b) 35 mm film

Using film stock provided to him by George Eastman, this gauge was originally developed in 1890 by William Kennedy-Laurie Dickson while he was working for Thomas Edison. The approximate dimensions of the single frame were 35 mm by 25 mm. This was later adopted by the Lumière brothers.

Initially, the film had only one sprocket hole on each side of the frame, but this was later increased to four per side, which became the industry standard in 1909, and remains so to this day.

© 2018 Paul Henley