煤气
Before the mid-20th century coal gas was produced in retorts by heating coal in the absence of air, the process being known as coal gasification. Coal gas was first used for municipal lighting, the gas being passed through wooden or metal pipes from the retort to the lantern. The first public piped gas supply was to thirteen gas lamps installed along the length of Pall Mall, London, in 1807. The credit for this installation goes to the German inventor and entrepreneur Fredrick Winsor. Digging up streets to lay pipes required legislation, and this delayed both further installation of street lighting, and the installation of gas for domestic illumination, heating and cooking.