Person: D'Arcy, Patrick
Patrick d'Arcy was an Irish mathematician and soldier who studied in France and made original contributions to dynamics. He is best known for his part in the discovery of the principle of angular momentum.
Mathematical Profile (Excerpt):
- Let us note at this stage that d'Arcy's date of birth seems to be disputed.
- One of his sons, Patrick d'Arcy (1598-1668), trained as a lawyer and entered Parliament.
- D'Arcy was given lodgings in Paris in the home of Jean-Baptiste Clairaut.
- By the time d'Arcy arrived in Jean-Baptiste Clairaut's apartment, Alexis Clairaut was 26 years old and had been a member of the Academy of Sciences for eight years.
- Jean-Baptiste Clairaut now began to tutor the young d'Arcy in mathematics using similar high powered techniques to those he had used with his own son.
- D'Arcy's progress in mathematics was almost as remarkable as that of Alexis Clairaut.
- In 1742, when he was only seventeen years old, d'Arcy had a paper published by the Paris Academy of Sciences.
- D'Arcy decided on a military career and joined the Condé Infanterie.
- D'Arcy was in the Condé regiment of the French army which captured the village of Augenheim on 23 August 1744 and also when they concluded the campaign, in November 1744, with the taking of Freiburg, under the walls of which alone they lost twelve thousand men.
- After these campaigns, d'Arcy took part in an expedition which attempted to go to Scotland to support Prince Charles Edward Stuart, known as "Bonnie Prince Charlie" or the "Young Pretender".
- D'Arcy set out with Count Fitzjames and several hundred men on the ships Bourbon and Charité attempting to sail to Scotland to give support to Prince Charles Edward.
- D'Arcy was taken prisoner and held for a while in the Tower of London.
- Soon d'Arcy was back in the military.
- In 1757 d'Arcy was with the French troops as they took on the Prussians under Frederick the Great near the town of Rosburg.
- Many in Fitzjames' Regiment were killed and the remainder, including d'Arcy, returned to France.
- D'Arcy now worked for Antoine Ricouart d'Herouville (1713-1782) who was planning a French attack on England.
- D'Arcy had considerable expertise concerning the waters round Ireland and he joined with d'Herouville in the project and carried out some surveys.
- The plan came to nothing for it was never carried through but for the enthusiastic way that d'Arcy had undertaken the work he was promoted to brigadier.
- Let us return to d'Arcy's mathematical and other scientific studies which he carried out after the military campaigns we described above.
- D'Arcy also published Précis de l'essai sur la théorie de l'artillerie Ⓣ(Summary of an essay on the theory of artillery) (1760), Mémoire sur la durée de la sensation de la vue Ⓣ(Memorandum on the duration of the sensation of vision) (1765), and Recueil de pièces sur un nouveau fusil Ⓣ(Digest of remrks on a new rifle) (1767).
- In 1767 d'Arcy made a visit to Kiltullagh in Ireland, the place of his birth.
- She had previously moved to Paris to receive an education there and d'Arcy had become very fond of her.
- The marriage took place in the church of Saint Philippe du Roule in the 8th arrondissement, which at that time was near the outskirts of Paris where d'Arcy owned property.
- D'Arcy carried on with his scientific work, collaborating with Jean Baptiste Le Roy (1720-1800) on electricity, and their work was of interest to Benjamin Franklin who was a close friend of Le Roy.
- Le Roy and d'Arcy had jointly worked on measuring electricity in 1748 and had invented a floating repulsion electrometer to measure electrostatic repulsion.
- We know that d'Arcy was in London in 1770 since he delivered a letter, a book and pump machine from Le Roy to Franklin's London home.
- Only two years after his marriage, d'Arcy died having contracted cholera.
- Sadly, although the names of Euler, Bernouilli, D'Alembert, and Clairaut still "adorn the history of science", the name of Patrick d'Arcy has been almost totally forgotten.
- Let us hope that this biography goes just a little way towards remembering d'Arcy in the 21st century.
Born 27 September 1725, Kiltullagh near Athenry, County Galway, Ireland. Died 18 October 1779, Paris, France.
View full biography at MacTutor
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Origin Ireland
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- @J-J-O'Connor
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References
Adapted from other CC BY-SA 4.0 Sources:
- O’Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive
