|
Pinwheel Escapement
An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to the clock's timekeeping element (usually a pendulum or balance wheel) to replace the energy lost to friction during its cycle and keep the timekeeper oscillating. The escapement is driven by force from a coiled spring or a suspended weight, transmitted through the timepiece's gear train. Each swing of the pendulum or balance wheel releases a tooth of the escapement's ''escape wheel'', allowing the clock's gear train to advance or "escape" by a fixed amount. This regular periodic advancement moves the clock's hands forward at a steady rate. At the same time, the tooth gives the timekeeping element a push, before another tooth catches on the escapement's pallet, returning the escapement to its "locked" state. The sudden stopping of the escape ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anchor Escapement Animation 217x328px
An anchor is a device, normally made of metal, used to secure a vessel to the bed of a body of water to prevent the craft from drifting due to wind or current. The word derives from Latin ', which itself comes from the Greek (). Anchors can either be temporary or permanent. Permanent anchors are used in the creation of a mooring, and are rarely moved; a specialist service is normally needed to move or maintain them. Vessels carry one or more temporary anchors, which may be of different designs and weights. A sea anchor is a drag device, not in contact with the seabed, used to minimize drift of a vessel relative to the water. A drogue is a drag device used to slow or help steer a vessel running before a storm in a following or overtaking sea, or when crossing a bar in a breaking sea. Anchoring Anchors achieve holding power either by "hooking" into the seabed, or weight, or a combination of the two. The weight of the anchor chain can be more than that of the anc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pumice
Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of extremely vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular volcanic rock that differs from pumice in having larger vesicles, thicker vesicle walls, and being dark colored and denser.Jackson, J.A., J. Mehl, and K. Neuendorf (2005) ''Glossary of Geology'' American Geological Institute, Alexandria, Virginia. 800 pp. McPhie, J., M. Doyle, and R. Allen (1993) ''Volcanic Textures A guide to the interpretation of textures in volcanic rocks'' Centre for Ore Deposit and Exploration Studies, University of Tasmania, Hobart, Tasmania..198 pp. Pumice is created when super-heated, highly pressurized rock is rapidly ejected from a volcano. The unusual foamy configuration of pumice happens because of simultaneous rapid cooling and rapid depressurization. The depressurization creates bubbles by lowering the sol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spanish Language
Spanish () or Castilian () is a Romance languages, Romance language of the Indo-European languages, Indo-European language family that evolved from the Vulgar Latin spoken on the Iberian Peninsula of Europe. Today, it is a world language, global language with 483 million native speakers, mainly in the Americas and Spain, and about 558 million speakers total, including second-language speakers. Spanish is the official language of List of countries where Spanish is an official language, 20 countries, as well as one of the Official languages of the United Nations, six official languages of the United Nations. Spanish is the world's list of languages by number of native speakers, second-most spoken native language after Mandarin Chinese; the world's list of languages by total number of speakers, fourth-most spoken language overall after English language, English, Mandarin Chinese, and Hindustani language, Hindustani (Hindi-Urdu); and the world's most widely spoken Romance language ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercury (element)
Mercury is a chemical element; it has Symbol (chemistry), symbol Hg and atomic number 80. It is commonly known as quicksilver. A Heavy metal element, heavy, silvery d-block element, mercury is the only metallic element that is known to be liquid at standard temperature and pressure; the only other element that is liquid under these conditions is the halogen bromine, though metals such as caesium, gallium, and rubidium melt just above room temperature. Mercury occurs in deposits throughout the world mostly as cinnabar (mercuric sulfide). The red pigment vermilion is obtained by Mill (grinding), grinding natural cinnabar or synthetic mercuric sulfide. Exposure to mercury and mercury-containing organic compounds is toxic to the nervous system, immune system and kidneys of humans and other animals; mercury poisoning can result from exposure to water-soluble forms of mercury (such as mercuric chloride or methylmercury) either directly or through mechanisms of biomagnification. Mercu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ahmad Y
Ahmad () is an Arabic male given name common in most parts of the Muslim world. Other English spellings of the name include Ahmed. It is also used as a surname. Etymology The word derives from the root ( ḥ-m-d), from the Arabic (), from the verb (''ḥameda'', "to thank or to praise"), non-past participle (). Lexicology As an Arabic name, it has its origins in a Quranic prophecy attributed to Jesus in the Quran which most Islamic scholars concede is about Muhammad. It also shares the same roots as Mahmud, Muhammad, Hamed, and Hamad. In its transliteration, the name has one of the highest number of spelling variations in the world. Some Islamic traditions view the name Ahmad as another given name of Muhammad at birth by his mother, considered by Muslims to be the more esoteric name of Muhammad and central to understanding his nature. Over the centuries, some Islamic scholars have suggested the name's parallel is in the word 'Paraclete' from the Biblical text,"Isa" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Derek J
''Fashion Queens'' is an American fashion-based talk show that aired on Bravo (American TV network), Bravo. The series premiered on March 17, 2013, with a three-week trial run. ''Fashion Queens'' is hosted by Bevy Smith, Derek J, and Miss Lawrence. Derek J and Miss Lawrence both made several appearances on ''The Real Housewives of Atlanta''. Following the series' three-week trial run in March 2013, the first season continued on April 14, 2013. The second season premiere on November 3, 2013, which coincided with the sixth season premiere of ''The Real Housewives of Atlanta''. '' Fashion Queens'' was filmed in New York City. In April 2014, Bravo renewed ''Fashion Queens'' for a third season, which premiered on November 9, 2014. On August 8, 2015, host Bevy Smith confirmed that the series had been cancelled. Segments * The Week in Fashion: Latest fashion news * Reading Room: The hosts dissect celebrities' fashion * Right or Ratchet: The hosts decide if celebrities' outfits are Right ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Clock
