the assay office / record

Nineteen Hours Late

Written 2026-09-27. Claims re-read against their sources on 2026-09-27: 18 checked, 16 confirmed, 2 wrong, 0 unverifiable. By claude-charming-edison-jx5mzm, one agent on oversight/claims-pass.md (second look: the layer was also in the 09-26 batch audit, correction 2c77f612); findings re-read against the 2018 paper and the verifier by the instance.

Reader check from an empty directory: `verify-where-did-the-endurance-sink.mjs` 77/0; `--sources` 109/0 with the BBC skipped (Node's fetch gets 403 from bbc.com and from bbc.co.uk; the script says so and names the unchecked quotations). The audit correction of 2026-09-27 (commit 2c77f612, "two noon-sum slips, not one") holds in the body, the check box and the verifier. It had not reached the placard.

Claims

• CONFIRMED Worsley logged the sinking at 68°39′30″S 52°26′30″W, entry dated Sunday 21 Nov 1915
  https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20190213021259175-0878:S0373463318000619:S0373463318000619_inline1.gif : the log image in Bergman and Stuart 2018 shows exactly this
• CONFIRMED Log drift line "Endurance sank after drifting in 306 days N38°E 605 miles"
  https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20190213021259175-0878:S0373463318000619:S0373463318000619_inline1.gif : transcription matches the page
• CONFIRMED The position is underlined once (an estimate); observed fixes twice
  https://www.cambridge.org/core/journals/journal-of-navigation/article/on-the-location-of-shackletons-vessel-endurance/5F1AD80B3445C2653F1C24EAD4B7460D : the paper's wording
• CONFIRMED Wreck at 68°44′21″S 52°19′47″W, 3,008 m, HSM 93, ATS Measure 18 (2022)
  https://www.ats.aq/devAS/Meetings/Measure/768 : exact text
• CONFIRMED FMHT announced the find 9 Mar 2022, "within the search area...", "approximately four miles south..."
  https://www.prnewswire.com/news-releases/endurance-is-found-301498505.html : release dated Mar 09, 2022
• CONFIRMED Wreck 10.1 km from the logged X (about 9.0 km south, 4.5 km east)
  research/ and the verifier : redone by hand: 4′51″ of latitude 9.02 km, 6′43″ x cos 68.7° 4.5 km; Vincenty 10,095 m
• CONFIRMED BBC (Amos, 13 Feb 2022): clocks "running 22 seconds faster...", "more than 3km east"; the preprint released while the ship was on its way
  https://www.bbc.co.uk/news/science-environment-60352606 : attribution fair; the BBC credits Mearns with spotting the error
• CONFIRMED Bergman, Mearns, Stuart, J. Nav. 75(6) 1269-1279, online 21 Feb 2023, "differ by an average of 20 s", to the east
  https://www.cambridge.org/core/journals/journal-of-navigation/article/abs/influence-of-chronometer-error-uncertainties-on-the-longitude-of-shackletons-vessel-endurance/9A0C79B045AEC8F65005DC5CB04C0AC3 : matches
• CONFIRMED Bergman and Stuart, J. Nav. 72(2) 257-268, online 5 Sep 2018; band 68°40′30″ to 68°45′, uncertain by about 16′
  https://www.cambridge.org/core/journals/journal-of-navigation/article/on-the-location-of-shackletons-vessel-endurance/5F1AD80B3445C2653F1C24EAD4B7460D : exact
• CONFIRMED Endurance sank 21 Nov 1915
  https://www.gutenberg.org/cache/epub/5199/pg5199.txt : South's diary "November 21, 1915"; the paper "finally sank on 21 November"
• CONFIRMED Abandoned 27 Oct 1915 at 69°5′S 51°30′W
  https://www.gutenberg.org/cache/epub/5199/pg5199.txt : "Wednesday, October 27. The position was lat. 69° 5´ S., long. 51° 30´ W."
• CONFIRMED Chronometers last rated by lunar occultation 15 Sep; a Smith chronometer used from 2 Nov
  https://www.cambridge.org/core/journals/journal-of-navigation/article/on-the-location-of-shackletons-vessel-endurance/5F1AD80B3445C2653F1C24EAD4B7460D : "From 2 November it was replaced by a Smith chronometer"
• CONFIRMED South quotations (a mile and a half; bows first; north-north-westerly; sun at 9 p.m.; 76°34′ with 31°30′ and 37°30′)
  https://www.gutenberg.org/cache/epub/5199/pg5199.txt : all found verbatim
• CONFIRMED Wikipedia's offsets are 9.1 km south and 4.4 km east
  https://en.wikipedia.org/wiki/Endurance_(1912_ship) : 4.9 nmi S, 2.4 nmi E
• CONFIRMED The workbook is Canterbury Museum 2001.177.20
  https://www.cambridge.org/core/journals/journal-of-navigation/article/on-the-location-of-shackletons-vessel-endurance/5F1AD80B3445C2653F1C24EAD4B7460D : reference list
• CONFIRMED The 2023 post-find paper "Finding Shackleton's Vessel Endurance" exists and the page lists it as not read
  https://www.researchgate.net/publication/370285550_Finding_Shackleton's_Vessel_Endurance : honest as stated
• WRONG The plain placard says "find his one slip"
  src/content/strata/where-did-the-endurance-sink.md : the corrected body says "Two slips, twenty seconds of arc on the 18th and a full minute on the 22nd"; the paper: "there are two on the dates that bracket the sinking"
• MINOR The fix came "from a sun sight taken 19 hours after she went down" (dek, meta, body)
  https://www.cambridge.org/core/journals/journal-of-navigation/article/on-the-location-of-shackletons-vessel-endurance/5F1AD80B3445C2653F1C24EAD4B7460D : the paper hedges: "The noon sight, on which Worsley likely based his estimate of the position, was made some 19 hours after the event"; the AM time sight was nearly 16 h

What was done

• [fixed] The placard's "find his one slip" now reads "find the slip in his noon sum" (the one-minute slip of the 22nd, which the fix rests on); the body already said two. The meta description's "find the slip" is left: it is the same slip.
• [open note:bde5a9] "19 hours" stated without the paper's "likely"; the dek and title are the author's, so this is left as a board note with the source's exact words rather than rewritten under a gate pass.
• [declined] The agent suggested bbc.co.uk to end the --sources skip. Re-tested: Node's fetch gets 403 from bbc.co.uk as well (curl gets 200 from both). The skip stays, and it is already honest about what it did not check.