight hundred and soventy-one, in the

page_text: thirty-fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Ferdinand Silas, Her special licence
that I, the said Ferdinand Silas, my executors, administrators, and
assigns, or such others as I, the said Ferdinand Silas, my exccutors,
administrators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, excrcise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "AN IMPROVED MODE OF WRITING
IN CIPHERS, AND IN APPARATUS THEREFORE," upon the condition (amongst
others) that I, the said Ferdinand Silas, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands
and scals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Scal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Ferdinand Silas, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement and the Drawings therein referred to (that is to
say) :-
My Invention has reference to an improved system for enabling
private messages, dispatches, or other correspondance to be transmitted
in cipher without divulging or revealing the secret to other persons not
in possession of the formula, and consists in constructing and employing
for the above purpose a board or frame having a printed or otherwise
inscribed table divided into columns in which a series of alphabetically
arranged words and syllables or the most used terminations thereof, such
as "tion," "ary," "ous," "tress," "by," etc., are also employed in
connection with endless sliding tapes formed of silk, leather, or other
flexible material running upon brass or wooden rollers fitted to the said
board or frame through the medium of fixed shafts and bearings so as to
admit of the said bands or slides moving freely thercon within hori-
zontally formed grooves in the table, by the arrangement of which cach
slide or endless band can be shifted round at pleasure by fixed studs, and
re-arranged or otherwise figured and graduated as in practise may be.
found necessary.

page_text: And in order that my said Invention may be more fully understood
and readily carried into effect I now proceed to describe the same by
the aid of the accompanying Drawings, reference being had to the
lotters and figures thereon markod (that is to say) :—
Fig. 1 represents a front view of my improved instrument or apparatus
(for deciphering dispatches) which I term the cryptograph; Fig. 2,
edgo view thereof; Fig. 3, end view of the same, and Fig. 4 a transverse
vertical section taken through the dotted line in Figure One. In each
Figure the same letters of reference denote similar corresponding parts.
A, A, wooden framic or board forming the body of the cryptographi
aforesaid; B, B, inscribed or printed table of words placed upon the
face of the said apparatus and arranged in columus as shown; C, C,
figured endless bands or slides; D, D, friction rollers over which the
bands revolve; E, E, rod or axis mounted upon fixed end bearing plates
secured to the sides of the said frame; F, F, finger studs or buttons
riveted to the said endless bands for the purpose of enabling the same to
be moved upwards or downwards over the rollers as required; G, G,
grooves or beadings for directing the tapes or endless bands aforesaid;
H, H, compartments or divisions containing the words constituting the
inscribed or printed table; I, I, figures forming the sliding numbers
upon the endless bands for being shifted in numerical order with the
words upon the table; J, J, end bearing plates for carrying the fixed
rod or axis aforesaid. The directions for using the apparatus or
cryptograph are as follows:-Any word upon the printed or inscribed
table may be taken together with any red number upon the slides as
the key word and key number, thus, supposing the word "again," in the
first column of the table to be the key word, and the red number 13
on the slide to be the key number, the rest of the slides have simply to
be moved round untill the number 13 aforesaid on cach of them shall
be in a line with the word "again," the writer has then merely to look in
the table for each word or syllable of the sentence to be interpreted, and
write in licu thereof the black number on the next slide, it will therefor
he obvious that the person receiving the above message in cipher will
be easily enabled to read it if having been previously informed of the
key word and number to be used, so that when the slides are placed as
above described the words corresponding to the numbers of the cipher
message will be found in the table. Also when necessary to mislead any
inquisitive investigator numbers may be agreed upon in like manner

page_text: which will read unintelligibly to others, such numbers to consist of any
of those which cover the part of the slides immediately out of sight,
for instance, supposing the key word to be the word at the head of a
column, say the second column, and the key numbers previously agreed
upon to be 10, 47, 97, 29, 29, etc., the writer in order to interpret a
message in ciphers has only to bring the slides into the position shown
at Figure 1 of the accompanying Drawing so that the red number 10,
on the first slide will correspond at the head of the table with the red
numbers 47, 97, 29, 29, on the other slides.
In conclusion to the foregoing description I would here briefly note
that the combinations to be agreed upon to form the key may be
greatly varied by cach person using his own method as also the number
of slides and columns and arrangement of the different compartments
and number of the words to be inscribed on the table, but for ordinary
uso a table containing a thousand words divided into ten columns
of a hundred words cach will be found sufficient for ordinary purposes.
And I would further note that the said slides should be printed with
small type so as to leave a vacant space suitable for being filled up
with any numbers convenient for the correspondent's own use, having
thereby for each word a double number to be employed alternately
or together, namely, their own written figures in conjunction with the
printed ones, or in like manner some of the compartments or divisions
in tho columns may be left blank for the reception of a selection of
proper names that may sometimes occur in private correspondence.
And I would again further note that upon my improved system
the words comprised in the various columns may be printed, written,
or otherwise inscribed on movable slides and placed in the table as
required, so as to break, when desired, the alphabetical succession, by
which method greater secrecy would be observed as each correspondent
could arrange the slides according to any plan of their own existing
between themselves, and furthermore, the said table may be printed in
several languages and employed on both sides of the board so that the
endless bands can be made to apply in either case and admit of being
removed from one pulley to another or interchanged as in practise may
be found necessary.
Having now fully described and ascertained the nature of this my
said Invention, and the manner in which the same is to be performed,
I would have it clearly understood that I do not intend to confine

page_text: myself to the precise details hercin-before described and set forth, as
the same might be otherwise varied (by substituting a revolving disk
or dial in place of the endless slides and arranging the words and
numbers in a concentric form upon the margin or circumference within
radiating columns, as also employing music notes in lieu of corro-
sponding letters) without departing from the general principle of this
my said Invention, but that which I do claim as new and of my said
Invention is the construction and employment of the instrument or
apparatus called by me the cryptograph for writing or corresponding
in cipher in the manner and for the purposes herein-before set forth
and described.
In witness whereof, I, the said Ferdinand Silas, have hereunto
set my hand and scal, this Thirty-first day of July, in the
year of our Lord One thousand cight hundred and seventy-
one.
FERDINAND SILAS. (L.S.)
Witness,
B. F. WEATHERDON,
Law Chambers, 77, Chancery Lane.