Originally a house, it was designed by Sir William Chambers and completed in 1772; the dome was added in 1858.
Sir William Chambers wanted a dome added to the house but couldn't afford it at the time.
mnli hypothesis: Sir William Chambers wanted a dome added to the house but couldn't afford it at the time. premise: Originally a house, it was designed by Sir William Chambers and completed in 1772; the dome was added in 1858.