The Cyanometer 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.
(Christopher Jobson, ‘The Cyanometer Is a 225-Year-Old Tool for Measuring the Blueness of the Sky’ Colossal)
the 53 sections of Saussure’s Cyanometer, skies over Geneva, Chamonix and Mont Blanc
21 Tue Jun 2022
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