Prague Astronomical Clock

A clock stood on the Old Town Hall tower by 1402, tended by a clockmaker named Albert. The Orloj proper dates from 1410, when the mechanical movement and the astronomical dial were built by the horologist Mikuláš of Kadaň, probably to a design by Jan Šindel, professor of mathematics and astronomy at the Prague university. It is first documented in a charter of 9 October 1410, in which the town council thanks Mikuláš for good work, unlike his predecessor, and rewards him with a house and a large yearly salary.

The calendar dial below the astronomical face was added later, presumably around 1490, when gothic sculpture was added to the facade. The Orloj is the third-oldest astronomical clock in the world and the oldest still working.

For centuries the clock was credited to Jan Růže, called Master Hanuš, who took charge of it in 1475 and kept it until his death in 1497. The legend retold by Alois Jirásek has Hanuš blinded on the order of the Prague councillors so that he could never build its like again; in revenge he disabled the clock, and no one could repair it for the next hundred years. The attribution rests on a misreading of period records: Jan Táborský of Klokotská Hora, who repaired the Orloj in 1552 and kept it, in two spells, until his death in 1572, named Hanuš as its maker in his report on the clock of 1570. Zdeněk Horský corrected the error; the 1410 letter to Mikuláš came to light in a keeper's book in 1962.

Probably in 1629 or 1659 the medieval striking train was brought down from the tower and joined to the clock, and wooden figures were added. Interest then fell away, and by the 18th century the Orloj was in critical condition, the Prague magistracy considering selling it for scrap. Antonín Strnad, meteorologist and professor at Charles University, understood its historical value and persuaded the magistracy to release money for repair. Under his supervision the clockmaker Šimon Landsperger did the work in 1787–1791 for 793 gulden; the figures of the Apostles were added soon afterwards.

The overhaul of 1865–1866 brought the astronomical functions back into operation and added the crowing rooster above the apostle windows. The old escapement, losing up to a quarter of an hour a day, gave way to Romuald Božek's chronometer, accurate to within three seconds a week. A new calendar panel by Josef Mánes was fitted at the same time; a copy replaced it in 1880, the original going to the Prague City Museum.

The Orloj was heavily damaged on 7 and especially 8 May 1945, during the Prague uprising, when Nazi forces fired on the south-west side of the Old Town Square from several armoured vehicles in an unsuccessful attempt to destroy one of the centres of the rising. The town hall and nearby buildings burned, taking the wooden sculptures, the calendar face and the timber structure carrying the apostle mechanism; brickwork around the movement spared it the worst. The damage seemed beyond repair, and replacing the Orloj with a modern machine was discussed. The machinery was mended, largely through the efforts of the Vesecký brothers, Vojtěch Sucharda restored the wooden Apostles, and the clock ran again in 1948.

The 1948 repair painted the coloured horizons on the dial wrongly, so that the clock showed dawn and dusk out by as much as six hours; the fault was put right only in 1979. The statues and the lower calendar ring were restored in autumn 2005. The clock went out of service on 8 January 2018 for a restoration in which the electric drive of 1948 gave way to a weight-driven mechanism on the old pattern, with hemp ropes and stone weights. It restarted at six in the evening on 28 September 2018, opening the centenary celebrations of Czechoslovakia; the chain moving the Apostles jammed at the first start and had to be shifted by hand.

The new copy of Mánes's calendar panel, painted by Stanislav Jirčík, drew a formal complaint in 2022. Milan Patka of the Club for Old Prague told the Ministry of Culture that the restorer had departed from the spirit and detail of the original, and heritage critics held that the ages, skin tones, dress and even the genders of Mánes's figures had been changed. The National Heritage Inspectorate opened an investigation, and the city's deputy mayor for heritage called the work banal and amateur.

The clock is protected as part of a national cultural heritage site in the Czech Republic, in Prague's historic Old Town, and has its own keeper: Petr Skála, who inspects it every Friday.