IMPROVEMENTS IN APPARATUS FOR WRITING, READING, AND CORRECTING DISPATCHES, SECRET AS WELL AS NOT SECRET
Year: 1875

page_text: LETTERS PATENT to William Morgan-Brown, of the Firm of Brandon
and Morgan-Brown, Engineers and Patent Agents, of 38, South-
ampton Buildings, London, and 13, Rue Gaillon, Paris, for the
Invention of "IMPROVEMENTS IN APPARATUS FOR WRITING, READING, AND
CORRECTING DISPATCHES, SECRET AS WELL AS NOT SECRET."-A com-
munication from abroad by Elisæus Janus Sommerfeldt, Captain,
Danish Royal Engineers, Copenhagen, and Christian Nissen,
Copenhagen.
PROVISIONAL SPECIFICATION left by the said William Morgan-Brown
at the Office of the Commissioners of Patents, with his Petition,
on the 11th June 1875.
I, WILLIAM MORGAN-BROWN, of the Firm of Brandon and Morgan-
5 Brown, Engineers and Patent Agents, of 38, Southampton Buildings,
London, and 13, Rue Gaillon, Paris, do hereby declare the nature of
the said Invention for "IMPROVEMENTS, IN APPARATUS FOR WRITING, READING,
A

page_text: AND CORRECTING DISPATCHES, SECRET AS WELL AS NOT SECRET," to be as
follows:-
This Invention of improvements in apparatus for writing, reading,
and correcting dispatches, secret as well as not secret, is as follows :-
In secret dispatches according to the Sommerfeldt system, the letters
are written in mutually equal divisions round the circumference of a
circle or in line along a list. A like number of signs differing from
each other (which may also be letters of the alphabet) having been
agreed upon by the corresponding to the first, or in a line in another list
marked in divisions and then repeated once, the row of the last-named
signs or letters is called the cipher line, and it is with these signs that
the secret writing is composed. The row of the letters of the alphabet
is on the other hand called alphabet line. On each of the lines is a
certain marked square, and on beginning to read or write a dispatch the
two circles are so placed the one over the other, and the lists so
laid by the side of each other that the two squares stand opposite one
another.
In order to write a dispatch in cipher we begin with the first letter of
tho dispatch. We look it up in the alphabet line and the cipher or
letter that stands opposite in the cipher line is written down. The disc
of the circle is then turned or the list with the alphabet line moved, so
that the letter in the alphabet line comes opposite the marked square in
the cipher line. The next letter in the dispatch is then looked up in
the alphabet line and the cipher or letter in the cipher line that stands
opposite it is noted down for it. The circle disc or the list with the
alphabet line is turned or showed again, so that the last letter comes
opposite the marked square in the cipher line, and we proceed to the
third letter in the dispatch, and so we keep on until the whole dispatch
is written down in signs or letters on the cipher line.
The reading or deciphering of the secret writing is accomplished in
the same way as it is written only with this difference, that we
invariably commence with the cipher circle instead of with the alphabet
circle. After having brought the marked parts on the alphabet circle
and on the cipher circle to bear exactly on each other we begin with
the first sign or letter in the secret writing, look it out in the cipher line
and note the letter on the alphabet line which stands directly opposite.
The latter line is then so set that the letter so found comes opposite the

