The name for a loop between each reel of film and the lens of a projector, designed to ease pressure and keep the film from breaking and allowing unlimited film length for the first time. Developed by brothers Otway and Gray Latham and their father, Woodville, in 1894-1895, and first used in a device they invented called the Eidoloscope. This device could record and project an uninterrupted eight-minute film (previously, motion pictures were made on a Kinetograph, viewed on a Kinetoscope, and were generally no longer than one minute).
In 1895, Thomas Armat used the Latham loop in a device he invented, which Thomas Edison purchased (along with the right to manufacture it as his own invention) and renamed the Vitascope. The Vitascope was publicly exhibited in April 1896 as an Edison invention (giving credit to Armat as the "designer").