Thomas Tredgold, an English engineer, born at Brandon, near Durham, Aug. 22, 1788, died in London, Jan. 28, 1829. In 1808 he went to Scotland, where he worked five years as a journeyman carpenter and joiner, studying ardently in spare hours. In 1813 he went to London, and entered the service of William Atkinson, architect to the ordnance, and in 1823 commenced as civil engineer on his own account. He published "Elementary Principles of Carpentry" (4to, London, 1820); "A Practical Essay on the Strength of Cast Iron and other Metals" (8vo, 1821); "The Principles of Warming and Ventilating Public Buildings, Dwelling Houses," etc. (2d. ed., 1824); "A Practical Treatise on Railroads and Carriages" (1825); "Remarks on Steam Navigation, and its Protection, Regulation, and Encouragement" (1825); and "The Steam Engine, comprising an Account of its Invention and progressive Improvement, with an Investigation of its Principles" (4to, 1827), a later edition of which (1850-'53) is in 4 vols. 4to, with 226 steel plates and 164 woodcuts.