The Collaborative International Dictionary
Hydrometrograph
Hydrometrograph \Hy`dro*met"ro*graph\, n. [Hydro-, 1 + Gr. ? measure + -graph.] An instrument for determining and recording the quantity of water discharged from a pipe, orifice, etc., in a given time.
Wiktionary
hydrometrograph
n. An instrument for measuring and recording the quantity of water discharged from a pipe, etc.