Person: Mathieu, Claude-Louis
Claude-Louis Mathieu was a French astronomer who was one of those responsible for the adoption of the metric system.
Mathematical Profile (Excerpt):
- Mathieu graduated in 1805 and became a student engineer of Ponts et Chaussées.
- After Arago and Biot left Paris in 1806 to begin their measurements in Spain, Mathieu was appointed as secretary of the Paris Observatory to replace Arago.
- In 1808 Mathieu, together with the astronomers Alexis Bouvard and Jean Burckhardt, worked on reducing the data obtained by Arago and Biot in their extension of the meridian measurements to the Balearic Islands.
- Both Mathieu and Biot received a prize from the Academy of Sciences in 1809 for this highly accurate work, and in 1812 they received a second prize from the Academy for their achievements.
- Between August 1812 and November 1813, Mathieu and Arago carried out numerous observations on the star 61 Cygni, attempting to measure its parallax.
- Mathieu and Arago arrived at the correct conclusion that the parallax of this star was less than half a second, but the actual determination of its parallax had to wait until 1838 when Bessel computed it.
- Mathieu was elected to fill this vacant place later that year.
- Mathieu was appointed professor of analysis at the École Polytechnique in 1828, a position he held for ten years when he resigned to take up an appointment as an examiner for students completing their courses at the École.
- For many years Claude Mathieu's work for the Bureau des Longitudes involved editing the work on population statistics L'Annuaire du Bureau des Longitudes.
- This was used by Mathieu as the basis for the biography of Delambre that he wrote and published in Biographie universelle Ⓣ(Universal Biography).
- Mathieu, who had been left as Delambre's scientific executor, completed the work and it was published in 1827.
- In this he discussed in detail the fact that Méchain had deliberately falsified the data when measuring the meridian and this made Mathieu decide not to publish the work as he felt it might damage the case he was making for having the metric system reinstated.
- By 1837 Mathieu was a representative for Mâcon in the House of Deputies.
- The fact that the project had been so major and unrepeatable was its great virtue, argued Mathieu, for the metre was now fixed for all time and even if the Archive Metre were damaged, its length was known in relation to the pendulum so could be reconstructed.
- Claude Mathieu was elected as the president of the Commission.
- It is remarkable that Mathieu was able to undertake the work of president of this Commission despite being 90 years old.
Born 25 November 1783, Mâcon, France. Died 5 March 1875, Paris, France.
View full biography at MacTutor
Tags relevant for this person:
Astronomy
Thank you to the contributors under CC BY-SA 4.0! 
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- non-Github:
- @J-J-O'Connor
- @E-F-Robertson
References
Adapted from other CC BY-SA 4.0 Sources:
- O’Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive
