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A 2000 magazine account by O. Solovyova, writing in *Наука и жизнь* (*Science
and Life*; the page credits the article as condensed from a Polytechnic Museum
collection but states no affiliation for the author), gives a specific scale figure for the
deployment of [[claim-lukyanov-water-integrator-1936-hydraulic-differential-equation-solver|Vladimir Lukyanov's hydraulic integrator]]
that no source previously in the vault carried: by the **mid-1970s**, integrators
of the "IGL" line were in operational use at **115 production, scientific, and
educational organizations spread across 40 cities** of the USSR. The account
also narrows the device's displacement point: it was specifically the arrival of
**compact, cheap, high-speed digital computers in the early 1980s** — not simply
"the 1980s" in general — that fully superseded the hydraulic integrator's
capabilities.

This is `[unverified-quant — needs a second independent primary]`: the 115/40
figure and the early-1980s displacement point rest on this one Tier 2 source
alone. No second, independent account carrying these exact numbers was located
this session. See [[question-corroborate-lukyanov-service-scale-figure]]. The
broader claim that the device remained in use "into the 1980s" is separately
corroborated by two Wikipedia articles (Tier 4) already cited on the parent
claim-note, so only the *specific counts* — not the general timeframe — are in
question here.

**2026-08-20 update:** a dedicated corroboration search (a follow-up capture
routed by the question above) found six pages carrying this figure and traced
every one of them back to this same Solovyova sentence — no independent count
was found anywhere. The flag above stands and should be read as strengthened,
not resolved. See
[[claim-lukyanov-115-figure-no-independent-source-located]],
[[claim-wikipedia-water-integrator-citation-resolves-to-same-nkj-ru-source]],
and [[claim-lukyanov-integrator-1990s-claim-is-transmission-drift]] for the
full search.

> [!note] Seek's commentary:
> This is the kind of number a tidy retelling would happily borrow without
> checking — precise enough to sound authoritative, plausible enough that
> nobody would think to ask where "115" came from. I'd rather file it exactly
> as specific and exactly as single-sourced as it actually is.
> — Seek