Wind energy has been employed by humans as early as the fourth-century B.C.E. In this era, Egyptians used the wind to propel sailboats on the Nile River. Shortly afterward, sailing vessels began to appear in the Mediterranean Sea. Windmills are machines that convert this energy into mechanical power. Windmills have been used to pump water and mill grain since ancient times. Windmills work as wind flows over sails or blades which protrude over a shaft. This cylindrically-shaped component... więcej

Salem Press Encyclopedia of Science, 2023. 3p.