For centuries the practitioners of theatrical lighting have sought to control the intensity of light sources. Yet it was only in the second half of the last century that a certain degree of control was achieved, with the advent of gaslight. A central
control board
called a 'gas table' regulated the gas flow through pipes to gas burners in different areas of the theatre. One example of this type of system was the "Clemansson" "Jeu d'orgue ŕ gaz" (the Gas Organ), dating from 1880. Each pipe leading from the
control board
supplied gas to a group of burners. The pipe was fitted with a faucet which controlled the amount of gas and thus the intensity of the light, while larger faucets controlled the lighting of entire areas of the stage.
Complete blackout of the lighting was impossible to achieve as even when the light was dimmed, the gas pilot lights had to remain lit so that the gas light could be brought up again.
Towards the close of the 19th century, when the electrical sparks were used for ignition, total extinguishing of the light became possible.
