His first major invention was the Meyer expansion valve, used to improve efficiency in stationary steam engines. The first locomotives to use this invention were a pair of 2-2-2 locomotives Mayer built for the Chemin de fer de Strasbourg à Bâle in 1842. Named L'Espérance (Hope) and Le Succès (Success), they continued in service for S-B's successor, the Chemins de fer de l'Est until 1859.
- a rigid single frame supporting cabin, and boiler;
- two revolving units like bogies made up each one of a steam engine involving a group of driving wheels and possibly comprising carrying wheels.
The first engine of this type built by the Société J. F. Cail et Cie. in 1868 was a 0-4-0+0-4-0 named L'Avenir (Future). The design was developed by Gaston du Bousquet, who designed a class of 0-6-2+2-6-0 tank locomotives for hauling heavy goods trains on the Chemins de fer du Nord and the Chemins de fer de Ceinture de Paris.
The above information is taken from the French Wikipedia article on the subject.
- Davies, John (January 1997). Chemins de fer du Nord Locomotive List 1842–1938. Sunnybank, Queensland: Dr. John Davies. ISBN 0-646-30938-2.
- Davies, John (July 2001). Chemins de fer de l’Est Locomotive List 1839–1938 (Third ed.). Woodbridge, Queensland: Dr. John Davies. ISBN 0-646-06600-5.