A hemispherical cup anemometer of the type invented in 1846 by John Thomas Romney Robinson.
An anemometer is a device used for measuring wind speed and direction. It is also a common weather station instrument. The term is derived from the Greek word anemos, which means wind, and is used to describe any wind speed instrument used in meteorology. The first known description of an anemometer was given by Leon Battista Alberti Most widely used for wind-speed measurements is the revolving-cup electric anemometer, in which the revolving cups drive an electric generator.