Philippe de La Hire

Philippe de La Hire, born on 18 March 1640 in Paris, was a multifaceted French intellectual known for his contributions as an astronomer, mathematician, professor, architect, and naturalist. He was the son of the esteemed artist Laurent de La Hire and Marguerite Coquin. In 1660, he ventured to Venice for four years to refine his painting skills, returning to Paris to study under the renowned Girard Desargues, from whom he mastered geometrical perspective and was recognized as a master painter on 4 August 1670.

La Hire's intellectual pursuits extended beyond painting; he developed a keen interest in science and mathematics, influenced by the Jesuit scholar Honoré Fabri. He became part of a distinguished circle that included notable figures such as Giovanni Domenico Cassini and Christiaan Huygens. His membership in the French Academy of Sciences began in 1678, following the death of Jacques Buot, marking the start of his active engagement in astronomy. He meticulously calculated the movements of celestial bodies and designed innovative devices for aerial telescopes.

From 1679 to 1682, La Hire conducted significant observations of the French coastline and played a crucial role in extending the Paris meridian northward in 1683. He assumed the chair of mathematics at the Collège Royal in the same year and later taught at the Académie d’architecture from 1687 onwards. His scholarly works included treatises on graphical methods, conic sections, epicycloids, roulettes, and conchoids, showcasing his deep understanding of mathematical principles.

In addition to his mathematical endeavors, La Hire made contributions to descriptive zoology and physiological optics. His legacy continued through his sons, Gabriel-Philippe and Jean-Nicolas, both of whom achieved prominence in their respective scientific fields. Notably, Mons La Hire, a mountain on the Moon, bears his name, commemorating his impact on astronomy. On 19 December 1699, he presented groundbreaking observations on friction at the Académie Royale des Sciences, proposing what are now known as Amontons’ laws of friction.