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

Tour en fer de 300 mètres de hauteur by Eiffel, Koechlin, Nouguier, and Sauvestre is an engineering proposal and technical report written in the late 19th century. It outlines the conception of a 300‑meter iron tower for a world exposition, explaining its structural logic, construction approach, and intended public and scientific uses. The likely topic is the design, feasibility, and purpose of a monumental iron tower. The text describes a new structural principle that curves the four iron corner uprights so wind forces are carried within them, avoiding heavy vertical lattice bracing. It details the form: four square-section legs set 100 meters apart, a grand entry arch, a first platform with large galleries for restaurants and gatherings, and a glazed summit with balconies and an electric beacon. It presents wind-load and stability calculations, total weight and foundation pressures, and predicts very small deflections under strong winds. It outlines elevators with controlled ascent, an electric lighting scheme, an erection schedule of about a year, and a total cost estimate including foundations and lifts, with smaller, cheaper variants possible. It argues iron or steel is practical while masonry is not, citing limits of mortar and the cautionary case of a very tall stone obelisk. Finally, it highlights scientific applications (astronomy, meteorology, physics, signaling) and proposes the tower as a lasting symbol of modern engineering. (This is an automatically generated summary.)