At a glanceNot solved · text not obtained
- The letters
- Two letters from Paris to a correspondent in England, 7 and 10 February 1719, by the same writer, a few days after Lord Stair’s entry as ambassador. Clear French with runs of figures.
- Where
- British Library, Add MS 32305 ff. 6–7, catalogued as “unidentified cipher keys”; DECODE R2964 and R2965. The volume is a codebreaker’s working file of intercepts.
- The cipher
- A two-part code of three-figure groups, about 900 entries. The 7 February letter has 354 groups, 191 distinct, 116 of them seen once.
- How it was tried
- The first letter was transcribed with the decipherer’s glosses. The glosses are not in alphabetical order, so the code is two-part and its order says nothing about the other values.
- Still open
- Everything but the dozen glossed values. A key, a clear copy or many more letters in the code would be needed.
Catalogue item 78 listed six DECODE records of this volume under one unknown sender in Paris. The images show a working file of unrelated intercepts. This page is the Paris 1719 code. The letters to Mr Carré in Pall Mall, 1742–45 (R2968, R2970, R2972), are in a different code: Letters to Mr Carré, 1742–45 (a different cipher, with its own page). R2963 and R2974, and the other records around them, were deciphered at the time in their own ciphers.
01 What the six records are
| Record | Folio | Letter | State |
|---|---|---|---|
| R2963 | f. 5 | German, to a “Marquis”, 28 January [1719]; figures for names and words (1203 London, 1439 Theophili) | deciphered interlinear: read |
| R2964 | f. 6 | “A Mr [name struck out]”, Paris, 7 February 1719, Extrait | open; about a dozen glosses |
| R2965 | f. 7 | Paris, 10 February 1719, Extrait, same writer and code | open; the same glosses |
| R2968 | ff. 11–12 | “Anonyme à Monsr Carré en Pellmall à Londres”, March 1742, all figures | a different code: carre1742 |
| R2970 | ff. 14–17 | “Copie d’une Lettre en Chiffre, sans date”, to Mr Carré in Pall Mall; endorsed “R Aug. 22 1742” | a different code: carre1742 |
| R2972 | ff. 22–23 | “Lond. 19 Janv. 1745”, all figures, the Carré code | a different code: carre1742 |
| R2974 | ff. 25–28 | “L. 17/28 Nov. 1749”, 2-figure letter cipher | deciphered letter by letter: read |
Around them are R2966 (a 2-figure letter cipher, deciphered), R2967 (London, July 1740, a few code groups glossed, 0813 = le Sr Walpole), R2969 (the Carré frequency count), R2971 (a 4-figure code with a full decipherment, about the Queen of Hungary) and R2973 (6 March 1749, glossed).
02 The Paris letters of February 1719
The writer reports Lord Stair’s formal entry into Paris and his audience with the King, and tells his correspondent that he will stay in England “jusqu’au retour de S. M. Brit.” The clear text uses a family cover (“vos Parens”, “votre Cousin”, “le caractère des esprits de votre Famille”), and the second letter opens on the coming war with Spain and Cardinal Alberoni. The persons are figures marked with a cross: 27, 258, 285, 611.
The decipherer glossed 36 = re, 88 = pas, 95 = le, 184 = que, 243 = vous, 347 = a, 531 = pour, 652 = qu’il and 786 = s, the same values in both letters. That is 33 of the 354 groups of the first letter. In a one-part code, where values run in alphabetical order, these would bracket the rest. Here re (36) comes before pas (88), le (95) and que (184), and a comes at 347, so the code is two-part and its order says nothing. The Carré letters of 1742–45 in the same volume are in another two-part code, of about 800 entries. With about 700 groups in the two letters for a code of some 900 entries, most values occur once, and the decipherer glossed no more than the recurring values.
03 Catalogue item 79: the Dresden and Hague records
Item 79 put the last two records of the volume together as “Unknown sender (Dresden), 1750–53”. They were viewed on 21 September 2026, and neither is an open cipher. R2978 (f. 32) is a French letter headed “Dresde 25. Janv. 1750” in a 2-figure letter cipher. The decipherer of the time wrote the plaintext letter by letter over every line (“…que l’on ignore pas les dangers auxquels notre position nous expose… les insinuations de Mr de Guydickens…”). R2979 (f. 34), “Hanau to Fer., Hague 9 Aout 1753”, is the decipherer’s own working copy of a letter in a 4-figure syllable and word code. The clear syllables are written out and the groups he decoded are glossed (1688 = si, 1560 = roi, 3227 = Devonshire). The rest are left as figures, and the sheet ends “Ici on parle du mariage de 3245 avec 3263” beside a column of question marks. The first record was deciphered in full at the time, and the second in part. Item 79 has been removed from the catalogue.
04 What is needed
- The key of the code, or a clear copy of either letter, in the Newcastle or Carteret papers (BL Add MS 32686–33057) or SP 107/SP 78 at Kew.
- More letters in the 1719 code: its common values are known, so a few thousand groups would let the syllables be built up from context.
05 Sources
- DECODE records R2963, R2964, R2965, R2974, R2978, R2979 (images by login; not in the public domain).
- British Library, Add MS 32305, “unidentified cipher keys”, 39 folios.
Transcription of R2964, notes and profile: targets/bl32305/ in the repository.