Full image caption
Policeman at police telephone box. Police boxes were kiosks topped by electric lights. Each one contained a telephone linked directly to the local police station. Officers on patrol could report their whereabouts from them without having to meet their sergeants at fixed points. The flashing light could indicate to the patrolling officer that he should make contact with the station, or show where assistance was required if the box had been used to report a local incident.
© Henry Grant Collection/Museum of London