Teleview was the earliest utilized alternate-frame sequencing form of stereoscopic projection. Previous attempts had been made as far back as 1897, but Hammond's invention was the first time the idea had been put to use. With projectors running in interlock, alternating left/right frames were projected one after another in rapid succession. Synchronized viewers attached to the arm-rests of the seats in the theater open and closed at the same time as the shutters in each projector, and took advantage of the viewer's persistence of vision, thereby creating a true, stereoscopic image.
Hammond and Cassidy's device won praise, but because of its limitations of having equipment installed -- which was also uncomfortable to view through -- the idea was dropped after the show's initial engagement.