et Geometricæ’ (Leyden, 1729, 4to). Some of Tredgold's results were taken from Dumont's ‘Parallèle’ (Paris, 1767, fol.). Several editions of Tredgold's work have been published, and it remains an authority on the subject. The latest edition, by Edward Wyndham Tarn, appeared in 1886 (London, 4to). This work was followed in 1822 by ‘A Practical Essay on the Strength of Cast Iron and other Metals’ (London, 8vo; 5th edit., by Eaton Hodgkinson [q. v.], London, 1860–1, 8vo), which is mainly founded on the works of Thomas Young (1773–1829) [q. v.] Though they were long the standard text-books of English engineers, the scientific value of both these works is seriously impaired by Tredgold's lack of sufficient mathematical training, and more particularly by his ignorance of the theory of elasticity, which often leads him into error and always renders his reasoning obscure.
In 1823 the increase of business and the demands of literary labour led him to resign his position in Atkinson's office and to set up on his own account. In 1824 he published ‘Principles of Warming and Ventilating Public Buildings’ (London, 8vo), which reached a second edition in the same year (3rd edit., with appendix by Bramah, 1836). In 1825 appeared ‘A Practical Treatise on Railroads and Carriages’ (London, 8vo; 2nd edit. London, 1835), which was followed by a pamphlet addressed to William Huskisson [q. v.], president of the board of trade, and entitled ‘Remarks on Steam Navigation and its Protection, Regulation, and Encouragement’ (London, 1825, 8vo), which contained several suggestions for the prevention of accidents. His last important work, ‘The Steam Engine,’ appeared in 1827 (London, 8vo). A new edition, greatly enlarged, by Westley Stoker Barker Woolhouse, was published in 1838 (London, 4to); a third edition appeared in 1850–3 (London, 4to), and a French translation by F. N. Mellet in 1838 (Paris, 4to).
Tredgold died, worn out by study, on 28 Jan. 1829, and was buried in St. John's Wood chapel cemetery. He left in poor circumstances a widow, three daughters, and a son Thomas, who held the post of engineer in the office of stamps of the East India Company at Calcutta, where he died on 4 May 1853. The elder Tredgold's portrait and autograph are prefixed to the later editions of his ‘Steam Engine.’ Besides the works mentioned, Tredgold edited Smeaton's ‘Hydraulic Tracts’ (1826, 8vo; 2nd edit. 1837), added notes and articles to Robertson Buchanan's ‘Practical Essays on Millwork’ (ed. Rennie, London, 1841, 8vo), and revised Peter Nicholson's ‘New Practical Builder’ (London, 1861, 4to). He also contributed the articles on joinery and stone masonry to the supplement of the ‘Encyclopædia Britannica’ (ed. 1824), and contributed numerous technical articles to the ‘Philosophical Magazine’ and to Thomson's ‘Annals of Philosophy.’
[English Cyclopædia, Biography, vi. 153; London and Edinburgh Philosophical Mag. 1834, p. 394; Architectural Mag. 1834, p. 208; Todhunter's History of the Theory of Elasticity, i. 105–7, 454–6, 542, ii. 649; Artizan, 1859, xvii. 289; Encyclopædia Britannica, 8th edit. i. 876, xix. 402, xxi. 327; Dictionary of Architecture; Allibone's Dict. of Engl. Lit.]
TREDWAY, LETICE MARY (1593–1677), English abbess in Paris, was the daughter of Sir Walter Tredway of Beckley, Buckinghamshire, and afterwards of Northamptonshire, by Elizabeth Weyman. Born in 1593 at Beaconsfield, Buckinghamshire, and losing her father in 1604, she took the veil in 1615 at the Augustinian convent, Douai, which in 1624 was removed to the neighbouring village of Sin-le-Noble, and took the title of Notre-Dame de Beaulieu. At Douai she made the acquaintance of Thomas Carre [q. v.], and they conceived the idea of establishing an English scholastic nunnery in that town. Pending its erection English girls were to be received at Sin, and in 1632 two accordingly arrived, escaping from Dover, where they had been arrested. In the following year Carre returned from London with two others; but meanwhile George Leyburne [q. v.], president of Douai College, had persuaded Lady Tredway, as she was styled, to fix on Paris as the site. Carre consequently went thither to consult Richard Smith [q. v.], bishop of Chalcedon, who by his influence with Richelieu, and notwithstanding the opposition of Archbishop Gondi, obtained royal sanction for the scheme, letters patent being granted in 1633. A house was hired in the Rue d'Enfer, and was opened in 1634 with five pupils. The numbers increased, and in 1635 the convent was transferred to the Faubourg St.-Antoine; but that site proved unhealthy, and in 1638 four houses were purchased in the Rue du Fossé St.-Victor, one of which had been occupied by De Baïf, whose musical and literary gatherings were the nucleus of the French academy. The buildings were remodelled, and a chapel was erected, which was consecrated by Smith in 1639. The chief English catholic families began sending their daughters as pupils, and lady boarders, mostly French, were also admitted; but till 1655 the convent was debarred from taking French pupils. During
