Millstone 167364 222115500 2008-06-27T17:06:34Z Timcrall 1782995 {{Otheruses}} [[Image:WatermillWealdandDownland.JPG|thumb|right|100px|The interior of a functional water mill]] [[Image:Millstone_Anatomy.jpg|thumb|left|100px|The basic anatomy of a millstone. Note that this is a runner stone. A bedstone would not have the "Spanish Cross" into which the supporting millrynd fits.]] [[Image:StamfordCTMILLSTONECoveIslPark09182007.JPG|thumb|100px|left|Millstone with furrows]] [[Image:Greenwich CT millstone.JPG|thumb|100px|left|Another millstone with furrows]] [[Image:Millstones.jpg|thumb|100px|right|Grinding [[maize]] in a working [[watermill]], Thethi, northern Albania.]] [[Image:An Old Man Dressing A Millstone.jpg|thumb|right|100px|Making furrows on a millstone]] '''Millstones''' or '''mill stones''' are used in [[windmill]]s and [[watermill]]s, including [[tide mill]]s, for grinding [[wheat]] or other grains. The type of stone most suitable for making millstones is a siliceous rock called '''buhrstone''' (or burrstone), an open-textured, porous but tough, fine-grained [[sandstone]], or a silicified, fossiliferous [[limestone]]. In some sandstones, the cement is calcareous.<ref> {{cite book | last = Bucksch | first = Herbert | authorlink = | title = Dictionary Geotechnical Engineering, Vol. 1 | publisher = Springer-Verlag | date = 1997 | location = | pages = pp. 80 | url = | doi = | id = | isbn = 978-3540581642 }} </ref> Millstones used in [[UK|Britain]] were commonly of two types: *[[Derbyshire]] Peak stones of grey [[millstone grit]], cut from one piece, used for grinding [[barley]]; imitation Derbyshire Peak stones are used as decorative signposts at the boundaries of the [[Peak District National Park]]. Derbyshire Peak stones wear quickly and are typically used to grind animal feed since they leave stone powder in the flour, making it undesirable for human consumption. *French burr stones, used for finer grinding. Not cut from one piece, but built up from sections of quartz, cemented together with [[plaster]], and bound with iron bands. French Burr comes from the Marne Valley in northern France. ==Patterning== The surface of a millstone is divided by deep grooves called ''furrows'' into separate flat areas called ''lands''. Spreading away from the furrows are smaller grooves called ''feathering'' or ''cracking''. The furrows and lands are arranged in repeating patterns called harps. A typical millstone will have six, eight or ten harps. The grooves provide a cutting edge and help to channel the ground flour out from the stones. When in regular use stones need to be ''dressed'' periodically, that is, re-cut to keep the cutting surfaces sharp. Millstones come in pairs. The base or bedstone is stationary. Above the bedstone is the turning [[runner stone]] which actually does the grinding. The runner stone is supported by a cross-shaped metal mill [[rynd]] fixed to a "mace head" topping the main shaft or spindle leading to the driving mechanism of the mill (either water or wind powered). The pattern of harps is repeated on the face of each stone, when they are laid face to face the patterns mesh in a kind of "scissoring" motion creating the cutting or grinding function of the stones. Millstones need to be evenly balanced, and achieving the correct separation of the stones is crucial to producing good quality flour. The experienced miller will be able to adjust their separation very accurately. ==Idiom== A Millstone around one's neck is also a phrase used constituting a metaphor meaning a burden or large inconvenience one has to endure. ==Ancient history== [[Neolithic]] man used millstone functionality to process [[grain]]s, nuts and other vegetable food products for consumption. These implements are often called '''grinding stones'''. They used either saddlestones and rotary [[quern]]s turned by hand. Such devices were also used to grind pigments and metal ores prior to [[smelting]]. ==See also== *[[Bedrock mortar]] *[[Edge mill]] *[[Querns]] == References == <references /> == External links == * [http://www.angelfire.com/journal/millrestoration/article.html Millstone Dressing Tools] * [http://meuliere.ish-lyon.cnrs.fr/index.html European millstone quarries : a data base] <nowiki>[sic]</nowiki> [[Category:Watermills]] [[Category:Grinding and lapping]] [[an:Ruello (molín)]] [[de:M%C3%BChlstein]] [[es:muela de molino]] [[fr:meule]] [[nl:Molensteen]] [[pl:Żarna]] [[pt:Mó]] [[he:ריחיים]]