Wide-screen process created by Fred Waller and used commercially beginning in 1952. The system employed a vast curved screen with three overlapping 35mm projectors each in a separate booth, with one on the right projecting onto the left third of the screen, the one in the center pointed straight ahead, and the one on the left projecting onto the right third of the screen. Most productions were travelogues, and "How the West Was Won "(1962) was one of the few fiction films produced in Cinerama.

Source: Art & Architecture Thesaurus

http://vocab.getty.edu/page/aat/300375203