In progress here. targets/delacroix1797 is working on this cipher (status: in progress (not deciphered; attempted 2 Nov 2026, no reading; blocked on the clear minute or a key, which need archive access)). Read its NOTES.md before you start, and hand it to your agent with this page: it records what was transcribed, tried and ruled out, and the next step.
Hand this page to your AI agent
Give your agent (Claude, ChatGPT or any assistant that can open web pages) this address and ask it to do the task on the page:
https://dbourdeau.github.io/cyphersolver/solve/649.html
Or copy the block below into the chat. It is the whole task: what the cipher is, where the images are, what has been tried, the steps, and how to report back.
TASK: help read Unsolved Catalogue no. 649 of the cyphersolver project
This page: https://dbourdeau.github.io/cyphersolver/solve/649.html
You are helping a public research project read historical cipher letters that nobody has read yet.
START HERE: the project is already working on this cipher. Read these notes before anything else and
build on them; they record what was transcribed, tried and ruled out, and the next step:
https://github.com/dbourdeau/cyphersolver/blob/main/targets/delacroix1797/NOTES.md (status: in progress (not deciphered; attempted 2 Nov 2026, no reading; blocked on the clear minute or a key, which need archive access))
THE CIPHER
Title: Delacroix (French Foreign Minister) → Létombe (French consul general, Philadelphia), despatch No. 5 entirely in a French numeric code, copy sent by Rufus King
Date: 25 Messidor an V (13 July 1797); enclosed in King No. 53, London, 12 Nov 1797
Correspondents: Charles Delacroix → Philippe de Létombe (copy forwarded by Rufus King to Timothy Pickering)
Place: Paris
Language: French (expected)
Held at: NARA RG 59, Despatches from US Ministers to Great Britain, vol. 5 (10 Aug 1796-28 Dec 1797) = microfilm M30 roll 4 (image path M30-004), catalog naId 188512917; frames 0244 right, 0245 left and right (0244 left blank): 653 code groups, values 2-1198, 297 distinct, in a clerk's copy marked 'Dup.', '(Copy)', 'No. 5 Duplicata'; heading and close in clear, signed 'Ch. Delacroix'; catchwords (806, 278) at the page feet confirm no group lost between pages. King's covering No. 53 ends on frame 0243.
Images/records:
- NARA M30 vol. 5: https://catalog.archives.gov/id/188512917
- frame 0244: https://catalog.archives.gov/medialz/dc-metro/rg-059/603720/M30/M30-004/M30-004-0244.jpg
- frame 0245: https://catalog.archives.gov/medialz/dc-metro/rg-059/603720/M30/M30-004/M30-004-0245.jpg
WHAT IS KNOWN
Status: Transcribed in full by Michael Brackx (issue #122, 27 Oct 2026; transcription in the issue). King's No. 53: 'I have no means of decyphering it'; no decipherment on frames 0236-0252. Turner, Correspondence of the French Ministers 1791-1797 (AHA 1903) does not print No. 5, but prints Létombe's reply No. 42 (22 Brumaire an VI, p. 1077, from the ministry's decipherment, CP États-Unis 48 f. 355): he will follow what the 25 Messidor despatch prescribed for keeping his political correspondence, 'dont je dicte moi-même les chiffres'. So part of No. 5 is probably about the keeping and ciphering of his political letters. Statistics: repeats 705 806 711/400 405 ×7, 474 670 1068 ×3; adjacent frequent pairs 972/973 and 81/82 hint at a one-part code, but a one-part word anneal did not converge; flat profile (top ten 14%). Not on DECODE. 2 Nov 2026: worked in targets/delacroix1797/, still unread. Near-repeated passages interchange neighbouring numbers (e.g. 417 269/416 268, 123 151/124 152), which suggests homophones in small numeric blocks, and a calibrated one-part test found no alphabetical order (real text overlaps scrambled numbers; the method recovers about half of a synthetic one-part letter). Annealers failed calibration on synthetic letters of the same size; seven French keys in the repo are within chance.
Outcome so far: In progress here, in targets/delacroix1797/ (earlier: attempted, open).
Prior-art check: open (27 Oct 2026). Turner 1903 checked by Michael Brackx: No. 5 not printed; reply No. 42 printed p. 1077.
Check first: Find the clear minute of 25 Messidor an V in AMAE CP États-Unis 47 or 48, or Nasatir & Monell's calendar (1967). Alternatively, find Létombe's 1797-98 ciphered despatches with the ministry's decipherments (CP États-Unis 48; Turner prints them from the decipherment) to rebuild the code. New lead: CADN Nantes, Philadelphia consulate 519PO/1 art. 1 (ministry letters received, March 1793-Feb 1798).
