Sewers were known to harbour things that were lethal to humans and the environment. In these early days of sanitisation one of these was the problem of the build-up of noxious and explosive gases such as Methane, Carbon Monoxide, etc. To solve the problem sewer lamps were installed or ventilation chimneys were built like this one (c1885) which is still in service and connected to the ‘Dead Lake Sewage System’
