This lamp was brought in during the event as a donation to the museum. It was originally used in the 1940's and 50's during the blackout.
During the war there was no floodlighting in the train yards to light the trains for inspection as lights posed the risk of attracting German bombers. The engineers would use the brilliant light of the acetylene lamps to inspect the wheels of the train.
Unlike their robotic, ultrasonic counterparts the engineers would go along the train, tapping the wheels with a small hammer. A dull thud meant the wheels were cracked and would need to be replaced whilst a bright ring meant they were in good condition.
This acetylene lamp contains two chambers; one for water and one for Calcium Carbonate or 'lime'. Water slowly drips into the main chamber reacting with the lime to produce acetylene gas.
This type of lamp was initially used in theatre spotlights for lighting the stage and gave rise to the phrase, 'in the limelight'.
Comments
Interesting text; I wonder though, did "the blackout" and corresponding risk of German bombers last into the 50's?
Small correction regarding the chemical reaction: the calcium carbide lamp has one chamber filled with calcium *carbide* (CaC2). Though Calcium Carbonate (CaCO3) may slowly dissolve in water, it does not generate a combustible gas.