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Pages in category "Astronomical clocks"
The following 36 pages are in this category, out of 36 total. This list may not reflect recent changes (learn more).
|Wikimedia Commons has media related to Astronomical clocks.|
The following 36 pages are in this category, out of 36 total. This list may not reflect recent changes (learn more).
1. Astronomical clock – The term is loosely used to refer to any clock that shows, in addition to the time of day, astronomical information. The term should not be confused with astronomical regulator, a high precision, Astronomical clocks usually represent the solar system using the geocentric model. The center of the dial is marked with a disc or sphere representing the earth. The sun is represented by a golden sphere, shown rotating around the earth once a day around a 24-hour analog dial. This view accords both with daily experience and with the world view of pre-Copernican Europe. Research in 2011 and 2012 led a group of researchers to posit that European astronomical clocks are descended from the technology of the Antikythera mechanism. In the 11th century, the Song Dynasty Chinese horologist, mechanical engineer, Su Song is noted for having incorporated an escapement mechanism and earliest known endless power-transmitting chain drive for his clock-tower and armillary sphere to function. They no longer exist, but detailed descriptions of their design and construction survive, wallingfords clock may have shown the sun, moon, stars and planets, and had, in addition, a wheel of fortune and an indicator of the state of the tide at London Bridge. De Dondis clock was a construction with 107 moving parts, showing the positions of the sun, moon. Both these clocks, and others like them, were less accurate than their designers would have wished. The gear ratios may have been calculated, but their manufacture was somewhat beyond the mechanical abilities of the time. Astronomical clocks were built as demonstration or exhibition pieces, to impress as much as to educate or inform, the challenge of building these masterpieces meant that clockmakers would continue to produce them, to demonstrate their technical skill and their patrons wealth. The philosophical message of an ordered, heavenly-ordained universe, which accorded with the Gothic era view of the world, the Science Museum has a scale model of the Cosmic Engine, which Su Sung, a Chinese polymath, designed and constructed in China in 1092. A full-sized working replica of Su Sungs clock exists in the Republic of China s National Museum of Natural Science and this full-scale, fully functional replica, approximately 12 meters in height, was constructed from Su Sungs original descriptions and mechanical drawings. The most sophisticated water-powered astronomical clock was Al-Jazaris castle clock, considered to be an example of a programmable analog computer. It was a device that was about 33 meters high. The Strasbourg Cathedral has housed three different astronomical clocks since the 14th century, the first clock was built between 1352 and 1354 and stopped working sometime at the beginning of the 16th century. A second clock was built by Herlin, Conrad Dasypodius, the Habrecht brothers
2. Strasbourg astronomical clock – The Strasbourg astronomical clock is located in the Cathédrale Notre-Dame of Strasbourg, Alsace, France. It is the clock on that spot and dates from the time of the first French possession of the city. The first clock had been built in the 14th century, the second in the 16th century, the current, third clock dates from 1843. Its main features, besides the automata, are a perpetual calendar, an orrery, a display of the position of the Sun and the Moon. The main attraction is the procession of the 18 inch high figures of Christ, the first astronomical clock of Strasbourg cathedral was erected between 1352–1354, against the south transept. The name of its maker is not known and this clock was known as the Three Kings clock and had several automata. This bird, a symbol of Christs passion, was made of iron, copper, at noon it flapped its wings and spread out its feathers. It also opened its beak, put out its tongue, and by means of a bellows, in the top compartment at noon, to the sound of a small carillon, the Three Kings bowed before the figure of The Virgin Mary and the Christ Child. The clock most certainly had an astrolabe dial and a calendar dial and it was standing on the wall opposite the current clock, and a staircase led to its various levels. Supports for former balconies can still be today, and suggest that the height of the clock was about 18 m. At the