Astronomical clocks are not just regular clocks. These elaborate and enormous timepieces display astronomical information such as the time, date, positions of the sun and moon, tides, lunar phases, and even zodiac signs. They’re also works of art and engineering masterpieces, first coming to widespread prominence in medieval European cities. Proudly displayed in public spaces, they boasted of a city’s prestige, technological advancement, wealth, and artistic accomplishment.
With such fascinating devices came interesting legends and histories. Some have survived German bombs and shells, others said to have inspired Einstein’s theories, or even carry an evil curse. While some have been destroyed or lost over the centuries, there are dozens which are still available to see. Here is a selection of some of the impressive astronomical clocks in Europe.
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Early Astronomical Clocks
Astronomical clocks are thought to date back to the Antikythera Mechanism, an ancient Greek clock dating to 205-87BCE. This complex clock of bronze gears, discovered in a sunken ship, was centuries ahead of its time. Chinese horologist Su Song built a water-driven astronomical clock in the 11th century. Muslim engineers were also building astronomical clocks, such as Ismail al-Jazari’s revolutionary Tower Clock in 1206, which even included a procession of mechanical musicians every hour.
The Prague Astronomical Clock, also known as the Prague Orloj, is one of the oldest and most recognisable astronomical clocks in the world. Located on the wall of the Old Town Hall, the clock was first unveiled in 1410. The Orloj is known for its wonderful Gothic design, as well as its mechanical procession which takes place every hour, with wooden figurines and a golden rooster announcing the time.
The Prague Orloj has rumours of a curse that date back to its creator, Mikuláš of Kadaň. The legend goes that when Mikuláš completed his masterpiece, other cities wanted to hire him to create other astronomical clocks for them. When the Prague city councillors discovered this, they burned out the master clockmaker’s eyes. Driven mad, he threw himself into the mechanism of the clock, killing himself and stopping the clock, and cursing it henceforth. While almost certainly not true, the story of the clockmaker adds a certain mystique to this already fascinating timepiece.
In the small Belgian city of Lier is the Jubilee Clock, installed in the Zimmer Tower. It is the creation of astronomer and clockmaker Louis Zimmer, who built the clock in 1930, as well as renovating the historic tower and saving it from demolition. Previously a watchtower, this fascinating sight is a way to observe all kinds of astronomical metrics, whilst enjoying a Belgian beer in the cafes below.
As one of the more recent astronomical clocks, the Jubilee clock is easier to read than some of the others. Instead of overlapping functions and designs, it has its many functions set out in 13 clear, separate faces.
The largest astronomical clock in the world is located in the northern Italian city of Cremona, in the Lombardy region. It is installed in Italy’s highest bell tower, the Torrazzo of Cremona, the 112-metre (367 feet) bell tower that dwarfs the city. Because of the size of the Torrazzo, the intricately detailed astronomical clock is situtated right at the bottom, so people can read the clock face. The clock is absolutely enormous – 8.2 metres (26.9 feet) wide, and 8.4 metres (27.6 feet) including the copper frame. That’s larger than Big Ben, at 6.85 metres (22.5 feet) wide!
The tower was built between the 13th and 14th centuries, with the clock built between 1583 and 1588 by father and son Francesco and Giovan Battista Divizioli. The central dial represents the sky filled with zodiac symbols, with the position of the sun and moon moving across them. The clock also displays the seasons, lunar phases, and even predicts eclipses when the hands cross.
A medieval masterpiece and the jewel of the old town of Rouen, Le Gros Horloge is one of France’s oldest astronomical clocks. Built in stages from 1389 to 1529, the clock hangs on an archway over a pedestrian street for all to see.
Measuring 2.5 metres in diameter, Le Gros Horloge is not one of the largest astronomical clocks. But, what it lacks in size, it certainly makes up in grandeur and beauty. It is miraculous that the clock is still here today for us to appreciate; the city of Rouen was heavily bombed in WW2, and while much of the city was damaged or destroyed, the clock survived unscathed.
The detailed and ostentatious astronomical clock at Hampton Court Palace was the commission of King Henry VIII. Installed above the Anne Boleyn arch in 1540, the clock was as much a practical timepiece to help plan river barge journeys as it was a display of wealth.
Created by master horologist and astronomer Nicholas Kratzer, the clock is still in position at the palace, and is just 20 minutes drive south of London for all to admire.
The Zytglogge Astronomical Clock, Switzerland
It wouldn’t be a list about timekeeping masterpieces without mentioning Switzerland. The Zytglogge Astronomical Clock, which dates back to the 15th century, pre-dates the Swiss mastery of producing fine watches, but it is an incredible clock nevertheless. Installed in the Zytglogge Tower, a former watch tower that was part of Bern’s city walls, it now defines this medieval tower as a timekeeping treasure.
The Zytglogge has had an unexpected impact on the world of theoretical physics, too. In 1905, a young Albert Einstein working in the patent office of Bern had just completed his thesis, and was putting together his special theory of relativity. The story apparently goes that Einstein heard the chimes of the clock as he passed by the tower, and imagined a scene in which a streetcar was moving away from the tower at the speed of light. If he looked at his watch, it would show time as normal, but from his perspective the time at the Zytglogge would appear to have stopped. His groundbreaking paper outlining the special theory of relativity was published just weeks later.
While today they are more admired for aesthetics than their time keeping ability, astronomical clocks must have been the wonder of their age for the people who relied on them to keep time. There are many more astronomical clocks to explore in Europe today, each one with their own rich history and elegant design. Which is your personal favourite? Let me know in the comments below!