page_text: dispatch.
As may be seen by the foregoing, every sign or letter in the secret
writing only denotes how many squares the letter in whose stead it
stands is to be found from the preceding letter in the line of the
alphabet. Hereby it is difficult in the highest degree, or rather
impossible for the uninitiated to read this secret writing.
It is also evident that every wrong letter or sign in the written
dispatch will involve crrors in the reading of all the following signs or
letters in the dispatch. If, however, the number of errors does not
exceed all reasonable bounds, the receiver of the dispatch will be able to
correct them, which is a characteristic property of the system. The
wrong letters in the dispatch are to be found out always the same
number of divisions away from the right letters in the alphabet line.
To correct the dispatch it is therefore merely necessary to copy off the
alphabet line in perpendicular rows by the side of each other, so that the
letters found to be wrong stand by the side of each other in a horizontal
line in the order in which they are found, and the highest up in the
alphabet lines in queston. The right letters will then be found in
another horizontal line as many lines away from that which is found as
the error made in the writing of the dispatch by the wrong turning or
sliding of the alphabet line comprises divisions.
Instead of writing down the alphabet line every time, we may have
slips of paper marked off into equal divisions. On each of these slips of
paper the alphabet line is written down in order, but so that at every
list it begins with a new letter. We must then have as many lists as
there are signs in the alphabet line. When correcting a dispatch the
lists are taken in which the letter discovered to be wrong stands first,.
and these are laid by the side of each other so that the wrong reading of
the dispatch stands highest. The right reading will then be found in
another horizontal line. Finally, the alphabet line may also be written
in divisions of equal size around the circumference of circles or discs of
which the one is so much less than the other, that on each disc there is
room for the alphabet line when the discs are laid one over the other
according to their diminishing size. The divisions of the circles must
correspond mutually; if the discs are as we have said then laid one over
the other according to diminishing size, and in such wise that "the
15
"

page_text: wrong reading of the dispatch comes on a radial line, the right reading
will be found on another radial line which of the lines it is, which in
both cases gives the right solution is easily seen from the connexion
between the letters in the lines, being such as to yield a sensible
meaning.
The Sommerfeldt system of secret correspondence is described above
in its simplest form; it can however, moreover, furnish besides the
letters of the alphabet punctuation marks, intervals between the several
words, numbers, fractions, abbreviations, and others. Such an employ-
ment of the system in its fullest extent is illustrated by Figure 1.
Besides the alphabet lino itself set down in the usual order in a circle,
and containing besides the letters of alphabet a square marked with
'Rep," one with "Nyt Ord" (new word), one with II, and one
with III, there are within this first circle two other circles on the same
disc, the one within the other, with divisions answering to those of the
alphabet circle. The circle nearest the alphabet circle is called the circle
of numbers. On this we find ten squares marked from 0 to 9, one with
"Brok" (fractions), one with "Brökstreg" (fraction dash), one with
"Ordenstal" (Order number), one with "I," one with "II," and one
with "Rep." The squares in the third and innermost circle which is
denominated the circle of abbreviations are marked one with II, and
one with I. All the other squares in the circle of numbers, and in the
circle of abbreviations may be marked with punctuation marks and with
abbreviations or entire words. The writing and deciphering of the
dispatch always begins with the alphabet circle, and continues with this
until one of its squares marked with II, and with III refers either to
the number, circle, or the abbreviation circle. The reading or writing
then keeps to the circle so denoted until one of its squares marked with
Roman numerals, refers us to another circle. Then we begin and go on
with that, and in this way we continue until the dispatch is written or
deciphered.
The squares entitled "
Nyt Ord" (new word) are used to denote the
interval between two successive words when no punctuation mark is to
be there employed; the squares entitled "Rep" are used to denote
repetitions.

page_text: Forasmuch as we in the alphabet circle can diminish the number of
squares occupied by the letters for example, in one and the same square,
set down and j, omit w, or the like, the vacant squares are to be
marked with the Roman numerals IV, V, and so forth. These numerals
refer to interposed circles, abbreviation circles, but as these could not
1

page_text: The dispatch 5% French funds closed firm will then be written in
common writing "V b c d V." The first V indicates that all that follows
á is to be read in the fifth circle; therefore the meaning of bed and V
is to be looked for in this circle, and a is then found to be 5% French
funds closed firm I. The final I indicates that we are again to read in
the first circle the alphabet circle. As will be seen the deciphering of
the dispatch before and after this insertion may be continued without
interruption. The meaning of the interposed ciphers may be decided
immediately or later. The system of abbreviations can easily, by
employing the first circle of abbreviations as a common index to a table,
be made to contain about 800 words.
It will be evident that in like manner as above mentioned we may add
lines of numbers, and one or several abbreviation lines to the line of the
alphabet, when the last and the cipher line are written down in lists of
equal length instead of in circles around the circumference of the
disc.
It will furthermore be evident that the order in which the signs on
the line of the alphabet, the line of numerals, and the line of abbre-
viation, as well as the line of cipher is arbitrary, forasmuch as the
writing is not protracted by the difficulty of looking out the signs. The
correction of errors in the writing of the dispatch takes place in the
more perfect system in the same manner as in the more simple.
Figure 2 illustrates the writing down of the alphabet circle on the
before-mentioned disc. To further help there are in all ten such discs.
The only drawback is that the correcting is somewhat more difficult

