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Cyanometer, 1789


i’ve read about the cyanometer in three places recently. this fabulous invention is attributed to Horace-Bénédict de Saussure who is credited with inventing this in 1789. made from squares of paper dyed in graduated shades of blue and arranged in an open circle or square, cyanometers are used for easy comparison with the sky’s colour when held up to it. de Saussure’s, like the one above, had 53 sections – ranging from white through varying shades of blue to black – and was circular in shape. he used the device to measure the colour of the sky in geneva, chamonix and mont blanc, eventually coming to the conclusion that the colour of the sky was dependent on the amount of suspended particles in the atmosphere.

right now, the sky here is somewhere between 17 and 23 i’d say…