The Aachen Wind-tunnel Balance
A 1934 technical report from the NASA Technical Reports Server, catalogued from a government aeronautics archive, describing the Aachen wind-tunnel balance, an instrument for measuring aerodynamic forces on models. The two plates show a photographed balance mechanism with levers and mounts on a flat base, and a line diagram of a drag balance with a pivot point B, a suspended weight and a wire linkage. A designer might take from them the precise, mechanical look of early engineering apparatus, with its clean diagrammatic linework and labelled schematic detail.