page_text: when the wrong meaning of the sign has to be looked up in the circle
of numbers. We must then continue to read the secret dispatch in the
alphabet circle. The letters found here after the reference to the circle
of numbers will then lead to the correction.
As example we may premise that the appearance of the dispatch
If the before-mentioned discs are set as shown in Figure 3 the right
reading will be found to be "Les Affaires de l'Allemagne vout."
If code dispatches be used in which the language affords no clue to
the meaning a certain sign is introduced at intervals, which experience
has taught us are expedient. When the sign used comes out at the
right manner in the dispatch we have the assurance of the dispatch
being right. If the deciphering is wrong the error is indicated by the
error lying between the wrong sign and the last given right controlling
sign, while the wrong sign also indicates how great the displacement is.
It will in general be possible to correct the dispatch.
If the numeral code be used they are transcribed in the usual manner
in ciphers, and the correction can take place exactly in the same way as
if we had to do with letters.
If the ten discs before mentioned be employed for the correcting of
code despatches, and "Nyt Ord" (new words) is the interposed sign,
which by its wrong redition denotes that in the dispatch there is a
telegraphic error the apparatus is set so that the wrong sign that is
employed instead of "Nyt Ord" is on the smallest disc. The right
reading must then be sought in the radius which on the inner plate
bears the inscription "Nyt Ord" (new words).
Apparatus for writing in ciphers and deciphering as well as correcting
of despatches according to the Sommerfeldt system may be very different
in their construction. There is here only question of the apparatus that
may be regarded as the most practical.
Figures 1 and 2 show a larger apparatus for office use for writing and
deciphering dispatches, a cryptograph; Figure 1 shows it from above,

page_text: and in Figure 2 it is seen in profile cut perpendicularly through the
middle of it. The alphabet circle, the circle of numbers, and the
abbreviation circle are here in a moveable disc in the uppermost plane
of a round case. The cipher circle is here on a moveable ring around
the above-named disc, and is kept in its place with small screws.
Within the case is a clockwork that moves the disc with the alphabet
circle. On the outside of the case is fixed a stop, which reaches over
the disc of the alphabet circle. In each of the squares of the alphabet
circle there is a hole for a stopple pin. One of these stopple pins is set
in the square that is to project from the marked square of the cipher
circle. The stop will then by pressing on the stopple pin hinder the
movement from turning the disc. The other stopple pin is set in the
square that is to be brought in front of the marked square of the cipher
circle. As soon as the first stopple pin is taken out of the square on the
disc the disc turns and places itself in the new position.
Figures 5 and 6 shows a cryptograph of another construction. The
alphabet line, together with the line of numbers and the line of abbre-
viation, are set down three times on an endless strap that passes over
two moveable rollers in an oblong four cornered case. This case is
open at top, excepting where two wooden lists lie along the long sides,
one on each side of the strap. The line of ciphers is set down on each
of these two lists.
In the squares of the alphabet line there are holes for the stopple
pins, which are applied in the same manner as in the cyptograph
described above. Besides the stopple pins above being stopped by a
stop lever above the strap it is also stopped below by the closing of a
groove, in which its lower end moves with the strap.
The endless strap may be set in motion as well by a clockwork move-
ment as by the hand. The stop arm, as may be seen, is at the extremity
of the cipher list. If the strap be moved by the hand the marked square
may be also in any other place on the cipher line, but in that case the
strap must be moved backwards and forwards to the sides. Instead of
the stop arm the groove must then have a hollow opposite the marked
square, in which the stopple pins can be fixed if we do not prefer
omitting the stopple pins entirely. It must be regarded as an
advantage with strap apparatus that all the letters and signs turn
one way.

