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28mm THE FIRST SAFETY GAUGE

AN HISTORICAL REVIEW
By Alan E. Lott

France and the USA invented cellulose acetate
FOREWARD.
almost simultaneously. This new substance was
During the last fifty years or so various short much more stable chemically and although not
articles have been written about the 28mm film entirely non-inflammable was slow to ignite
gauge. A survey of these makes it clear that and then burned only slowly like thick brown
each one has described (sometimes incorrectly) paper. (As a result of continuing development
only a small part of the overall situation, as it over several decades it eventually evolved into
existed between 1912 and 1934. This review is
an attempt to bring together the various pieces the now well-known cellulose tri-acetate).
of the jigsaw to obtain as complete a picture as Also during the early years between 1894 and
possible. However, in so doing, it has become 1912 a variety of now long forgotten film
clear that several parts of the picture are still
missing, in particular, the use of 28mm in gauges appeared only to disappear after a short
Europe outside of Great Britain and France. I life. (Refs 1, 2, 3 and 4.) The purpose of these
would welcome any authenticated information was to circumvent many of the sudden plethora
to help fill these blank areas. of invention patents involved in the early days
of motion pictures. That purpose is in no way to
Four of the documents I have accumulated and
quoted as references (Refs 2, 9, 10 and 12) are be related to, or confused with, 'the reason for
photocopy extracts and do not carry any means the introduction of yet another gauge in 1912,
of identifying their source or date of that of 28mm. This was aimed entirely at the
publication. Apologies to the authors and safety aspects of film projection for non-
publishers concerned and I shall be glad to professional and educational purposes for
receive the missing information.
amateur operators.
…………………………………………………
Charles Pathé had
From the earliest days of moving pictures when realised that this
Edison first showed his peepshow Kinetoscope represented a
in 1893-94 the only transparent flexible base considerable
available for films was celluloid, (cellulose untapped market;
nitrate). This is a chemically unstable and the main obstacle
very inflammable substance. Several serious to exploiting this
fires resulted from its use and after a terrible market had been
tragedy at a charity event in Paris in May 1897 the hazardous
spool boxes, projection booths and other fire nature of the
precautions were insisted on by all authorities. films themselves. Fig 1 Dimensions of
Pathe 28mm Film
As a result strenuous attempts were made on The advent of
both sides of the Atlantic to find a suitable virtually non-inflammable film removed this
alternative and after two years of research obstacle but it was necessary to prevent
which commenced in 1906-1907 chemists in unscrupulous film suppliers selling nitrate prints