the Ante-Library is the only one preserved. Much of the scientific library of Henry Cavendish (1731–1810) is in this room. The most notable addition by the 6th Duke to Chatsworth was the Wyatville-designed North Wing. Plans for a symmetrical wing to the south were begun, but later abandoned. The entire ground floor of the North Wing was occupied by service rooms, including a kitchen, servants' hall, laundry, butler and housekeeper's rooms. On the first floor, facing west, were two sets of bachelor bedrooms called "California" and "The Birds". The main rooms in the new wing face east and were accessed from the main house through a small library called the Dome Room. The first room beyond is a dining room, with a music gallery in the serving lobby where the musicians played. Next is the sculpture gallery, the largest room in the house, and then the orangery. The Belvedere Tower contains a plunge bath, using marble from the 1st Duke's bathroom, and a ballroom that was later turned into a theatre by the 8th Duke. Above the theatre is the belvedere itself, an open viewing platform below the roof. Private rooms Chatsworth has 126 rooms, with nearly 100 of them closed to visitors. The house is well adapted to allow the family to live privately in their apartments while the house is open to the public. Deborah, Dowager Duchess of Devonshire, described the family rooms in detail in her book Chatsworth: The House. She lived at Edensor until her death in 2014; the present (12th) Duke and Duchess live at Chatsworth. The family occupies rooms on the ground and first floors of the south front, all three floors of the west front, and the upper two floors of the north front. Staircases in the north-east corner of the main block and in a turret in the east front enable them to move about without crossing the public route. The main family living rooms are on the first floor of the south front. The family dining room is in the south-east corner and has the same dimensions as the State Dining Room directly above. This has been the usual location of the family dining room; the Bachelor Duke's dining room in the north wing took over that role for an interlude of little over a hundred years. Both Bess of Hardwick's house and the 1st Duke's house had a hierarchy of