POST15 Review: “Three Mathematicians from Poznan”
POST15 Review: “Three Mathematicians from Poznan”
Post file: _posts/2026-04-12-Three-mathematicians-from-Poznan.md
Review date: 2026-04-08
Status: Pre-publication fact-check and enhancement review
A. Factual Errors and Corrections
1. CONFIRMED CORRECT: Rejewski’s age when cracking Enigma
Post claim: “a 27-year-old Polish mathematician cracked the German Enigma cipher” (also in section heading text) Verdict: Correct. Born 16 August 1905; received Schmidt documents and recovered rotor wirings approximately 9–10 December 1932. Age at time: 27.
2. MINOR ISSUE: Timing of Enigma crack (“end of 1932” vs. exact date)
Post claim: “By the end of 1932, Rejewski had recovered the wiring of all three rotors and the reflector.” Research: The French documents arrived approximately 9–10 December 1932. The recovery of wirings happened in the days/weeks after that – so “by end of 1932” is correct but somewhat compresses events. More precisely: documents received ~9–10 December 1932; rotor wirings recovered in late December 1932; full solution including reflector confirmed by year’s end. Verdict: Acceptable as written. The phrase “by the end of 1932” is accurate.
3. CONFIRMED: “Theorem that won World War II” – Cipher A. Deavours attribution
Post claim: “Cipher historian Cipher A. Deavours called the underlying theorem ‘the theorem that won World War II.’” Verdict: Confirmed. The attribution appears in an afterword by I.J. Good and Cipher A. Deavours in Rejewski’s posthumous paper “How Polish Mathematicians Deciphered the Enigma,” IEEE Annals of the History of Computing, vol. 3, no. 3, July 1981. Deavours was co-editor of Cryptologia, not purely a “cipher historian” – both descriptions are defensible. The research file (crypto_to_computing_research.md) correctly describes him as “mathematics professor and Cryptologia co-editor.” Suggested minor improvement: “Cipher A. Deavours, co-editor of Cryptologia” is marginally more precise than “cipher historian” but either works for a general readership.
4. CONFIRMED: Knox reaction at Pyry – “tantrum”
Post claim: Knox’s reaction was complex. He was “furious that the solution was one he had rejected” – yet “grasped everything very quickly, almost quick as lightning.” He was “chagrined – but grateful.” Note: The post does NOT actually use the word “tantrum” in the final text – that word appears in the research notes but was wisely softened in the post to “furious” and “chagrined – but grateful.” The research file (crypto_to_computing_research.md) notes Knox “threw a tantrum – not at the Poles but at himself,” and multiple secondary sources confirm Knox’s frustration was directed at himself for having dismissed the alphabetical wiring. Verdict: The post handles this correctly and tactfully. The “tantrum” framing is supported by secondary sources including the Dilly Knox Wikipedia article (“Knox was so furious … that he threw a tantrum”) but the post’s softer characterisation is more historically defensible and appropriate.
5. ERROR (nuanced): “Over 200 British Bombes were eventually built”
Post claim: “Over 200 British Bombes were eventually built.” Research file (crypto_to_computing_research.md): “224 British bombes (73 standard, 14 Jumbo, 57 Mammoth, 12 Cobra, 68 ‘new’ standard)” plus 121 US Navy and 10 US Army = approximately 355 total. Web search findings: Wikipedia Bombe article confirms more than 200 British Bombes; the figure 211 appears in some sources (number built before production stopped). The figure 224 appears in the detailed research notes. Some sources use “211” as the British total; others cite “more than 200.”
Analysis:
- “Over 200 British Bombes” is technically accurate but undersells the reality – the research file gives 224.
- The total number of Bombes across all Allied forces (British + US Navy + US Army) was approximately 355.
- Earlier in the same research file’s section on Polish bomba (Section 3, “From Bomba to Bombe”), the text also says “Over 200 Bombes were eventually built” – this is internally consistent, but the 355 total figure is a better measure of the scale of the industrial operation.
