Evaluating the load bearing capacity of wood elements in early 19th century France

This paper presents a discussion on the long search for the correct solution to the problem of bending with reference to timber beams, spanning over the two centuries long debate from Galileo to Navier. In an overview of the French engineering and architecture treatises written in the 18th and early 19th century, two unpublished French manuscripts are considered; subsequently, attention is focused on the experimental data and bending theory by Jean Baptiste Rondelet and the load bearing tables by Jean Henri Hassenfratz; finally, Navier’s theory and some of its consequences are discussed. One of the first documented applications of this theory to a real design case is also presented; specifically, the verification of a temporary wood bridge built in 1820 in France according to Ithiel Town’s patent is illustrated.