Charles Brush's windmill of 1888, used for generating electricity. Wind power has been used as long as humans have put sails into the wind. For more than two millennia wind-powered machines have ground grain and pumped water. Wind power was widely available and not confined to the banks of fast-flowing streams, or later, requiring sources of fuel.
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The Old Mill is 50 feet high, with four vanes 30 feet in length. The interior mechanism has a driving wheel at the top, connected to the blades. It has a fixed body containing machinery and a cap that turns to face the sails into the wind. Projecting from the driving wheel are wooden cogs that intersect with another set of wooden teeth in a vertical shaft, which in turn revolves the upper grindstone.
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Brill windmill, a 17th century post mill in Buckinghamshire The post mill is the earliest type of European windmill. Its defining feature is that the whole body of the mill that houses the machinery is mounted on a single vertical post, around which it can be turned to bring the sails into the wind. The earliest post mills in England are thought to have been built in the 12th century. The earliest working post mill in England still used today is to be found at Outwood, Surrey.
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Thrigby Post Windmill was built in about 1790 by Robert Woolmer who was the owner of close-by Thrigby Hall. The mill was constructed to grind wheat produced on the Thrigby estate. The post mill has a two-foot-square oak main post that rises vertically through the round house roof and carries the weatherboard clad body or "buck" of the mill, which contains all the machinery. The post mill was able to be turned on the centre post to bring the sails into the wind.
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A method of keeping the cap and sails into the wind automatically is by using a fantail, a small windmill mounted at right angles to the sails, at the rear of the windmill. These are also fitted to tail poles of post mills and are common in Great Britain and English-speaking countries of the former British Empire, Denmark, and Germany but rare in other places. Around some parts of the Mediterranean Sea, tower mills with fixed caps were built because the wind's direction varied little most of the time.
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The windmill was built in 1809 and was added to the National Historic Register in 1978. See also: Still retaining its internal machinery, this windmill is unusual for Long Island, in that it has a fantail to turn the sails into the wind. The Hayground Windmill, in 1984, was one of eleven surviving 18th and early 19th century wind-powered gristmills on Long Island It was also the busiest, turning out more bushels than nearby windmills. Open seasonally, it operated 4 months of the year, turning out in 1870 800 bushels of wheat, 800 of oats and 400 of corn.
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It has been owned by Cambridge Past, Present and Future (formerly known as the Cambridge Preservation Society) since 1932. The body of the mill, the 'buck', contains all the machinery and is balanced on a 'post' supported by an oak trestle, which supports the entire weight of the mill, and bolted to four brick piers. Four sails and millstones in front of the post balance the double steps (which act as a thrust support when down) and the tail pole behind (which is used to turn the sails into the wind). It is called a 'Post Mill' because of its supporting post.
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Note: Italicized terms are defined in the mill machinery article. Stembridge Mill is a tower mill, a type of windmill which consists of a brick or stone tower, on top of which sits a roof or cap which can be turned to bring the sails into the wind. The advantage of the tower mill over the earlier post mill is that it is not necessary to turn the whole mill ("body", "buck") with all its machinery into the wind; this allows more space for the machinery and storage. In the earliest tower mills the cap was turned into the wind with a long tail- pole which stretched to the ground at the back of the mill.
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