Recurve bow
In archery, a recurve bow is one of the main shapes a bow can take, with limbs that curve away from the archer when unstrung. A recurve bow stores more energy and delivers energy more efficiently than the equivalent straight-limbed bow, giving a greater amount of energy and speed to the arrow. A recurve will permit a shorter bow than the simple straight limb bow for given arrow energy, and this form was often preferred by archers in environments where long weapons could be cumbersome, such as in brush and forest terrain, or while on horseback. Recurved  limbs also put greater stress on the materials used to make the bow, and they may make more noise with the shot. Extreme recurves make the bow unstable when being strung. An unstrung recurve bow can have a confusing shape and many Native American weapons, when separated from their original owners and cultures, were incorrectly strung backwards and destroyed when attempts were made to shoot them. A test performed by Hepworth and Smith in 2002 of a preparation manufactured from bovine tendon and pearl glue and used in traditional Asiatic recurve bows showed that the composite "was found to absorb  18 MJ/m3 of energy to failure, comparable to carbon fibre composites, spring steel and butyl rubber." Historical use. Recurve bows made out of composite materials were used by, among other groups, the Persians, Parthians, Sarmatians, Scythians, Alans, Dacians, Cumans, Hyksos, Magyars, Huns, Bulgars, Greeks, Turks, Mongols, Koreans and Chinese. The recurve bow spread to Egypt and much of Asia in the second millennium BC. Perhaps the most ancient written record of the use of recurved bows is found Psalm 78:57 ("They were turned aside like a deceitful bow" KJV), which is dated by most scholars to the eighth century  BC. 19th century Bible scholar Adam Clarke pointed out that "If a person, who is unskillful or weak, attempt to recurve and string one of these bows, if he take not great heed, it will spring back, and regain its quiescent position; and, perhaps, break his arm. And sometimes I have known it, when bent, to start aside, - regain its quiescent position, to my no small danger... this is precisely the kind of bow mentioned by Homer, Odyssey xxi, which none of Penelope's suitors could bend, called καμπυλα τοξα ['] in the state of rest; but τοξον παλιντονον ['], the recurved  bow when prepared for use." The standard weapon of Roman imperial archers was a composite recurve, and the stiffening laths (also called siyah in Arabic/Asian bows and "szarv" (horns) in Hungarian bows) used to form the actual recurved ends have been found on Roman sites throughout the Empire, as far north as Bar Hill Fort on the Antonine Wall in Scotland. The Turkish archer used recurve bows, which were manufactured from laminates of wood glued with animal tissue like horn and sinew, to great destructive effect during the reign of the Ottomans. Its use by the Mongol horde allowed  massed individuals on horseback to raid from the Pacific to central Europe, thanks to the relatively short length of recurve bows, with which archers could maneuver while seated on their mount. The rise of the Mongols can be partially attributed to the good range and power of the bows of Genghis Khan's hordes. These bows were made of a bamboo core, with horn on the belly (facing towards the archer) and sinew on the back, bound together with animal glue. During the Middle Ages composite recurve bows were used in the drier European countries because the laminate glue would  not moisten and thereby lose its adhesive power; the all-wooden straight longbow was the normal form in wetter areas. Recurve bows depicted in the British Isles (see illustrations in "The Great War Bow") may have been composite weapons, or wooden bows with ends recurved by heat and force, or simply artistic licence. The bows of many Indigenous North American were recurved, especially West Coast Indian bows. Recurve bows went out of widespread use in warfare with the greater availability of effective firearms in various nations at the end of the 19th century. Modern use. Self bows, composite bows, and  laminated bows using the recurve form are still made and used by bowyers, amateurs, and professional archers. The unqualified phrase "recurve bow" or just "a recurve" in modern archery circles usually refers to a typical modern recurve bow, as used by archers in the Olympics and many other competitive events. It employs advanced technologies and materials. The limbs are usually made from multiple layers of fibreglass, carbon and/or wood on a core of carbon foam or wood. The riser (the centre section of the bow) is generally separate and is constructed from wood, carbon, aluminium alloy or magnesium alloy. The  term 'riser' is used because, in a one-piece bow, the centre section rises from the limbs in a taper to spread the stress. Several manufacturers produce risers made of carbon fibre (with metal fittings) or aluminium with carbon fibre. Risers for beginners are usually made of wood or plastic. The synthetic materials allow economic, predictable manufacture for consistent performance. The greater mass of a modern bow is in itself an aid to stability, and therefore to accuracy. However, accuracy is also related to a bow's draw weight, as well as how well an archer handles it. It is  therefore imperative for an archer, particularly a beginner, never to overestimate their capabilities, and to choose a draw weight that is appropriate for their body build and level of experience. The modern recurve is the only form of bow permitted in the Olympics (though the compound bow is permitted in some categories at the Paralympic Games) and is the most widely used by European and Asian sporting archers. There is a movement to have future Olympic Games include the compound bow in competition, due to its framework technology being more available and widespread, which would make competitive stat-tracking and  testing easier. The modern Olympic-style recurve is a development of the American flatbow, with rectangular-section limbs that taper towards the limb tips. Most recurves today are "take-down" bows; that is, the limbs can be detached from the riser, for ease of transportation and storage as well as interchangeability. Older recurves and some modern hunting recurves are one-piece bows. Hunters often prefer one-piece bows over take-down bows, because the limb pockets on take-down bows can make unwanted noise while drawing. Other equipment. Archers often have many other pieces of equipment attached to their recurve  bows, such as: