Prague astronomical clock Orloj, Czech Republic
1400AD-Present-Modern Era Czech Republic Europe

Orloj | The legend and symbols of Prague astronomical clock

June 18, 2020
TypeLandmark – Astronomical clock
Age600 years
LocationPrague,  Czech Republic

About Orloj

Prague astronomical clock or Prague Orloj is a medieval astronomical clock.

Prague astronomical clock is the third-oldest astronomical clock in the world and the oldest clock still operating.

The clock shows the time, the date, shows astronomical and zodiacal information.

Photo: Wikimedia Commons

Apostle Parade

Every hour during the day (9 am-11 pm) you can see the apostle parade. The Apostles appear in the left and right windows of the astronomical clock as viewed from the square in this order: James / Peter, Andrew / Matthias,  Thaddeus / Philip, Thomas / Paul, John / Simon, Barnabas / Bartholomew.

The four figures that are set in motion represent four things:

  • Vanity – figure admiring himself in the mirror
  • Greed (usury) – a man holding a bag of gold
  • Death – a skeleton that strikes the time upon the hour
  • Lust and earthly pleasures – a figure playing a pipa

Around the clock plate, there are a few stone animals. They correspond to the secret stonemasons’ language. A dragon, reclining demon and several monster faces can be seen. There is also a bat, a dog, a hedgehog, a lion, and a frog.

Prague astronomical clock Prague Orloj
Image: USA-Reiseblogger / Pixabay
Prague astronomical clock Prague Orloj
Image: Monica Volpin /Pixabay

The clock plate

There are both Roman and Arab numbers on the clock

The background represents the Earth and the local view of the sky. The blue circle in the center represents the Earth, and the upper blue is the portion of the sky which is above the horizon.

Inside the large black outer circle lies another movable circle marked with the signs of the zodiac which indicates the location of the Sun on the ecliptic.

You can view the clock on Google Street View. With Google Street View you to see the outside area.

The clock was built nearly 310 years before the United States of America was discovered.

The clock was designed by two men, Jan Sindel, a Catholic priest and scientist, and Mikulas of Kadan.

The movement of the Moon on the ecliptic is shown similarly to that of the Sun, although the speed is much faster, due to the Moon’s orbit around the Earth.

The half-silvered, half-black sphere of the moon also shows the Lunar phase. The Moon has a 57-tooth gear inside its sphere, and is slowly rotated by a screw-thread attached to a weight, advancing two teeth per day. This movement, powered only by gravity, makes the Orloj unique in the world among astronomical clocks showing the phases of the Moon. The mechanism was created by an unknown maker, probably in the mid-17th century.

Prague astronomical clock Prague Orloj
Image: Hermann Traub / Pixabay

The Legend

The legend says that the city will suffer if the clock is neglected. The skeleton statue on the clock will nod it’s head when the clock stops working due to neglect and condemn Prague until it is fixed.

The Calendar Plate

The calendar plate below the clock was replaced by a copy in 1880. The original is stored in the Prague City Museum.

Prague astronomical clock Prague Orloj
Image: Birgit Böllinger / Pixabay

The Astronomical Clock is filled with symbolism. For example, it has four levels, which can correspond to earth, water, air, and fire, the four basic elements, or can also be read as Earth, Moon, Sun, and Cosmos.

There are four statues next to the Calendar plate, two on each side, Archangel Michael, Philosopher, Astronomer, and the Chronicler.