Design of Wind Tunnels and Wind Tunnel Propellers II
This is a 1921 NACA-era technical report on designing wind tunnels and their propellers, issued through the NASA Technical Reports Server for engineers and aerodynamics researchers. The pictures are plain graphs and oscillograph traces: ruled line charts of propeller slip and efficiency against air speed, plus wavy and flat recorded traces marked in seconds and miles per hour. A designer could take their clean grid layouts, labelled curves and restrained two-tone palette as a model for technical diagrams.
