3144, 3294 CZECH REPUBLIC (Prague) - Prague astronomical clock - part of Historic Centre of Prague (UNESCO WHS)

3144 Prague astronomical clock (1)

Posted on 07.09.2017, 17.12.2019
The Prague astronomical clock, mounted on the southern wall of Old Town Hall in the Old Town Square, was first installed in 1410, making it the third-oldest astronomical clock in the world and the oldest one still operating. Its oldest part, the mechanical clock and astronomical dial, was made by clockmaker Mikuláš of Kadaň and Jan Šindel, then later a professor of mathematics and astronomy at Charles University. Later, presumably around 1490, the calendar dial was added and the clock facade was decorated with gothic sculptures.

3294 Prague astronomical clock (2)

The clock mechanism itself has three main components: the astronomical dial, representing the position of the Sun and Moon in the sky and displaying various astronomical details; "The Walk of the Apostles", a clockwork hourly show of figures of the Apostles and other moving sculptures - notably a figure of Death (represented by a skeleton) striking the time; and a calendar dial with medallions representing the months. According to local legend, the city will suffer if the clock is neglected and its good operation is placed in jeopardy.

Alternatively, one may consider the clock to be a primitive planetarium, displaying the current state of the universe. The astronomical dial is a form of mechanical astrolabe, a device used in medieval astronomy. It has a background that represents the standing Earth and sky, and surrounding it operate four main moving components: the zodiacal ring, an outer rotating ring, an icon representing the Sun, and an icon representing the Moon. At the outer edge of the clock, golden Schwabacher numerals are set on a black background. These numbers indicate Old Czech Time (or Italian hours), with 24 indicating the time of sunset.

Prague astronomical clock is part of the UNESCO World Heritage Site Historic Centre of Prague, about which I wrote here.  

About the stamps
On the postcard 3144
The stamp is a Postcrossing stamp, about which I wrote here.

On the postcard 3294
The stamp, depicting a Dandelion, is part of a large series of definitive stamps named Beauty Of Flowers, about which I wrote here.  

References
Prague astronomical clock - Wikipedia

Sender 3144: Marius Vasilescu
Sent from Prague (Prague / Czech Republic), on 25.08.2017
Photo: Radim Sulk 
Sender 3294: Irina Vasilescu
Sent from Prague (Prague / Czech Republic), on 01.12.2019
Photo: Julius Pufler