Correction for ‘Robert Willis and Franz Reuleaux: pioneers in the theory of machines’ by F. C. Moon (Notes Rec. R. Soc. Lond. 57, 209–230. (doi: 10.1098/rsnr.2003.0207)).
p. 228. The legend to figure 11 should read as follows: Figure 11. Sketch by Willis of the front claw of a common crab. From R. Willis, Principles of mechanism, 2nd edn (London 1870).