Suggested correction for the post: The line currently reads: “Over 200 British Bombes were eventually built.” This could be improved to either:
- “More than 200 British Bombes were eventually built, with a further 131 built in the United States.” (adds US context)
- Or simply change to: “More than 350 Bombes were eventually built, the vast majority by Britain.” (reflects the 355 total)
The current phrasing is not false, but it undersells the scale of the programme and is potentially confusing given the research file contains the more precise 224 / 355 breakdown.
6. CONFIRMED: Bomba designed October 1938
Post claim: “In October 1938, Rejewski designed something more ambitious: the bomba kryptologiczna.” Verdict: Confirmed. Wikipedia and research file agree: “designed by Rejewski probably in October 1938” (following German procedural change on 15 September 1938); operational by mid-November 1938.
7. CONFIRMED: SS Lamoriciere casualties
Post claim: “carrying 272 passengers and 122 crew”; “Of 394 people aboard, only 93 survived.” Verdict: Fully confirmed. Wikipedia and research file both give 272 passengers, 122 crew = 394 total; 93 survivors.
One small discrepancy: The post states “212 passengers and 89 crew” died (implied by 394 - 93 = 301 dead). The research file gives “212 passengers and 89 crew” as dead. However, the Wikipedia SS Lamoriciere article gives “212 passengers and 80 crew” fatalities – a discrepancy of 9 in the crew count. Both sources give 93 survivors. The difference may reflect ambiguity in how “crew” is counted (some sources may include officers separately). The post does not state the breakdown of dead; it only cites total aboard and survivors, which are consistent across all sources. Action: The post is correct. No change needed in the post itself. The research file’s “89 crew dead” vs. Wikipedia’s “80 crew dead” is a discrepancy worth noting in Polish_codebreakers.md but doesn’t affect the post.
8. CONFIRMED: Rejewski “returning from shopping”
Post claim: “He died of a heart attack on February 13, 1980, while returning from shopping in Warsaw.” Research status: Multiple sources confirm date (13 February 1980), cause (heart attack), and location (Warsaw). The specific detail “returning from shopping” appears in the Polish_codebreakers.md research file, which cites it directly. Web search did not independently confirm this specific detail from news sources – most obituaries simply say “died in Warsaw.” Assessment: The detail “returning from shopping” appears in Kozaczuk’s research and is repeated in the Polish_codebreakers.md notes with apparent confidence. It is not contradicted by any source found. The IEEE obituary (“In Memoriam Marian Rejewski”) states he “died at his home in Warsaw” – which might suggest he had returned home before the heart attack, or that this was how it was described at the time. Recommendation: The detail is plausible and appears in credible secondary sources but cannot be independently verified from the web searches conducted. If the source is Kozaczuk (1984) or the Polish Applicationes Mathematicae obituary, that is sufficient for a blog post. Consider footnoting the source of this specific detail, or softening to “died of a heart attack in Warsaw on February 13, 1980” if provenance is uncertain.
9. CONFIRMED: Zygalski died August 30, 1978
Post claim: “Henryk Zygalski died on August 30, 1978.” Verdict: Confirmed across multiple sources – Wikipedia, Find a Grave, MacTutor History of Mathematics, prabook.com – all give 30 August 1978, in Liss, Hampshire, England.
10. MINOR ISSUE: “Schmidt had been selling secrets to the French since 1931”
Post claim: “Schmidt had been selling secrets to the French since 1931” Research: The first meeting was 1 November 1931 at Verviers; documents were first handed over at the second meeting, 8 November 1931. So “since 1931” is correct. Verdict: Accurate.
11. MINOR ISSUE: “Bertrand passed Schmidt’s documents – operating manuals, monthly key tables for September and October 1932 – to the Poles”
Post claim: Bertrand passed “operating manuals, monthly key tables for September and October 1932” to the Poles. Verdict: Confirmed. The September and October 1932 key tables are specifically cited in multiple sources as what Rejewski used to close his equations.
