Tour en fer de 300 mètres de hauteur : destinée à l'exposition de 1889

Tour en fer de 300 mètres de hauteur by Eiffel, Koechlin, Nouguier, and Sauvestre is a technical engineering proposal written in the late 19th century. It outlines a monumental iron tower conceived for a Paris exposition, presenting its purpose, structural principles, construction methods, and public and scientific value. The text explains a new structural idea: four curved corner uprights of a pyramid-like frame channel wind forces internally, avoiding heavy lattice bracing. It describes the tower’s form and program—a vast entry arch; a first platform with large gallery spaces for dining and gatherings; and a glazed summit platform for panoramic views, scientific observations, and an electric beacon. Engineering calculations cover wind loading, overturning and stability, material stresses, foundations, and predicted deflections, showing the design can stand without guy wires, with added security from anchoring. It details elevators, lighting, erection within roughly a year, and a full cost estimate, plus scaled alternatives. Arguing that iron or steel is the only practical material at such height, it contrasts this with masonry’s limits and cites the Washington obelisk as a cautionary example. The proposal closes by emphasizing public appeal, a rich program of scientific experiments (astronomy, meteorology, physics, telegraphy), and the ambition to symbolize modern engineering, industry, and the spirit of progress. (This is an automatically generated summary.)