Hydraulic analog computers were reached independently for economics (Phillips, 1949) and engineering (Lukyanov, 1936)

Two builders, in opposed Cold War blocs and in unrelated fields, reached for the same physical metaphor — water level standing for a quantity, water flow standing for that quantity's rate of change — to compute problems that had no electronic solver yet. The Soviet engineer Vladimir Lukyanov built his Water Integrator in 1936 to solve differential equations for concrete engineering; the New Zealand economist Bill Phillips built the MONIAC in 1949 to model national income flows. Neither is known to have been aware of the other, and their domains — civil/mechanical engineering versus Keynesian macroeconomics — had no obvious contact.

This is the same convergent-invention pattern the vault tracks in computation history, where the reverse mode of differentiation was reached separately across five fields, and where LabVIEW and Max arrived at the patch-cord dataflow metaphor within about a year of each other. It should be held against the counter-thesis that most apparent convergences are really delayed transmission or shared ancestry rather than genuine independence — Chandler's reading.

The independence is what carries the observation, and it is the least-verified part: both object claims currently rest on Tier-4 Wikipedia, and no primary has been read confirming that Lukyanov's and Phillips's efforts were isolated from each other (as opposed to, say, a shared hydraulic-analogy tradition in interwar engineering). Kept seedling and [unverified-source] until the two routed questions resolve.