Experimental and Analytical Determination of the Motion of Hydraulically Operated Valve Stems in Oil Engine Injection Systems
A 1930 NASA technical report on experiments and analysis of how hydraulically operated valve stems move in oil engine fuel injection systems, written for engineers rather than general readers. The pictures are engineering graphs and mechanical drawings: a pressure-against-time curve, a stem lift diagram with labelled opening and closing periods, and a cross-section of a timing valve mechanism with rocker arm and cam. A designer could take from them the clean, labelled line-graph and technical cutaway conventions of early engineering reports.
