From John Quincy Adams to Thomas Boylston Adams, 8 January 1810
[8 Jan. 1810]
The cypher consists of two parts—a Lock and a Key.
The Lock is a sheet of paper, with four columns of letters at the left, and three columns of words at the right side of the page.—The Key is a strip of paper, adapted to the Lock, in the middle of the page, between the columns of letters at the left, and the columns of words at the right.—On the left border of the key, is an alphabet of Small letters, twice written, and to the right of the small letters a succession of six or seven sillables, mostly commencing with the letter on the same line, and having distinct accents over each syllable.—The arithmetical figures are placed in the line of the letters which commence their names—On the right border of the Key is an alphabet twice written in Capitals.—The Key is made to slide up and down to vary the cypher every time it is used.—The Key-Letter for each dispatch, is that letter on the key, which is brought to correspond with the four letters at the top of the four left hand Columns on the Lock.
The two Correspondents, who would use that Cypher must agree together upon the manner in which they shall ascertain the key-letter of each dispatch.—This may be varied at pleasure—For instance—The letters which you and I write to one another are numbered—Let the number of each letter in which the cypher is used indicate the key letter—Thus if I enclose you anything cyphered in Number 5—the key letter will be e. that being the 5th. letter of the alphabet—But as the alphabet consists only of 25 letters, when the number of the dispatch exceeds 25 begin again—let a be the key letter of Number 26. b. of 27. and so on as long as the correspondence shall continue.—When you would use the cypher observe the following directions.
Draw the key up or down, untill the key-letter shall stand opposite to the letters a. b. c. d on the Lock—Write first in your ordinary hand what you would put in cypher—Then instead of the first letter of the word you would disguise, substitute the letter in the first column of the lock, standing opposite to that letter upon the key—for the second letter, substitute the corresponding letter in the <first> second column; then the third and fourth, using alternately and in succession the letters on the four columns.—Suppose for example you would put in cypher the word “Secret”—your dispatch being Number 5.—The key letter being e. Draw the key down, untill e shall stand opposite to a. b. c. d. on the lock—Then instead of s. the first letter of the word, write c. which stand opposite to it in the first column of the Lock—instead of e write b the corresponding letter in the second column of the Lock—for c write its corresponding letter in the third column and so on—“Secret” thus cyphered would be written “cbubah.”
But if your dispatch were number 10. and k of course the key-letter, then by observing the same process “Secret” would be written “hgcgfn.”
To abridge labour however, and to vary still more the cypher, by putting an accent over a letter it is made to represent a syllable standing on the key, and marked with the same accent—Thus with c. for the key letter “Secret” might be written “cbǔk”—the two first letters being as in the firm example above—But in a line with c the third letter of those composing the word Secret, you find upon the key the syllable, cre, with the invicted circumflex accent over it—The letter <is> therefore with the same accent, taken from the third column of the Lock and represent that syllable upon the key; and the remaining letter t to finish the word secret, must be taken from the fourth column of the Lock.—On the same principle if k be the key-letter “Secret” will be written hgqp.—The words in the columns, upon the Lock, on the right of the key, are represented by the Capital Letters on the right border of the Key—Thus if e is the key-Letter—E—will stand for America—Ê with the circumflex accent over it, Washington, and E with the same accent invicted, for Republic.—At the commencement of a new line, after a period closed, and after the rise of a capital Letter, always begin the small letter of the first column.—
Directions for decyphering.—
On receiving a cyphered dispatch draw the key if your cypher, up or down, untill the four left letters of the left-hand columns on the Lock stand in a horizontal line, with the key letter indicated by the number of the Dispatch.—Then seek in the first left hand columns on the lock, the first letter in the cyphered dispatch—If unaccented, it will be revealed by the small letter on the border of the key standing opposite to it—If accented, it will be explained by the syllable on the same line, bearing the same accent.—Whenever a capital letter occurs, look for it on the right border of the key, and detect its meaning in the word standing on the same horizontal line—Observing always that the letters of the four left hand columns are used in succession from the first, beginning anew after every period, when the next sentence begins a new line, and after every capital letter.
Suppose for example in my letter to you Number 5. you find the following
Dmw nx CqpC ipu K eedz pisable le T. J. W.
G jauc n rdg s I rlocca n wricf
The dispatch being number 5. The 5th. letter of the Alphabet is the key-letter e
To prepare your cypher then, you must drawn down your key, untill the e on its left border stands opposite the top letters a. b. c. d. of the four left hand columns on the Lock.—Look in the first of those columns for the letter d, and you find it stands for m on the key—Then look in the second column and for m to correspond <on> the key is u—Look for w in the third column; and as it has in the present instance an accent over it, seek on the key the combination of letters, on the same line, having the same accent—it stands for them—Thus w in the third column stands on a line with ch on the key—w therefore with the same accent over it stands for ch and dinw signifies “much.”
The next letters for which you are to seek the prototype are nx—Look for n in the fourth column—It is explained by a on the key—after which you return to the first column for x, and find on the same line in the key do with the accent over it—“nx” therefore means “ado”—Pursuing the same rules you will easily discover the remainder if the cyphered sentences.—Observing only that when you come to the Capital Letter J you change your process; look for it on the Key, and find its meaning on the same line of the Lock.—Thus J here stands for U.S. and W. for Russia—Remember too that in returning to the small letters, after the use of any Capital, you begin from the first column. When there is an accent over a capital letter, it stands for the word in the column over the top of which the same accent appears—Thus J signifies U.S.—J Saxony, and J Government—And the same W. which stands for Russia, with the accent thus W signifies April and thus W Commerce.—
In using the cypher, you must be particularly careful to observe the regular succession of the columns, and the distinct and exact marking of the accents—The slightest mistake in either of which, produce inextricable confusion.
I conclude with the following lines, appropriate enough for the practice of a cypher, but which I give you only as an exercise of skill, which will cost you little trouble under these instructions.
E s f fqby sk raoxg wsc
I g hqc smuxso kck zmce.
MHi: Adams Family Papers, Letterbooks.