Annual report - National Advisory Committee for Aeronautics
This 1915 annual report from the United States National Advisory Committee for Aeronautics, printed in Washington by the Government Printing Office, was written for government officials and engineers tracking early aviation research. Its pictures are plain technical charts: grid-ruled line graphs of airfoil lift, drag, and moment curves, propeller efficiency plots, and tabulated aerodynamic data, offering a designer a stark, precise vocabulary of graph paper, fine black curves, and small serif labels.
