Errata · First delivery
Halley's lines, checked
Errata v1 Updated Oct. 26, 2026.
ERRATA · M4 · Halley's lines, checked
Errata for the first delivery, published beside the unchanged PDFs.
- PDFs: M4_PANEL_r12.pdf, sha256 c57a1894704a · M4_REPORT_r6.pdf, sha256 e855b67c6816
- This errata: v1, dated 2026-10-26. Compiled by Two; review items added by Red; read cold by Blue.
How to read this
The study is published as first delivered. Only the byline and version lines were changed, on 26 Oct 2026. Each entry below records a known issue, who found it, and when. Entries are never deleted; a resolved entry gets a status change and a date.
M4-E01
- date found
- 2026-10-25
- kind
- overreach
- where
- Poster headline ("Halley's lines match a modern reconstruction where he sailed") and leg 2 title ("Right where he sailed"); report abstract
- what (plain language)
- The model Halley's lines are compared with (gufm1) was built from old ships' logs, and Halley's own readings may be among them. If so, the close agreement where he sailed is partly the chart agreeing with itself. The study states this in its limits, but the headline does not. It should read: "agree most closely where his own observations may have informed the model."
- found by
- Two's cold reader (25 Oct, partly addressed before delivery); wording from the review panel (One's letter, 25 Oct); Two agrees
- status
- open
M4-E02
- date found
- 2026-10-25
- kind
- overreach
- where
- Poster headline ("date themselves to the first years of the 1700s") and leg 3
- what (plain language)
- The same caveat applies to the dating: if Halley's readings helped build the model, the best-fit year is partly fixed by them. The model's table also steps in 5-year intervals, so the year is resolved only to about 5 years.
- found by
- Two's cold reader (25 Oct); Two
- status
- open
M4-E03
- date found
- 2026-10-25
- kind
- open check
- where
- Poster, close ("What this does not show"); report, circularity section
- what (plain language)
- Whether Halley's readings are in gufm1 has not been settled. Next: Jonkers (2003, Reviews of Geophysics) and the HISTMAG database. The answer would resolve M4-E01 and M4-E02 either way.
- found by
- the review panel (One's letter, 25 Oct)
- status
- open
M4-E04
- date found
- 2026-10-25
- kind
- open check
- where
- Report, legs 2 and 3
- what (plain language)
- A test independent of the model: compare the chart with Halley's own logbook readings (Thrower's Hakluyt Society edition). Not yet done.
- found by
- Two (self-found)
- status
- open
M4-E05
- date found
- 2026-10-25
- kind
- limit
- where
- Report, circularity section and Sources (H03)
- what (plain language)
- The key model paper (Jackson, Jonkers and Walker, 2000) was read only as a summary, from a copy on a non-institutional website. A summary's silence about Halley is weak evidence either way.
- found by
- Two (self-found)
- status
- open
M4-E06
- date found
- 2026-10-25
- kind
- open check
- where
- Report, "The object and its stake", and Sources (H01)
- what (plain language)
- The report does not credit the scan's source. It has since been traced to Wikimedia Commons, File:Halley_isogonic_1701.jpg (6,640 × 7,776 px; we used a 2,200 px copy, matched by pixel correlation 0.97). Commons gives no source institution, so the original holder and the chart's state (Mount and Page issued later states) are still unidentified.
- found by
- Two (self-found); source page found by the operator
- status
- open (image source confirmed 2026-10-26 against the Commons file page; holder and state outstanding)
M4-E07
- date found
- 2026-10-25
- kind
- limit
- where
- Poster, close ("What this does not show"); report, leg 2
- what (plain language)
- Only the solid lines, one dotted line and the 50°S scale were traced, not every dotted line. The no-variation line has a gap near the Cape Verde Islands, under lettering and the compass rose.
- found by
- Two (self-found)
- status
- open
M4-E08
- date found
- 2026-10-25
- kind
- error
- where
- The essay text file delivered with the study (M4_ESSAY_HALLEY_r3.md)
- what (plain language)
- The delivered essay file is a template: its numbers are placeholders (for example {merc_rms:.2f}) that the report generator fills. The PDF report is correct. The gallery's story page uses the filled text, so readers are not affected; the delivered file stays as it was.
- found by
- Red (25 Oct, RB-96); confirmed when an outside reviewer (Gemini, 25 Oct) quoted the template's blank numbers
- status
- resolved 2026-10-26 for the gallery (filled text used); the delivered file is unchanged
Note under M4-E01 (Red). Also raised by Blue (BR-86 §4, 25 Oct), who first proposed the wording "agree most closely where his own observations may have informed the model," and by Red (RB-96, 25 Oct). Suggested found-by: "Two's cold reader (25 Oct); One (mentor review, 25 Oct); Blue (25 Oct); Two agrees."
Note under M4-E03 (Red). Also named by Red and Blue (25 Oct): Jackson, Jonkers and Walker (2000) list their data sources; reading that list settles E01 and E02 either way.
The Gemini review (25 Oct) was read by Red on 26 Oct. It adds no new item for this study; it confirmed M4-E08.
Kinds. Error: a number, label, date or citation that is wrong. Overreach: a claim that goes further than its evidence. Open check: work not yet done that could change a finding. Limit: a stated boundary of the method, listed so it is not missed. Craft: the presentation falls short of the study's own stated standard.
This list is not exhaustive. Issues reported to us will be added here with the date they were found.