page_text: Besides cryptograph for office use they may also be constructed more
or less simple to carry in the pocket, or even in the cover of a pocket
book; the alphabet must then be moved by the hand.
Where this apparatus is to be employed only to correct chance
telegraphic errors in dispatches the inscription on the cipher circle
can be unalterable, and it is then more casy to work the apparatus
when the inscription is in alphabetical order (the outer circle in
Figure 1). The method of working the apparatus is otherwise un-
altered.
The apparatus for the correction of dispatches, the receiver, can, like
the crytograph, be of various different constructions according with
their intended use. Figures 3 and 4 shows a receiver for office use; it
consists of a round metal disc, in which is turned a groove for nine
rings, which each for itself can be turned round in the above-mentioned
groove in the disc. On every ring is set down the line of the alphabet,
as well as on the upper plane of the margin of the disc, so that there are
in all ten alphabet circles.
.
In each of these squares there is a hole for a stopple pin, of which
there is one for every alphabet circle; they serve at once both to mark
the squares and to make fast the rings, as there are holes in the disc in
which they reach through the rings. Of course the receiver can also be
constructed with an endless strap in the same manner as described for
the cryptograph.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Morgan-Brown in the Great Seal Patent
Office on the 29th November 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
MORGAN-BROWN, of the Firm of Brandon & Morgan-Brown, Engineers
and Patent Agents, of 38, Southampton Buildings, London, and 13, Rue
Gaillon, Paris, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eleventh day of June, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty-

page_text: eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant, unto me, the said William Morgan-Brown, Her special
licence that I, the said William Morgan-Brown, my executors, admini-
strators, and assigns, or such others as I, the said William Morgan-
Brown, my executors, 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,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IM-
PROVEMENTS IN APPARATUS FOR WRITING, READING, AND CORRECTING DISPATCHES
SECRET AS WELL AS NOT SECRET," a communication to me from abroad
by Elisæus Janus Sommerfeldt, Captain, Danish Royal Engineers,
Copenhagen, and Christian Nissen, Copenhagen, upon the condition
(amongst others) that I, the said William Morgan-Brown, my executors
or administrators, by an instrument in writing under my, or their, or
one of their hands and seals, 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 William Morgan-Brown, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascer-
tained in and by the following statement thereof, that is to say :-
This Invention of improvements in apparatus for writing, reading, and
correcting dispatches, secret as well as not secret, is as follows:-In
secret dispatches, according to the Sommerfeldt system, the letters are
written in mutually equal divisions round the circumference of a circle
or in line along a list. A like number of signs differing from each other
(which may also be letters of the alphabet) having been agreed upon by
the corresponding to the first, or in a line in another list marked in
divisions and then repeated once. The row of the last named signs or
letters is called the cipher line, and it is with these signs that the secret
writing is composed. The row of the letters of the alphabet is on the
other hand called alphabet line. On each of the lines is a certain
marked square, and on beginning to read or write a dispatch the two
circles are so placed the one over the other, and the lists so laid by the
side of each other that the two squares stand opposite one another.

