The Astronomical Clock

One of Prague’s most famous attractions, the Astronomical Clock, also known as Prague orloj among the locals, have an over 600 years long history, dating from 1410, when it was first installed. Prague’s Astronomical Clock was the third such time measuring mechanism in the world. Nowadays, it is the oldest still functioning astronomical clock.

Astronomical Clock’s Dials

Mounted on Prague’s Old Town Hall’s southern wall, in the very touristy Old Town Square, the Astronomical Clock is a top landmark of the Czech capital city. Its mechanism has three main components:

Astronomical clock dials1. The astronomical dial

The astronomical dial’s background depicts the position of the Earth and the Moon in sky. The Sun and the Moon move around the dial surrounded by the zodiacal ring as well as by an outer rotating ring. The Earth standing at the heart of the dial represents the Earth. During the day, the Sun stands on the background’s blue part (that stands for the portion of sky above the horizon line), while at night you will notice the Sun hovering over the black part of background (that stands of the portion of sky below the horizon). The transitional periods such as the sunrise and the sunset are marked by a different position of the Sun – on the red part of the background. The same dial features some Latin inscriptions that mark the moment of the day: on its left side, you will notice aurora (dawn) and ortus (rising), while on the right side, the Latin words occasus (sunset), and crepusculum (twilight) are inscribed.

The external edge of the blue background features golden Roman numbers – the 24 hours of the day, displaying Prague’s local time. The hours are not the 60 minute periods we are used to. Each hour is a 12th of the period of time between sunrise and sunset, and this can vary depending on the season, as during the summer, days are longer and during the winter, days are shorter.
Prague astronomical cloc
2.The Walk of the Apostles
Every hour the Astronomical Clock in Prague is home to a show of moving sculptures embodying the Twelve Apostles. The window is flanked by four symbolic figures: Vanity (a moving figure holding a mirror), Greed (a moving figure holding a bag of gold), Death (a skeleton ringing a bell) and the Turk (a figure holding a mandolin).
3. The calendar dial
The calendar or zodiac dial displays 12 medallions that stand for the months of the year. Using a 366 teeth gear mechanism, this dial tells the position of the Sun and the Moon among the zodiac houses. A particularity – the zodiac signs are displayed in anticlockwise order.

Astronomical Clock’s History

The Astronomical ClockThe story of Prague’s Astronomical Clock begins in 1410 when its oldest parts – the mechanical clock and the astronomical dial – were manufactured by the Imperial clockmaker Mikuláš of Kadaň in collaboration with the scientist Jan Šindel. The first mention of the clock in historical documents dates from October 9th 1410.

The calendar dial and the façade adorned with Gothic sculptures were added around the year 1490. The legend says that the local clockmaker Hanuš Rose who redid the clock’s mechanism was blinded by the Prague authorities so that he would not be able to repeat a similar work. In revenge, he broke down the clock, which did not function until 1552, when it was repaired by Jan Taborský. The clock stopped working several times along the history, but it was repaired in a timely manner because of a superstition that says that as long as the clock will be working, Prague city will flourish.

The wooden statues that were adorning the clock’s façade before World War II were added some time at the middle of the 17th century, while the figures of the Apostles appeared after a major repair work in 1787-1791. Severely damaged during World War II, when what we know today as the Old Town Hall and surrounding buildings burned, Prague’s Astronomical Clock was repaired and started working again in 1948. Vojtěch Sucharda is the one who was in charge of restoring the wooden Apostles.

Prague Sightseeing Tours

Prague History and Bohemian Culture Tour

Delve into Prague’s rich Bohemian history and culture on this enlightening 4-hour walking tour.Book Now
Prague by Night Walking Tour & Cruise
End a day in Prague on a high note with this evening walking tour and River cruise!Book Now
Prague in One Day Sightseeing Tour

Discover the magic of Prague, a modern and vibrant city full of energy, on this introductory tour.Book Now
Stories of Jewish Prague Walking Tour

Hear many stories and visit the five remaining synagogues, the Old Jewish Cemetery & Town Hall.Book Now

Leave a Reply