ABSTRACT
The empirical knowledge which came in the early 19th century from bridge building on a scale unknown in the Old World led entirely without the aid of theory to the evolution and perfection of all major types of wooden bridge truss. Fortunately Killer, who at first intended to publish merely a short paper exposing the error, was persuaded to undertake the detailed study of the family and their works which finally appeared in book form in 1941. In the first essay he took a normal frame configuration with vertical posts, diagonal braces and counter-braces, but instead of using arch reinforcement he employed struts below the bottom chords at the ends and over the top chords at mid-span to give, in effect, polygonal reinforcement. By the time his book was published Haupt had become a convert to the Howe truss, which was the crowning glory of the wooden bridge era, generally accepted as the best ever.