base a painted figure of a man showed the relationship between the signs of the zodiac and parts of the human body. There is also a big circle engraved in the wall, and it was added at a later stage, for some unclarified reason. The entire structure was dismantled in 1572–4 when the second and even more ambitious clock was mounted on the wall of the south transept. The first clock stopped working and a new one was started in the 16th century and it was designed by the mathematician Christian Herlin. Construction was resumed in 1571 by Conrad Dasypodius, a pupil of, Dasypodius enrolled the Swiss clockmakers Isaac Habrecht and Josia Habrecht, as well as the astronomer and musician David Wolckenstein, and Swiss artists Tobias Stimmer and his brother Josias. The clock was completed in 1574 and this clock was remarkable both for its complexity as an astronomical device and for the range and richness of its decorations and accessories. At the base of a clock there was an 86 cm diameter celestial globe, the globe was connected to the clock movement, and set for the meridian of Strasbourg. Most of the works are preserved in the Museum of Decorative Arts
3. Zytglogge – The Zytglogge is a landmark medieval tower in Bern, Switzerland. Built in the early 13th century, it has served the city as guard tower, prison, clock tower, centre of urban life and it is a heritage site of national significance, and part of the Old City of Bern, a UNESCO World Cultural Heritage site. When it was built around 1218–20, the Zytglogge served as the tower of Berns western fortifications. These were erected after the citys first westward expansion following its de facto independence from the Empire, at that time, the Zytglogge was a squat building of only 16 metres in height. At this time, the Zytglogge also received its first slanted roof, in the great fire of 1405, the tower burnt out completely. It suffered severe damage that required thorough repairs, which were not complete until after the last restoration in 1983. The prison cells were abandoned and a clock was first installed above the gate in the early 15th century, probably including an astronomical clock. This clock, together with the bell cast in 1405, gave the Zytglogge its name. In the late 15th century, the Zytglogge and the other Bernese gate towers were extended and decorated after the Burgundian Romantic fashion, the Zytglogge received a new lantern, four decorative corner towerlets, heraldic decorations and probably its stair tower. The astronomical clock was extended to its current state, in 1527–30, the clockwork was completely rebuilt by Kaspar Brunner, and the gateway was overarched to provide a secure foundation for the heavy machinery. The Zytglogges exterior was repainted by Gotthard Ringgli and Kaspar Haldenstein in 1607–10, the corner towerlets were removed again some time before 1603. Both façades were again repainted in the Rococo style by Rudolf von Steiger in 1890, in 1981–83, the Zytglogge was thoroughly renovated again and generally restored to its 1770 appearance. In the advent season and from Easter until the end of October, the Bernese German Zytglogge translates to Zeitglocke in Standard German and to time bell in English, Glocke means bell in German, as in the related term glockenspiel. A time bell was one of the earliest public timekeeping devices, the name of Zytglogge was first recorded in 1413. Previously, the tower was referred to as the kebie and after its post-1405 reconstruction, the Zytglogge has an overall height of 54.5 metres, and a height of 24 metres up to the roof-edge. Its rectangular floor plan measures 11.2 by 10.75 metres, the wall strengths vary widely, ranging from 260 centimetres in the west, where the tower formed part of the city walls, to 65 centimetres in the east. The outward appearance of the Zytglogge is determined by the 1770 renovation, only the late Gothic cornice below the roof and the stair tower are visible artifacts of the towers earlier history. The main body of the tower is divided into the plinth, whose exterior is made of alpine limestone
