Polyvision

Polyvision was the name given to a specialized widescreen film format devised exclusively for the filming and projection of Abel Gance's 1927 film Napoleon. It involved the simultaneous projection of three reels of silent film arrayed in a horizontal row, making for a total aspect ratio of 4.00:1 (1.33:1 x 3). This configuration is considered a largely similar precursor to Cinerama, which would debut a quarter of a century later; however, it is uncertain whether or not it was a direct inspiration, as the Polyvision sequence of Napoleon was cut from the film by its distributors after only a few screenings and was not restored again until Kevin Brownlow compiled his restorations from the 1970s onwards. Three cameras were stacked vertically to shoot the widescreen compositions which would be viewed across all three sections. Gance also used the three strips to create triptych compositions of panels contrasting or simultaneous action, mirrored sides framing the center strip, and... full article at wikipedia