In the Victorian period, the expression in the limelight meant the most desirable acting area on the stage, front and center. Today, the expression simply means someone is getting public recognition and acclaim.
The limelight effect was discovered by Goldsmith Gurney in the 1820s based on his work with an oxy-hydrogen blowpipe. Scottish inventor, Thomas Drummond (1797-1840), built a working model of the calcium light in 1826 for use in the surveying profession.
The calcium light was created by super heating a cylinder of quicklime (calcium oxide) with an oxy-hydrogen flame that gives off a bright light with a greenish tint.
Eleven years later, the term limelight was coined to describe a form of stage illumination first used in 1837 for a public performance at the Covent Garden Theatre in London.
By the 1860s, this new technology of stage lighting was in wide use in theaters and dance halls around the world. It was a great improvement over the previous method of stage lighting, candle powered footlights placed along the stage apron.
Limelight lanterns could also be placed along the front of the lower balcony for general stage illumination providing more natural light than footlights alone.
A lighthouse-like lens (Fresnel lens) was developed that could direct and focus concentrated light on the stage to spotlight a solo performance. Actors and performers must have felt they were living in the heyday of the theater.
The term green room has been used since the Victoria period to describe the waiting area performers used before going on stage. Theater lore has it that actors would sit in a room lit by limelight to allow their eyes to adjust to the harsh stage lighting, preventing squinting during their stage entrances.
Although the electric light replaced limelight in theaters by the end of the nineteenth century, the term limelight still exists in show business, as does the term green room.
Today, the green room celebrities use before appearing on talk shows is not usually painted green. The room still performs a similar function as in the Victoria age--to prepare a performer to go on stage.