The Influence of the Form of a Wooden Beam on Its Stiffness and Strength II : Form Factors of Beams Subjected to Transverse Loading Only
This is a 1924 technical report from NASA's Technical Reports Server, a government engineering study on how the cross-sectional shape of wooden beams affects their stiffness and strength under transverse loading. It was written for structural engineers and timber testers. The pictures show a testing laboratory setup, cross-section diagrams with stress and load figures, matching diagrams of beam specimens cut from planks, and a graph of supporting ratio against depth. A designer could take from them the clean line-drawing style of early engineering documentation, with its labelled isometric timber sections and plotted curves.
