till his death. In the cathedral, over the entrance to the choir, he put up the inscription to Sir Christopher Wren, designed the pulpit and fitted up the building in 1789 for the visit of the houses of parliament (view among J. C. Crowles's collection to illustrate Pennant's ‘London,’ xi. 95, in Brit. Mus.), and again in 1797, &c., for the charity children. He was made joint-engineer (with Henry Mill [q. v.]) to the New River Company in 1767, sole engineer after Mill's death in 1770, and resigned the post in favour of his son, William Chadwell Mylne [q. v.], in 1811. In 1800 he erected an urn with inscription at Amwell, Hertfordshire, to the memory of Sir Hugh Myddelton [q. v.], projector of the New River. He was appointed surveyor to Canterbury Cathedral in 1767, and clerk of the works to Greenwich Hospital (where he executed improvements) in 1775.
He published in 1757 a map of ‘The Island and Kingdom of Sicily,’ improved from earlier maps (reissued, London, 1799). In 1819 an elevation was issued of the ‘Tempio della Sibylla Tiburtina,’ at Rome, restored according to the precepts of Vitruvius and drawn by Mylne.
He became a fellow of the Royal Society in 1767, and was an original member of the Architects' Club, founded in 1791. Mylne's architectural style was almost too thoroughly Roman to suit his time. He was the last architect of note who combined to any great degree the two avocations of architect and engineer. With his death the connection of the family with the ancient masonic lodge of Edinburgh, which had been maintained for five successive generations, ceased. He was admitted ‘prentice’ on 14 Jan. 1754, and raised to the degree of master-mason 8 April 1754. His name appears for the last time in 1759.
Mylne married on 10 Sept. 1770 Mary, daughter of Robert Home (1748–1797) the surgeon, and sister to Sir Everard Home [q. v.], by whom he had ten children, four of whom survived him. His wife died 13 July 1797. Mylne died 5 May 1811, and was, at his own desire, buried in the crypt of St. Paul's Cathedral, near to the remains of Sir Christopher Wren. For the latter years of his life he had resided at Great Amwell, Hertfordshire. His portrait, painted by Brompton in Rome in 1757, was engraved by Vangelisti in Paris in 1783. It is reproduced on a smaller scale in Nichols's ‘Literary Anecdotes,’ ix. 233. A drawing of him by George Dance and engraved by W. Daniell was published in 1810, and again in 1814 in Dance's ‘Collection of Portraits.’ Another portrait is in Mylne's ‘Master Masons.’ Among the satirical prints in the British Museum are two concerning Mylne. No. 3733, entitled ‘Just arriv'd from Italy The Puffing Phenomenon with his Fiery Tail turn'd Bridge builder,’ dated October 1760, represents Mylne perched on an abutment of the bridge, with the rival competitors and others down below, freely commenting on him. The plate was afterwards altered and the title changed to ‘The Northern Comet with his Fiery Tail &c.’ No. 3741, ‘The (Boot) Interest in the (City) or the (Bridge) in the (Hole),’ represents a conclave of architects, of whom Mylne is one. Some accompanying verses refer to the influence of Lord Bute (Boot) alleged to have been used in his favour. Mylne was reported to be of sharp temper, but he was always scrupulously just.
William Mylne (d. 1790), brother of Robert, was entered apprentice on 27 Dec. 1750, and was with his brother in Rome in 1755–6. He was admitted freemason in Edinburgh in 1758, and was deacon of masons in 1761–2 and 1765. He became architect to the city of Edinburgh, member of the town council, and convener of trades in 1765. On 27 Aug. 1765 he contracted for the erection of the North Bridge, part of the walls and abutments on the north side of which gave way on 3 Aug. 1769, when the work was already well advanced towards completion. Differences arose between the town council and Mylne respecting the increased expense of finishing the bridge, and the question was brought before the House of Lords in 1770. Terms were, however, agreed upon, and the bridge was completed in 1772 (view in Cassell's Old and New Edinburgh, i. 338). He afterwards removed to Dublin, where he effected great improvements in the waterworks of the city. He died 6 March 1790, and was buried in St. Catherine's Church, Dublin, where a tablet to his memory was placed by his brother Robert.
[Dict. of Architecture; Mylne's Master Masons, pp. 250–83; Laurie's Hist. of Free Masonry, p. 514; Maitland's Edinburgh, p. 182; Scots Mag. 1758, p. 550; Gent. Mag. 1811, pp. 499–500; Hist. MSS. Comm. 12th Rep. App. x. pp. 252–253; Cresy's Encyclopædia of Engineering, pp. 427–9, where is a history of the construction of Blackfriars Bridge (views of the bridge in figs. 431, 432, 433); diagrams in Weale's Bridges, ii. 163; see also Encycl. Brit. 8th edit. article ‘Arch,’ iii. 409 (plate xlix. opposite p. 408), and article ‘Centre,’ vi. 382. For criticisms of the bridge see Gent. Mag. 1797 p. 623, 1813 pt. i. pp. 124, 411, pt. ii. pp. 223; Notes and Queries, 2nd ser. xii. 121–2, 159, 233, 3rd ser. vii. 177, viii. 41. Boswell's Life of Johnson, ed. Birkbeck Hill, i. 251–2; Hawkins's Life of Johnson, pp. 373–8; Smiles's Lives of the Engineers, i. 264–5; Builder, 1855, p. 429; Annual Register, 1760 pp. 74–5, 122, 143,
