Thomas, an able engineer, was born at Brandon, near Durham, where he received the small share of learning which is usually bestowed upon a youth destined to a mechanical trade. At the age of fourteen he was apprenticed to a carpenter in his native village, whom he served for six years. He afterwards came to Scotland, where he worked five years as a journeyman. From Scotland he proceeded to London, and there obtained employment in the office of an architect, with whom he remained for ten years. The intervals of labour are too often wasted by artisans in listless inactivity or debasing pleasures; but Tredgold employed his leisure hours in a very different manner. Under circumstances as little favourable for such pursuits as can well be imagined, he applied himself to the study of chemistry, geology, and the mathematics; with what success is well known, and has been acknowledged by the most competent judges in this country, in America, and in France, where many of his works have been translated. When he began to practise as an engineer, we know not; but it was during the period in which he was so engaged that he published the scientific treatises, which have entitled him to an honourable place among those who have made important exertions for the advancement of the useful arts. We subjoin a list of his principal publications. Elementary Principles of Carpentry. Lond. 1820, 4to. Practical Essay on the Strength of Cast Iron, and other Metals. 1824, 8vo. Principles of Warming and Ventilating Public Buildings, &c. Second Edition. 1824, 8vo. A Practical Treatise on Railroads and Carriages. 1825, 8vo. The Steam Engine, comprising an Account of its Invention and progressive Improvement; with an Investigation of its Principles, &c. 1827, 4to. Treatise on the Steam Engine, in 2 vols. 4to. Tracts on Hydraulics. He was likewise the author of some valuable contributions to the present work. He died in the year 1834; and it is painful to add, that notwithstanding the unwearyed exercise of his talents, he left his family without any adequate provision.