|
Clockwork refers to the inner workings of either a mechanical clock (where it is also called a movement) or another device that operates in a similar fashion (such as a dial indicator). Specifically, the term refers to mechanisms utilizing a complex series of gears.〔(【引用サイトリンク】title=Clockwork - Definition of clockwork by Merriam-Webster )〕〔(【引用サイトリンク】title=Clockwork - Define Clockwork at Dictionary.com )〕 A clockwork motor is a clockwork device mechanically powered by a mainspring, a spiral torsion spring of metal ribbon. Energy is stored in the mainspring manually by ''winding it up'', turning a key attached to a ratchet which twists the mainspring tighter. Then the force of the mainspring turns the clockwork's gears, until the stored energy is used up. The adjective ''wind-up'' refers to mainspring-powered clockwork devices, which include clocks and watches, kitchen timers, music boxes, and wind-up toys. ==History== One of the earliest known examples of a clockwork mechanism is the Antikythera mechanism, a first-century BC geared analogue computer, somewhat astrolabe-like, for calculating astronomical positions and eclipses, recovered from a Greek shipwreck. There are many other accounts of clockwork devices in ancient Greece, even in its mythology, and the mechanism itself is sophisticated enough to indicate a significant history of lesser devices leading up to its creation. At some point, this level of sophistication in clockwork technology was lost or forgotten in Europe, and only returned when brought from the Islamic world after the Crusades, along with other knowledge leading to the Renaissance. Clockwork finally recovered the equivalent of pre-Roman technological levels in the 14th century.〔(The Role of Automata in the History of Technology ) There appears to be no longer any question, on the basis of recent research, that the mechanical clock and fine instrumentation evolved in a direct line without substantial change from the mechanical water clocks of the Alexandrine civilization, transmitted through Islam and Byzantium from a tradition that may have originated in China, that reached Europe in the twelfth and thirteenth centuries.〕 As in Greek mythology, there are ambitious automation claims in the legends of other cultures. For example, in Jewish legend, Solomon used his wisdom to design a throne with mechanical animals which hailed him as king when he ascended it; upon sitting down an eagle would place a crown upon his head, and a dove would bring him a Torah scroll. It's also said that when King Solomon stepped upon the throne, a mechanism was set in motion. As soon as he stepped upon the first step, a golden ox and a golden lion each stretched out one foot to support him and help him rise to the next step. On each side, the animals helped the King up until he was comfortably seated upon the throne.〔http://www.chabad.org/holidays/purim/article_cdo/aid/1345/jewish/King-Solomons-Throne.htm〕 In ancient China, a curious account of automation is found in the Lie Zi text, written in the 3rd century BC. Within it there is a description of a much earlier encounter between King Mu of Zhou (1023-957 BC) and a mechanical engineer known as Yan Shi, an 'artificer'. The latter proudly presented the king with a life-size, human-shaped figure of his mechanical handiwork (Wade-Giles spelling):
Other notable examples include Archytas's dove, mentioned by Aulus Gellius.〔''Noct. Att. L.'' 10〕 Similar Chinese accounts of flying automata are written of the 5th century BC Mohist philosopher Mozi and his contemporary Lu Ban, who made artificial wooden birds (''ma yuan'') that could successfully fly according to the ''Han Fei Zi'' and other texts.〔Needham, Volume 2, 54.〕 By the 11th century, clockwork was used for both timepieces and to track astronomical events, in Europe. The clocks did not keep time very accurately by modern standards, but the astronomical devices were carefully used to predict the positions of planets and other movement. The same timeline seems to apply in Europe, where mechanical escapements were used in clocks by that time. Up to the 15th century, clockwork was driven by water, weights, or other roundabout, relatively primitive means, but in 1430 a clock was presented to Philip the Good, Duke of Burgundy, that was driven by a spring. This became the standard technology until the mid 16th century, when Christiaan Huygens took an idea from Galileo Galilei and developed it into the first modern pendulum mechanism. The Smithsonian Institution has in its collection a clockwork monk, about high, possibly dating as early as 1560. The monk is driven by a key-wound spring and walks the path of a square, striking his chest with his right arm, while raising and lowering a small wooden cross and rosary in his left hand, turning and nodding his head, rolling his eyes, and mouthing silent obsequies. From time to time, he brings the cross to his lips and kisses it. It is believed that the monk was manufactured by Juanelo Turriano, mechanician to the Holy Roman Emperor Charles V.〔King, Elizabeth. "Clockwork Prayer: A Sixteenth-Century Mechanical Monk" ''Blackbird'' 1.1 (2002) ()〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「clockwork」の詳細全文を読む スポンサード リンク
|