Biggar Gasworks made coal gas from 1839 to 1973. It was one of the first small-town gas works 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 equipment was used to detect levels of carbon monoxide in the air. It has a test tube containing the chemical palladium chloride, and strips of paper. The paper was dipped in the palladium chloride solution and exposed to the air. If the colour of the damp paper became dark, then this meant carbon monoxide was present. This is because palladium chloride reacts with carbon monoxide to create this colour change.
Carbon monoxide is poisonous and can be fatal. Therefore, this detector was an important technology that increased health and safety at the gasworks.