12. CLARIFICATION NEEDED: Knox described as “Britain’s chief Enigma cryptanalyst”
Post claim: “Dilly Knox, Britain’s chief Enigma cryptanalyst” Actual title: Knox was GC&CS’s “chief cryptanalyst” (or “chief cryptographer”) – not specifically the “Enigma cryptanalyst.” He worked on many cipher problems, not Enigma alone. Verdict: The post’s phrasing is a useful simplification for a general audience, and Knox was indeed the senior GC&CS cryptanalyst who led the Enigma work. Technically the phrase is a reasonable shorthand, though “GC&CS’s chief cryptanalyst” would be slightly more accurate.
13. POST SAYS “reading German Enigma traffic since 1933” – verify start date
Post claim: “the Poles had been reading German Enigma traffic since 1933.” Research: Rejewski cracked the wiring in December 1932. Regular reading of traffic began in 1933 once the Cipher Bureau had the methods and replica machines in place. This is confirmed by Kozaczuk and the research file. Verdict: Correct.
B. Unsupported or Weakly Sourced Claims
14. RUSI quote: “the most consequential intelligence-sharing arrangement of World War Two”
Post claim: The RUSI described the Pyry disclosure as “the most consequential intelligence-sharing arrangement of World War Two.” Verdict: This quote appears in the research file (crypto_to_computing_research.md) attributed to RUSI, and is widely cited in secondary literature. The post’s reference list does not directly cite the RUSI source – GCHQ’s own page on the Pyry conference is cited instead. The GCHQ page may use similar language. No web search found the exact RUSI source document. Recommendation: If this quote cannot be traced to a specific RUSI publication, consider attributing to “GCHQ” (which uses similar language on its Pyry pages) or paraphrase without direct quotation.
15. Peter Twinn quote – who said “Tony Kendrick”?
Post claim: “not Dilly Knox or Tony Kendrick or Alan Turing” Verdict: The quote is widely attributed to Peter Twinn. The post correctly attributes it to “Knox’s colleague Peter Twinn.” However, note that the crypto_to_computing_research.md quotes it slightly differently: “not Dilly Knox, not Alan Turing” (omitting Tony Kendrick). The fuller version including Kendrick appears in Kozaczuk (1984) and is likely authentic. The post version (with Kendrick) is actually more complete and accurate.
C. Enhancement Opportunities
16. The bomba name origin – cut for brevity, but an interesting detail
The research file notes that Rejewski said the device was dubbed “bomb” “for lack of a better idea,” and that the popular story of Rozycki naming it after a bombe glacee (ice-cream dessert) was dismissed by Rejewski as improbable. This is a charming detail that could be a one-line aside.
Suggested addition (optional, after “an electromechanical device that automated the search”):
Rejewski said the device was named “bomb” simply “for lack of a better idea.” The popular story – that Rozycki named it after a bombe glacee, a Polish ice-cream dessert – was dismissed by Rejewski himself as improbable.
17. Welchman’s diagonal board – the post could mention it
The post notes that the British Bombe was “directly inspired by the Polish bomba” but does not mention Gordon Welchman’s diagonal board, which made the British Bombe immensely more powerful than the Polish original. The research file (crypto_to_computing_research.md) covers this in detail. Given Welchman is already quoted in the post (“Hut 6 Ultra would never have got off the ground…”), a brief mention would close the loop.
Possible one-liner (e.g., after “directly inspired by the Polish bomba”):
Gordon Welchman – who already features in this post through his assessment of the Polish contribution – added the “diagonal board,” which exploited the Enigma plugboard’s reciprocal property and made the British Bombe far more powerful than the Polish original.
