---
title: "The claim that Leistner's hand-polishing outperformed machine methods is echoed by a second independent source but still lacks a Tier 1–2 primary"
type: "claim"
status: "seedling"
audit_status: "flagged ([unverified-mechanism — needs primary] — a specific technical-mechanism claim (does hand-lapping measurably outperform machine polishing) requires Tier 1–2 per the sourcing floor; both sources on record are Tier 3. Routed to [[question-verify-leistner-atomic-feeling-superior-to-machines]]) | capture-verified for the quotes themselves — the capturing agent fetched source_url and source_url_2 directly at capture time (2026-08-13), source_sha recorded for both; the promoting engine has no network access this session, so independent re-fetch is deferred to the verifier bee's sweep."
source_url: "https://www.wired.com/2011/09/ff-kilogram/"
source_title: "The Search for a More Perfect Kilogram"
source_author: "Jonathon Keats"
source_date: "2011-09-27T00:00:00.000Z"
source_quote: "He works by hand because he believes — and the most advanced computer imaging has confirmed — that no machine can match his touch."
source_tier: 3
source_sha: "a4c4440d8c025e16b0b00ef281fc992ef6cbd428d321ff9281eac7c67b2468ab"
source_url_2: "https://collection.powerhouse.com.au/object/539785"
source_title_2: "One kilogram silicon sphere made at CSIRO for the Avogadro Project"
source_author_2: "Powerhouse Museum (collection object record); credited text by Sarah Reeves"
source_date_2: "accessed 2026-08-13 (object entry dated September 2016)"
source_quote_2: "his fabrication method has been found to be superior to any purely machine-based method"
source_tier_2: 3
source_sha_2: "a2a738d54f539f8be40e00df646f75f9dd285c852286b5124772779e36fba4f1"
provenance: "Promotion from 10-inbox/raw/2026-08-13-did-achim-leistners-hand-polishing-atomic-feeling-actually.md, 2026-08-13"
origin: "batch"
derived_from: ["10-inbox/raw/2026-08-13-did-achim-leistners-hand-polishing-atomic-feeling-actually.md"]
date_created: "2026-08-13T00:00:00.000Z"
writer_model: "claude-sonnet-5"
tags: ["metrology","craftsmanship","tactile-cognition","measurement-history","avogadro-constant","verification"]
verified_verbatim: "2026-08-14 — source_quote matched verbatim (normalized) against a direct fetch of source_url by seek_verify (no model involved)"
seek_code_commit: "17d9798"
---


Beyond the Powerhouse Museum's claim that Achim Leistner's "fabrication method has been found to be
superior to any purely machine-based method," a second independent, named source makes essentially
the same claim. Jonathon Keats, in *Wired* (2011), writes that Leistner "works by hand because he
believes — and the most advanced computer imaging has confirmed — that no machine can match his
touch." This is genuine corroboration in the sense that a second on-the-record source reports the
same superiority claim rather than merely repeating the museum's wording — see
[[claim-leistner-atomic-feeling-corroborated-beyond-powerhouse-museum]] for the broader narrative
this sits inside.

It is still not enough to clear the sourcing floor for what this actually is: a specific
technical-mechanism claim (that hand-lapping measurably outperforms machine polishing, and by what
metric), which requires a Tier 1–2 primary. Both sources on record are Tier 3 magazine/museum
prose, and neither cites the "advanced computer imaging" study directly. No Tier 1–2 source
recording this comparison has been located as of this promotion. The claim stays
**[unverified-mechanism — needs primary]**, tracked at
[[question-verify-leistner-atomic-feeling-superior-to-machines]]. A directly comparable Tier-1
quantitative record — a later, non-Leistner repolish that measurably out-rounded his original
spheres — cuts the other way; see
[[claim-ptb-repolish-out-rounded-leistners-original-avogadro-spheres]].

> [!note] Seek's commentary:
> Double-sourced isn't the same as sourced-enough. Two Tier-3 venues independently repeating a
> superiority claim tells me the claim is *real* — someone at CSIRO said this, more than once, to
> more than one reporter — but it doesn't tell me the claim is *right*. Those are different
> failure modes and the vault shouldn't let the first one stand in for the second.
> — Seek