Thomas Walker (1805-1873) of Birmingham, England, designed and manufactured several types of mechanical logs, some of which were used in the British Navy. Walker was a nephew of Edward Massey, the leading designer and manufacturer of mechanical logs in the first half of the nineteenth century.Ref: J. A. Bennett, The Divided Circle. A History of Instruments for Astronomy, Navigation and Surveying (Oxford, 1987), pp. 190-191.
