page_title: Meudon Great Refractor
section_title: Background & Development
hierarchical_section_title: Meudon Great Refractor / Background & Development
caption_attribution_description: Français&#160;: Observatoire de Meudon
context_page_description: Meudon Great Refractor is a double telescope with lenses, in Meudon, France. It is a twin refracting telescope built in 1891, with one visual and one photographic, on a single square-tube together on an equatorial mount, inside a dome. The Refractor was built for the Meudon Observatory, and is the largest double doublet refracting telescope in Europe, but about the same size as several telescopes in this period, when this style of telescope was popular. Other large telescopes of a similar type include the James Lick telescope, Potsdam Great Refractor, and the Greenwich 28 inch refractor.
  Institutionally it was part of the Meudon Observatory, which later became integrated with the Paris observatory.
  The Great Refractor was used for research well into the 1980s, after nearly a century of use. In the 21st century it was renovated and re-opened for public outreach.
  The telescope is noted for being used to disprove the theory of Martian canals, which was a popular story in the late 19th century.
  The telescope lenses were made by the Henry Brothers, and the mounting was made by Gautier.
context_section_description: Meudon Observatory was founded in 1876, but became part of the Paris Observatory in the 1926. In this period the observatories were not just a telescope, but more like a laboratory, with integrated equipment, libraries, and workshops for practical and theoretical astronomy. A major focus was developing new kinds of instruments.
  The chief developer was Pierre Janssen, who orchestrated the construction of the large refractor. Janssen was famous for his role in the discovery of Helium in 1868, and by 1875 he was authorized to build a large astrophysical observatory.
  The facilities were built on the ruins of an old French palace, noted in the publication Scientific American for "beautiful view of Paris and the river seine." As one era ended a new one started, with the foundations of the telescopes built on the ruins, and old stables converted into laboratories.
  The dome building took about ten years of construction from 1880 to 1890. The site has a long history going back to a summer palace designed by Le Primatic, then a summer Palace of the Grand Dauphin by the end of the 17th century; some expansion were done by Jules Hardouin-Mansart. The old château Vieux was replaced by the château Neuf, which was used until the Franco-Prussian War of 1870. The usuefull location meant the sites involvement in the activities of that war, and by the end it was left ruin. On these ruins Janssen was able to use location for the new observatory, that would house the great telescope.
caption: Dome of the Great refractor of Meudon
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