Guillaume-Henri Dufour (15 September 1787, Konstanz – 14 July 1875, Geneva) was a Swiss army officer, bridge engineer and topographer. He served under Napoleon I and held the office of General to lead the Swiss forces to victory against the Sonderbund. He presided over the First Geneva Convention which established the International Red Cross. He was founder and president of the Swiss Federal Office of Topography from 1838 to 1865.
Dufour was born in Konstanz, where his parents were temporarily exiled from Geneva. His father Bénédict was a Genevan watchmaker and farmer, who sent his son to school in Geneva, where he studied drawing and medicine. In 1807, Dufour travelled to Paris to join the École Polytechnique, then a military academy. He studied descriptive geometry under Jean Nicolas Pierre Hachette, and graduated fifth in his class in 1809, going on to study military engineering at the École d'Application. In 1810, he was sent to help defend Corfu against the British, and spent his time mapping the island's old fortifications.
By 1814, he had returned to France, and was awarded the Croix de la Légion d'Honneur for his work repairing fortifications at Lyons. In 1817, he returned to Geneva to become commander of the Canton of Geneva's military engineers, as well as a professor of mathematics at the University of Geneva. His duties included preparing a map of the Canton.
In 1847 the Catholic cantons of Switzerland attempted to form a separate alliance of their own, known as the Sonderbund, effectively splitting from the rest of the country. Dufour led the federal army of 100,000 and defeated the Sonderbund under Johann-Ulrich von Salis-Soglio in a campaign that lasted only from November 3 to November 29, and claimed fewer than a hundred victims. He ordered his troops to spare the injured.
Saint Antoine Bridge
Dufour acted as state engineer from 1817, although he was not officially appointed as such until 1828. His work included rebuilding a pumping station, quays and bridges, and he arranged the first steam boat on Lake Geneva as well as the introduction of gas streetlights.
The scientist Marc-Auguste Pictet had visited Marc Seguin's temporary wire-cable simple suspension bridge at Annonay in 1822, the first wire-cable bridge in the world, and published details in Switzerland. He joined with others to promote a new bridge across the Genevan fortifications, consulting with Seguin on how it might be built, receiving back a series of sketches. Dufour developed the design in late 1822, proposing a two-span suspension bridge using wire cables - this would become the first permanent wire cable suspension bridge in the world. The design used three cables on each side of an iron and timber bridge deck. The cables stretched 131 feet between the towers, although the largest span was only 109 feet.
- Peters, Tom F., "Transitions in Engineering: Guillaume Henri Dufour and the Early 19th Century Cable Suspension Bridges", Birkhauser, 1987, ISBN 3-7643-1929-1
- Chisholm, Hugh, ed. (1911). "Dufour, Wilhelm Heinrich". Encyclopædia Britannica (11th ed.). Cambridge University Press.
- Reynolds, Kev, The Swiss Alps , Cicerone, 2012, p. 278.
- Drewry, Charles Stewart, "A Memoir of Suspension Bridges", 1832, online at 
|Wikimedia Commons has media related to: Guillaume Henri Dufour|
- Dufour map in the house of parliament
- Information at Spartacus Schoolnet
- Information at asst.ch (French)
- Guillaume-Henri Dufour information at Structurae
- Obituary at NY Times