solar dial(solar dial is type of time switch used primarily for controlling lighting. They were/are primarily manufactured by the companies Venner, Horstmann and Sangamo. The solar dial time switch has largely been superseded by photocell control, which is cheaper and requires less maintenance. Solar dials are still used for lighting stairwells and car parks, and in some cases local authorities may request them for street lighting, though this is rare. Solar dials are often found in the rural United Kingdom, but as these fail they are invariably replaced by a photocell, usually on a new lantern and sometimes with a whole new column. – WAD Alexander Demidov)
