'No-Glare' motor headlamp, 1911.
© Science Museum / Science & Society Picture Library
This is a motor car head lamp patented by Mr K H Evans in 1906. It was designed to prevent the light dazzling the eyes of people facing the car. The lamp itself, which burns acetylene, is of the holophotal form introduced by Scottish author Robert Louis Stevenson's father Thomas Stevenson, in 1849, for lighthouse illumination. The burner and lens are surrounded by a parabolic reflector, which receives the rays that escape the lens and projects them parallel with the others, thus reducing glare from the lamp.