A MACHINE OR APPARATUS FOR COMPOSING AND TRANSLATING SECRET CORRES- PONDENCE
Year: 1871

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of "A
MACHINE OR APPARATUS FOR COMPOSING AND TRANSLATING SECRET CORRES-
PONDENCE." A communication from abroad by Paolo Calcagno, of
Turin, in the Kingdom of Italy.
Sealed the 3rd October 1871, and dated the 18th April 1871.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition,
on the 18th April 1871.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "A MACHINE OR APPARATUS FOR COMPOSING AND TRANSLATING
SECRET CORRESPONDENCE," a communication from abroad by Paolo Caleagno,
of Turin, in the Kingdom of Italy, to be as follows:-
―
This Invention relates to a mechanical appliance for composing secret
correspondence, and also for translating such correspondence so com-

page_text: posed into the language in which it was originally written so as to be at
once read off by the receiver.
The machine or apparatus to be employed for the purposes above set
forth, and which constitutes the essential feature of this Invention
consists of a cylinder, composed of as many discs as there are letters in
any one or more of the existing alphabets, or even in conventional ones
if desired. Near to this cylinder is a keyboard, the keys of which
correspond to each disc. The first key to the left hand gives a regu-
lating or key number whilst upon the rest are fixed or marked the
letters of the alphabet employed, and the numerals from 1 to 9, the
letter O serving as the zero.
In using this apparatus the despatch to be forwarded is written on
paper in its own proper letters, and after having depressed with the
fingers of the left hand the keys which correspond to each letter in the
despatch, those letters and numerals which present themselves behind
each depressed key are written down with the right hand, and form in
fact the secret or cipher despatch, which is composed of a combination
of letters and numerals. This despatch is then transmitted by electric
or other telegraph as in the form of writing by post or otherwise to the
person to whom it is addressed. The receiver who is supposed to
possess a corresponding machine or apparatus to that of the sender,
adjusts his apparatus according to the regulating number, and performs
the same operation as the sender, that is to say, he depresses those keys
the letters and numerals on which correspond to the letters and numerals
in the cipher despatch, whereupon the translation of the same or the
true letters in which it was originally written will be disclosed in the
machine, thus enabling the words to be read off at once. The machines
are or may be constructed in pairs of different combination, so that a
despatch transmitted and received by one pair working in concert with
each other could not possibly be deciphered by any of the other
machines not in concert or set to accord with the original pair of
machines. A secret correspondence may however be maintained with
any number of persons having identically adjusted machines, and any
two of these may communicate also with each other.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 18th October 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middle-
sex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of April, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Henry Johnson, Her special
license that I, the said John Henry Johnson, my executors, adminis-
trators, and assigns, or such others as I, the said John Henry Johnson,
my executors, administrators, or 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, usc, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "A MACHINERY
OR APPARATUS FOR COMPOSING AND TRANSLATING SECRET CORRESPONDENCE," a
communication to me from abroad by Paolo Calcagno, of Turin, in
the Kingdom of Italy, upon the condition (amongst others) that I,
the said John Henry Johnson, my executors or administrators, by an
instrument in writing under my hand and seal, 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 Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying
Drawings, and to the letters and figures marked thercon (that is to
say) :-
The said Invention relates to a mechanical appliance for composing
secret correspondence, and also for translating such correspondence into
the language in which it was originally composed, so as to be at once
read off by the receiver.

page_text: The machine or apparatus to be employed for the purposes above set
forth, and which constitutes the essential feature of this Invention,
consists of a cylinder composed of as many annular divisions or united
discs as there are keys in a keyboard, situate in front of the said cylinder,
which keys serve to rotate the cylinder step by step, at each depression
as will be fully explained herein-after. On the said annular divisions,
there are marked the letters of the alphabet and the numerals 1 to 9
inclusive arranged circumferentially round the cylinder in the manner
herein-after described. Each key of the keyboard corresponds or is
opposite to a different annular division of the cylinder. The first key to
the left hand serves to vary the cipher, and to give the regulating or
key number to which the instrument of the receiver of the message in
cipher must be adjusted before he can translate the same, and this key is
opposite to an annular division which may contain numerals only. On
the rest of the keys (the number of which should be an even number)
there are attached or marked individually the letters of the alphabet to
be employed, and also the numerals from 1 to 9 inclusive, the letter O

