question: What is the last name of the person who designed the building with Oamaru stone facings in the suburb that has two Category II heritage buildings on Fitzroy Street?
context: Hillside Railway Workshops dominate the southeast of Caversham and the neighbouring suburb of South Dunedin. Established at this site in 1875, the workshops are the main railway construction and repair shop in the South Island. The workshops cover 8 hectares (20 acres), of which 3 hectares (7.4 acres) are covered floor space.To the north of the workshops is Carisbrook, Dunedin's former main sports venue. Opened in 1883, the ground had a capacity of 35,000 people, and was floodlit from the 1990s. Used primarily for rugby union, but also for other sports (notably as a Test cricket venue), Carisbrook lost its pre-eminence among the city's sports arenas with the construction of a new stadium in the northern end of the city in 2011; demolition began in 2013. The ground is named for the former home of early colonial settler James Macandrew, which in turn was named for Carisbrooke Castle on the Isle of Wight in southern England.Lisburn House is one of the finest surviving 1860s townhouses in New Zealand. Now run as a bed and breakfast establishment, this house was built in 1865 for the Fulton family, a pioneer farming family at their "Ravenscliffe" property on the Taieri Plains. The house was named for the family's origins in Lisburn, Northern Ireland, and is Category I heritage listed. William Clayton designed the 12-room house, notable for its steeply angled slate roof and polychromatic brickwork. Two other Category II heritage buildings are on Fitzroy Street: Faringdon Villa, and an untitled house.Other buildings of note in Caversham include the suburb's churches. The Presbyterian church is located on Thorn Street, roughly halfway between the South Road retail area and Forbury Corner. It was built in 1883 following the destruction of the previous building by fire. The current building, built in Port Chalmers bluestone with Oamaru stone facings, was designed by T. B. Cameron.
  Caversham's Anglican church, St. Peter's, is located on Hillside Road. Designed by H. F. Hardy, the foundation stone was laid in 1882. The original design called for the church to have a spire, but because of problems with the tower's foundations (which left the tower leaning 6 inches (15 cm) from the perpendicular) this was never constructed.Caversham Baptist church is located at the corner of South Road and Surrey Street, close to Caversham School. Unusual among Dunedin buildings, this church has a formal Classical style, with its brickwork augmented by pediments and square columns. The foundation stone for the building was laid in 1906. The former Baptist Church, in Playfair Street, is now used as a Gospel Hall.
answers.text: Cameron