Class B: part of a key or a known cipher family of the same office is in print or on DECODE.
Project notes (read these before anything else; they record what was tried and ruled out): https://github.com/dbourdeau/cyphersolver/blob/main/targets/delacroix1797/NOTES.md
Project notes (read these before anything else; they record what was tried and ruled out): https://github.com/dbourdeau/cyphersolver/blob/main/targets/jqa/NOTES.md
STEPS
0. Set up. If you can run a shell, fork and clone the repository and work inside it:
git clone https://github.com/dbourdeau/cyphersolver.git
Then read, in this order: CONTRIBUTING.md (how a contribution is sent and credited); README.md, sections
"Repository layout" and "Conventions" (how readings are measured and named); targets/delacroix1797/NOTES.md (everything
already tried on this cipher, with the files it used); and lang/README.md (shared language models).
Put all your work in targets/delacroix1797/: transcription, key, decipherment, scripts. Add your findings to its NOTES.md
under a dated heading, without rewriting what is there. Keep WORKLOG.md there too:
one dated line per step (transcription, hypothesis, solver run, crib, key found, control), failures included.
Do not edit docs/ (the site is generated and rebuilt on merge) and do not commit large images: link them.
If you cannot run a shell, do the same work in files you keep and send them with the issue below.
1. Make sure it is still unread. Search the web and the literature for the shelfmark, the correspondents and the date:
printed editions and calendars of the correspondence, Satoshi Tomokiyo's cryptiana pages
(https://cryptiana.web.fc2.com/), the DECODE record and the files attached to it, and the project notes above.
If a decipherment already exists, stop and report where it is. That is a useful result.
2. Get the images. For Gallica items, a page image is
https://gallica.bnf.fr/iiif/ark:/12148/<ark>/f<page>/full/full/0/native.jpg (page numbers from the manifest).
DECODE records (de-crypt.org) need a free account: if you cannot log in, ask your human to download the images for you.
3. Look for key material before attacking the ciphertext, in this order: a decipherment written between the lines or
in the margin; a clear copy or a deciphered sibling letter in the same volume or DECODE series; a key sheet from the
same office and years (DECODE key records, Tomokiyo's articles, printed editions); clear passages in the letter
itself that can serve as a crib.
4. Transcribe exactly what is on the page: one token per sign or number group, line by line, with folio and line
numbers, unclear signs marked with ?. Keep the transcription as a file. It is worth sending even if nothing else works.
5. If no key exists, identify the system (count the distinct symbols, tokens and repeats: simple or homophonic
substitution, nomenclator with code words, syllabary, two-digit figures) and recover the key from the ciphertext
with a solver scored on a language model of the period (French). In the clone, use the shared models in lang/
(from lang import lm; lm.load('<model>'), lm.best_language(text)) rather than building your own; add a corpus there
if none fits. Before trusting a result, run the same solver on a control text you encipher yourself in the same
system and at the same length. If it cannot solve the control, its output on the real letter means nothing.
6. Measure the result against the project's bar (README.md, Conventions). A text is "complete" only when (1) at least
95% of its cipher tokens give sense, counted from a reading file, not estimated; (2) no gap is left untried;
(3) every letter in the item is covered; (4) what stays open is scattered code groups or names, or pieces blocked
from outside (no key material, too short, illegible, needs the archive). Otherwise it is "partial": say which
pieces are open and why. Mark every uncertain word with [?] and leave unread groups as their numbers or signs.
Never fill gaps with plausible guesses. A failed attempt that records what was ruled out is still a contribution.
7. Name how the text was obtained with one of the project's methods (do not write just "solved" or "read"):
- ciphertext-only break: The key was rebuilt from the ciphertext alone: frequencies, solvers, pattern words, the order of the key. No plaintext and no existing key was used. If someone had solved the same text earlier and it was found only afterwards, the write-up says so: an independent re-solution.
- key from external plaintext: The key was rebuilt by matching the ciphertext against a plaintext found elsewhere: a printed edition, a calendar of state papers, a copy of the same letter in another archive.
- key from adjacent plaintext: The key was rebuilt from plaintext next to the ciphertext: a partial decipherment written between the lines or in the margin, clear passages in the same letter, a deciphered copy in the same file.
- external key matched: An existing key that had not been connected with this document (a key for another correspondent or series, a key sheet filed elsewhere) was found to fit, and applied.
- known key applied: The key was already identified for this document or its correspondence (on its archive or DECODE record, published for it, filed with it) and was applied. The work is transcription and decipherment, which is not mechanical when the key is polyphonic or variable-length.