4. Prague astronomical clock – The Prague astronomical clock, or Prague orloj, is a medieval astronomical clock located in Prague, the capital of the Czech Republic. The clock was first installed in 1410, making it the third-oldest astronomical clock in the world, the Orloj is mounted on the southern wall of Old Town Hall in the Old Town Square. According to local legend, the city will suffer if the clock is neglected and its operation is placed in jeopardy. According to the legend, the hope was represented by a boy born on New Years night. The first recorded mention of the clock was on 9 October 1410, later, presumably around 1490, the calendar dial was added and the clock facade was decorated with gothic sculptures. Formerly, it was believed that the Orloj was constructed in 1490 by clockmaster Jan Růže, in 1552 it was repaired by Jan Taborský, master clockmaker of Klokotská Hora, who also wrote a report of the clock where he mentioned Hanuš as the maker of this clock. This mistake, corrected by Zdeněk Horský, was due to an interpretation of records from the period. The mistaken assumption that Hanuš was the maker is probably connected with his reconstruction of the Old Town Hall in the years 1470–1473, the clock stopped working many times in the centuries after 1552, and was repaired many times. In 1629 or 1659 wooden statues were added, and figures of the Apostles were added after a repair in 1787–1791. During the next major repair in the years 1865–1866 the golden figure of a rooster was added. The hall and nearby buildings burned along with the sculptures on the clock. After significant effort, the machinery was repaired, the wooden Apostles restored by Vojtěch Sucharda, the Orloj was last renovated in autumn 2005, when the statues and the lower calendar ring were restored. The wooden statues were covered with a net to keep pigeons away, on 9 October 2010, the Orlojs 600th anniversary was celebrated with a light show on the face of the clock tower. Two projectors were used to project several animated videos on the clock, the videos showed it being built, torn down, rebuilt, and peeled away to show its internal mechanisms and the famous animated figures, as well as various events in the clocks history. The video interacted with the architecture, such as rain rolling off the arch. On its 605th anniversary,9 October 2015, the Orloj appeared on the Google home page as a Google Doodle, the astronomical dial is a form of mechanical astrolabe, a device used in medieval astronomy. Alternatively, one may consider the Orloj to be a primitive planetarium, the background represents the Earth and the local view of the sky. The blue circle directly in the centre represents the Earth, the red and black areas indicate portions of the sky below the horizon
5. Torrazzo of Cremona – The Torrazzo is the bell tower of the Cathedral of Cremona, Lombardy, in northern Italy. However the Torrazzo is older than the Landshut tower and the Bruges tower, according to popular tradition, construction on the tower began in 754. The seven bells are tuned in the scale of A major, archaeological excavations made in the 1980s have discovered the presence of underlying structures which are supposed to be the remains of a more ancient churchyard, or even previous Roman buildings. In the Torrazzos fourth storey resides the largest astronomical clock in the world, the mechanism was built by Francesco and Giovan Battista Divizioli between 1583 and 1588. Galeati, G. Il Torrazzo di Cremona, Il Torrazzo ed il suo restauro. Loffi, F. Il Torrazzo di Cremona, ghidotti, P. Il Torrazzo di Cremona. Archeologia e storia di un monumento medievale
6. St Mark's Clock – For the building containing the clock see St Marks Clocktower St Marks Clock is the clock housed in the Clocktower on the Piazza San Marco in Venice, Italy, adjoining the Procuratie Vecchie. The clock has had an eventful history, and been the subject of many restorations. After restorations in 1551 by Giuseppe Mazzoleni, and in 1615, by Giovanni Battista Santi, in 1858 the clock was restored by Luigi De Lucia. In 1996, a restoration, undertaken by Giuseppe Brusa and Alberto Gorla, was the subject of controversy, amid claims of unsympathetic restoration. In 1493, the Venetian Republic commissioned Giovan Paolo Rainieri to make a clock movement and he had already constructed clocks in his home town of Reggio Emilia in 1481. These figures are referred to as Moors because of the colour of the bronze patina. Paolo died in 1498 and his son Gian Carlo completed the work, the clock was inaugurated on February 1,1497. The dial was an astronomical clock similar to the Padua clock of 1434, rather than the astrolabe type with offset zodiac dial. The 24 hours of the day were marked, in Roman numerals, around the edge, with I at the right-hand side, the relative positions of five planets were shown, as were the moons phases and the position of the Sun in the zodiac. The four circular windows around the dial may have contained astrolabe-type devices or orreries, the Venetian Government paid Raineri and his family to live in the Clock Tower and maintain the clock in good order. He was the first clock-keeper or temperatore, and this post continued to be filled, often by