Did you know....?
· The astronomical clock's main function was to depict the movement of celestial bodies (including the Sun and the Moon); showing the time was merely a secondary element.
· The faithful depiction of the movement of celestial object was based on the ecliptic.
· When looking from Earth, the ecliptic is the apparent path the Sun moves along in the sky in the course of a year. It is in the shape of a circle. The apparent movement of the Sun in the sky is in fact the result of the Earth revolving around the Sun. A number of stars, all planets in the solar system and the Moon are near the ecliptic. When viewing from Earth, the Sun travels along the ecliptic and goes through various constellations during the year. These are called zodiac constellations. The ecliptic crosses the celestial equator twice per year. These moments are called the equinox. The celestial equator is the where the plane of the Earth's equator intersects with the celestial sphere. The Sun is always in the northern hemisphere for half a year and in the southern hemisphere for half a year. On the spring equinox, the ecliptic crosses the celestial equator towards the northern hemisphere.
· The movement and depiction of the stars on the astrolabe are created in the spirit of geocentrism. This theory is based on the idea that the Earth is the centre of the universe and that all celestial bodies, including the Sun and the Moon, revolve around it. To this day astrology still employs the practical application of geocentric models.
· Every astronomical clock always calculated the movement of the celestial bodies at that given site. As a result, it was impossible to transport astronomical clocks from place to place without changing or resetting them.
· The sun on the astrolabe must orbit once per day (24 hours).
· Figures and masks created by Parler's workshop are visible on the stone moulding around the astronomical clock.
· The dial on the astronomical clock is decorated with richly braided cut vines created in the period of Vladislas II. For this reason, the Vladislas Gothic (Sondergotik) period is given as the period when ornamentation appeared.
· The date of 1410 as the year when the astronomical clock was established was discovered and proven only recently. Only after 1980 was it proven that Mikuláš of Kadaň can be credited with creating the astronomical clock based on Jan Šindel's calculations.
· A calendar dial was added below the astronomical dial (astrolabe) only in 1490. Each night, however, the calendar plate was manually shifted to the next day.
· From 1566 the astronomical clock was fully mechanized, including the daily shifting of the calendar plate.
· In 1570, Jan Táborský of Klokotská Hora described very important information about the astronomical clock in his Report on the Prague Astronomical Clock.
· Because the calendar plate on the astronomical clock rotates clockwise, the order in which the calendar is written is in the opposite direction.
· The circumference of the calendar is divided into 365 days, and each day always shifts at midnight.
· If it is a leap year, the wheel does not move one night.
· The cisiojanus is the most important part of the Calendarium. It stems from the 16th century and is written in Czech. Karel Jaromír Erben made a major contribution to inscribing the cisiojanus in the 19th century. The cisiojanus is a mnemonic device used to help remember the most important feasts in the given day of the month.
· The Prague Astronomical Clock did not only always show the hour, it also struck the hour. The striking of the hour had two parts. First it rang according to the old style of church bells which rang the end of another hour. This was followed by striking or beating the hours with one to twenty-four strikes, according to Old Czech Time.
· Two side west and east dials also belong to the Astronomical Clock. These were added when the Astronomical Clock was repaired in the latter half of the 19th century.
· A public fundraising effort was announced in 1865–1866 to repair the astronomical clock. People contributed in cash and bonds. A total of 4,265 Gulden and 89 Kreuzer were collected.
· At the end of World War II, on May 8, 1945, Prague's Astronomical Clock was seriously damaged. The astronomical dial was shot, the bent zodiac dial hung by what was left of its axis, the canopy over the astronomical clock had fallen and the left side of the ornamentation, including the figures of Vanity and Miser, were completely destroyed.
· During the attack against the Old Town Hall, the Nazis also used incendiary shells which wreaked serious damage inside the chamber of the astronomical clock. The clockwork of the astronomical clock was taken apart and taken by cart to the workshop of the Hainz company in Prague – Holešovice.
· The Calendarium was also entirely destroyed. Fortunately it was a copy, and not the Mánes original.
· Given that the wooden figures of the apostles were completely destroyed, the opinion was aired that the exterior ornamentation of the astronomical clock and its moving parts should be completely redesigned. According to this version, consideration was given to adding the figures of Christ and Judas to the original 12 apostles, with Christ commencing and concluding the apostle parade.
· Vojtěch Sucharda, the artist who created the new apostle figures, originally conceived of entirely new, modern exterior figure ornamentation. This was also supposed to be movable in all three levels he wanted to implement. This ornamentation was supposed include a depiction of Chronos, the god of time, and Amore with a bow and arrow. In addition, various jobs and activities were to be presented: laundress, tailor, shoemaker, cabinetmaker, mason, architect, etc. The figures would not be wooden but instead polychrome metal that would hold up to the changes in the weather better.
· According to this design, the astronomical clock would also be lit with a large neon light. None of these plans were carried out.
· The new wooden figures of the apostles are made of linden wood. Following the war there was a dire shortage of good quality, dry carving wood, but people throughout the country were happy to send in donations of wood for the cause.
· If was only during these repairs from 1945–1948 when electric engines were attached to wind the individual cylinders of the mechanism. The order to wind the cylinders is given from an automatically set switch.
· Painter Bohumír Číla (1885–1957) created a new copy of Josef Mánes' calendar plate following World War II.
· Since 1948, the bell and drum mechanism are set to chime on the hour according to Central European Time.
· Old Czech Time shown on the 24-hour ring was put back into operation in as late as 1957.
· During repairs in 1979, the bottom plate of the astrolabe was recreated and all colours were added showing the part of the day, including the twilight circle, in the right dimensions and with the correct placement.
· All of the figures on the Prague Astronomical Clock have been copies since 1976. The originals are located in the Prague City Museum.
· The Prague Astronomical Clock does not show daylight savings time. An attempt was made to adapt the astronomical clock to daylight savings time, but several months later it was shown that the time on the clock was imprecise.
· Astronomical clocks were created at a time when it was not necessary to show the minutes on the clock. A moment of time did not matter much. The tower clockmakers created separate dials to show the minutes.
· The figure of the crowing rooster has been on the astronomical clock only since 1882, when it was made during a repair carried out by the Hainz company. It is first played on December 31, 1882. Together with the mechanical rooster, whistles and bellows are created to imitate the rooster's crow.
· The apostle figures became part of the astronomical clock probably from the mid-16th century. They seem to have been added during the repair in 1659, but to this day there is a lack of clear proof.
· Mikuláš of Kadaň was duly rewarded for his work. He received a house near Havel Gate, 3,000 Groshen in cash (a very high payment), a regular annual salary of 600 Groshen and guarantees of property for his heirs.
· The apostle parade can be seen on the Prague Astronomical Clock every hour on the hour from 9 a.m. till 11 p.m.