III - A note on John Robison

Summary

The state of knowledge of applied mechanics in Britain at the beginning of the nineteenth century is probably reflected in David Brewster's Robison's Mechanical Philosophy (1822) which is based mainly upon articles published by John Robison, professor of natural philosophy at Edinburgh University, in the fourth edition of the Encyclopaedia Britannica (1797). The first of the four volumes includes chapters on strength of materials, carpentry, roofs, construction of arches and construction of centres for bridges. With regard to strength of materials Robison refers (in general terms) to the experiments of Couplet, Pitot, De La Hire and Duhamel in relation to cohesion. He also refers specifically to elasticity and ductility and mentions plastic substance and properties. Robison is much concerned with cohesion in terms of attraction between particles, referring to the theories of Newton and Boscovich. Then he suggests that ‘connecting forces are proportional to the distances of the particles from their quiescent, neutral or inactive positions’. This ‘seems to have been first reviewed as a law of nature by the penetrating eye of Dr Robert Hooke’. Robison quotes what he describes as Hooke's cipher, ceiiinosssttu, for the law of elasticity (ut tensio sic vis) which bears his name and he records Hooke's anticipation – and rejection – of the facts used by John Bernoulli in support of Leibnitz's doctrine of vires vivae.