different generations of the same family, repairs and restorations have been frequent. In 1550 there were accusations that some of the gears had been stolen, in 1752 Bartolomeo Ferracina started work on replacing the clock, having successfully tendered for the job in public competition. He received the old mechanism and dial as part of his payment, ferracinas new movement reflected the great advances in horology that had been made since the original clock had been installed. A Graham dead-beat escapement replaced the foliot, with a 4m pendulum, mounted away from the central arbor, beating once every 1.97 seconds. The new striking system used a new pair of hammers that struck six groups of 22 blows at 12,00 and 0,00 on the bell on the tower. Ferracina also restored the Magi procession, which then was restricted to occurring only on 15 days of the year around Ascension Day, in 1857 Luigi de Lucia started another restoration, and added a digital display. These were illuminated from behind by gas lamps, so that the numbers could be seen from the square below, during the Magi procession, the wheels were lifted away from the doors to allow the statues to pass through, and the temperatore changed the numbers manually. De Lucia modified the escapement, replacing it with a pinwheel, in 1886, the Arabic numerals installed by Ferracina were removed, and the original Roman numerals showing the Italian numbering were revealed again
7. Astrarium of Giovanni Dondi dell'Orologio – The Astrarium of Giovanni Dondi dellOrologio was a complex astronomical clock built between 1348 and 1364 in Padova, Italy, by the doctor and clock-maker Giovanni Dondi dellOrologio. The Astrarium had seven faces and 107 moving parts, it showed the positions of the sun, the moon and it was one of the first mechanical clocks to be built in Europe. The Tractatus survives in manuscript sources. The autograph in the Biblioteca Capitolare of Padova and a copy of it, the other sources are rewritten versions of the autograph, to which Dondis contribution is as yet unclear. The autograph manuscript was published in 1987 in an edition with colour facsimile and French translation by Poulle as the first volume of the Opera omnia of Jacopo. The astrarium was considered to be a marvel of its day, Giovanni Manzini of Pavia writes that it is a work full of artifice, worked on and perfected by your hands and carved with a skill never attained by the expert hand of any craftsman. I conclude that there was never invented an artifice so excellent and marvelous, Dondi writes that he obtained the idea of an astrarium from the Theorica Planetarum of Giovanni Campano da Novara, who describes the construction of the equatorium. The astrarium was primarily a clockwork equatorium with astrolabe and calendar dials, and indicators for the sun, moon and it provided a continuous display of the major elements of the solar system and of the legal, religious, and civil calendars of the day. Dondis intention was that it would help understanding of astronomical and astrological concepts. The astrarium stood about 1 metre high, and consisted of a brass or iron framework resting on 7 decorative paw-shaped feet. The lower section provided a 24-hour dial and a large drum, showing the fixed feasts of the church, the movable feasts. The upper section contained 7 dials, each about 30 cm in diameter, showing the data for the Primum Mobile, Venus, Mercury, the moon, Saturn, Jupiter. Dondi constructed the clock, with its 107 gear wheels and pinions, no screws were used, and every part was held together by over 300 tapering pins and wedges, with some parts being soldered. Most of the wheels have triangular shaped teeth, although some are blunt-nosed, in some cases, Dondi used near-elliptical wheels, in order to more accurately model the irregular motions of the planets. On some of these wheels, the teeth varied in size, to indicate dimensions in his descriptions, Dondi used units such as the width of a goose quill, the thickness of a blade of a knife, or the breadth of a mans thumb. For data on the motion of the planets, he consulted the Alfonsine tables, the clock movement had a balance wheel regulated to beat at the rate of 2 seconds. Its simple wheel train turned a dial marked on the margin with a scale of 24 equal hours, at the time the clock was made, the dates of the solstices were 13 June and 13 December. The annual calendar wheel or drum in the section was about 40 cm across