page_text: In order to write a dispatch in ciphers we begin with the first letter
of the dispatch. We look it up in the alphabet line, and the cipher or
letter that stands opposite in the cipher line is written down; the disc
of the circle is then turned, or the list with the alphabet line moved, so
that the letter in the alphabet line comes opposite the marked square in
the cipher line. The next letter in the dispatch is then looked up in
the alphabet line, and the cipher or letter in the cipher line that stands
opposite it is noted down for it. The circle disc or the list with the
alphabet line is turned or showed again, so that the last letter comes
opposite the marked square in the cipher line, and we proceed to the
third letter in the dispatch; and so we keep on until the whole dispatch
is written down in signs or letters on the cipher line.
The reading or deciphering of the secret writing is accomplished in
the same way, as it is written only with this difference, that we
invariably commence with the cipher circle instead of with the alphabet
circle; after having brought the marked parts on the alphabet circle and
on the cipher circle to bear exactly on each other we begin with the
first sign or letter in the secret writing, look it out in the cipher line, and
note the letter on the alphabet line which stands directly opposite;
the latter line is then so set that the letter so found comes opposite
the marked square of the cipher line, and so we go on through the
dispatch.
As may be seen by the foregoing every sign or letter in the secret
writing only denotes how many squares the letter in whose stead it
stands is to be found from the preceding letter in the line of the
alphabet. Hereby it is difficult in the highest degree or rather
impossible for the uninitiated to read this secret writing.
It is also evident that every wrong letter or sign in the written
dispatch will involve errors in the reading of all the following signs or
letters in the dispatch. If however the number of errors does not
exceed all reasonable bounds, the receiver of the dispatch will be able to
correct them, which is a characteristic property of the system. The
wrong letters in the dispatch are to be found out always the same
number of divisions away from the right letters in the alphabet line.
To correct the dispatch it is therefore merely necessary to copy off the
alphabet line in perpendicular rows by the side of each other, so that
the letters found to be wrong stand by the side of each other in a hori

page_text: zontal line in the order in which they are found, and the highest up in
the alphabet lines in question; the right letters will then be found in
another horizontal line as many lines away from that which is found as
the error made in the writing of the dispatch by the wrong turning or
sliding of the alphabet line comprises divisions.
every time we may have
On each of these slips of
Instead of writing down the alphabet line
slips of paper marked off into equal divisions.
paper the alphabet line is written down in order, but so that at every
list it begins with a new letter; we must then have as many lists as
there are signs in the alphabet line. When correcting a dispatch the
lists are taken, in which the letter discovered to be wrong stands first,
and these are laid by the side of each other so that the wrong reading of
the dispatch stands highest; the right reading will then be found in
another horizontal line. Finally, the alphabet line may also be written
in divisions of equal size around the circumference of circles or discs of
which the one is so much less than the other, that on each disc there is
room for the alphabet line when the discs are laid one over the other
according to their diminishing size. The divisions of the circles must
correspond mutually, if the discs are as we have said then laid one over
the other according to diminishing size, and in suchwise that the wrong
reading of the dispatch comes on a radial line the right reading will be
found on another radial line. Which of the lines it is, which in both
cases gives the right solution is easily scen from the connection between
the letters in the lines, being such as to yield a sensible meaning.
The Sommerfeldt system of secret correspondence is described above
in its simplest form, it can however moreover furnish besides the letters
of the alphabet punctuation marks, intervals between the several words,
numbers, fractions, abbreviations, and others. Such an employment
of the system in its fullest extent is illustrated by Figure 1. Besides
the alphabet line itself, set down in the usual order in a circle, and con-
taining besides the letters of alphabet a square marked with "Rep," one
with "Nyt Ord" (new word), one with II, and ono with III; there are
within this first circle two other circles on the same disc, the one within
the other, with divisions answering to those of the alphabet circle. The
circle nearest the alphabet circle is called the circle of numbers. On
this we find ten squares, marked from 0 to 9, one with "Brök"
[fractions], one with "Brökstreg" [fraction dash], one with "Ordenstal"
[order number], one with "I," one with " II," and one with “
Rep."

