This afterwards declined, but it is now one of the principal points of communication between England and France, the railway company maintaining a daily service of fast steamers to Dieppe in connexion with the Chemin de fer de 1'Ouest.
This principle of construction has since been followed in the construction of the Boston subway, of the Chemin de Fer Metropolitain in Paris, and of the New York underground railway.
He has published, besides the works already mentioned, Traite de mecanique rationnelle (1858); De l'analyse infinitesimale (1860, revised ed., 1881); Des pentes economiques en chemin de fer (1861); Emploi des eaux d'egout en agriculture (1869); Principes de l'assainissement des villes and Traite d'assainissement industriel (1870); Essai sur la philosophise des sciences (1896); La Question d'Egypte (1905); besides some remarkable "Pensees" contributed to the Contemporain under the pseudonym of "Alceste."
Her poems were edited by Maurice Roy for the Societe des anciens Textes fran9ais (1886, &c.), and her Livre du chemin du long estude, by Puschel (Berlin, 1887).
Of these companies the Union miniere du Haut Katanga had for object the development of the mineral wealth of the district named, while the Chemin de fer du Bas Congo undertook to build a railway from Leopoldville to Katanga.