Gabriel Jars

Antoine-Gabriel Jars (born January 26, 1732 in Lyon , † August 20, 1769 in Clermont-Ferrand ) was a French engineer and metallurgist . Together with the industrialist François Ignace de Wendel , he developed a casting process in which hard coal coke replaced the previously used charcoal. This process, previously only available to English industry, allowed higher quality.

Origin, education and travel

Gabriel Jars (also known as "the younger") was the second son of the copper mine director of Chessy and Sain-Bel, Gabriel Jars and his wife Jeanne-Marie Valioud. He was one of the few students Daniel-Charles Trudaine accepted because of his talents in order to focus with them on special topics in metallurgy. The group undertook several study trips through Europe for this purpose, which shaped Jars' further work.

In 1751 he entered the École Nationale des Ponts et Chaussées , the oldest technical university in Europe. Here he learned technical drawing and land surveying, having previously graduated from the Jesuit school in Lyon . The miner Koenig, a well-known mine engineer from Saxony and mine director in Poullaouen and Huelgoat at the time , instructed Jars together with Jean-Pierre-François Guillot-Duhamel in the German language and in practical mining operations. After his activity had taken him through France and allowed him to work in various French mining companies and establishments, e.g. B. Poullaouen, Pont-Péan, Ingrande (oil production) in Anjou, Sainte-Marie-aux-Mines to visit and study, he devoted himself from 1757 to 1759 together with Jean-Pierre-François Guillot-Duhamel Mine Visit in Saxony, Salzburg, Bohemia, Hungary, Tyrol, Carinthia and Styria . Then he returned to his parents' business.

In 1765 he visited England and Scotland, which was leading in the metallurgical industry at the time, from where he reported on the innovative processes of mine production. From here he also brought his ideas with him to develop a superior casting process in which hard coal coke replaced the previously used charcoal . In 1766 he traveled to Holland, the Harz, Hanover, Saxony, Norway and Sweden. After he had already been appointed correspondent of the Academy of Sciences on January 10, 1761 , he was made titular member on May 19, 1768 - against Antoine Laurent de Lavoisier , although that had been placed first. The government rewarded Antoine Gabriel Jars for his services to the mining industry and metallurgy.

Innovations and careers in France

Despite his travels, Jars found time in Saint-Bel to experiment and to test the application of his experiences. He demonstrated the first use of coke in copper smelting in France and the coke casting process (1769). When he repeated this in an experiment on the premises of the Wendel industrial family in Hayange , it was not immediately adopted. Nevertheless, "the English procedures" then successfully established themselves in France. The period of Jars' industrial exchange also saw the work of the famous engineer and artillery general Jean-Baptiste Vaquette, Viscount de Gribeauval , who in 1765 modernized the Artillery Corps and the Mining Department by reducing the number of cannon calibers and standardizing them while himself André Fougeroux de Secval stayed in a number of smelting operations to improve the quality of materials and processes for the benefit of the army. Here, too, Jars led the groundwork.

Jars' reports and publications were initially kept under lock and key by the French government, as it was feared that the findings could help other governments industrially and serve the purpose of arms production. The books he wrote, including the Voyages métallurgiques in 3 volumes, were only published by his older brother Gabriel Jars (“the elder”) after his early death. Another achievement of Gabriel Jars is the natural ventilation of mines. He is also considered the "father of Le Creusot ", the industrial site. Shortly before his death in 1768, Gabriel Jars toured the mines of Mont Cenis in Bourgogne as an engineer and correspondent for the Academy of Sciences . He noticed a larger coal deposit and demonstrated to the owner François de la Chaise the way in which coke was made from coal in England. He was the first to consider it sensible to link the Riaux valley - rich in coal and traders - with the road to Chalon and the Saône and Arroux rivers that flow into the Loire .

Antoine-Gabriel Jars died in Clermont at the age of only 37 from a sunstroke that he suffered while studying basaltic formations in the Langeac area .

Web links

• Google book search
• Google book search

swell

For a compilation of the works by Jars from the years 1757–1769, see: Voyages métallurgiques ou recherches et observations sur les mines et forges de fer. . ., Gabriel Jars, ed., 3 vols. (Lyon, 1774-1781). From the Mémoires of the Paris Academy of Sciences

• “Observations on the circulation of the air in the mines” (1768), pp. 218-235;
• “D'un grand fourneau á raffiner le cuivre” (1769), pp. 589-606;
• “Procédé des Anglois pour convertir le plomb en minium” (1770), pp. 68-72;
• “Observations métallurgiques sur la séparation de métaux,” ibid., Pp. 423-436, 514-525; * “Observations sur les mines en general,” ibid., Pp. 540-557.

• Secondary literature: On Jars and his work, see (listed chronologically): Grandjean de Fouchy, “Éloge de M. Jars,” in Histoires de l'Académie Royale des Sciences (1769), p. 173; ibid. (1770), p. 59; Charles Ballot, L'introduction du machinisme dans l'industrie française (Paris-Lille, 1923), pp. 437 ff .; and Jean Chevalier, “La mission de Gabriel Jars dans les mines et les usines britanniques en 1764,” in Transactions. The Newcomen Society for the Study of the History of Engineering and Technology, 26 (1947-1949), 57.

Individual evidence

1. ^ List of members since 1666: letter J. Académie des sciences, accessed on November 30, 2019 (French).