Experimental Study of Ignition by Hot Spot in Internal Combustion Engines
This 1938 NASA technical report, issued as a memorandum for engineers and researchers, studies how a hot spot ignites fuel inside internal combustion engines. The pictures are plain black-and-white line drawings and graphs: pressure-style traces of wave curves, a thermocouple and wiring schematic, and a cylinder head sectional drawing with its plan view. A designer could take their clean technical linework, dense hatching and labelled diagram layout as a model for precise instructional illustration.
