Page:Library Construction, Architecture, Fittings, and Furniture.djvu/96

72 provided with a castor, which runs along brass or iron quadrants screwed into the floor. A bolt is also provided which enters a socket in the floor, and holds the swinging-door securely open at right angles to the bookcase. The doors work right and left, and when open are back to back, forming miniature alcoves some 30 inches deep and 5 feet wide. It will be apparent that a great economy of space is thus obtained.