This is the first (No.1 no longer exists) of three films about Gas Holders, or ‘Gasometers’ as they are known in England. They were located in a large industrial area of North London. Before natural gas was discovered in the North Sea in the 1960s, it was made from coal. Every town had a gas works, where gas was processed from the coal, and every gas works included a large storage device, a telescopic metal drum, often contained within an iron framework. Most of these were constructed between 1860 and 1890. The Gasometers in this film have now been removed and part of the removal process is documented in the film. However, my primary interest with the film is in terms of the way they filter, reflect, refract and break up the light that falls on them.