The internal work of the wind
Samuel Pierpont Langley's 1893 Smithsonian paper on wind gustiness and the energy available to soaring flight, issued in Washington for physicists and the small circle of early aeronautical researchers. The plates are engraved measuring apparatus in plan, elevation and section — whirling arm, recording cylinder, rolling carriage, knife-edge pivots and bearings — drawn in fine hairlines with dimension arrows, hatched sections and letterspaced capital labels, alongside ruled plotting grids.