18. Lamoriciere: the “Lamoriciere Principle” in maritime law
The research file notes that a 1950s French lawsuit established the sinking was “four-fifths due to the storm and one-fifth due to the unseaworthiness of the vessel,” a ruling that became known in French maritime law as the “Lamoriciere Principle.” This is a fascinating footnote about how Rozycki’s death had legal aftershocks.
19. Rozycki’s companions in death
The post focuses on Rozycki’s death but does not mention that fellow Polish cryptologists Piotr Smolenski and Captain Jan Gralinski (of the Bureau’s Russian section) also died on the Lamoriciere. This detail adds texture to the scale of the loss.
20. Rejewski’s son Andrzej – the post says “aged 11”; research says he died “summer 1947”
Post claim: “his son Andrzej had died of polio in 1947, aged 11.” Research file: Andrzej was born 1936, died summer 1947, aged 11, “after only five days’ illness.” Verdict: Correct. The post omits “after only five days’ illness” – this detail is in the research file and adds poignancy. Optional enhancement.
21. Ciezki’s fate – the man who directed the work
The post names Maksymilian Ciezki but does not mention his fate: he was captured alongside Langer in March 1943, imprisoned, and died destitute in London in 1951 “after living the last three years on subsidies from the Assistance Board.” This would strengthen the “injustice” section.
22. Bertrand’s capture is not mentioned
The post describes Rejewski and Zygalski’s escape but does not mention Gustave Bertrand – the French officer who had brokered the whole operation – was himself captured and escaped. This is a gripping detail (captured January 1944, escaped by Lysander four days before D-Day) that fits the post’s narrative of wartime drama.
23. Schmidt and Lemoine – the spy who made it possible
The post correctly names Schmidt and Bertrand, but is brief. The full story – Schmidt selling secrets out of resentment and gambling debts, Lemoine eventually betraying Schmidt to the Gestapo, Schmidt dying in custody – is a remarkable sub-narrative. Whether to expand it depends on post length and focus.
D. Cross-References to Other Posts in the Series
24. Beurling post cross-reference – already done
The post cross-references the Beurling (“The Magician Who Told No Secrets”) and Beurling/BESK/Swedish NWP posts. Good.
25. Colossus connection – not mentioned in the post
The post notes that Colossus cracked the Lorenz SZ42 “a machine from the same family as the Geheimschreiber” in the opening paragraphs, but does not develop the Colossus connection in the body. The research file suggests this was planned (narrative thread item 7). If a future post covers Colossus directly, a seed sentence here would help.
26. Von Neumann / IAS post connection
The post references “von Neumann’s blueprint” in the intro but the connection to computing/weather is not developed beyond the opening framework. The research file has a detailed “mathematical parallel” section (Rejewski and Charney) that is not used in the post. Whether this is deliberate compression or a future expansion opportunity is a judgement call.
27. The “computing pipeline” section from research is absent from post
The research file (crypto_to_computing_research.md) has a rich Section 4 tracing the pipeline from Bletchley to Manchester Baby to Ferranti to ACE to DEUCE to BESK. None of this appears in the post, which jumps from the bomba to the Bombe and then to the fates. This pipeline content could support a separate “bridge” post connecting the Polish story to the Manchester/Ferranti/ACE computing posts already written.
E. Summary of Required Changes
| # | Type | Post change needed? | Priority |
|---|---|---|---|
| 5 | Accuracy | “Over 200 British Bombes” – consider updating to reflect 224 British / 355 total | Medium |
| 8 | Sourcing | “Returning from shopping” – verify source or soften | Low |
| 12 | Precision | “Britain’s chief Enigma cryptanalyst” – minor | Low |
| 14 | Sourcing | RUSI quote – verify source or change attribution to GCHQ | Low |
All other items are either confirmed correct or are enhancement opportunities, not errors.
F. Research Files Created in This Review
/home/michal/repos/michalbrennek.github.io/research/people/Schmidt_Asche.md/home/michal/repos/michalbrennek.github.io/research/people/Bertrand.md/home/michal/repos/michalbrennek.github.io/research/people/Knox.md