8. Zimmer tower – The Zimmer tower is a tower in Lier, Belgium, also known as the Cornelius tower, that was originally a keep of Liers fourteenth century city fortifications. In 1930, astronomer and clockmaker Louis Zimmer built the Jubilee Clock, the tower was built no later than 1425 though the precise date of construction is unknown. In 1812 the tower was sold by the authorities, but after World War I, they repurchased it. However, in 1928 clockmaker Louis Zimmer presented to city, his work, the anniversary and these clocks showed time on all continents, phases of the moons, times of tides and many other periodic phenomena. It was decided to place this new design in the old tower, in honor of the astronomer they renamed the tower the Zimmer tower. In 1960 a pavilion for the new clock was next to the tower to present Zimmers masterpiece the wonder-clock. Around one of these moves the slowest pointer in the world - its complete revolution will take 25800 years. Subsequently Zimmer attached to the clocks a mechanical planetarium, the wonder-clocks impressed Albert Einstein, who congratulated Zimmer with the creation of these unusual mechanisms. On the small square at the foot of the tower an exhibition of the system was arranged with the aid of metallic circles. These also show asteroids Felix and Zimmer, which were named after Felix Timmermans and Louis Zimmer when discovered in 1929, in 1980 the tower obtained the status of state protected monument. Now the Zimmer tower and pavilion with the wonder-clocks is a museum, the Centenary clock has one large dial in the centre. This dial shows the exact time and this dial shows the difference in minutes between the apparent solar time and the mean solar time. Positive values indicate that the apparent solar time is ahead of the solar time, with maxima around November 3. Negative values indicate that the apparent solar time is behind of the solar time, with a maximum lag around February 12. The difference is zero four times a year, around April 16, June 15, September 1, every year the sun describes an imaginary circle around the earth, called the zodiac. The zodiac is divided in twelve segments, each denoted by an associated with a constellation. This dial shows the zodiac signs, the signs of spring, Ram, Bull and Twins. The signs of the summer, Crab, Lion and Virgin, the signs of the fall, Balance, Scorpion and Bowman
9. Jacopo Dondi dell'Orologio – Jacopo Dondi dellOrologio, also known as Jacopo de Dondi, was a doctor, astronomer and clock-maker active in Padua, Italy. He is remembered today as a pioneer in the art of clock design and he was the father of Giovanni Dondi dellOrologio. Jacopo Dondi wrote on a number of subjects, including surgery, pharmacology, astrology, Jacopo Dondi was born in Chioggia, the son of a doctor named Isacco. He attended the University of Padua and was elected municipal physician in Chioggia in 1313, in about 1327 he married Zaccarota Centrago or Centraco, with whom he had eight children, the second-born, Giovanni, became famous as the builder of the Astrarium. On the 28 February 1334, Jacopo received Venetian citizenship from the Doge Francesco Dandolo, in 1342 he moved to Padova, where he became a professor of medicine and of astronomy at the University. He supervised the construction of a public clock with a dial. He may also have contributed to its design, the clock was installed in the tower of the Palazzo Capitaniato, Padua in 1344. There is some evidence that it indicated and struck the hours from 1 to 24, and also that it displayed the age and phase of the moon, both the tower and the clock were destroyed in 1390, when the Milanese stormed the palace. A replica of the clock is in the Torre dellOrologio of Padua and he died in Padua between 29 April and 26 May 1359, and was buried outside the Baptistry of San Giovanni, Padua. It was published in Strasburg in about 1470 by the R-printer and it was reprinted in Venice in 1542 by Tommaso and Giovanni Maria Giunta, and again in 1576. The Aggregator should not be confused with the illustrated Herbarius of Peter Schöffer, Dondis treatise on the tides, De fluxu atque refluxu maris, probably dates from between 1355 and 1359. Dondi is credited with having painted the first topographic map of the territory of Padua, Dondi made an adaptation to the meridian of Padua of the astrological Tabulae de motibus planetarum or Toletanae, the alfonsine tables attributed to Alfonso X el Sabio, King of Castile. The work was in the possession of Giovanni in 1389, and was cited and praised by Beldomandi in his Canones de motibus corporum supercoelestium and it has also been suggested that it was the work not of Jacopo but of one of his sons, either Gabriele or Giovanni. A short historical work preserved in manuscripts in the Biblioteca Nazionale Marciana, bernardino Scardeone records a manuscript copied in Venice in 1372 of Dondis expositiones on the Magnae derivationes of Uguccione da Pisa. Thought to be lost, the work survives in manuscripts in the Fitzwilliam Museum, Cambridge, the Bodleian and the Biblioteca universitaria of Pavia. Andrea Gloria Monumenti della Università di Padova, in Memorie del Reale Istituto Veneto di Scienze, Lettere, ed Arti,22 Andrea Gloria Monumenti della Università di Padova, in Univ. Andrea Gloria I due orologi meravigliosi inventati da Jacopo e Giovanni Dondi, in Arti del Reale Istituto Veneto di Scienze, Lettere, ed Arti, Series 7
