the work and incorporating the company was not enacted until May 1830. Fowler's building was finally opened in 1833. Donaldson praised the way in which Fowler exploited the complex, multi-level site, describing the "playful picturesqueness of the group, where court rose above court, galleries above galleries, and where the series of roofs outtopped each other." In this building, Fowler demonstrated his preference for lightweight construction. He later added an iron roof over the main courtyard. Later in the 19th century the building was demolished to make way for Charing Cross Station. He later designed the Cornmarket at Tavistock (1835) for the Duke of Bedford and the Lower Market at Exeter, where he also supervised the construction of the Higher Market, following the death of its architect . Conservatory at Syon House In 1827 he designed and built a Conservatory at Syon House for the Duke of Northumberland. This ambitious building, which still exists, is composed of several glasshouses of varying width and height, with a total frontage of ; the central tropical house is in the form of a Greek cross, with a glass dome wide. Churches At Honiton, Devon, Fowler built the church of St Paul (1837–8) in what Nikolaus Pevsner described as "the Norman style, or at least with plenty of Norman motifs". Fowler's roof there was of an experimental design, incorporating cast-iron ribs supporting a cement and tile covering; this, however, had to be replaced due to the excessive amount of condensation it collected. His other ecclesiastical work included a chapel at Kilburn and several churches in the Gothic style, including: Church at Teffont Evias, Wiltshire, later dedicated to St Michael (rebuilding and enlargement, 1824–26) St John the Evangelist, Hyde Park, London (1829–32) St Andrew's church at Charmouth, Dorset (1836) St Mary's church, Bickleigh, Devon (rebuilding and enlargement, 1838) Hospitals In around 1842, after winning a competition, Fowler built the Devon County Lunatic Asylum, designed on a radial plan of the panopticon type pioneered at Millbank Prison. He was also responsible for the London Fever Hospital in Liverpool Road, Islington, a commission he received due to the influence of the Earl of Devon. The circumstances caused some controversy as a competition had already had been held to choose a design, and one by David Mocatta had been formally decided upon by the committee. This however, was set aside and Fowler brought in to carry out the work.