In the first part of the 19th century gaslight was used in the theatre mainly in order to wash the
stage
with diffused light. The use of focused, concentrated light became possible when in 1825 a Scotsman named Drummond invented the
limelight
. Limelight used oxygen mixed with hydrogen in order to heat a block of limestone to incandescence, producing intense and very white light. A
reflector
shaped the light into a narrow, condensed beam, and later a
lens
was added to further concentrate the beam.
It was some time before Drummond's invention was adopted in the theatre. Apparently, the first instance in which
limelight
was used on
stage
was at Covent Garden in 1837-1838, during a pantomime season . As each
limelight
required a separate, dedicated operator, limelights were extremely expensive to run, and so were restricted for special effects of a colored
beam
of light or a strong concentrated light .
Later, the
limelight
principle was incorporated into wide angle floodlight instruments, extending the use of
limelight
to washing large areas of the stage.
Although the
electric arc
was invented as early as 1809 by Andre M. Ampere (1775 -1836), it was many years before it was adapted for theatrical use. It was only in 1846 that
electric arc
lights were introduced into the Paris Opera.
An
electric arc
is created when two electrodes are brought close to one another for a brief moment . When they are about to touch, a spark is generated, creating a 'short circuit' and an incandescent area of about 4000°C, which serves as the
light source
in arc lights. Carbon-arcs used carbon
rods
about 20cm long, had reflectors and lenses to condense the beam, and put out immensely brilliant illumination . However, there were drawbacks. These lights were noisy, the light flickered and, like the limelight, they needed the constant attention of a dedicated operator for each arclight .
The arc-light could be used both for floodlighting and for spotlighting, and had a sliding shutter between the
light source
and the
lens
which served to dim the light. Electricity was supplied by huge electric batteries installed in the
stage
basement.
The effect of strong limelight, 1855.
Gaslight,
limelight
and the
carbon arc
were used in theatre throughout most of the 19th century, until introduction of the carbon-filament electric
lamp
which marked the end of the use of coal gas as a source of light in the theatre.
The mechanisim of the electric carbon arc, 1877.
An effect achuved with an electric carbon arc, 1855.
