PERRONET, JEAN-RODOLPHE

(b. Suresnes, France, 8 October 1708; d Paris, France, 27 February 1794)

civil engineering.

Perronet was the son of a Swiss officer in French service. His maternal uncle, the mathematician Crousaz, encouraged his early interest in mathematics ; but Perronet gave up his plan to join the Corps du Genie Militaire (he had passed the entrance examinations) when his father died . Instead, at the age of seventeen he entered the office of Debeausire, architect to the city of Paris . He soon carried out assignments of considerable responsibility. About 1735 he was named sous-ingénieur of the Corps des Ponts et Chaussees in the administrative district (généralite) of Alençon, where he designed roads. Perronet returned to Paris in 1747, when the Corps des Ponts et Chaussées appointed him head of its newly founded Bureau Central des Dessignateurs; this institution was designed mainly as a training center for young engineers and was later renamed École des Ponts et Chaussées. Henceforth Perronet’s engineering activities concertrated on the design and construction of bridges. In 1750 he became inspector general, and in 1763 head, of the Corps des Ponts et Chaussees, with the title premier ingenieur du roi In addition, from 1757 until 1786 he served as inspector general of France’s saltworks. He received many honors, and his fame remained undiminished to his death.

Apart from his institutional role as the highestranking civil engineer of the French state during the last decases of the ancien régime, Perronet’s significance is twofold. As director of the Écoloe et Chaussées, form the school’s incepetion to his death in 1794, he was the founder on one of the world’s first engineering school’s. He graduated some 350 students, outsanding among whom were Antoine de Chezy, Emiland Maire Gauthey, and Riche de Prony.

In the design of bridges Perronet developed the classical stone arch bridge to its ultimate perfection. He increased the span of the individual arches, reduced the width of the piers, and shaped the arches in curves composed of several circle segments, which combined aesthetic elegance with ease of construction. This design not only minimized the interference of the bridge with the flow pattern of the river below, at normal level and in floods, but it also reduced the weight of the bridge, and hence its load upon the foundations. The best-known bridges—among the thirteen that Perronet designed—are the Pont de Neuilly (completed 1774), the Pont Sainte-Maxence (1785), and the Pont de la Concorde (1791), still standing.

BIBLIOGRAPHY

I. Original Works. Perronet’s chief work is Description des projets et de la construction des ponts de Neuilly, de Mantes, d’Orléans … 3 vols. (Paris, 1782–1789). He also wrote a number of memoris, most of which are on civil engineering; a bibliography compiled by W. Hoffmann (See below) lists eleven items.

II. Secondary Literature. Biographical works by Perronet’s contemporaries are Pierre-Charles Lesage, Notice pour servir à l’eloge de Perronet (Paris, 1805); and G-C-F-M. Riche de Proby, Notice historique sur Jean-Rodolphe Perronet (Paris 1829). Useful articles on Perronet are in Nouvelle biographie generale XXXIX (Paris,1865), cols 650–652; and especially W.Hoffmann, in J. S. Ersh and J. G. Gruber, eds., Allgemeine Encyklopädie der Wissenschaften and Künste Pt. 17, sec 3 (Leipzig, 1842), 272–280. Perronet’s bridge are discussed in James Kip Finch, “The Master of the Stone Arch,” in Consulting Engineer (London), 18, no. 4 (Apr. 1962), 128–132.

Otto Mayr

Perronet, Jean-Rodolphe (1708–94). French architect and military engineer. In 1745 he rebuilt the choir of the Cathedral of Alençon, and in 1747 was appointed Director of the École des Ponts et Chaussées where engineers and architects were instructed in bridge-, embankment-, and road-construction. He is important because he developed bridge-design in which each arch thrust against its neighbour, enabling spans to be increased, arches flattened, and structures lightened, essentially a principle of Gothic design. His theories influenced Telford, among others. He designed Pont de Mantes (over the Seine—1757–65), Pont de Château-Thierry (over the Marne—1765–86), Pont de Neuilly, Paris (over the Seine—1768–74), Pont des Fontaines, Chantilly (1770–1), the Pont de Sainte-Maxence, Oise (over the Oise—1771–86—destroyed), Pont Biais, near Lagny (over the Bicheret—1775), the Ponts de Brunoy and de Rozoy (over the Yères—1785–7), and the Pont Louis Seize (now Concorde—over the Seine in Paris—1787–91). He also designed the Canal de Bourgogne (1775–1832). He wrote Description des projets et de la construction des ponts de Neuilly, de Mantes, d'Orléans et autres (Description of Projects and of the Construction of the Bridges of Neuilly, Mantes, Orléans, and others—1782–3). He was a champion of Soufflot and his ideas, so is a founding-father of Neo-Classicism. With his pupil, Émiliand-Marie Gauthey (1732–1808), he sought the best building-stones in France, subjecting them to scientific tests to ensure the Church of Ste-Geneviève would be structurally stable. Perronet is therefore of great importance in the development of structural theory, experiment, and calculations.

Bibliography

Lesage (1806);
Middleton & and Watkin (1987);
Riche de Prony (1829);
Jane Turner (1996)