Limelight is a non-electric type of stage lighting once used in theatres and music halls, and was the first solid-state lighting device. An intense illumination is created when a flame fed by oxygen and hydrogen is directed at a cylinder of quicklime, which can be heated to 2,572 °C (4,662 °F) before melting. The light is produced by a combination of incandescence and candoluminescence. Although it has long since been replaced by electric lighting, the term has nonetheless survived, as someone in the public eye is still said to be "in the limelight". The actual lamps are called "limes", a term which has been transferred to electrical equivalents.