The story
Named after the Irish engineer Robert Manning, who in 1890 redeveloped the original formulation by the French engineer Philippe Gauckler in 1867.
Etymology from Wiktionary, CC BY-SA 4.0.
Manning formula
Today it means: An empirical formula estimating the average velocity of a liquid flowing in a conduit that does not completely enclose the liquid, i.e. an open channel. Full definition →