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MAKING LIMELIGHT Kev Franzi

Above is a schematic arrangement of the The preferred fuel was the vapour of low flash-
equipment used by the Limelight Department point liquids, usually ether or gasoline.
to make oxygen for its lanterns ‘on the spot’.
Cylinders of compressed oxygen were not The fuel vaporised in a “Saturator ”, a set of
available to them until about about 1905, not small cylinders packed with an absorbent
long before arc light supplanted limelight. material like sawdust or flannel and connected
(All “Lanternists” had done that originally, in series between the oxygen reservoir and the
until bagged oxygen became available. That’s burner.
right, bagged! They were made of ‘mackin-
tosh’ fabric, as in raincoats. The saturator was filled with the liquid fuel,
and after a soaking period any free liquid was
In the late 1880s “how to” articles for drained off. When connected to the oxygen
Lanternists gave detailed instructions for the reservoir, the gas pressure drove an enriched
amount of weight to be placed on ‘pressure vapour to the burner nozzle, where it was
boards’ laid on the bags to produce the ignited in combination with another flow of
required gas pressure. Cylinders soon replaced oxygen direct from the reservoir.
the gasbags, but not before the term entered the
language.) That was if everything went well. If the
saturator wasn’t fully drained, slugs of liquid
1. Retort. Oxygen was obtained by heating a fuel were carried with the gas flow into the
mixture of potassium chlorate and manganese flame. Little slugs made a ‘popping’ sound.
dioxide crystals in a closed container.
2. Wash bottle, which also functioned as a Big slugs... Well, the wonder is that fires and
one-way valve. explosions weren't far more common than they
3. Gas reservoir, about one cubic metre. were.
4. Saturator
5. Burner

10 REEL DEALS December 2024