ἄνεμος + μέτρον

The anemometer combines Greek anemos ('wind') and metron ('measure'). The concept of measuring wind dates back to ancient Greece, but Leon Battista Alberti in Florence designed the first mechanical anemometer around 1450—a rotating vane or plate that indicated wind force by the angle of its deflection.

Three centuries later, in 1846, Irish engineer John Thomas Romney Robinson invented the cup anemometer—three (or four) hemispherical cups mounted on horizontal arms extending from a vertical shaft. The cups catch the wind, the arms spin, and the rate of rotation indicates wind speed. Robinson's design is so elegant that nearly every anemometer built since has used it.

Weather stations adopted the anemometer as a standard instrument. Meteorology became a data-driven science once you could quantify wind speed instead of just describing it as 'strong' or 'gentle.' Severe wind warnings depend on anemometer readings. Hurricane forecasts, tornado tracking, and coastal storm preparation all rest on cups spinning in the breeze.

Modern digital anemometers replaced mechanical ones, but the cup design persists. A spinning cup anemometer on a rooftop or a weather balloon still tells meteorologists the truth about wind in the same way Robinson's 1846 design did: faster spinning means faster wind. The engineering has barely changed because Robinson got it right on the first try.