The telephone allowed two way communications, but they were not yet mobile. Telephones were placed in boxes similar to the fire alarm call boxes from around the 1880s. The ‘Police Box' or ‘Private Box' however also featured a red light on top. If a police officer on patrol saw the red light blinking, he knew he had to call the station for an assignment.
The fire alarm call boxes did not contain a telephone. For communication back to the fire station, the fire fighters carried a hand held telephone that they could plug-in in the nearest fire alarm call box.