Measuring the distance from the North Pole to the equator became the primary objective for Jean-Baptiste Joseph Delambre in 1792, when he took charge of a northern expedition to define the metre. Born in Amiens in 1749, the mathematician and astronomer spent his career formalising precise geodetical measurements that established a new standard for global scientific length.
Early Education and Linguistic Skill
A childhood fever compromised his eyesight, prompting Delambre to develop exceptional memory techniques. He studied at the College Duplessis from 1765 to 1766 and later attended the Collège de France between 1780 and 1783. This period was marked by an immersion in Greek and Latin literature, alongside fluency in Italian, English, and German. He authored an unpublished guide on learning the English language, reflecting his commitment to intellectual mastery.
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Take the IQ test →The Metric Meridian Survey
In 1790, the French Academy of Sciences initiated the development of the metre, seeking to define it as one ten-millionth of the distance from the North Pole to the equator. Delambre joined the project in 1792, directing the northern portion of the survey from Dunkirk to Rodez. This work, conducted alongside data gathered by Pierre Méchain, provided the empirical basis for the decimal metric system. The results were compiled in the three-volume work, Base du système métrique décimal, published between 1806 and 1810.
Administrative and Academic Leadership
Delambre held numerous influential positions, serving as the Permanent Secretary for the Mathematical Sciences at the French Academy of Sciences from 1801 until his death in 1822. He directed the Paris Observatory starting in 1804 and held a professorship at the Collège de France from 1807. His membership in international scholarly bodies included the Royal Society, the Royal Swedish Academy of Sciences, and the American Academy of Arts and Sciences.
Late Career and Historical Scholarship
During his final years, Delambre produced an extensive history of astronomy, documenting developments from ancient times through the 18th century. His six-volume survey included titles such as Histoire de l'astronomie ancienne and Histoire de l'astronomie moderne. In 1821, he was named an Officer of the Legion of Honour. Delambre died in 1822 in Paris and is buried at Père Lachaise Cemetery.
Fast facts
- Born: 1749, Amiens
- Died: 1822, Paris
- Primary occupations: Astronomer, mathematician, historian
- Key work: Arc measurement of Delambre and Méchain
- Education: College Duplessis, Paris Observatory, Collège de France
- Burial site: Père Lachaise Cemetery
- Legacy: One of 72 names on the Eiffel Tower
- Scientific honour: Fellow of the Royal Society (1791)
Questions readers ask
What was Delambre's role in the creation of the metric system?
He led the northern expedition from 1792 to 1798 to measure the meridian arc between Dunkirk and Rodez, which established the length of the metre.
Where did Delambre serve as a professor?
He held a professorship in astronomy at the Collège de France from 1807 until 1822.
Achievements
- Officer of the Legion of Honour — 1821
- Knight of the Legion of Honour — 1815
- Notable work: Arc measurement of Delambre and Méchain
- Affiliated with Collège de France, Bureau des Longitudes and Jean-Claude Geoffroy d’Assy
- Educated at Collège de France and College Duplessis
- Worked as astronomer, mathematician and historian
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