The Prague Astronomical Clock
The medieval astronomical clock in Prague, called Orloj, was built in 1410 by clockmaker Mikulas of Kadan in collaboration with Jan Sindel, a professor of mathematics and astronomy from Prague Charles University. A popular tourist attraction, the clock is constructed on the southern wall of Old Town City Hall in the Prague Old Town Square.
Photos provided by Panoramio are under the copyright of their ownersIt is composed of the astronomical dial, marking the position of the Sun and Moon, with various astronomical details and symbols, the "Walk of the Apostles", an hourly show of Apostle statues and of other moving sculptures added in the 19th century, and a calendar dial with medallions which represent the months.
Around the and of the 15th century the calendar dial received a clock facade decorated with Gothic sculptures. The astrolabe mechanism has been functional for over 6 centuries now.
The four sculptures at the clock dial are symbols of the Prague medieval society. There is the figure of Vanity admiring himself in a mirror and the Miser or Jew holding a bag of gold. On the right side, Death is represented ringing his bell and a Turk (or The Piper) shaking his head.
The astrolabe mechanisms they have built over 600 years ago are still functional.
The Calendar under the clock dial was painted by Josef Manes in 1805. The figures on the Calendar represent a chronicler, an angel, an astronomer and a philosopher.
The Clock Tower features exquisite coats of arms and different royal symbols as decoration, as well as a rooster that crows when the Apostles have finished their blessing.
The clock dial shows the most important astronomical events: movement of the sun- here, the sun is represented moving around the Earth - phases of the moon, the equinoxes, the seasons, days and the zodiac symbols, indicating the location of the sun on the ecliptic. Thus, the Prague Orloj can be regarded as a primitive planetarium, with these effigies of the Universe and its workings.
The Orloj is an intricate work of art. The astronomical dial representing the standing Earth and sky is surrounded by four moving components: the zodiacal ring, an outer ring, an icon representing the Sun, and an icon representing the Moon. The mechanical sun moves its position according to dusk or dawn, since the red and black areas of the dial represent the horizon.
A golden star shows the position of the vernal equinox and a scale of roman numbers marks the sidereal time. A half-silvered sphere shows the lunar phase.
