John Wallis and the Numerical Analysis of Structures.

In 1695, in his Opera Mathematica, John Wallis (Savilian Professor of Geometry at the University of Oxford) published an analysis of the forces in a reciprocal grillage structure. The structure itself was an extended version of a famous design often attributed to Serlio, but first sketched much earlier by Villard de Honnecourt. The extended structure was also sketched by Leonardo da Vinci. Wallis's analysis is remarkable for the fact that he systematically (and correctly) solved a set of 25 simultaneous equations to obtain the required forces. The main steps in the analysis closely parallel the essential stages in modern Finite Element Analysis, and Wallis's calculations can be seen as a key step in the development of structural analysis techniques. [ABSTRACT FROM AUTHOR]