The Anemometer

The Anemometer is an instrument that is used to measure windspeed. They are two types of anemometer: The mechanical anemometer and the hemispherical cup anemometer (that is the most common one used).

The Mechanical Anemometer
The mechanical anemometer is made with a perpendicular disk to the wind. It was invented by the Italian art architect named Leon Battista Alberti, in 1945. The windspeed could be told by looking at the inclination of the disk in the wind. The mechanical anemometer was later reinvented by the Englishman Robert Hooke, who is usually mistaken for the first inventor, in the same time that Mayans built windtowers (basically anemometers). Wolfius also re-invented the anemometer in 1709.

The Hemispherical Cup Anemometer
The hemispherical cup anemometer is consisted of of four hemispherical cups that rotate with the wind. A arrangement of wheels say how many times did the cups rotate a full revolution in a specific amount of time. the hemispherical cup anemometer is still used today. It was invented in 1846 by John Thomas Romney Robinson, an Irish researcher.

Source of information: www.about.com

Hemsipherical Cup Anemometer