'Theorie Elementaire des Poulies' (Theory of Pulleys), 1850-1860.
© Science Museum / Science & Society Picture Library
Coloured engraving by Langevin, Paris, illustrating 50 asorted knots, 37 pulleys and 20 other asemblages, with key diagrams. The blocks shown in this engraving were used in large quantities on every sailing ship, a demand which led Marc Brunel (1769-1849) to develop his ideas for block-making machinery. Overall dimensions: 550mm x 7150mm.