The Effect of Kiln Drying on the Strength of Airplane Woods
A 1920 technical report from the NASA Technical Reports Server, issued for aeronautics engineers and materials testers, on how kiln drying changed the strength of wood used in aircraft. The plates are photographs of test specimens, each a wooden bar with a printed label and a fracture across its middle, laid out in grids on a black ground. A designer could take from them the orderly grid arrangement of many small rectangular forms with numbered tags, and the jagged broken-wood edges that read as a clear record of failure.