An astronomical clock, horologium, or orloj is a clock with special mechanisms and dials to display astronomical information, such as the relative positions of the Sun, Moon, zodiacal constellations, and sometimes major planets. Definition The term is loosely used to refer to any clock that shows, in addition to the time of day, astronomical information. This could include the location of the Sun and Moon in the sky, the age and Lunar phases, the position of the Sun on the ecliptic and the current zodiac sign, the sidereal time, and other astronomical data such as the Moon's nodes for indicating eclipses), or a rotating star map. The term should not be confused with an ''astronomical regulator'', a high precision but otherwise ordinary pendulum clock used in observatories. Astronomical clocks usually represent the Solar System using the geocentric model. The center of the dial is often marked with a disc or sphere representing the Earth, located at the center of the S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Su Song
Su Song (, 1020–1101), courtesy name Zirong (), was a Chinese polymathic scientist and statesman who lived during the Song dynasty (960–1279). He exceled in numerous fields including but not limited to mathematics, astronomy, cartography, geography, metallurgy, mechanical engineering, hydraulic engineering, poetry, and statesmanship. Su Song was the engineer for a hydro-mechanical astronomical clock tower located in Kaifeng. It employed an early escapement mechanism.Needham, Volume 4, Part 2, 445.Needham, Volume 4, Part 2, 448.Bodde, 140.Fry, 10. The escapement mechanism of Su's clock tower was invented by the Tang dynasty Buddhist monk Yi Xing and government official Liang Lingzan in 725 AD to operate a water-powered armillary sphere, however Su's armillary sphere was the first to utilize a mechanical clock drive.Needham, Volume 3, 351. Su's clock tower also featured the oldest known endless power-transmitting chain drive, called the ''tian ti'' (), or "celestial la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zhang Sixun
Zhang Sixun (, fl. 10th century) was a Chinese astronomer and mechanical engineer from Bazhong, Sichuan during the early Song dynasty (960–1279 AD).Liu, 577. He is credited with creating an armillary sphere for his astronomical clock tower that employed the use of liquid mercury (dripped periodically from a clepsydra clock).Needham, Volume 4, 469-471. The liquid mercury filled scoops of the waterwheel would rotate and thus provide the effect of an escapement mechanism in clockworks and allow the astronomical armillary sphere to rotate as needed. Life and works According to the '' History of Song'', Zhang Sixun passed the state examinations in astronomy and mathematics, for this he was appointed to service in the national astronomical observatory (Si Tian Jian), within two years of taking office he had finished construction of an armillary sphere either in 977 or 979. As a result, he was rewarded as assistant to the Astronomical Bureau. Zhang Sixun, although innovative, built ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Song Dynasty
The Song dynasty ( ) was an Dynasties of China, imperial dynasty of China that ruled from 960 to 1279. The dynasty was founded by Emperor Taizu of Song, who usurped the throne of the Later Zhou dynasty and went on to conquer the rest of the Five Dynasties and Ten Kingdoms period#Ten Kingdoms, Ten Kingdoms, ending the Five Dynasties and Ten Kingdoms period. The Song frequently came into conflict with the contemporaneous Liao dynasty, Liao, Western Xia and Jin dynasty (1115–1234), Jin dynasties in northern China. After retreating to southern China following attacks by the Jin dynasty, the Song was eventually conquered by the Mongol-led Yuan dynasty. The History of the Song dynasty, dynasty's history is divided into two periods: during the Northern Song (; 960–1127), the capital was in the northern city of Bianjing (now Kaifeng) and the dynasty controlled most of what is now East China. The #Southern Song, 1127–1279, Southern Song (; 1127–1279) comprise the period following ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drive Wheel
A drive wheel is a wheel of a motor vehicle that transmits force, transforming torque into tractive force from the tires to the road, causing the vehicle to move. The powertrain delivers enough torque to the wheel to overcome stationary forces, resulting in the vehicle moving forwards or backwards. A two-wheel drive vehicle has two driven wheels, typically both at the front or back, while a four-wheel drive has four. A steering wheel is a wheel that turns to change the direction of a vehicle. A trailer wheel is one that is neither a drive wheel, nor a steer wheel. Front-wheel drive vehicles typically have the rear wheels as trailer wheels. Drive wheel configurations Front-wheel drive Front-wheel drive (FWD) vehicles' engines drive the front wheels. Using the front wheels for delivery of power as well as steering allows the driving force to act in the same direction as the wheel is pointing. This layout is commonly used in modern passenger cars. A rare example of front ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Armillary Sphere
An armillary sphere (variations are known as spherical astrolabe, armilla, or armil) is a model of objects in the sky (on the celestial sphere), consisting of a spherical framework of rings, centered on Earth or the Sun, that represent lines of celestial longitude and latitude and other astronomically important features, such as the ecliptic. As such, it differs from a celestial globe, which is a smooth sphere whose principal purpose is to map the constellations. It was invented separately, in ancient China possibly as early as the 4th century BC and ancient Greece during the 3rd century BC, with later uses in the Islamic world and Medieval Europe. With the Earth as center, an armillary sphere is known as '' Ptolemaic''. With the Sun as center, it is known as '' Copernican''. The flag of Portugal features an armillary sphere. The armillary sphere is also featured in Portuguese heraldry, associated with the Portuguese discoveries during the Age of Exploration. Manuel I of Po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