- existing decipherment: A complete decipherment already existed (between the lines, on a separate copy, or in print). The work was transcribing the cipher and checking the decipherment against it.
- not solved: Attempted; neither the key nor the text was obtained. What was learned is recorded. A target whose key was obtained but whose text does not read keeps the method that obtained the key, with extent "none (text not read)".
- not applicable: Not a cipher (clear text, shorthand, a key sheet, instructions), or the item could not be reached.
REPORT BACK
With a clone: open a pull request with your targets/delacroix1797/ folder. Say in the description how you want to be
credited (name, initials or handle, and a link) and include the same points as the issue below.
Without one: open an issue: https://github.com/dbourdeau/cyphersolver/issues/new?template=solution.yml&title=Solution%3A+catalogue+649&target=catalogue+649
(other kinds of contribution: https://github.com/dbourdeau/cyphersolver/issues/new/choose). Include:
- Target: catalogue 649
- the documents and the images you worked from;
- the key: sign-to-value table, code groups with values, nulls;
- the decipherment line by line against the ciphertext, with uncertain passages marked;
- the method (step 7), the share of tokens that give sense, complete or partial (step 6), and whether the
reading was already published anywhere;
- your step log (WORKLOG.md), and the tools and the AI model you used.
If you cannot open issues or pull requests, write this report for your human to send. Credit goes to the person who sends it.Where the cipher is
Cipher located and confirmed. A French numeric code, groups separated by full stops, no clear text beyond the heading; no decipherment or interlinear gloss on 0244 or 0245 (lower half of each scan is blank). Neighbouring frames 0236-0252 were reported without decipherment by the earlier triage and by Brackx (issue 122). (NARA M30 roll 4 images 0244 and 0245 (catalog.archives.gov/medialz/dc-metro/rg-059/603720/M30/M30-004/M30-004-0244.jpg, fetched by curl 2 Nov 2026, 4568x2952 px); checked 2026-11-02 by claude vetting batch L20)
What is known
Status and prior art. Transcribed in full by Michael Brackx (issue #122, 27 Oct 2026; transcription in the issue). King's No. 53: 'I have no means of decyphering it'; no decipherment on frames 0236-0252. Turner, Correspondence of the French Ministers 1791-1797 (AHA 1903) does not print No. 5, but prints Létombe's reply No. 42 (22 Brumaire an VI, p. 1077, from the ministry's decipherment, CP États-Unis 48 f. 355): he will follow what the 25 Messidor despatch prescribed for keeping his political correspondence, 'dont je dicte moi-même les chiffres'. So part of No. 5 is probably about the keeping and ciphering of his political letters. Statistics: repeats 705 806 711/400 405 ×7, 474 670 1068 ×3; adjacent frequent pairs 972/973 and 81/82 hint at a one-part code, but a one-part word anneal did not converge; flat profile (top ten 14%). Not on DECODE. 2 Nov 2026: worked in targets/delacroix1797/, still unread. Near-repeated passages interchange neighbouring numbers (e.g. 417 269/416 268, 123 151/124 152), which suggests homophones in small numeric blocks, and a calibrated one-part test found no alphabetical order (real text overlaps scrambled numbers; the method recovers about half of a synthetic one-part letter). Annealers failed calibration on synthetic letters of the same size; seven French keys in the repo are within chance.
Outcome so far. In progress here, in targets/delacroix1797/ (earlier: attempted, open). Prior-art check: open (27 Oct 2026). Turner 1903 checked by Michael Brackx: No. 5 not printed; reply No. 42 printed p. 1077..
Check first. Find the clear minute of 25 Messidor an V in AMAE CP États-Unis 47 or 48, or Nasatir & Monell's calendar (1967). Alternatively, find Létombe's 1797-98 ciphered despatches with the ministry's decipherments (CP États-Unis 48; Turner prints them from the decipherment) to rebuild the code. New lead: CADN Nantes, Philadelphia consulate 519PO/1 art. 1 (ministry letters received, March 1793-Feb 1798).
- targets/delacroix1797/NOTES.md: what was tried and ruled out (the folder)
- targets/jqa/NOTES.md: what was tried and ruled out (the folder)
Scores
- Importance
- 4 of 5
- Solvability
- 3 of 5
- Difficulty
- 3 of 5
- Class B
- part of a key or a known cipher family of the same office is in print or on DECODE
- Note
- Scored from the NARA OCR and the frame image(s) named in folio_note during the Oct 2026 NARA bulk-scan triage (research/nara_triage_a/)
Send a result
A reading, a partial reading, a transcription, or a source that shows it was read long ago: all of it counts and is credited to you on the site.