page_text: The squares in the third and innermost circle, which is denominated the
circle of abbreviations, are marked one with II, and one with I.
All
the other squares in the circle of numbers, and in the circle of abbrevia-
tions, may be marked with punctuation marks, and with abbreviations
or entire words. The writing and deciphering of the dispatch always
begins with the alphabet circle, and continues with this until one of its
squares marked with II and with III refers either to the number circle
or the abbreviation circle. The reading or writing then keeps to the
circle so denoted until one of its squares marked with Roman numerals
refers us to another circle. Then we begin and go on with that, and in
this way we continue until the dispatch is written or deciphered.
The squares entitled "Nyt Ord" (new word) are used to denote the
interval between two successive words when no punctuation mark is to
be there employed. The squares entitled " Rep" are used to denote
repetitions.
In the abbreviation circle there will scarcely be any use for this
denomination, which is therefore omitted here.
Double letters are written, the first in the usual manner, the second
with the letter standing on the marked square. The turning of the
disc is in this case to no effect. Should a letter be repeated many times
in succession in the dispatch when written in common writing the first
repetition is substituted on the circle of the alphabet with the squaro
marked "Rep," the next repetitition with the right letter, and the third
repetition with the square "Rep," and so on.
As an example to illustrate more clearly the process, premising that
the signs which are agreed upon by the corresponding partics to be
used in their secret writing are,-
a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z, ä, æ, à.
and the appointed key "Les Etats unis de l'Amerique du Nord," to be
by convention written down. The key in every other square, then we
first take the several different letters of the key in the order in which
they stand:
1, e, s, t, a, u, n, i, d, m, r, q, o,
the remaining letters or signs of this cipher series are,-
b, c, f, g, h, j, k, p, u, v, w, x, y, z, ä, æ, à.
According to convention is written down in the cipher circle in the
first square, e in the third, s in the fifth, and so on. When the letters

page_text: of the key are in their proper places the other letters are added in inverse
order from the thirtieth square thus:-6 in the thirtieth square, c in the
twenty-ninth, f in the twenty-eighth, and so on to æ in the fourth, and à
in the second square.
By this conventional agreement, which does not
require to be kept secret, we attain this, that the letters least frequently
employed are sufficiently spread. The key should never be too brief,
but rather of some length.
Have we for example to write a dispatch in ciphers "Les Affaires de
l'Allemagne vout," it will present the following appearance :-
w q w x 8-b o zad-wilt v-àeg kq-fe ä
Forasmuch as we in the alphabet circle can diminish the number of
squares occupied by the letters for example in one and the same square,
set down and j, omit to, or the like; the vacant squares are to be
marked with the Roman numerals IV, V, and so forth. Thesc numerals
refer to interposed circles, abbreviation circles; but as these could not
find room on the disc of the alphabet it is better to keep them in tabular
form by the side of the same.
The dispatch 5% French funds closed firm will then be written in
common writing "V, b, c, d, V." The first V indicates that all that
follows is to be read in the fifth circle, therefor the meaning of b c d
and V is to be looked for in this circle, and a is then found to be
5% French funds closed firm I. The final I indicates that we are again
to read in the first circle the alphabet circle. As will be seen the
deciphering of the dispatch before and after this insertion may be
continued without interruption. The meaning of the interposed cyphers
may be decided immediately or later. The system of abbreviations can
easily by employing the first circle of abbreviations as a common index
to a table be made to contain about 800 words.

page_text: It will be evident that in like manner as above mentioned we may
add lines of numbers, and one or several abbreviation lines to the line of
the alphabet when the last and the cipher line are written down in
lists of equal length instead of in circles around the circumference of
the disc.
It will furthermore be evident that the order in which the signs on
the line of the alphabet, the line of numerals and the line of abbreviation
as well as the line of cipher is arbitrary for as much as the writing is not
protracted by the difficulty of looking out the signs. The correction of
errors in the writing of the dispatch takes place in the more perfect
system in the same manner as in the more simple.
Figure 2 illustrates the writing down of the alphabet circle on the
before mentioned disc. To further help there are in all ten such dises;
the only drawback is that the correcting is somewhat more difficult,
when the wrong meaning of the sign has to be looked up in the circle of
numbers. We must then continue to read the secret dispatch in the
alphabet circle. The letters found here after the reference to the
circle of numbers will then lead to the correction.
As example, we may premise that the appearance of the dispatch

