- Murray Campbell
(b Gainsborough, 1689; d Cambridge, 1768). English mathematician. He entered Trinity College, Cambridge, in 1708, and became a senior Fellow in 1739 and Master in 1742; he was also a Fellow of the Royal Society and Plumian Professor of Astronomy (1716–60). His work on acoustics is contained in Harmonics, or the Philosophy of Musical Sounds (London, 1749/R, enlarged 2/1759) and Postscript … upon the Changeable Harpsichord (London, 1762). The first includes a table showing the rates of beating of tempered 5ths on the various notes of the scale calculated for a series of pitches of performance; the temperaments used are mean-tone and Smith’s own system of equal harmony. It is significant that his approach to the problem of tuning a keyboard instrument was through the judgment of the musician’s ear: he tried out his equal harmony on the harpsichord, and the first organ of the Foundling Hospital, with its system of alternative notes actuated by selective stops, is said to have been built under his direction. In several striking respects he anticipated Helmholtz, who, however, did not know his work....