Static longitudinal stability of "Ente" airplanes
This is a 1931 NASA technical report on the static longitudinal stability of Ente-type aircraft, a canard configuration with the tailplane placed forward of the wing. Its pictures are engineering diagrams of pitching-moment curves plotted against angle of attack for hands-off, fixed and free elevator conditions, with a grid chart of elevator and stabilizer angles. A designer could take from them the clean line-graph conventions of early aeronautical analysis, with labelled axes, dashed and dash-dot curves, and tidy rectilinear grids.
