[2] King Louis XIV's minister of finance organized a "scientific powerhouse" to increase understanding of astronomy, maritime navigation, and science in general.

[3] [4] Administratively, it is a grand établissement of the French Ministry of National Education, with a status close to that of a public university.

[6] It remains the source of legal time in France,[7] using multiple atomic fountain clocks maintained by its SYRTE (Sytèmes de Référence Temps Espace) department.

[8] The Paris Observatory Library, which was founded in 1785, provides the researchers with documentation and preserves the ancient books, archives, and heritage collections of the institution.

[citation needed] The Paris Observatory was proposed in 1665–1666 by the French Academy of Sciences, which had recently been founded by the Minister of Finance Jean-Baptiste Colbert.

On Midsummer's Day 1667, members of the Academy of Sciences traced the future building's outline on a plot outside town near the Port Royal abbey, with the Paris meridian exactly bisecting the site north–south.

"[10] The architect of the Paris Observatory was Claude Perrault whose brother, Charles, was secretary to Jean-Baptiste Colbert and superintendent of public works.

[15] The world's first national almanac, the Connaissance des temps, was published by the Observatory in 1679, using eclipses in Jupiter's satellites to aid sea-farers in establishing longitude.

In 1882, a 33 cm (13 in) astrographic lens was constructed, an instrument that catalysed what proved to be the over-ambitious international Carte du Ciel project.

The title of Director of the Observatory was officially given for the first time to César-François Cassini de Thury by a Royal brevet dated November 12, 1771.

With a million francs and permission to build on the ruins of the old royal palace, he constructed one of the grandest observatories of its day, with a focus on astronomy and solar physics.

Even into the 21st century solar observations are conducted at the Meudon site, and the preserved Great Refractor (Grande lunette) and astronomical gardens overlooking the city of Paris have delighted visitors for decades.

The site includes: After the Second World War, French astronomers began designing and building instruments for radio astronomy.

A coronograph was in operation there for ten years; the dome was moved there from the Perrault building of the Observatoire de Paris.

Nowadays, the AstroQueyras amateur astronomy association operates the facility, using a 60 cm (24 in) telescope on loan from the Observatoire de Haute Provence.

[32] The tower could hold the objective lens for extremely long focal length aerial telescopes.

[37] In 1875 a 120 cm aperture silver-on-glass reflecting telescope was built, for 400,000 francs[39] (the French unit of currency at that time).

This 120 cm diameter aperture telescope was a silvered glass mirror polished by Martin.

[40] However, when it was mounted it was realized the gravity altered its shape because of the mirror's weight, thus causing an image quality issue.