Among the collection in the Thames River Police Museum is a rather fine blue lamp. These are hung in front of police stations, one of those features of English life we take for granted. When, though, did this practice begin?
Blue lamps appeared outside London police stations in 1861. They would spread throughout not only Britain but also the empire: Bahamian police stations, for example, still have these lamps today.
There seems to be some uncertainty as to why the light is blue. Probably it was chosen to match the colour of police uniforms, themselves selected because blue was a fairly neutral colour and clearly distinct from the red of the military. However, it wasn't popular with everyone: according to the Met's website, Queen Victorian objected to the lamp outside Bow Street Police Station. Every time she went to the nearby opera house in Covent Garden, it reminded her of the blue room in which Prince Albert had died. Bow Street was therefore unusual in having a white lamp.
Whatever its origins, the blue lamp became a symbol of British policing and in particular of its positive features. Dixon of Dock Green gave his monologues under this light; he had made his first appearance in a 1950 Ealing Studios film titled The Blue Lamp . However, with station closures and greater scepticism about policing, will the blue lamp continue to maintain its symbolic status?