Isolated columns of iron appeared in many edifices from the 1790s on. The most notable extant examples, perhaps, are those in the kitchen and in several of the rooms that were added by Nash to the Royal Pavilion at Brighton in 1818-21 (Plate 58A). His ‘Chinese’ staircases of 1815-18 there are entirely of decorative pierced ironwork and the framing of his big onion dome is also of metal, although of course invisible. From the early use of iron columns for gallery supports in churches, increasingly general by the early 1800s, there shortly developed the aspiration to exploit iron still more extensively in such edifices. In three churches that Rickman and the ironmaster John Cragg built in Liverpool, St George’s, Everton, and St Michael’s, Toxteth Road, both begun in 1813, and St Philip’s, Hardman Street, completed in 1816, the entire internal structure is of iron. At St Michael’s the new material is not restricted to the interior but appears on the outside as well. Rickman’s increasing archaeological erudition and that of his contemporaries soon limited the use of iron in Gothic churches, however; by Pugin and the Camdenians it was rigidly proscribed. Structural elements of iron in churches of any architectural pretension became acceptable again only in the fifties (see Chapter 10). Turning to what long remained the most notable field of metal construction, bridge building,[155] one finds a rapid increase in the numbers and the spans of English metal bridges from the mid 1790s on. In Shropshire, where the first iron bridge and the first all-iron-framed factory had been built, one of the greatest English engineers, Thomas Telford (1757-1834),[156] built the Buildwas Bridge with a span of 130 feet in 1795-6. At the same time the much longer and handsomer metal arch of the Sunderland Bridge in County Durham was rising to the designs of Rowland Burdon. He was assisted, it appears, by certain ideas supplied by Thomas Paine (1737-1809), better known for his political writings than as a technician, who had had some association with bridge-building in America. Burdon was a Member of Parliament and neither an architect nor an engineer. Telford, however, though not professionally trained as an architect, had worked for Sir William Chambers as a journeyman-mason on Somerset House in his youth; throughout his career he built masonry toll-houses and even, on occasion, modest churches in a competent if rudimentary Romantic Classical vein.