Metal Construction Development. Part II : Strip Metal Construction - Wing Spars
This is a 1929 NASA Technical Memorandum from the NACA series, issued by the National Advisory Committee for Aeronautics, on strip metal construction for aircraft wing spars, written for aeronautical engineers. Its pictures are black-and-white engineering drawings of corrugated and channel-section metal strips, lattice truss frames, and dimensioned cross-section profiles with fine linework and tabular callouts. A designer might borrow the precise hatched shading, the repeating lattice geometry, and the labelled figure-plate layout as a source of technical diagram texture.
