Glass held in wooden frames had for some time been extensively employed for greenhouses. How early iron began to be substituted for wood is not clear, and not perhaps of much consequence.[164] Hopper’s ornately Gothic Conservatory of iron and glass at Carlton House in London, demolished in the twenties, has been mentioned several times already (Plate 60B). In 1833, at the Jardin des Plantes in Paris, Charles Rohault de Fleury (1801-75) built a very large and handsome iron greenhouse without any stylistic decoration. The structure of the square pavilions was as transparent and rectilinear as the interior framework of Veugny’s slightly later market seems to have been, and the ranges between were covered, just as so many wooden greenhouses had been, with transparent roofs rising in two quadrants. At Chatsworth in Derbyshire the Great Conservatory was built in 1836-40 by the 6th Duke of Devonshire’s gardener, Sir Joseph Paxton (1803-65), possibly with some minor assistance from Decimus Burton. This quite outclassed the largest earlier greenhouse, the Anthaeum at Brighton, designed in 1825 and built in 1832-3 for the horticulturist Henry Phillips, with a dome of iron and glass 160 feet in diameter which collapsed before it was quite completed. The Chatsworth conservatory was a still larger rectangle, 227 feet by 123 feet, with the exterior rising in a double cusp like the side ranges of Rohault’s Paris greenhouse—or, for that matter, like the section of the Anthaeum. The columns and beams here were of iron, but the great arched principals of the ‘nave’ and the ‘aisles’ were of laminated wood and four-foot long panes of glass were held in wooden sashes arranged in a ridge-and-furrow pattern. A particular invention of Paxton’s, whose name was given to such roofs, was the hollowing out of the wooden members at the base of the furrows to serve as gutters. Decimus Burton’s still extant Palm Stove at Kew, carried out by the contracting engineer Richard Turner of Dublin in 1845-7, with rounded ends and a higher central area, is more bubble-like than Paxton’s because of the absence of ridges and furrows on its continuously glazed surface (Plate 67A). But both these great greenhouses were among the most striking monuments of their Early Victorian day and were never exceeded later in elegance though often in size. French rivals, long since destroyed, were the Jardins d’Hiver in Lyons and Paris of 1841 and 1847 by Hector Horeau (1801-72), the latter a rectangle 300 by 180 feet and 60 feet tall.