page_text: If the ten discs before mentioned be employed for the correcting of
-code dispatches, and "Nyt Ord" (new words) is the interposed sign,
which by its wrong redition denotes that in the dispatch there is a
telegraphic error, the apparatus is set so that the wrong sign that is
employed instead of "Nyt Ord" is on the smallest disc. The right
reading must then be sought in the radius, which on the inner plate
bears the inscription "Nyt Ord" (new words).
Apparatus for writing in ciphers and deciphering as well as correcting
of dispatches, according to the Sommerfeldt system may be very different
in their construction. There is here only queston of the apparatus that
may be regarded as the most practical.
.
Figures 1 and 2 show a larger apparatus for office use for writing and
deciphering dispatches, a cryptograph; Figure 1 shows it from above, and
in Figure 2 it is seen in profile cut perpendicularly through the middle
of it. The alphabet circle, the circle of numbers, and the abbreviation
circle are here in a moveable disc in the uppermost plane of a round
case. The cipher circle is here on a movcable ring around the above
named disc, and is kept in its place with small screws. Within the caso
is a clockwork that moves the disc with the alphabet circle. On the
outside of the case is fixed a stop which reaches over the disc of the
alphabet circle; in each of the squares of the alphabet circle there is a
hole for a stopple pin; one of these stopple pins is set in the square that
is to project from the marked square of the cipher circle. The stop
will then by pressing on the stopple pin hinder the movement from
turning the disc; the other stopple pin is set in the square that is to be
brought in front of the marked square of the cipher circle.
As soon as
the first stopple pin is taken out of the square on the disc the disc turns
and places itself in the new position.
Figures 5 and 6 show a cryptograph of another construction. The
alphabet line together with the line of numbers and the line of abbrevia-
tion are set down three times on an endless strap that passes over two
moveable rollers in an oblong four-cornered case; this case is open at
top, excepting where two wooden lists lie along the long sides, one on
each side of the strap. The line of ciphers is set down on each of these
two lists.
In the squares of the alphabet line there are holes for the stopple pins

page_text: above. Besides the stopple pins above being stopped by a stop lever
above the strap it is also stopped below by the closing of a groove in
which its lower end moves with the strap.
The endless strap may bes et in motion as well by a clockwork move-
ment as by the hand. The stop arm as may be seen is at the extremity
of the cipher list. If the strap be moved by the hand the marked
square may be also in any other place on the cipher line, but in that
case the strap must be moved backwards and forwards to the sides.
Instead of the stop arm the groove must then have a hollow opposite the
marked square in which the stopple pins can be fixed if we do not prefer
omitting the stopple pins entirely. It must be regarded as an advantage
with strap apparatus that all the letters and signs turn one way.
Besides cryptographs for office use they may also be constructed more
or less simple to carry in the pocket or even in the cover of a pocket
book, the alphabet must then be moved by the hand.
Where this apparatus is to be employed only to correct chance
telegraphic errors in dispatches the inscription on the cipher circle can
be unalterable, and it is then more easy to work with the apparatus
when the inscription is in alphabetical order (the outer circle in Figure 1).
The method of working with the apparatus is otherwise unaltered.
The apparatus for the correction of dispatches, the receiver, can like
the cryptograph be of various different constructions according with their
intended use. Figures 3 and 4 show a receiver for office use. It
consists of a round metal disc in which is turned a groove for nine rings,
which each for itself can be turned round in the above mentioned groove
in the disc. On every ring is set down the line of the alphabet as well
as on the upper plane of the margin of the disc, so that there are in all
ten alphabet circles.
In each of these squares there is a hole for a stopple pin, of which
there is one for every alphabet circle. They serve at once both to mark
the squares and to make fast the rings as there are holes in the disc in
which they reach through the rings. Of course the receiver can also be
constructed with an endless strap in the same manner as described for
the cryptograph.
Having now described and particularly set forth the nature of the
said Invention, I would have it understood that I claim as the Invention,
apparatus, for the Sommerfeldt system of writing, namely,—

page_text: First. Cryptographs for writing in cipher and deciphering as well
secret dispatches as those that are not secret, substantially as described.
Second. Receivers for correcting dispatches both as well of simple as
of more complicated constructions, and as well with as without move-
ments (clockwork), according to the intended use of the apparatus,
substantially as described.
In witness whereof, I, the said William Morgan-Brown, have here-
unto set my hand and seal, this Twenty-ninth day of November,
in the year of our Lord One thousand eight hundred and seventy-
five.
WILLIAM MORGAN-BROWN. (L.S.)