The Low pressure Six-column steam engine designed by James Watt - this is the advanced version developed in 1784, with a reciprocal cylinder motion and (crucially) the rotary output which could drive ... anything. Engraving from fourth edition of Meyers Konversations-Lexikon from 1885-1890.
Also available in red, and as a tote bag in maroon, navy and bottle green.
See also the Locomotive Section and Steam Turbine totes and notebooks in the same series.
