A windmill is a machine which translates linear motion of wind to rotational motion by means of adjustable vanes called sails. The main use is for a grinding mill powered by the wind, reducing a solid or coarse substance into pulp or minute grains by crushing, grinding, or pressing. Other uses of windmill are Wind energy conversion systems as windpumps (US term - called Drainage windmills in UK) and wind turbines. History Vertical axis windmills The windwheel of Heron of Alexandria marks on… (More on Windmill)