This antique planet machine is on display at the Rundetaarn (the Round Tower) in Copenhagen. There is a sign next to it (in Danish) explaining its history.
From the Rundetaarn's website (note: this text refers to the machine as a 'planetarium' even though in English we think of a planetarium as the a building):
"The Round Tower’s planetarium shows the planetary positions right now. Let your glance wander from the Sun in the middle over Mercury and Venus to the little white ball depicting Earth, and on to Mars, Jupiter and, finally, Saturn with its rings. The eyelets allow the planets to move without hindrance.
Behind the planetarium is a clockwork mechanism that is wound up once a week. Formerly you could set the planetarium to show the planetary positions at a given time by cranking a handle that was inserted into the device below the planetarium.
Employed by the Sun King
The story of the planetarium begins in Paris, where the Danish astronomer Ole Rømer made the groundbreaking discovery of the speed of light. He was also skilled in constructing astronomical mechanisms. Commissioned by the French king, several replicas of one of his smaller devices were made and sent as gifts to, among others, the Danish king and the emperor of China.
Returning to Denmark
After his return, Ole Rømer became the leader of the Observatory in the Round Tower, and in 1697 he installed a planetarium in the ceiling at the top of the tower, one purpose being educational. The planetarium was similar to one he had made in Paris or perhaps the very same, as some sources state. The planetarium showed the planetary positions according to the Danish astronomer Tycho Brahe, that is with Earth as the centre of the Universe and the other planets orbiting the Sun.
Competing Systems
The planetarium was later modified to show both Tycho Brahe’s system and the competing Sun-centered system suggested by Nicolai Copernicus. However, the mechanism was severely damaged in the fire of Copenhagen in 1728 and was not rebuilt until several years later, this time designed to show only Copernicus’ system.
During a restoration in 1822, it was placed in its current vertical location, and some 100 years later the clockwork was connected. On the same occasion, the star map behind the planets was also renewed. The old back is on display in the Bell Loft."
Source: (
visit link)
Text of the sign translated into English via Google Translate:
"The planetary machine
The Astronomer, the later Chief of Police in Copenhagen, was constructed in Paris in 1680
OLE CHRISTENSEN RØMER,
Set up in Rundetaarn in 1697. By the Copenhagen fire in 1728, the planetary machine was destroyed, but after the fire it was reconstructed in 1742 by instrument maker J. J. Lincke at the expense of master of ceremonies Vincenz de Lercke. For Rundetaarn's Funds, the Planetarium was restored again in 1928 and partly renewed by Taarnur manufacturer Bertram Laren. The planetary disk is reproduced by Conservator Svend Rønne.
The above schematic drawing of the front of the planetary machine explains the significance of the figures on the planetary machine. The star in the center represents the sun, and in planets, namely in the following order from the center: Mercury, Venus, Earth (the white sphere), Mars, Jupiter and Saturn (the ring planet), the planets describe using a clockwork set up in space behind the disk, an orbit around the sun in the same time period as the real planets. The distance conditions, however, do not correspond to the real Background is a Map of the Northern Starry Sky, essentially reproduced after the Bayer Sky Map (1572-1625). The small hemisphere under the vault contains a counter."