The Determination of the Effective Resistance of a Spindle Supporting a Model Airfoil
A 1921 technical report from the NASA Technical Reports Server on measuring the drag of a spindle that holds a model airfoil, presumably written for aeronautical engineers and researchers. The single picture is a blueprint-style drawing of two wing-mounting arrangements, one on a standard spindle and one on an auxiliary spindle with a dummy spindle and housing, shown as circular cross-section views with dimension lines and labels. A designer might take from it the clean white-line-on-blue technical drawing style, with its circular framing, crosshair centerlines and labelled callouts.
