Colour wheel. A colour wheel is a representation of the primary, secondary and tertiary colours. This colour wheel is based on blue, red and yellow (primary colours). The primary colours are mixed to make secondary colours (green, orange and violet). The tertiary colours are created by mixing the secondary colours. These are: red-orange, red-violet, yellow-orange, yellow-green, blue-violet and blue-green.
© SCIENCE PHOTO LIBRARY
Billiard Room, Union Jack Club, Lambeth, London
View of the Billiard Room at the Union Jack Club, Waterloo Road, Lambeth, London. The club opened in 1907 to cater for members and ex-members of the armed forces. Date: circa 1910s
© Mary Evans Picture Library 2015 - https://copyrighthub.org/s0/hub1/creation/maryevans/MaryEvansPictureID/10527603
1910s, Armed, Billiard, Billiards, Club, Edwardian, Floor, Fluted, Forces, Game, Jack, Lambeth, Lamp, Lamp Shade, Leisure, Parquet, Pillar, Pocket, Relaxation, Road, Room, Shade, Table, Union, Waterloo
Children under a sunlamp, 1960
Phototherapy. Children sitting under a sun lamp. Such lamps have a very bright, broad spectrum output. At the longer wavelength end of the spectrum (red and infrared) this gives a sensation of warmth on the skin while the higher wavelengths (blue and ultraviolet) promote the production of Vitamin D. In many northern European countries such therapies used to be given during winter periods, ostensibly to make the children 'healthy'. Photographed in Russia in 1960.
© RIA NOVOSTI/SCIENCE PHOTO LIBRARY