 Most notable were his restorations of Southwell Minster in Nottinghamshire, begun in 1851, and Carlisle Cathedral in Cumbria (1853–70).At Southwell the work went on for 37 years, repairing the walls and masonry and re-roofing the building and its famous Chapter House to the original steeper pitch.The building of the impressive pyramidal spires on the western towers (1881) restored a lost feature to the church – the originals had been destroyed in a fire of 1711 and Christian's work replaced flat roofs of 1802.