page_text: successively those keys the letters and numerals on which correspond
to the letters and numerals in the cipher despatch, the translation of
the same or the true letters in which it was originally written being
disclosed singly and successively in the machine behind each key as it
is depressed, thus enabling the words to be read off at once in the
language in which it was originally composed. The machines are or
may be constructed in pairs of the same combination and arrangement
of letters or signs, but each separate pair contains a different com-
bination of letters or signs, so that a despatch composed and received by
one pair working in concert with each other could not possibly be
deciphered by any of the other machines not in concert or set to accord
with the original pair of machines. A secret correspondence may
however be maintained with any number of persons having identical
machines, and any two of these may communicate also with each other.
And in order that the said Invention may be fully understood, I shall
now proceed more particularly to describe the same, and for that pur-
pose shall refer to the several Figures on the annexed Sheet of Drawings,
the same letters of reference indicating corresponding parts in all the
Figures.
Figure 1 of the Drawings represents a front elevation of the machine
or apparatus for composing messages or despatches in cipher and for
translating the same; Figure 2 is a corresponding transverse vertical
section of the same, shewing the cylinder actuating mechanism in
action; Figure 3 is a plan, corresponding to Figure 1, with the top or
cover removed to shew the annular divisions in the revolving cylinder,
and Figure 4 is a view similar to Figure 2 shewing the cylinder actuating
mechanism out of action or at rest.
A is an oblong box or case of wood, metal, or other suitable material,
containing a cylinder B also of wood or other suitable material, which
rotates on the axis C in bearings in the opposite ends of the box. A
knob or handle D on one end of the cylinder axis enables the cylinder
to be turned or adjusted by hand when required. The cylinder is sub-
divided longitudinally into a number of annular divisions, or if preferred
it may be composed of a number of discs fast on a spindle forming
the common axis of the same, so that they will all revolve together.
Immediately in front of this cylinder there is a keyboard E containing
as many keys as there are letters, signs, or numerals to be employed in
composing the despatches.

page_text: In the example shewn in the Drawings I have represented thirty-five
keys, namely, one for each of the twenty-five letters of the alphabet,
(omitting the letter W) and the numerals 1 to 9 inclusive, which letters
and numerals are marked on their corresponding keys as shewn clearly
in Figure 3. The additional key marked in Figure 3 on the extreme
left hand of the keyboard is for the scle purpose of ascertaining the
particular numeral to which the receiver or translator of the message
must adjust his machine before commencing to operate. These keys
may be arranged to operate in various ways, so as to impart a rotatory
movement to the cylinder at each depression, and each key should be
so connected to a small door or shutter in front of the box or casing as
that on its depression, the said door or shutter shall be opened so as to
expose to the view of the operator, the letter or sign on the cylinder
immediately behind the aperture as shown in Figure 1 where the
adjusting key and the letter R of the composing keys are represented
as depressed. I have shewn the key and shutter in one piece in
Figures 2 and 4, a representing the finger surface of the key, and b the
shutter which is turned up at a right angle to the actual key. As the
several keys and shutters fit closely together side by side (see Figures 1
and 3) and are disposed in a row, so as to close the upper portion of the
oblong opening c, d, e, f, (Figure 1) in the case it follows that the
depression of any one key will leave a rectangular aperture (see Figure 1)
through which the letter or sign on the cylinder which may have been
brought behind the opening, simultaneously with and by the act of
depressing the key will be exposed. Each key is mounted on a vertical
sliding spindle g, g, and is held up by a helical or other spring h,
(Figures 2 and 4). The lower ends of these spindles may be slightly
notched or forked, so as to fit over the edge of a bar i common to all the
keys, so that the depression of any one key will cause the depression of
the bar i, as shewn in Figures 1 and 2. This bar is connected at each
end to a radius rod or lever or oscillating rigid frame k working on a
fixed fulcrum l, and is held up by the springs m, so as to remain when
at rest in contact with the lower ends of the several key spindles g. To
each of these radius rods or to each rod of a rigid frame there is
hinged a pall n, the acting end of which is kept engaged by the spring n'
with the teeth of a ratchet wheel o mounted on the axis C at each end
of the cylinder. There are as many teeth in each of these ratchet
wheels o as there are letters or signs disposed circumferentially round
the cylinder in each annular division or disc, so that for every movement

