Editing Windmill (section)

== Vertical windmills ==

[[File:Windmill in Finland in 1987 (1).jpg|thumb|A windmill in [[Kotka]], Finland in May 1987]]

The horizontal-axis or vertical windmill (so called due to the plane of the movement of its sails) is a development of the 12th century, first used in northwestern Europe, in the triangle of northern [[France]], [[eastern England]] and [[Flanders]].<ref>{{cite book|title=Civilization and Capitalism, 15th–18th Century, Vol. I: The Structure of Everyday Life|page=[https://archive.org/details/structuresofever01brau/page/358 358]|author-link=Fernand Braudel|first1=Fernand|last1=Braudel|publisher=University of California Press|year=1992|isbn=9780520081147|url=https://archive.org/details/structuresofever01brau/page/358}}</ref>
It is unclear whether the vertical windmill was influenced by the introduction of the horizontal windmill from Persia-Middle East to Southern Europe in the preceding century.<ref>{{citation|title=Shadows in the Desert|first=Kaveh|last=Farrokh|publisher=Osprey Publishing|year=2007|isbn=978-1-84603-108-3|page=280}}
Lynn White Jr. ''Medieval technology and social change'' (Oxford, 1962) p. 86 & p. 161–162.

{{citation|title=History of, and Recent Progress in, Wind-Energy Utilization|author=Bent Sorensen|journal=[[Annual Review of Energy and the Environment]]|volume=20|issue=1|pages=387–424|date=November 1995|doi=10.1146/annurev.eg.20.110195.002131|doi-access=free|author-link=Bent Sørensen (physicist)}}

</ref><ref name=Lucas>{{citation |first=Adam |last=Lucas |year=2006 |title=Wind, Water, Work: Ancient and Medieval Milling Technology |publisher=Brill Publishers |isbn=90-04-14649-0 |pages=106–7 }}</ref>

The earliest certain reference to a windmill in [[Northern Europe]] (assumed to have been of the vertical type) dates from 1185, in the former village of Weedley in Yorkshire which was located at the southern tip of the [[The Wolds|Wold]] overlooking the [[Humber Estuary]].<ref>{{cite book|last=Laurence Turner|first=Roy Gregory|title=Windmills of Yorkshire|year=2009|publisher=Stenlake Publishing|location=Catrine, East Ayrshire|isbn=9781840334753|page=2|url=http://www.stenlake.co.uk/books/view_book.php?ref=687|access-date=2013-02-13|archive-date=2019-11-01|archive-url=https://web.archive.org/web/20191101221626/http://stenlake.co.uk/books/view_book.php?ref=687|url-status=dead}}</ref> Several earlier, but less certainly dated, 12th-century European sources referring to windmills have also been found.<ref name="Price2005">Lynn White Jr., ''Medieval technology and social change'' (Oxford, 1962) p. 87.</ref>
These earliest mills were used to [[gristmill|grind cereals]].<ref name="Sathyajith2006">{{Cite book|last=Sathyajith|first=Mathew|title=Wind Energy: Fundamentals, Resource Analysis and Economics|publisher=[[Springer Science+Business Media|Springer Berlin Heidelberg]]|year=2006|isbn=978-3-540-30905-5|pages=1–9}}</ref>

=== Post mill ===
{{main|Post mill}}

The evidence at present is that the earliest type of European windmill was the post mill, so named because of the large upright post on which the mill's main structure (the "body" or "buck") is balanced. By mounting the body this way, the mill can rotate to face the wind direction; an essential requirement for windmills to operate economically in north-western Europe, where wind directions are variable. The body contains all the milling machinery. The first post mills were of the sunken type, where the post was buried in an earth mound to support it. Later, a wooden support was developed called the [[trestle (mill)|trestle]]. This was often covered over or surrounded by a roundhouse to protect the trestle from the weather and to provide storage space. This type of windmill was the most common in Europe until the 19th century when more powerful [[tower mill|tower]] and [[smock mill]]s replaced them.<ref>Hills, Power from wind: a history of windmill technology, (1996), 65</ref>

==== Hollow-post mill ====

In a hollow-post mill, the post on which the body is mounted is hollowed out, to accommodate the drive shaft.<ref>{{cite book
 | title = Windmills
 | author = Martin Watts
 | publisher = Osprey Publishing
 | year = 2006
 | isbn = 978-0-7478-0653-0
 | page = 55
 | url = https://books.google.com/books?id=PJ7-M8lFo_UC&pg=PA55
 }}{{Dead link|date=April 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>
This makes it possible to drive machinery below or outside the body while still being able to rotate the body into the wind. Hollow-post mills driving scoop wheels were used in the Netherlands to drain wetlands since the early 15th century onwards.<ref name="hollow-postMills">{{Britannica URL | url=https://www.britannica.com/technology/energy-conversion/Windmills | title=Windmills | author= Rex Wailes, Fred Landis }}</ref>

=== Tower mill ===
{{main|Tower mill}}

[[File:Açores 2010-07-21 (5123960230) (cropped).jpg|thumb|upright|left|Windmill in the [[Azores]] islands, Portugal.]]

[[File:Molinos de Consuegra.jpg|right|thumb|Tower mills in [[Consuegra]], Spain]]

By the end of the 13th century, the masonry tower mill, on which only the cap is rotated rather than the whole body of the mill, had been introduced. The spread of tower mills came with a growing economy that called for larger and more stable sources of power, though they were more expensive to build. In contrast to the post mill, only the cap of the tower mill needs to be turned into the wind, so the main structure can be made much taller, allowing the sails to be made longer, which enables them to provide useful work even in low winds. The cap can be turned into the wind either by winches or gearing inside the cap or from a winch on the tail pole outside the mill. A method of keeping the cap and sails into the wind automatically is by using a [[Windmill fantail|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.{{citation needed|date = February 2016}}

=== Smock mill ===
{{main|Smock mill}}

[[File:Greetsieler Zwillingsmühlen 2010.jpg|thumb|Two [[smock mill]]s with a stage in [[Greetsiel]], Germany]]

The smock mill is a later development of the tower mill, where the masonry tower is replaced by a wooden framework, called the "smock", which is thatched, boarded, or covered by other materials, such as [[roofing slate|slate]], [[sheet metal]], or [[tar paper]]. The smock is commonly of octagonal plan, though there are examples with different numbers of sides.

Smock windmills were introduced by the Dutch in the 17th century to overcome the limitations of tower windmills, which were expensive to build and could not be erected on wet surfaces. The lower half of the smock windmill was made of brick, while the upper half was made of wood, with a sloping tower shape that added structural strength to the design. This made them lightweight and able to be erected on unstable ground.

The smock windmill design included a small turbine in the back that helped the main mill to face the direction of the wind.<ref>{{Cite web |date=2022-09-27 |title=History Of Windmills: Part 2 - Windmills Tech |work=Windmills Tech |url=https://windmillstech.com/history-of-windmills-part-2/ |access-date=2023-03-29 |language=en-US}}</ref>