Coal-gas
From Wikinfo
Coal-gas is the gaseous by-product of the distillation of coal to make coke. The liquid by-product produced by this process is commonly known as coal-tar. Commonly used as as fuel (particularly in gas lighting) before natural gas became widely available in the 1940s, it was commonly known as town gas.
References
- Adapted from the Wikipedia article, "Coal-gas" http://en.wikipedia.org/wiki/Coal-gas, used under the GNU Free Documentation License
