煤气
Coal gas was initially manufactured by independent companies but in the United Kingdom many of these later became municipal services. In 1948 there was a total of 1,062 gas undertakings. Both the private companies, about two-thirds of the total, and the municipal gas undertakings, about one-third, were nationalised under the Gas Act 1948. Further re-structuring took place under the Gas Act 1972. For further details see British Gas plc.