The Cyanometer is a magical yet simple instrument for measuring ‘blueness‘, not the feeling but specifically the colour intensity of blue sky. A Cyanometer consists of squares of paper dyed in graduated shades of blue and arranged in a color circle or square that can be held up and compared to the color of the sky. It helped lead to a successful conclusion that the blueness of the sky is a measure of transparency caused by the amount of water vapor in the atmosphere.
(Horace-Bénédict de Saussure’s cyanometer, 1760)
For a modern day meter Continue reading →