Windmill electric plants
An engineering thesis on windmill electric plants written by William Sumner Thayer at the University of Illinois in 1909, submitted for academic examination. Its plates are hand-lettered performance charts inked onto printed green grid paper — lamp-hour curves plotted across calendar months, fan-shaped load lines, watts against generator revolutions — usable as period graph textures, hand-drawn axis lettering, and plotted-curve motifs.
