Unused / unissued material - dates unclear or unknown.
A London double decker bus pass the camera as it crosses a bridge. Behind it is towed a gas trailer - this allows the bus to be converted from petrol.
Various shots of men - presumably politicians or civil servants - looking over various types of vehicles fitted with gas trailers. Various shots of the gas systems. Nice shot of sign on one lorry for 'Pickfords Collection and delivery service'. Some of the coal gas systems are mounted on top of the vehicles, some on trailers, and some on the front. Various shots of people looking over the systems.