Year: 1888

page_text: Date of Application, 18th Apr.; 1888
Complete Specification Left, 18th Feb., 1889
Complete Specification Accepted, 23rd Mar., 1889
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E. do hereby declare the nature of this invention to be as follows:-
The present invention relates to apparatus for writing or reading messages in
cipher, in which the disc indicating the ciphers is arranged in a recess of the
alphabet disc in such a manner that the surfaces of both are flush. Thus the apparatus
is simplified and rendered more durable as projecting parts which might easily be
shifted or damaged are obviated. The apparatus can also be constructed in form of a
watch in which case it is preferably combined with a deciphering or reading disc on
the side opposite the cipher indicating disc. Besides representing the letters of a
message by other letters they may also be represented by numbers of two figures and
the decipherer will then know that numbers of two figures represent letters and that
single figures stand as figures.
If the cipher disc is arranged in a recess of the alphabet disc the former is
provided with a slightly projecting rim so as to better enable the person using the
apparatus to turn and adjust it. The two discs are connected together by a pin or
stud.
If the apparatus is in form of a watch the outer disc is in form of a ring and the
inner disc is arranged in the same plane as the ring.
The deciphering or reading side differs from the other in so far as the alphabet disc
is arranged here as the inner one and the cipher disc as the outer one. The inner or
moveable discs are mounted rigidly on a spindle which is turned by bevel pinions
actuated by a spindle carrying at its upper end a worm wheel which engages with a
worm on the spindle of a turnbutton similar to that of a keyless watch.

page_text: With this apparatus which permits of endless combinations two persons can
correspond in cipher which a third person even if in possession of a similar apparatus
cannot read without the key. Supposing two persons have predetermined as the key
to their correspondence the letters that is b for the outer disc and for the inner
one, the inner disc is turned until the letter stands directly under the letter & of
the outer disc and the letters of the message are replaced by the letters or figures
or both mixed which are found under the respective letters of the outer or alphabet
disc. To read a message the apparatus is adjusted in the same manner and the
letters on the alphabet disc substituted for the letters or figures in the cipher disc.
If the apparatus be in watch form the ciphers on the reading or deciphering side
will be arranged alphabetically to facilitate the reading.
The key can be changed in endless combinations, for instance the first and last
letter of the day or the month may be taken or the initials of the Christian or
surnames of sender and receiver, or even within the message the key may be altered
in a predetermined manner for instance by beginning with a certain key and altering
it for every subsequent word by taking the last two letters of the previous word as
the key, in words of one letter the same letter will stand as key for both discs; or
the key for the first letter may be a b, for the second b c, for the third c d, and
so forth.
It is evident that the cipher disc may be arranged on a flat alphabet disc instead
of in a recessed one without deviating from the principle of the invention.
Dated this 18th day of April 1888.

page_text: I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E. do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in
and by the following statement :-
The present invention relates to apparatus for writing or reading messages in
cipher, in which the disc indicating the ciphers is arranged in a recess in the alphabet
disc or annulus in such a manner that the surfaces of both are flush. Thus the
apparatus is simplified and rendered more durable as projecting parts which might
easily be shifted or damaged are obviated. The apparatus can be constructed in the
form of a watch, in which case it is preferably combined with a deciphering or reading
disc on the side opposite the cipher indicating disc. Besides representing the letters
of a message by other letters they may also be represented by numbers of two figures
and the decipherer will then know that numbers of two figures represent letters and
that single figures stand as figures.
In the accompanying drawings;
Figs. 1 and 2 represent front views of the apparatus the two discs being set for
different keys.
Fig. 3 represents the back view of Figs. 1 and 2.
Fig. 4 represents a central section of the same.
Figs. 5 and 6 represent the writing and reading side of an apparatus in the form of
a watch.
Fig. 7 represents a central section of the same.
Fig. 8 represents an apparatus similar to the one represented in figures 1 and 2 on
a larger scale.
Figs. 9 and 10 represent a central section and side view respectively of the same.
A is the alphabet disc or annulus B is the cipher disc and C is the pin or stud
connecting the two together and round which B turns.
If the cipher disc B is arranged in a recess of the alphabet disc or annulus A, in
the form represented in figures 1 to 4 and 8 to 10, the former is provided with a
slightly projecting rim so as to better enable the person using the apparatus to turn
and adjust it. The two discs are connected together by a pin or stud C.
If the apparatus is in the form of a watch as in figures 5 to 7 the outer or alphabet
disc A is in the form of a ring or annulus and the inner or cipher disc B is arranged
in the same plane as this ring. The deciphering or reading side differs from the other
in so far that it is the alphabet which is depicted on the disc and the ciphers upon the

page_text: annulus. The inner or movable discs are mounted rigidly on a spindle E which is
turned by bevil pinions F actuated by a spindle G carrying at its upper end a worm
wheel H which engages with a worm on the spindle of a turn button J similar to that
of a keyless watch. The two sides of the case are provided with glasses K.
With this apparatus which permits of numerous combinations two persons can
correspond in cipher which a third person even if in possession of a similar apparatus
cannot read without the key. Supposing two persons have predetermined as the key
to their correspondence the letters bz, that is b for the alphabet annulus A and for
the cipher disc B, the dise B is turned until the letter z thereon stands directly under
the letter of the annulus A and the letters of the message are replaced by the letters
or figure or by both which are found under the respective letters of the alphabet
annulus. To read a message the apparatus is adjusted in the same manner and the
letters on the alphabet disc are substituted for the letters or figures on the cipher disc.
If the apparatus be in the form of a watch the ciphers on the reading or deciphering
side (Figure 6) will be arranged on the annulus to facilitate the reading.
The key can be. changed in a great variety of combinations, for instance the first
and last letter of the day or month may be agreed upon or the initials of the Christian
or surnames of sender and receiver, or even within the message the key may be altered
in a predetermined manner for instance by beginning with a certain predetermined
key and altering it for every subsequent word taking the last two letters of the
previous word as the key, in words of one letter, the same letter will then stand as
key for both discs. It may be also agreed upon between sender and receiver that
the key for the first message be a b, for the second be for the third c d and so
forth. It will be seen from this that numerous combinations are possible for the
changing of the key.
It is evident that the cipher disc may be arranged on a flat alphabet disc instead
of a recessed disc or annulus without deviating from the principle of the invention.
Having now particularly described and ascertained the nature of tho said invention,
and in what manner the same is to be performed, as communicated to me by my
foreign correspondent, I declare that what I claim is :-
1. In an apparatus such as described a cipher disc such as B formed with a
slightly projecting rim, and capable of being turned on a pivot C mounted in
anothor disc such as A provided with an annular arrangement of an alphabet sub-
stantially as herein described and illustrated in figures 1 to 4 and 8 to 10 of the
accompanying drawings.
2. In apparatus such as described and in the form of a watch the arrangement
on one side (Fig. 5) of a cipher disc such as B within a fixed alphabet annulus
such as A, and on the other side (Fig. 6) the inverse arrangement of an alphabet
disc within a cipher annulus, the two discs being capable of simultaneous adjustment
by means of the turn button J substantially as herein described and illustrated in
figs. 5 to 7 of the accompanying drawings.
3. In apparatus such as described providing the cipher disc with a series of
numbers of two figures so that messages may be ciphered in numbers of which those
of two figures would stand for letters and those of one figure for figures, substantially
as herein described.
100
1
13 1
1000