A Brief History Of Windmills_46091

The first windmills were developed to automate the tasks of grain grinding and water-pumping. It was felt that if these tasks could be automated, it would free laborers for more important work. The heavy grinding stone was attached to a vertical shaft running drown from the turning sails. Generally, the mill machinery and gears were enclosed in a building designed to block the incoming wind. This kept the worker dry and didn抰 blow the grain around. The history of wind power and windmill use is very interesting. It抯 fair to say that there has been an evolution from the use of simple, light devices to heavy, material-intensive drag devices to the increased use of light, material-efficient aerodynamic lift devices in the modern era. Don抰 think, however, that aerodynamic lift is a modern concept that was unknown to people in ancient times. The earliest known use of wind power, of course, is the sail boat, and this technology had an important impact on the later development of sail-type windmills. Ancient sailors understood lift and how it could steer and move a large ship卼hey used this knowledge every day. Vertical-axis windmills were also used in China, which is often claimed as their birthplace. While the belief that the windmill was invented in China more than 2000 years ago is widespread and may be accurate, the earliest actual documentation of a Chinese windmill was in 1219 A.D. by the Chinese statesman Yehlu Chhu-Tshai. Here also, the primary applications were apparently grain grinding and water pumping. The first windmills to appear in Western Europe were of the horizontal-axis configuration. The reason for the sudden evolution from the vertical-axis design is unknown, but the fact that European water wheels also had a horizontal-axis configuration -- and apparently served as the technological model for the early windmills -- may provide an answer. In the late 14th century the Dutch began to improve and enhance the tower mill design, which had appeared somewhat earlier along the Mediterranean Sea. To this day the Dutch windmills have remained as some of the most beautiful around. Basically they attached the standard post mill to the top of a multi-story tower, with separate floors devoted to grinding grain, removing chaff, storing grain, and living quarters for the windsmith and his family. Both the post mill and the later tower mill design had to be pointed into the wind manually, by pushing a large lever at the back of the mill. Optimizing windmill energy and power output and protecting the mill from damage by furling the rotor sails during storms were among the windsmith's primary jobs. Hard work but definitely exciting. Imagine the thrill of predicting inclement weather and then bringing in those giant, magnificent sails. It must have been almost like furling and unfurling sails on a seagoing ship. The process of perfecting the windmill sail, making incremental improvements in efficiency, took nearly 5 centuries. Even today we are still making improvements in design and use of the beautiful, majestic creations.