Biggar Gasworks made coal gas from 1839 to 1973. It was one of the first small-town gasworks in Scotland to open and was among the last to close. The gas made was used by the town and surrounding district.

Coal gas was made by heating coal to very high temperatures. This involved many complicated steps and lots of equipment. Coal was firstly mined and then taken to the ‘Retort House’ for processing. This was named after the ‘retort’ – a main part of the equipment. Part of the process used large tanks of liquid. Floats, like this one, were used to keep an eye on the volume of liquid in the tanks.

This particular one was originally a fishing float but was perfect for this alternative industrial use.