# Jean-Charles de Borda

> French scientist, political advisor and sailor (1733-1799)

**Wikidata**: [Q369762](https://www.wikidata.org/wiki/Q369762)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Jean-Charles_de_Borda)  
**Source**: https://4ort.xyz/entity/jean-charles-de-borda

## Summary
Jean-Charles de Borda was a French scientist, political advisor, and sailor (1733‑1799) best known for developing the Borda voting method and the Borda–Carnot equation in fluid dynamics. His work spanned mathematics, physics, political science, military engineering, and writing, leaving a lasting legacy in science and institutional reform.

## Biography
- Born: 1733  
- Died: 1799  
- Nationality: French  
- Known for: Borda method (voting system) and Borda–Carnot equation (fluid dynamics)  
- Employer(s): French Army; French Navy; École royale du génie de Mézières  
- Field(s): Mathematics; Physics; Political science; Military engineering; Writing  

## Contributions
- **Borda method** – devised a preferential voting procedure where candidates receive points based on their rank in each voter’s list; used in early French elections and later influential in social choice theory.  
- **Borda–Carnot equation** – formulated an empirical relation describing energy losses due to sudden fluid flow expansions, a cornerstone of hydraulic engineering.  
- **Naval service** – participated as a sailor and military officer in the 1779 Siege of Savannah (American Revolutionary War) and the 1782 Battle of the Saintes (Anglo‑French naval conflict).  
- **Institutional leadership** – helped found the Bureau des Longitudes in 1795, serving as a key figure in its early work on astronomical navigation and timekeeping.  
- **Academic membership** – elected member of the French Academy of Sciences, contributing to its scientific agenda.  
- **Eponyms** – the lunar crater Borda, the French naval vessel *Valmy* (later renamed *Borda* and used as a training ship), and his name among the 72 scientists engraved on the Eiffel Tower (installed 1887).  

## FAQs
**Who was Jean-Charles de Borda?**  
He was a French polymath active from the mid‑18th century until his death in 1799, working as a scientist, political advisor, and sailor while contributing to mathematics, physics, political science, military engineering, and literature.  

**What is the Borda method and why is it significant?**  
The Borda method is a ranked‑choice voting system in which each voter assigns points to candidates according to their position; the candidate with the highest total wins. It introduced a systematic way to aggregate preferences and influenced later theories of social choice.  

**What does the Borda–Carnot equation describe?**  
The Borda–Carnot equation quantifies the loss of mechanical energy that occurs when an incompressible fluid undergoes a sudden expansion or contraction, providing a practical tool for engineers designing pipelines and hydraulic structures.  

**Which military engagements did he take part in?**  
Borda served as a sailor and officer in the 1779 Siege of Savannah during the American Revolutionary War and in the 1782 Battle of the Saintes, a major naval clash between the British and French fleets in the Caribbean.  

**What institutions was he affiliated with?**  
He was associated with the French Army and French Navy, trained at the École royale du génie de Mézières, elected to the French Academy of Sciences, and played a founding role in the Bureau des Longitudes established in 1795.  

**What honors and memorials bear his name?**  
His name appears among the 72 scientists and engineers inscribed on the Eiffel Tower, a lunar crater is named Borda, and the French naval ship *Valmy* was renamed *Borda* and used as a training vessel.  

**Why did he join the Bureau des Longitudes?**  
Motivated by the need for accurate astronomical tables to improve maritime navigation, Borda helped create the Bureau des Longitudes in 1795 to centralize French efforts in determining longitude at sea.  

## Why They Matter
Jean‑Charles de Borda’s innovations reshaped both theoretical and applied sciences. The Borda method introduced a mathematically grounded approach to collective decision‑making, anticipating modern voting theory and influencing later scholars such as Condorcet and Arrow. The Borda–Carnot equation remains a standard reference for estimating head loss in fluid systems, directly impacting the design of water supply, irrigation, and hydraulic machinery. His service in the French Navy and contributions to the Bureau des Longitudes advanced navigational accuracy, which was crucial for French maritime power and global exploration during the late 18th century. Membership in the French Academy of Sciences placed him at the heart of Enlightenment scientific discourse, while his name on the Eiffel Tower and the lunar crater Borda ensure his legacy is visible in both cultural and astronomical contexts. Without his work, the development of preferential voting techniques and fluid‑dynamic loss calculations would have lacked a key early milestone, and French naval science might have progressed more slowly.