10. Exeter Cathedral astronomical clock – The Exeter Cathedral Astronomical Clock is a fifteenth-century astronomical clock in Exeter Cathedral, England. The clock is thought to date from around 1484, the outermost disc is decorated with a fleur-de-lis which represents the sun, and which orbits the dial once every 24 hours. This indicates the hour of the day, counted from I to XII in Roman numerals in first the right and this is an example of a 24-hour analog dial. The tail of the suns fleur-de-lis points to the day in the month on the inner ring. The half-black, half-silver moon inside the lunar month ring rotates on its axis to show the phase of the moon. The earth is represented as a golden ball in the centre of the dial. The Latin inscription Pereunt et imputantur below the dial may be translated as The hours pass and are reckoned to our account. A small bell located behind the clock chimes the quarter-hours. On the hour, this is followed by the striking of the Peter Bell in the tower above, in 1759 the smaller upper dial was added with a single hand to indicate the minutes. The clock-room is behind the dial on the wall of the transept. Access is via a doorway visible in the wall directly beneath the clock. Legend suggests that the round hole cut in the bottom of the door was for the cat to gain entry to keep the clock clear of mice. The modern clock mechanism was installed in 1885 by Gillett & Bland of Croydon, the clock was restored in 1910 by John James Hall FRAS. The clock is also reputed to be the source of the nursery rhyme Hickory Dickory Dock, probably inspired by the round hole in the door described above
11. Jens Olsen's World Clock – Jens Olsens World Clock or Verdensur is an advanced astronomical clock which is displayed in Copenhagen City Hall. The clock was designed and calculated by Jens Olsen who was a skilled locksmith and he also took part in the beginning of the clocks construction, but died in 1945,10 years before the clock was completed. The clock consists of 12 movements which together have 15,448 parts, the clock is mechanical and must be wound once a week. Displays include lunar and solar eclipses, positions of the bodies. The fastest gear completes a revolution every ten seconds and the slowest every 25,753 years, the calculations for the clock were made up until 1928, after which they were supervised by the astronomer Professor Elis Strömgren. The drawings for the clock were made between 1934 and 1936, and the production of the clock took place from 1943 until 1955. The clock was started on 15 December 1955 by King Frederick IX, Clock of the Long Now Otto Mortensen Jens Olsens Clock, A Technical Description Technological Institute, Copenhagen,1957. The Story of the Astronomical Clock Description of Jens Olsens World Clock Archive. org
12. Myriad year clock – The Myriad year clock, was a universal clock designed by the Japanese inventor Hisashige Tanaka in 1851. It belongs to the category of Japanese clocks called Wadokei and this clock is designated as an Important Cultural Asset by the Japanese government. The clock is driven by a spring, once it is fully wound, it can work for one year without another winding. It can show the time in 7 ways and it also rings chimes every hour. It consists of more than 1,000 parts to realize these complex functions and it took more than three years for him to finish the assembly. In 2004 the Japanese government funded a project aimed at making a copy of this clock, more than 100 engineers joined the project and it took more than 6 months with the latest industrial technologies. However, even then it was not possible to make copies of some parts, such as the brass metal plate used as its spring. The original clock is displayed at the National Museum of Nature and Science, the clock, technologically comparable to contemporary Western clocks, was developed through a combination of Japanese ingenuity and study of Dutch sciences, during Japans seclusion period. The clock was listed in the Mechanical Engineering Heritage as item No.22 in 2007, National Project to Restore Man-nen Jimeisho