Gustave EIFFEL (1832-1923). Original plan signed with autograph apostille, Ligne de Commentry à Gannat, Viaduc de Neuvial, Paris January 29, 1868; tracing paper on canvas (83 x 57.5 cm). Original plan of elements of the Neuvial viaduct. The plan is drawn in black and red ink, with parts watercolored in blue, with dimensions and legends. It shows elements of the "7-storey stack" at "0.1 P.M. scale". Arbalétrier du 2me étage", for 2 pieces on the right and 2 pieces on the left. Cross-sections of the "Rabattement dans le plan des Croisillons" and the "Rabattement dans le plan des Arbalétriers", as well as the "Bride supérieure elliptique" and the "Bride inférieure elliptique". Ink stamp G. Eiffel Constructeur, and autograph note "Présenté par le constructeur soussigné Paris le 29 Janvier 1868 G. Eiffel". Apostille in red ink from engineer Wilhelm Nordling (1821-1908): "Approuvé Paris le 1er février 1868 W. Nordling".