## Notable For
- Founder‑member of the Bureau des Longitudes (established 1795)  
- Elected member of the French Academy of Sciences  
- Creator of the Borda voting method (ranked‑choice points system)  
- Author of the Borda–Carnot equation (fluid‑dynamic energy loss formula)  
- Participant in the 1779 Siege of Savannah and 1782 Battle of the Saintes  
- Namesake of the lunar crater Borda  
- Namesake of the French naval vessel *Valmy* (renamed *Borda*) used as a training ship  
- One of the 72 scientists and engineers engraved on the Eiffel Tower (installed 1887)  
- Recognized as mathematician, physicist, political scientist, military officer, military engineer, writer, and French national  

## Body
### Early Life and Personal Background
Jean‑Charles de Borda was born in 1733 and died in 1799. He was a French national and is described in the source as a human being. No further details about his family, birthplace, or early education are provided in the supplied material.

### Military and Naval Career
Borda served as a military officer in the French Army and as a sailor in the French Navy. His naval involvement includes participation in the 1779 Siege of Savannah, an action during the American Revolutionary War, and the 1782 Battle of the Saintes, a significant naval engagement between British and French fleets in the Caribbean. These events are explicitly listed under the “related” section.

### Scientific and Mathematical Contributions
He is identified as a mathematician and physicist. His most cited scientific work is the Borda–Carnot equation, which addresses energy loss in fluid dynamics during sudden expansions or contractions. In the realm of social choice, he devised the Borda method, a voting system where each voter assigns points to candidates based on rank, and the candidate with the highest total score wins. Both contributions are directly named in the source.

### Institutional Affiliations and Leadership
Borda’s institutional ties include:
- Training at the École royale du génie de Mézières, a former military academy.
- Service in the French Army and French Navy.
- Election to the French Academy of Sciences, a learned society founded in 1666 to promote French scientific research.
- A founding role in the Bureau des Longitudes, established on 25 June 1795, which focused on astronomical navigation and the determination of longitude at sea.

### Writing and Intellectual Pursuits
The source lists “writer” as one of his roles, indicating that he used written words to communicate ideas and produce literary works, though specific titles or publications are not detailed in the provided data.

### Honors, Memorials, and Eponyms
- His name is among the 72 scientists and engineers inscribed on the Eiffel Tower, a monument completed in 1887 honoring French contributors to science and industry from 1789 to 1889.
- A lunar crater bears the name Borda.
- The French ship *Valmy*, originally a 120‑gun ship of the line, was later renamed *Borda* and employed as a naval training vessel.
- These recognitions are captured in the “related” and “Awards / Recognition” sections.

### Legacy and Influence
Through his work in voting theory, fluid dynamics, naval service, and scientific institution‑building, Borda left a multifaceted legacy. The Borda method contributed to the early formalization of electoral systems, while the Borda–Carnot equation remains a practical tool for engineers. His participation in the Bureau des Longitudes helped improve maritime navigation, a strategic concern for France during his lifetime. The enduring presence of his name on the Eiffel Tower, the Moon, and a former warship underscores the lasting acknowledgment of his contributions across scientific, cultural, and astronomical domains.

## References

1. MacTutor History of Mathematics archive
2. BnF authorities
3. Integrated Authority File
4. [Source](https://www.google.cat/books?id=5yKdWzg2DD4C)
5. Find a Grave
6. [Source](https://books.google.cat/books?id=5yKdWzg2DD4C)
7. [Source](https://www.toureiffel.paris/fr/le-monument/tour-eiffel-et-sciences)
8. International Standard Name Identifier
9. Virtual International Authority File
10. CiNii Research
11. EB-11 / Borda, Jean Charles
12. SNAC
13. Brockhaus Enzyklopädie
14. Gran Enciclopèdia Catalana
15. GeneaStar
16. La France savante
17. Freebase Data Dumps. 2013
18. [Source](http://digitale.beic.it/primo_library/libweb/action/search.do?fn=search&vid=BEIC&vl%283134987UI0%29=creator&vl%28freeText0%29=Borda%20Jean%20Charles)
19. National Library of Israel Names and Subjects Authority File