One of Prague’s most popular landmarks is the Astronomical Clock located in Old Town Square. It is well over 600 years old and is one of the oldest functional astronomical clocks in the world.
The astronomical clock in Prague, otherwise known as The Orloj, shows the relative positions of the Sun, Moon, Earth, and Zodiac constellations. It also tells the time, provides the date, and, best of all, provides some theater for its viewers on the hour, every hour.
In order to provide this level of functionality, the clock is split into several distinct parts.
The first, and most striking, is its impressive and beautifully ornate astronomical dial. This represents the position of the Sun and Moon in the sky and other various astronomical details.
"Prague anatomical clock" by henweb is licensed under CC BY-NC 2.0
An astronomical dial is a form of the mechanical astrolabe which was commonly used in medieval timekeeping and astronomical studies.
The main stationary background to the clock's face has a wealth of information to anyone who is able to read it. On the outermost ring of the background is a series of glyphs that are representative of ancient Czech time.
Moving closer to the center, a set of Roman numerals can be seen. Like most traditional clocks, these are used to indicate 24 hour time.
Each of the various hues of blue and brown within the main plate indicate events like sunrise, daybreak, daytime, nighttime etc as well as including various geographical information like the location of tropics and the equator.
The Earth is located in the very center of the dial.
Superimposed on the main astrolabe is the Zodiacal ring. This displays the various signs of the zodiac and is intended to mark the location of the Sun on the ecliptic.
Just above the main clock are two blue doors that open to reveal "The Walk of the Apostles". Between 9 am and 9 pm, each hour, on the hour, the window of the clock in the upper part shows the 12 apostles moving. Simultaneously, the surrounding sculptures on the device are set in motion. One of the moving figures carrying an hourglass in his hand personifies Death. Another moving figurine has a mirror, representing Vanity. Other figurines, such as those of the Astronomer, the Philosopher, or the Chronicler, appear to be motionless. However, several of these figures are replicas because their originals were severely damaged by the Germans at the end of the Second World War.
Below the main astrolabe and clock is the calendar dial. In its center, it shows the symbol of the Old Town of Prague and its outer ring reads the description of each day for the entire year. The current day is shown at the very top. Each month is also represented by a zodiac sign situated in a medallion.
The current date is tracked around the circumference of the dial which also indicates annual events like each Saints Feast Day.
"Prague, Czech Republic" by gamillos is licensed under CC BY-SA 2.0
The Prague Astronomical Clock was first installed in 1410. This makes it the world's third-oldest astronomical clock and the oldest still in operation today.
The lower calendar dial was added in around 1490. Around the same time, the incredible gothic statues were also added.
At some time in the late 1600s, probably between 1629 and 1659, the wooden statues were installed. The Apostle statues were added during a major refit between 1787 and 1791.
The clock tower's iconic golden crowing rooster was added in around 1865.
For many years it was believed that the clock was designed and built by clock-master Jan Růže, also known as Hanuš. This has since been shown to be a historical mistake.
However, this mistake led to the creation of a local legend that is still told to tourists today. The tale states that after this clock was built, Hanuš was approached by many a foreign nation, each wishing to have its own town square topped with a marvelous astronomical clock. Hanuš refused to show the plans of his masterpiece to anyone, but word got back to the Prague Councilors. Overcome with fear that Hanuš might build a bigger, better, and more beautiful clock for another nation, the Councilors had the brilliant clockmaker blinded, ensuring that their clock would never be topped. Driven mad, the clockmaker took the ultimate revenge, throwing himself into his extraordinary work of art, gumming up the clock’s gears and ending his own life at the same time. In doing so, he cursed the clock. All who tried to fix it would either go insane or die.
In fact, this event never happened and Hanuš does not appear to be the original craftsman. According to a paper discovered in 1961 that contains an insightful description of how the clock’s astronomical dial works, the creator was the Imperial clock-producer Mikuláš of Kadaň.
It appears Mikuláš was also assisted by an astronomer and university teacher named Jan Sindel. Sindel offered an astronomers insight with Mikuláš making the clock actually work.
In 2018, while the clock was being refurbished, a secret hidden message was uncovered inside one of its statues.
Restoration work was being done on some of its sculpted figures when they noticed that the Apostle of St. Thomas was lighter than all of the other statues. When they knocked on the statue they discovered that it was hollow. The statue was then removed and X-rayed and a strange metal case was found inside.
The metal case contained an 18 page letter written by a sculptor named Vojtěch Sucharda. He was commissioned to re-create some of the sculptures after the clock tower was heavily damaged during the Prague Uprising of World War 2.
The message reveals the sculptor's more extensive plans for the Astronomical Clock, which were never completed. He also complained about the conditions at that time as well as the start of the communist era.
The restoration work also revealed some other hidden features of the clock tower dating back to around the 15th Century. Several stone creature sculptures were uncovered in the corners under the calendar dial behind some timbers. It appears these were some of the original details of the clock before the installation of the dial in the late 1400s.
All the artifacts discovered during the renovation work are set to undergo a detailed analysis. Restorers will also place a new message into the tower for future generations.