page_text: of a single tooth, a different letter or sign will be presented. In order
to ensure the cylinder rotating no more than the space of one tooth at
each impulse, a check lever p and additional ratchet wheel q are
employed. The lever P is hinged to the casing at and carries a tooth
or detent which engages when depressed with one or other of the teeth
in the small ratchet wheel g and thus checks the further rotation of the
cylinder till the key is released and again depressed, or a fresh key
lowered. The check lever is connected by a rod s to one of the two
radius rods k, and consequently moves simultaneously with them or with
the frame k; t is a spring detent which engages with the teeth of one
of the ratchet wheels o, in order to prevent the cylinder being turned
the wrong way.
In order that the operation of the two machines of a pair shall be
reciprocal, that is to say, that the cipher dispatch composed on one
machine shall be translated by the other, the letters and signs on the
cylinder must be arranged in a certain order, which I shall now proceed
to describe. The annular division or disc of the cylinder B corres-
ponding in position to the letter (A) for example on the keyboard may
have all the various letters of the alphabet or other signs and numerals
corresponding to those on the keyboard arranged in any order, either
regular or irregular with the exception of the letter of the corresponding
key (in this case the letter (A) which may be omitted if preferred from
the division, substituting for it a repeat of any other letter, so that no
one of the keys shall be capable of reproducing its own letter on the
cylinder, this however is not essential as each division may contain the
whole of the letters and signs in the keyboard.
It will thus be obvious that by depressing the key (A) thirty-four
times all the letters or signs on the corresponding annular division will
be brought in succession behind the aperture, and will each in turn
constitute the cipher for the letter (A). But in order to translate the
cipher back to the letter (A) it is requisite that the letter (A) be repeated
in each of the other annular divisions or discs of the cylinder, and in
such a position circumferentially as that it shall be in the same longi-
tudinal line or row, with the particular letter or sign on the disc opposite
to the key (A). For example in Figure 3 there are shown on the
annular division opposite to the key (A), the letters and numerals (B),
(P), (Y), (4), &c., then in the annular division corresponding to the
key (B), I insert the letter (A) but in a circumferential position exactly

page_text: corresponding to the position of (B) in the annular division opposite the
key (A), that is to say, in the same longitudinal line or row. In the
annular division corresponding to the key (P) I insert the letter (A) in
a line with (P) in the first division. In the division opposite the key (Y)
I place the letter (A) in a line with the letter (Y) in the first division
and in the division opposite the key marked with the numeral (4) I
place the letter (A) in a line with the numeral (4) in the first division,
and so on throughout the series, the letters (B) and (C) being also shewn
properly placed on the cylinder in Figure 3. By this arrangement of
the letters or signs, and by having two identically arranged machines,
the cylinders of both of which commence their movement from the same
point previously ascertained by the key note (*) the receiver can re-
produce the original letters of the dispatch by depressing in succession
the keys corresponding to the ciphers. If no two pairs of machines
be made alike, it would be absolutely impossible for the despatches of
one pair to be read or trauslated on or by other machines. It is abso-
lutely impossible to guess or discover the cipher, as it is continually
changing by the rotation of the cylinder, the repetition of a letter or
word, and in a despatch never practically being represented by a
repetition of the cipher letters.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used
or carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent is,―
First. The composing and translating of cipher despatches by means
of a rotatory cylinder, containing letters and signs arranged on its
surface in the order specified in combination with a set of keys cach
marked with and corresponding to one of the letters or signs on the
cylinder, and capable when depressed singly of causing the cylinder to
be rotated to the extent of one letter or sign only at a time and of
simultaneously opening a door or shutter in the cover of the apparatus
through which the cipher required or the correct or translated letter as
the case may be is presented to the view of the operator, substantially as
herein-before described and illustrated by the Drawings.
. Scoond. The combination with the said apparatus of a special key and
set of numerals or other signs, for the purpose of varying the cipher and
ascertaining the position to which the instrument of the receiver or

page_text: translator of the dispatch must be adjusted before commencing to
operate, as herein-before described.
Third. The so arranging or disposing the various letters or signs on
the cylinder of the said instrument, as that when two such instruments
identically arranged and adjusted are employed the depression of those
keys in one instrument which correspond to the ciphers obtained from
the other instrument shall expose successively the original letters or
translation of the despatch, as herein-before described.
.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and scal, the Eighteenth day of
October, One thousand eight hundred and seventy-one.
J. HENRY JOHNSON. (L.s.)