John Knibb
John Knibb (1650–1722) was an English clockmaker born in Claydon, Oxfordshire. He produced various clocks and watches including bracket clocks, lantern clocks, longcase clocks, and some wall-clocks, as well as building and maintaining several turret clocks. Even though his main market was catering to customers of modest means, he also dominated the higher-quality sector. Only six of Knibb's watches are known to survive.
Time
The most precise timekeeping device of the ancient world was the water clock, or clepsydra, one of which was found in the tomb of Egyptian pharaoh Amenhotep I (1525–1504 BC). They could be used to measure the hours even at night, but required manual upkeep to replenish the flow of water. The Ancient Greeks and the people from Chaldea (southeastern Mesopotamia) regularly maintained timekeeping records as an essential part of their astronomical observations. Arab inventors and engineers in particular made improvements on the use of water clocks up to the Middle Ages. In the 11th century, Chinese inventors and engineers invented the first mechanical clocks driven by an escapement mechanism.
History of timekeeping devices
Although the Greeks and Romans did much to advance water clock technology, they still continued to use shadow clocks. The mathematician and astronomer Theodosius of Bithynia, for example, is said to have invented a universal sundial that was accurate anywhere on Earth, though little is known about it. Others wrote of the sundial in the mathematics and literature of the period. Marcus Vitruvius Pollio, the Roman author of De Architectura, wrote on the mathematics of gnomons, or sundial blades. During the reign of Emperor Augustus, the Romans constructed the largest sundial ever built, the Solarium Augusti. Its gnomon was an obelisk from Heliopolis. Similarly, the obelisk from Campus Martius was used as the gnomon for Augustus's zodiacal sundial. Pliny the Elder records that the first sundial in Rome arrived in 264 BC, looted from Catania, Sicily; according to him, it gave the incorrect time until the markings and angle appropriate for Rome's latitude were used—a century later.
Jiří Dienstbier Jr.
Jiří Dienstbier Jr. is the son of Jiří Dienstbier Sr., former journalist and civil rights activist who became the first Minister of Foreign Affairs in the newly democratic Czechoslovakia, and Zuzana Dienstbierová, née Wíšová, a psychologist. His parents and his grandfather, Jaromír Wíšo, were signatories to the Charter 77 human rights declaration. Consequently, Dienstbier's family experienced intense political pressure from the Communist regime during the "Normalization" period after 1969. While Jiří Dienstbier Jr was 10 years old, his father was imprisoned for his work in a movement acting parallel to Charter 77, the Committee for the Defense of the Unjustly Prosecuted (; VONS).
Astronomical clock
The first clock was built between 1352 and 1354 and stopped working sometime at the beginning of the 16th century. A second clock was then built by Herlin, Conrad Dasypodius, the Habrecht brothers, and others, between 1547 and 1574. This clock stopped working in 1788 or 1789 (as it apparently stopped working gradually, each component being disconnected
History of science
The astronomer Aristarchus of Samos was the first known person to propose a heliocentric model of the solar system, while the geographer Eratosthenes accurately calculated the circumference of the Earth. Hipparchus (c. 190 – c. 120 BC) produced the first systematic star catalog. The level of achievement in Hellenistic astronomy and engineering is impressively shown by the Antikythera mechanism (150-100 BC), an analog computer for calculating the position of planets. Technological artifacts of similar complexity did not reappear until the 14th century, when mechanical astronomical clocks appeared in Europe.
Jiří Moravec
Jiří Moravec (born 13 February 1980 in Nymburk) is a Czech professional ice hockey defenceman who is currently a free agent.
Prague astronomical clock
The oldest part of the Orloj, the mechanical clock and astronomical dial, dates back to 1410 when it was made by clockmaker Mikuláš of Kadaň and Jan Šindel, then later a professor of mathematics and astronomy at Charles University. 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.
Jiří Kejval
Jiří Kejval (born 30 November 1967 in Prague) is an entrepreneur, President of the Czech Olympic Committee, member of IOC and former international rower.
Yerkes Observatory
The observatory, which called itself "the birthplace of modern astrophysics", was founded in 1897 by astronomer George Ellery Hale and financed by businessman Charles T. Yerkes.
Jiří Ptáček
Jiří Ptáček (born 15 January 1989) is a Czech football player who currently plays for Loko Vltavín in the Czech 2. Liga.
Pierre de Rivaz
Pierre de Rivaz (17111772) was a French clockmaker of the 18th century, from Saint-Gingolph. He built a clock in 1740 that was powered by variations in air temperature and pressure, a type of Atmos clock.
Jiří Trvaj
Jiří Trvaj (born 13 April 1974) is a Czech professional ice hockey goaltender who currently plays with HC Olomouc in the Czech Extraliga.
Clock Tower, Brighton
The Clock Tower (sometimes called the Jubilee Clock Tower) is a free-standing clock tower in the centre of Brighton, part of the English city of Brighton and Hove. Built in 1888 in commemoration of Queen Victoria's Golden Jubilee, the distinctive structure included innovative structural features and became a landmark in the popular and fashionable seaside resort. The city's residents "retain a nostalgic affection" for it, even though opinion is sharply divided as to the tower's architectural merit. English Heritage has listed the clock tower at Grade II for its architectural and historical importance.
Jiří Svoboda (volleyball)
Jiří Svoboda (born April 19, 1941) is a Czech former volleyball player who competed for Czechoslovakia in the 1968 Summer Olympics.
New Delhi
Jantar Mantar located in Connaught Place was built by Maharaja Jai Singh II of Jaipur. It consists of 13 architectural astronomy instruments. The primary purpose of the observatory was to compile astronomical tables, and to predict the times and movements of the sun, moon and planets.
Jiří Jebavý
Jiří Jebavý is a Czech professional ice hockey defenceman who currently plays for HC Slavia Praha of the Czech Extraliga.
Jiří Havlis
Jiří Havlis (16 November 1932 – 31 January 2010) was a Czech rower who competed for Czechoslovakia in the 1952 Summer Olympics.
Jiří Novák
Jiří Novák (; born 22 March 1975) is a former Czech tennis player, who was born in Zlín, Czechoslovakia but resides nowadays in Monte Carlo, Monaco.
Evening
Evening is the period of time at the end of the day, usually from about 6pm to bedtime. It is a daily astronomic event of variable time period between daytime and night, and the period in which the daylight is decreasing, after the afternoon and before night. There is no exact time for when evening begins and ends (equally true with night). Though the term is subjective, evening is typically understood to begin shortly before sunset and during twilight (sunset and twilight vary throughout the year), lasting until night -- typically astronomical sunset. There can be no precise definition in terms of clock time, but it is socially considered to start around 6 pm. and to last until nighttime or bedtime.
What was the construction year for the astronomical clock in Jiří Kejval's birthplace?
What is Jiří Kejval's birthplace?
Prague
when was the astronomical clock in #1 built
1410