Isolated light bulb window display
This item, probably from the 1930s, consists of a light bulb resting on a piece of wood which is itself supported by three columns of glass. The question is how can the bulb be shining when there is apparently no way for electricity to reach it? This was renovated in the 1970s and electronics fitted so that the frequency of flashing of the light could be changed. The window display was used to advertise a 1978 Pentacle Club magic show in Cambridge.