Cyanometer
Cyanometer - a device designed to measure the color of clear daylight / degree of blue sky, a kind of colorimeter. The cyanometer has a one-dimensional scale, which allows you to measure colors in sequence from white to white-blue to saturated blue. The first cyanometer was constructed by Horace Benedict de Saussure at the end of the XVIII century. It consisted of 53 strips of paper painted in Berlin blue in different colors: from almost black through the saturated blue to the light blue. Saussure carried out measurements of the color of the sky in Geneva, Chamonix, on the city of Mont Blanc. In the nineteenth century.