The original 1894 building includes two cylindrical copper domes on top of the East and West Towers. These were refurbished in 2010. The East Dome still shelters a 36-inch (0.9 m) Cassegrain reflector that was installed in 1930. This is part of the visitor centre exhibition, but is not operational any more. A 16/24-inch (0.4/0.6 m) Schmidt camera was installed in the West Dome in 1951. In 2010 this was removed to the National Museum of Scotland. The only working telescope is a 20-inch (0.5 m) reflector that was installed in 1967 in a hemispherical dome on top of the teaching laboratories. This telescope is used for undergraduate teaching.
Ref: http://en.wikipedia.org/wiki/Royal_Observatory,_Edinburgh