Sevres.science / Sèvres, the place

City & Region

Metrology in Sèvres: the Bureau on the hill

The Pavillon de Breteuil and its park lie within the Domaine national de Saint-Cloud. The site is on the territory of Saint-Cloud, with its entrance on the Sèvres side, and it has an extraterritorial status similar to that of an embassy. Its postal address is in Sèvres.

The International Bureau of Weights and Measures has four scientific departments: physical metrology (length, mass, electricity, photometry and related fields), chemistry, ionizing radiation and time. The chemistry department, for example, maintains reference standards for gases such as ozone and carbon dioxide. More on the Bureau on the Institutes & Facilities page.

Time in Sèvres: where UTC is computed

In Sèvres the BIPM computes Coordinated Universal Time (UTC) from data supplied by around 80 time laboratories and about 450 atomic clocks worldwide, and publishes the results every month in Circular T.

UTC itself is a calculated time scale. Each national laboratory keeps its own local realisation of it, called UTC(k), and Circular T lists how far each of them was from UTC. The second that UTC counts is defined by the caesium atom, as explained on the Base units page.

Ceramics in Sèvres: the porcelain town

The manufactory began in 1740 as a soft-paste porcelain workshop in the royal castle of Vincennes. It moved to Sèvres in 1756, into a building raised on the initiative of Madame de Pompadour, and in 1759 Louis XV placed it under the full control of the Crown.

In 1861 work began on new workshops and a ceramics museum, inaugurated in 1876. Today the manufactory and the museum form one national institution, Sèvres – Manufacture et Musée nationaux.

The main building of the manufactory, built between 1753 and 1756, is about 130 metres long. Some 25 buildings on its four-hectare site are protected as historic monuments.

Saint-Cloud next door

The park that surrounds the Bureau has a royal history. In 1658 Louis XIV bought a country house here for his brother Philippe, the future Duke of Orléans, and between 1660 and 1690 André Le Nôtre laid out a park of about 460 hectares around it. Louis XVI bought the château in 1785 for Marie-Antoinette.

On 10 November 1799, at Saint-Cloud, Napoleon Bonaparte’s soldiers drove the deputies out of the Orangerie, ending the Directory. The château itself did not survive the Franco-Prussian War: occupied in September 1870, it was set on fire by shells in October, and its ruins were razed in 1891. The Grande Cascade, one of the great pieces of 17th-century hydraulic engineering, still runs.

The Seine and the island

In the 17th century the port of Sèvres unloaded building materials for Versailles. The island in the river, once called Sève, is today's île Seguin, where Louis Renault's car works spread from 1919.

Sèvres on the Atlas

Sèvres lies on the Concept Cities route of the TheScience.fm Atlas, with Lyon, Bonn, Bologna and Frascati. On this route a city name often stands for an idea as well as a place: Sèvres for the International System of Units, Bologna for a process, Frascati for a family of measurement manuals.

• Big Machines

  Large research machines for particles, photons and plasma.

  Stops: Grenoble.science → Geneva.science → Lausanne.science → Villigen.science → Frascati.science

• Space

  Space agencies, mission centres and the people who build spacecraft.

  Stops: Pasadena.science → Noordwijk.science → Bonn.science → Frascati.science

• Concept Cities via Sèvres

  Cities tied to ideas about how science is judged, funded and measured. Frascati gave its name to the rules for counting R&D.

  Stops: Sevres.science → Lyon.science → Bonn.science → Bologna.science → Frascati.science

• Swiss Model

  How Switzerland organises research, from CERN's host city to its federal institutes.

  Stops: Geneva.science → Lausanne.science → Villigen.science → Zuerich.science

All hubs