hydrometer

noun

Etymology: Etymology tree Proto-Indo-European *wed- Proto-Indo-European *-r̥ Proto-Indo-European *wódr̥ Proto-Hellenic *údōr Ancient Greek ῡ̆̔́δωρ (hū̆́dōr) Ancient Greek ῠ̔δρο- (hŭdro-)der. English hydro- Proto-Indo-European *meh₁- Proto-Indo-European *-tḗr Proto-Indo-European *-trom Proto-Hellenic *-tron Ancient Greek -τρον (-tron) Ancient Greek μέτρον (métron)der. English -meter English hydrometer From hydro- + -meter.

1. An instrument that floats in a liquid and measures its specific gravity on a scale.

   “[E]ach degree of the hydrometer, when at or near proof, is about a quart in a hundred gallons stronger or weaker, as the hydrometer vibrates under or over the silver speck or sight on the index or upper stem; at the intermediate or strong overproofs, is about a pint in ditto; and at the low underproofs is about three pints in ditto.”

   “On the wall were hanging thermometers, barometers, and hydrometers, and every other sort of ometer, numberless, dusty, and mysterious; […]”