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THE STORY OF THE PERFORATION GAUGE

An edited extract from the 1912 book by F.A. Talbot
Moving Pictures - How They Are Made and Worked.

The early days of what became the motion It seems strange that all films should have to
picture industry saw a number of rival compa- be perforated according to the Edison system,
nies vying for prominence. Today we take for when it is remembered that the first commer-
granted that film has perforations for accu- cial cinematographic apparatuses for the pro-
rate transport within the camera and projec- jection of pictures upon a screen were made,
tor. Other methods and techniques were tried not by Edison, but by Paul and Lumiere, who,
and failed before a Standard was reached, one might think, would have established their
making 35 mm film a world-wide standard own gauges. This important point involves an
which has remained virtually unchanged dur- interesting little story.
ing its over 120 years of existence.
In the very earliest days of cinematography,
when a film of greater width was used than at
We have seen that before the film can be present, it was advanced by friction. Rollers,
used in the camera it has to be perforated on or clutches, gripped the edges of the film
either side in order that successive areas of tightly, and moved it forward the desired ex-
film three quarters of an inch deep—the tent. But their action was uncertain. Some-
equivalent of a picture can be seized and times the rollers became slack and the film
brought into position behind the lens. This slipped, the celluloid ribbon varied in thick-
perforation has become standardised in ac- ness or was a trifle slippery, with the result
cordance with what is known as the “Edison that the forward movement was irregular,
Standard Gauge,” which is 64 perforations and the pictures did not appear in rhythmic
per foot on either side. This perforation is of succession. Some were askew, others were
an elongated form, measuring about 1/8 of an overlapped by the preceding or succeeding
inch in width by approximately 1/16th of an image, or a wide gap was left between con-
inch in depth. secutive pictures.

The preliminary operation is carried out with In order to overcome the drawback, attempts
a machine, which stamps the holes by means were made to devise a system of moving the
of specially hardened steel punches. Extreme film forward by the aid of pins engaging with
care has to be taken to carry out the task with holes in the sides. But the apparatus em-
mathematical accuracy, in order that the film ployed was mechanically defective. The film
may be used with any type of camera and dragged, and the holes were either torn or
projector. Without it steadiness of the picture became so worn that they did not engage
upon the screen is absolutely impossible. accurately. Square holes were first tried, but

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