Êtes-vous un étudiant de l'EPFL à la recherche d'un projet de semestre?
Travaillez avec nous sur des projets en science des données et en visualisation, et déployez votre projet sous forme d'application sur Graph Search.
Concept
Quern-stone
Résumé
Quern-stones are stone tools for hand-grinding a wide variety of materials. They are used in pairs. The lower stationary stone of early examples is called a saddle quern, while the upper mobile stone is called a muller, rubber or handstone. The upper stone was moved in a back-and-forth motion across the saddle quern. Later querns are known as rotary querns. The central hole of a rotary quern is called the eye, and a dish in the upper surface is known as the hopper. A handle slot contained a handle which enabled the rotary quern to be rotated. They were first used in the Neolithic era to grind cereals into flour.
An old Gaelic proverb is "The quern performs best when the grindstone has been pitted."
The upper stones were usually concave while the lower ones were convex. Quern-stones are frequently identifiable by their grooved working surfaces which enabled the movement of flour. Sometimes a millrind was present as a piece of wood (or other material), which allowed the cereal etc. to be added but still acted as a centering device. The upper stone sometimes had a cup-shaped area around the hopper hole with a raised edge. Most handstones have a handle hole on the upper surface, but one class of quern-stones have a slot handle which indicates that a piece of wood was placed horizontally and protruded out from the edge so that the operator could turn the stone by standing and using a rod vertically. One class of upper quern-stones has from two to three sockets for the rod used to turn them and this is thought to reflect the need to reduce wear and tear by having alternative points of contact when in active use.
Quern-stones have been used by numerous civilizations throughout the world to grind materials, the most important of which was usually grain to make flour for bread-making. They were generally replaced by millstones once mechanised forms of milling appeared, particularly the water mill and the windmill, although animals were also used to operate the millstones.
Source officielle
À propos de ce résultat
Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.