Wylex thermostat, about 1960. White Bakelite box with gold dial

Part of the Bob Gray collection of electrical objects.

This thermostat was used to help maintain a constant temperature within someone's home as part of a central heating system. The thermostat senses the temperature within the room and switches the heating on or off depending on whether the system is too cold or too hot. Thermostats were fairly expensive devices and were not always fitted despite their energy saving benefits. This is a good quality model.