Verify the dates and details of Jevons's Logic Piano — built 1869, exhibited before the Royal Society 1870 — against a primary or scholarly source
claim-jevons-logic-piano-1869-mechanical-inference-machine rests on Tier-4 Wikipedia for its two load-bearing dates: the machine was "built from his specifications in 1869" and exhibited before the Royal Society in 1870. Under the sources.md escalation rule, a surprising and load-bearing historical claim should not stay on a tertiary source.
What to read / pull:
- Jevons's own writings on the machine (his 1870 paper "On the Mechanical Performance of Logical Inference," Philosophical Transactions of the Royal Society) — the primary that would confirm both the mechanism and the 1870 Royal Society exhibition.
- A scholarly history of logic machines (e.g. Martin Gardner, Logic Machines and Diagrams) for the 1869 construction date and the Marquand connection.
What it gates: moving the note off seedling / clearing its
[unverified-quant] flag. Also confirms the setup for
observation-jevons-double-bridge-victorian-logic-machine-to-ai-energy.
Update 2026-07-12 (headless), from sibling capture
10-inbox/raw/2026-07-11-hop-jevons-logic-piano.md: two Tier-2
history-of-computing secondaries now corroborate part of this — the Rutherford
Journal ("in 1869 he designed and built what is conceivably the world's first
machine for doing logic inference … anticipated the contemporary computer by 80
years") supports the 1869 construction and the first-machine priority, and the
Computer History Museum supports the elimination mechanism. Both are recorded in
the note's corroborating_sources. This narrows the gap but does not close
the question: neither Tier-2 source was independently re-fetched in the headless
run, and the exact 1870 Royal Society exhibition date still rests on the
paper's inferred venue (Phil. Trans. Royal Society) rather than the primary
itself. Question stays open; what remains is the primary — Jevons's 1870 paper
or the Royal Society record.
Separate, lower-priority thread (not gating this note): the Peirce→Marquand→Shannon electrical-switching lineage mentioned as context in the note rests on tertiary history-of-computing sites and would need Peirce's actual 30 Dec 1886 letter to Marquand to become its own claim. Left in the inbox as a lead, not routed here.
Answered 2026-08-10. A capture built specifically to close this question read
Jevons's own 1870 paper directly and cross-checked it against the Oxford History
of Science Museum's catalog page for the surviving object. Both confirm and
sharpen the dates — see answered_log above. What settled it: Jevons's own paper
header states "Received October 16, 1869, — Read January 20, 1870," giving an
exact day for the Royal Society exhibition where only a year existed before.
Progress log
- claim-jevons-1870-paper-received-16-oct-1869-read-20-jan-1870-royal-society — Jevons's own 1870 paper, read directly: received by the Royal Society 16 October 1869, read 20 January 1870, machine 'actually finished' by the receipt date. This is the primary the question named as the way to close it.
- claim-oxford-history-of-science-museum-catalog-dates-jevons-logic-machine-to-1869 — the Oxford museum holding the physical object independently dates its construction to 1869, a second Tier 1–2 line of a different kind (institutional catalog vs. author's own paper).
claude-opus-4-8 · raw markdown