Orrery
An orrery (neuter, [ ˈʔɔɹəɹi ]) or a planetary machine is a mechanical device that illustrates the orbit of the planets around the sun .
General
The Orrery was originally called the planetarium . Since 1713 John Rowley (1665–1728) had built a planetary machine for Charles Boyle (1674–1731), 4th Earl of Orrery, such devices are also known as Orrerys after this noble family. In Germany, Johann Georg Neßfell and Philipp Matthäus Hahn became famous for building such machines. A model by the Pietist Hahn is a clock with a calendar that shows the time until the apocalypse, combined with a synchronized helio- and geocentric world machine. This was only completed after Hahn's death.
A type of transparent orrerys that were illuminated by a projector so that the planetary movements could be shown on a screen is called an eidouranion .
Depending on which celestial objects were depicted, a distinction is made between various special forms such as tellurium or jovilabe .
Tellurium
A tellurium ( Latin tellus , the earth) is the special case of a planetary machine to demonstrate the movements of the earth and moon . The models of these heavenly bodies rotate on a lever arm around a light source that is supposed to represent the sun . The formation of the seasons, phases of the moon and eclipses can be illustrated with a tellurium. Some tellurias also have the model for an inner planet, mostly Venus , which actually makes them Orrerys.
Wilhelm Schickard (1592–1635) invented an early mechanical handheld planetarium with a self-made tellurium with which he is depicted in a portrait from 1631. The oldest surviving telluriums are assigned to the Dutchman Willem Janszoon Blaeu (1571–1638).
Tellurium is also the original spelling for the chemical element tellurium .
Jovilabium
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A jovilabium ( Latin Iovis , genitive singular of Iuppiter ) is the special case of a planetary machine that represents the orbit of the four Galilean moons - Io, Europa, Ganymede, Callisto - around the planet Jupiter . The name was derived from the astrolabe , a device used to determine star positions.
Starting in 1612 , Galileo Galilei was the first to design five cardboard versions. He called her Giovilabio . They had no gears and served as a calculating device to calculate the positions of the four moons and their eclipses in advance. The points in time were needed to determine the longitude, especially at sea. A brass version that was only made after Galileo's death is now in the Museum for the History of Science (IMSS) in Florence.
The astronomer Ole Rømer first designed a jovilabium with a gear drive in 1677 . It was driven with a hand crank and showed the orbit of the moons with eclipses and transits and should also be helpful in determining the longitude . But since the size of the moons as well as their orbits and distances were not made to the same scale, the times of the eclipse could not be displayed correctly, and thus the device could not be used. The device was probably built by Isaac Thuret, the clockmaker of Louis XIV. It is no longer preserved. A replica has been in the Tycho Brahe Planetarium in Copenhagen since 1991 .
Similar devices come from John Flamsteed and Lothar Zumbach von Koesfeld . A model is in the Astronomy Cabinet in Kassel. Another jovilabium was developed by Giovanni Domenico Cassini in 1677 . Instead of gears and rods, it had five rotating disks. With it the shadow area of Jupiter should be able to be drawn. The astronomer Vinzenzo Miotti of Murano built a jovilabium in Padua in 1781. It had rotating disks and reading tables on cardboard.
A significantly improved model was commissioned by William Pearson (1767–1847) in 1798. The mean orbit time and the different shadow directions when the earth revolves around the sun are displayed more correctly. It also exhibits the bound rotation of the moons. They always show the same side to Jupiter as the earth's moon does to earth. It is now in the Museum of the History of Science in Oxford .
Another device designed by Pearson 1800 is part of an astronomical clock in the Royal Institution in London. A Jovilabium by Pearson can also be seen in the Science Museum London.
A simple mechanical clock provides an imprecise but simple model for the orbit of the earth (minute hand) and Jupiter (hour hand).
Overall, it can be stated that the Jovilabia did not fulfill their purpose of being precise aids in determining the astronomical longitude.
See also
Models in public collections
- Astronomical sensualization tool by Gottlob Leberecht Schulze (1823) in the Hessian State Museum in Darmstadt (Inv. No. HLMD Ph. C. 58/100). The planetarium shows the sun on the central holding rod and the planets Mercury, Venus, Earth and Jupiter with four moons on metal brackets.
- Floor clock with planetarium (Allgäu ?, around 1920) in the Allgäu Museum in Kempten (Inv. No. 7448). The clockwork drives a planetarium in a glass ball. The sun stands firmly in the center and is orbited by the planets known at the time.
- Astronomical world machine by Philipp Matthäus Hahn and colleagues (around 1770–1790) in the Germanic National Museum in Nuremberg (Inv. No. WI 1029). At the front, a celestial globe contains a movement that drives a model of the geocentric world system. The time, monthly data and the current year are displayed on the dials of the clock tower behind it. To the left and right of this, a planet-moons system and a heliocentric planetarium complete the machine.
- Planetary machine in the Museo Correr in Venice.
literature
- David Brewster : Edinburgh Encyclopaedia. Volume 16: Orissa - Poland. Blackwood et al. a., Edinburgh 1830, pp. 623-651.
- Herbert Henck: Planetary machines. An inventory of the writings on four Franconian planetary machines of the 18th century from the circle around Johann Georg Neßtfell with special consideration of the contributions of Johann Ludwig Fricker and Johann Zick. With a bibliography on Johann Georg Neßfell. In: Leaves for Württemberg Church History. 79, 1980, ISSN 0341-9479 , pp. 62-139.
- Henry C. King, John R. Millburn: Geared to the stars. The evolution of planetariums, orreries, and astronomical clocks. University of Toronto Press, Toronto 1978, ISBN 0-8020-2312-6 .
- Alfred Munz: Philipp Matthäus Hahn pastor and mechanic. Reflections on life and work. Jan Thorbecke Verlag, Sigmaringen 1990, ISBN 3-7995-4122-5 ( cultural history miniatures ).
- Abraham Rees: The Cyclopedia. 1819, keywords: Planetary machines, Orrery
- Ernst Zinner : German and Dutch astronomical instruments of the 11th - 18th centuries. 2nd supplemented edition. Beck, Munich 1967.
- Klaus Hünig: AstroMedia - The Copernicus Planetarium. SunWatch Verlag, Neustadt in Holstein, 2008, ISBN 978-3-935364-37-9 .
- HB: Heaven and earth in the room . In: The Gazebo . Issue 50, 1863, pp. 792-793 ( full text [ Wikisource ]).
Web links
- Solar System, Models, Orreries . Picture Library
Individual evidence
- ↑ Frank Peter Unterreiner: A Swabian inventor: Philipp Matthäus Hahn and his "world machines" - miracles of clock technology . In: Stuttgarter Zeitung , November 29, 1991.
- ↑ Tellurium . Watch Wiki
- ↑ Gottlob Leberecht Schulze: New astronomical sensualization tools and their versatile use, described for teachers and friends of the astronomical sciences. A necessary appendix to the same author “Textbook of astronomy for schools and for self-teaching etc.” With two copper plates. Leipzig; Sorau: Friedrich Fleischer, 1823.
- ↑ Peter Frieß, Ingrid Seeger: Clocks. Catalog of the clock collection of the Museum of Art and Cultural History Kempten - Allgäuer Heimatmuseum. Allgäuer Zeitungsverlag, Kempten 1991, pp. 166–167, no. 63 (inventory catalogs of the museums of the city of Kempten, volume 1).
- ^ Anonymous Orrery , accessed July 19, 2014.