The Prague astronomical clock or Prague orlojis, a medieval astronomical clock located in Prague, was first installed in 1410, making it the third oldest astronomical clock in the world and the oldest one still working. It features an astronomical dial, representing the position of the Sun and Moon in the sky, the signs of the zodiac and moving sculptures like a figure of Death (represented by a skeleton) striking the time; and a calendar dial with medallions representing the months.
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. These, like most traditional clocks, are used to indicate 24 hour time.
Each of the various hues of blue and red 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, or position of the observer, is located in the very center of the dial.
Superimposed on the main astrolabe is the Zodiacal ring. This, you won’t be surprised to learn, displays the various signs of the zodiac and is intended to mark the location of the Sun on the ecliptic.
Another phase of renovation was undertaken in 2005 with the lower calendar ring and statures restored. Anti-pigeon nets were also installed around the wooden statues.
The last renovation of the astronomical clock was carried out from January to September 2018, following a reconstruction of the Old Town Tower. During the renovation, an electric clock mechanism that was in operation since 1948 was replaced by an original mechanism from the 1860s.
Credit : Interesting Engineering
Picture Credit : Google
