This trader advert from April 1950 is a rare advert for a very useful item; general time controlled switch.  Looking rather like a car speedometer this method of mechanical "tags" setting on and off times was used for many years to come.

This Silent Servant Sells!

This Sangamo time switch opens up new sales possibilities to the retailer and contractor. Automatic control of porch lighting is only one of many domestic applications which include the automatic switching on and off at pre-determined times of immersion heater, radio and any similar circuits. Send now for full details of types available together with information on window display units and counter literature to assist your selling.

Sangamo Time Switches
Sangamo Weston Limited, Enfield, Middlesex. Tel: Enfield 3434 (6 lines) and 1242 (4 lines)

Scottish Factory: Port Glasgow, Renfrewshire, Scotland