Experimental research on the friction of pivots
A 1930 technical report on pivot friction, issued through NASA's Technical Reports Server and drawn from engineering research archives for engineers studying bearings and lubrication. Its pictures are plain line graphs and engineering diagrams: friction coefficient curves plotted against velocity and load, a cross-section of a pivot assembly, and arc-shaped schematic drawings. A designer might borrow the clean measured-chart style, labelled axes, and sparse technical line work for diagrammatic graphics.
